CN116063805A - High-flow transparent ABS resin with pomegranate structure and preparation method thereof - Google Patents

Abstract

The invention prepares the hydrophilic polybutadiene latex with small particle size by copolymerization of hydrophilic monomer and butadiene, then constructs a transition layer on the surface of the polybutadiene latex with small particle size, and then obtains the polybutadiene latex with large particle size and hollow structure after further diameter expansion and alkali treatment. The latex is taken as core latex, monomers such as styrene, acrylonitrile, methyl methacrylate and the like are swelled into the hollow microsphere by a swelling technology, and an oil-soluble initiator is added to initiate polymerization to form a pomegranate structure. Finally, a polystyrene layer and a polymethyl methacrylate layer are constructed on the surface of the ABS resin to prepare the MABS graft copolymer, and the MABS graft copolymer and the MSAN resin are subjected to melt blending to obtain the transparent ABS resin.

Description

High-flow transparent ABS resin with pomegranate structure and preparation method thereof

Technical Field

The invention belongs to the field of synthetic resin, and particularly relates to a preparation method of transparent ABS resin with a pomegranate structure.

Background

The transparent ABS resin is a special brand product of ABS resin, has good light transmittance besides the advantages of good mechanical property, processability and solvent resistance of general-grade ABS resin, can reach more than 89%, and is widely applied to the fields of household appliances, automobiles and the like. The transparent ABS resin is different from the traditional ABS resin in that a low-refractive index monomer Methyl Methacrylate (MMA) is introduced, and the low-refractive index MMA and high-refractive index styrene (St) are adopted for copolymerization, so that the refractive index of the transparent ABS resin is regulated and controlled to enable the refractive indexes of a matrix phase and a disperse phase in the transparent ABS resin to be matched with each other, and the difference is smaller than 0.005, so that transparency is realized.

Currently, the methods for preparing transparent ABS resins in industry can be divided into two methods, bulk polymerization technology and emulsion blending technology. As disclosed in patent CN106699981a and CN 111944098A, a method for preparing transparent ABS resin by using a continuous bulk device is disclosed, the method uses a parallel two-stage serial tubular plug flow reactor, styrene-butadiene rubber is used as a rubber phase, styrene, methyl methacrylate and acrylonitrile are used as continuous phases to construct the bulk transparent ABS resin, and the technical key of the method is that the refractive index of the terpolymer of styrene, methyl methacrylate and acrylonitrile must be consistent with the rubber phase, so as to construct the transparent ABS resin; the patent CN106221114A discloses a large-phase-area-size transparent ABS resin composition and a preparation method thereof, which adopts a bulk polymerization technology as well, and is technically characterized in that besides matching the refractive index between a rubber phase and a resin phase, the phase-area size of a disperse phase in the continuous phase is controlled by regulating and controlling the molecular weight distribution of the continuous phase, so that the phase-area size of the disperse phase is between 0.3 and 1.2um, and the preparation of the large-phase-area-size transparent ABS resin is realized. The transparent ABS resin prepared by the method has an internal inclusion structure, and the method belongs to the technology for preparing the transparent ABS resin by using an intermittent bulk polymerization technology.

The patent CN 105008406A discloses a method for preparing an ABS resin and transparent ABS resin composition by emulsion blending technology, which uses polybutadiene latex with the size of 250-400 nm as core layer latex, graft-copolymerizing styrene, acrylonitrile and methyl methacrylate monomers on the surface of the polybutadiene latex by emulsion grafting technology to form core-shell structure particles with polybutadiene as a core and styrene, acrylonitrile and methyl methacrylate as shells, introducing a cross-linking agent during grafting to reduce the swelling effect of the styrene on butadiene as much as possible, and finally melt-blending the prepared ABS graft copolymer with the core-shell structure with MSAN resin prepared by a bulk method to prepare the transparent ABS resin. The journal of materials guidance (2022, 36:21070096-6) reports a method for preparing transparent ABS resin by agglomerating small-particle-size styrene-butadiene latex into large-particle-size styrene-butadiene latex by adopting an acetic acid agglomeration technology, then copolymerizing styrene and methyl methacrylate on the surface of the poly-styrene-butadiene latex by adopting an emulsion grafting technology to prepare a core-shell MBS graft copolymer, and then melt-blending the MBS graft copolymer with polymethyl methacrylate (PMMA) and a styrene-acrylonitrile copolymer (SAN), wherein the light transmittance of the method can reach 86%. The journal (2008, 36, 33-34) reports that styrene-butadiene latex is prepared by adopting a one-step emulsion polymerization technology, styrene and methyl methacrylate are grafted by adopting an emulsion grafting technology to prepare MBS graft copolymer, then MSAN resin and the MBS graft copolymer are prepared by adopting a suspension polymerization technology to carry out melt blending, and finally transparent ABS resin is prepared.

Summarizing the prior art, the rubber phase used for preparing the transparent ABS resin by the bulk polymerization method is butadiene or styrene-butadiene rubber prepared by solution polymerization, then the surface of the rubber is grafted by adopting an intermittent polymerization or continuous polymerization mode, and the grafted rubber has larger particle size and is generally larger than 1um in size. The emulsion blending technology is that polybutadiene latex or styrene-butadiene latex is used as core layer latex, then a shell layer of styrene, methyl methacrylate and acrylonitrile is constructed on the surface of the latex, and finally the transparent ABS resin is prepared by blending with MSAN resin by using a melt blending technology. The transparent ABS resin prepared by the method has poor fluidity, and the prepared transparent ABS resin has low impact strength and can only be maintained at 15KJ/m ² Left and right.

Disclosure of Invention

The invention adopts a polybutadiene latex with a large particle diameter and a hollow structure as a core layer latex, and then uses a swelling polymerization technology to completely swell styrene, acrylonitrile and methacrylate monomers into polybutadiene particles to form a pomegranate structure. And finally, constructing a styrene, acrylonitrile and methacrylate polymer layer on the surface of the polybutadiene latex with the formed pomegranate structure to prepare the MABS graft copolymer with the pomegranate structure, and finally, carrying out melt blending with MSAN resin prepared by bulk or suspension polymerization to prepare the high-flow transparent ABS resin. The invention is characterized in that the polybutadiene latex with a hollow structure is adopted to adsorb styrene, methyl methacrylate and acrylonitrile monomers into the polybutadiene latex, so that a pomegranate-type structure is built, on one hand, the polybutadiene particles with the pomegranate-type structure promote the fluidity of the transparent ABS resin, on the other hand, the refractive index of the dispersed phase and the refractive index of the continuous phase of the polybutadiene particles are more matched, and the light transmittance of the transparent ABS resin is further improved. In addition, the thickness of the polybutadiene particles with the garnet structure is only tens of nanometers, and the polybutadiene particles can not scatter light when passing through, thereby being beneficial to reducing the haze of the transparent ABS resin.

In order to achieve the above purpose, the invention adopts the following technical scheme:

a method for preparing a high flow transparent ABS resin having a garnet structure by hollow polybutadiene latex, comprising the steps of:

(1) Adding an emulsifying agent and a molecular weight regulator in parts by weight, adding distilled water into a polymerization reaction kettle, adding a butadiene monomer, a comonomer I, a comonomer II and an initiator into the reaction kettle, heating to 60-80 ℃ to initiate polymerization, and keeping the temperature for 2-5 hours to prepare the hydrophilic small-particle-size polybutadiene latex;

(2) Continuously adding butadiene monomer and comonomer I into the reaction kettle at the same time, wherein the adding time is controlled to be 2-to-2%

5 hours, constructing a transition layer on the surface of the hydrophilic polybutadiene latex with small particle size;

(3) Continuously adding butadiene into the high-pressure reaction kettle at a constant speed, controlling the adding time to be 5-15 hours, adding an initiator after the dripping is finished, heating to 85-90 ℃, and preserving heat for 1-3 hours; continuously adding strong alkali into the reaction kettle, and preserving heat for 1-3 hours to obtain the polybutadiene latex with large particle diameter and hollow structure; (4) The preparation method comprises the following steps of taking the polybutadiene latex with the large particle size and the hollow structure as core layer latex, and preparing MABS grafted latex with the pomegranate structure through emulsion graft polymerization after monomer swelling, wherein the specific steps are as follows: (1) the polybutadiene latex (dry basis) with the hollow structure is placed in a reaction kettle, and an emulsifier, an oil-soluble initiator, a redox initiation system, a comonomer I and swelling at normal temperature are added for 0.5 to 1 hour; (2) heating the system to 60-70 ℃, starting to initiate polymerization, and simultaneously dropwise adding a styrene monomer into the system for 0.5-1 hour; (3) continuously dripping methyl methacrylate monomer for 0.5-2 hours after finishing dripping, and heating to 75-to-over

Preserving the temperature at 85 ℃ for 0.5 hour to obtain MABS graft copolymer latex;

(5) Adding the MABS graft copolymer latex obtained in the step (4) to an aqueous flocculant solution at a concentration of 65% to

Performing flocculation demulsification at 85 ℃, separating solids from water after demulsification, and drying at 60-80 ℃ to obtain MABS graft copolymer powder;

(6) And carrying out melt blending extrusion granulation on the obtained MABS graft copolymer powder and MSAN resin to obtain the transparent ABS resin.

In the invention, the amount of the emulsifier in the step (1) is 2-3 parts by mass, the amount of the molecular weight regulator is 0.1-1 part by mass, the amount of distilled water is 80-150 parts by mass, the amount of the butadiene monomer is 5-10 parts by mass, the amount of the comonomer I is 0-3 parts by mass, the amount of the comonomer II is 0.5-3 parts by mass, and the amount of the initiator is 0.3-1 part by mass;

in the invention, in the step (2), the addition amount of the butadiene monomer is 10-20 parts by mass, and the addition amount of the comonomer I is 2-5 parts by mass;

in the invention, in the step (3), the addition amount of butadiene monomer is 70-85 parts by mass, the addition amount of initiator is 0.03-0.06 parts by mass, the addition amount of strong base is 0.2-1 part by mass, and the strong base is one of potassium hydroxide or sodium hydroxide;

in the invention, in the step (4), the addition amount of the polybutadiene latex with a hollow structure is 100 parts by mass, the addition amount of the emulsifier is 1-3 parts by mass, the addition amount of the oil-soluble initiator is 0.01-1 part by mass, the addition amount of the redox initiation system is 0.4-1 part by mass, the addition amount of the comonomer I is 0.5-5 parts by mass, the addition amount of the styrene monomer is 15-17 parts by mass, and the addition amount of the methyl methacrylate monomer is 45-51 parts by mass.

In the invention, the emulsifier in the step (1) and the step (4) is independently selected from one or more of disproportionated potassium abietate soap, potassium oleate soap and fatty acid potassium soap; the molecular weight regulator in the step (1) is tertiary dodecyl mercaptan; the comonomer I is one or a mixture of more of styrene, methyl methacrylate and acrylonitrile; the comonomer II is one of acrylic acid, methacrylic acid and itaconic acid, and the initiator used is potassium persulfate;

the oil-soluble initiator in the step (4) is one of azodiisobutyronitrile and benzoyl peroxide; the redox initiation system comprises a redox initiation system composed of cumene hydroperoxide, ferrous sulfate, glucose or fructose and sodium pyrophosphate, wherein the mass ratio of the cumene hydroperoxide, the ferrous sulfate, the glucose or the fructose to the sodium pyrophosphate in the redox initiation system is preferably as follows: 1:0.02:0.6:0.8.

the flocculant aqueous solution in the step (5) is sulfuric acid or magnesium sulfate aqueous solution with the concentration of 0.2-1%, preferably 0.3-0.6%.

The MABS graft copolymer powder in the step (6) is 23 to 27 parts and the MSAN resin is 73 to 77 parts; the melt extrusion temperature is 200 to 240℃and preferably 210 to 225 ℃. The MSAN resin is a terpolymer of styrene, acrylonitrile and methyl methacrylate, and can be obtained by methods of bulk polymerization, suspension polymerization and the like.

On the other hand, the invention also provides the high-flow transparent ABS resin with the pomegranate structure, which is prepared by adopting the preparation method.

Compared with the prior art, the invention has the beneficial effects that:

the hydrophilic polybutadiene latex with small particle size is prepared by copolymerizing hydrophilic monomers and butadiene, then a transition layer is constructed on the surface of the polybutadiene latex with small particle size, and then the polybutadiene latex with large particle size and hollow structure can be obtained after further diameter expansion and alkali treatment. The latex is taken as core latex, monomers such as styrene, acrylonitrile, methyl methacrylate and the like are swelled into the hollow microsphere by a swelling technology, and an oil-soluble initiator is added to initiate polymerization to form a pomegranate structure. Finally, a polystyrene layer and a polymethyl methacrylate layer are constructed on the surface of the ABS resin to prepare the MABS graft copolymer, and the MABS graft copolymer and the MSAN resin are subjected to melt blending to obtain the transparent ABS resin. The invention has the advantages that the formed pomegranate structure has smaller size, the light transmittance is not influenced, and the fluidity of the resin is enhanced. In addition, as the transition layers are arranged between the interfaces, the diffuse reflection effect of light is reduced, and the prepared transparent ABS resin has high transmittance and low haze value. In addition, due to the existence of the pomegranate-shaped internal inclusion structure, the interface effect between the disperse phase and the continuous phase is reduced, so that the transparent stability of the transparent ABS resin prepared by the invention is superior to that of the transparent ABS resin prepared by the prior art, and the transparent ABS resin is particularly characterized by small variance value of light transmittance test on the basis of high average value of light transmittance.

Drawings

FIG. 1 is a TEM electron micrograph of a frozen section stained with a transparent ABS resin of example 1 of the present invention in liquid nitrogen;

FIG. 2 is a TEM electron micrograph of a frozen section of the transparent ABS resin prepared by the method of comparative example 1 after staining it with liquid nitrogen.

Detailed Description

The technical solutions of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, but not all embodiments.

Raw materials and sources: monomers such as butadiene, styrene, methyl methacrylate and the like used in the invention are purchased from China Petroleum Jilin petrochemical company. The disproportionated potassium abietate soap is purchased from Xiangxin industry, lanzhou, and the potassium oleate is purchased from Shandong Ruenode New Material, inc. Other raw materials were purchased from Shanghai Ala Ding Shiji, inc.

Example 1

(1) Adding 2 parts of emulsifier disproportionated potassium abietate soap, 0.5 part of fatty acid potassium soap, 0.1 part of molecular weight regulator tertiary dodecyl mercaptan and 150 parts of distilled water into a high-pressure polymerization reaction kettle, adding 5 parts of butadiene monomer, 1 part of comonomer I styrene, 1 part of comonomer II acrylic acid and 0.3 part of initiator potassium persulfate into the reaction kettle by using a pressure pump, heating and polymerizing to 65 ℃ to initiate polymerization, and keeping the temperature for 3 hours to prepare hydrophilic small-particle-size polybutadiene latex;

(2) Continuously adding 10 parts of butadiene monomer and 2 parts of comonomer I methyl methacrylate into a high-pressure reaction kettle at constant speed, controlling the adding time to be 4 hours, and constructing a transition layer on the surface of the hydrophilic polybutadiene latex with small particle size;

(3) Continuously adding 85 parts of butadiene into a high-pressure reaction kettle at a constant speed, controlling the adding time to be 12 hours, adding 0.05 part of initiator potassium persulfate after the dripping is finished, heating to 85 ℃, and preserving heat for 2 hours. Continuously adding 0.2 part of potassium hydroxide into the reaction kettle, and preserving heat for 2 hours to obtain the polybutadiene latex with large particle size and hollow structure;

(4) The preparation method comprises the following steps of taking the polybutadiene latex with the large particle size and the hollow structure as core layer latex, and preparing MABS grafted latex with the pomegranate structure through emulsion graft polymerization after monomer swelling, wherein the specific steps are as follows: (1) 100 parts (dry basis) of the polybutadiene latex with the hollow structure obtained above is placed in a reaction kettle, 1 part of emulsifier disproportionated potassium abietate, 0.01 part of oil-soluble initiator azodiisobutyronitrile, 0.8 part of redox initiation system (the redox initiation system is configured according to the mass ratio of cumene hydroperoxide, ferrous sulfate, glucose and sodium pyrophosphate of 1:0.02:0.6:0.8), 0.5 part of comonomer I styrene, 1.5 parts of methyl methacrylate and swelling for 1 hour at normal temperature are added; (2) heating the system to 65 ℃ to start polymerization, and simultaneously dropwise adding 16 parts of styrene monomer into the system for 0.5 hour; (3) after the dripping is finished, 50 parts of methyl methacrylate monomer is continuously dripped for 1.5 hours, and the temperature is raised to 75 ℃ and kept for 1 hour after the dripping is finished, so that MABS graft copolymer latex can be obtained;

(5) Adding the MABS graft copolymer latex obtained in the step (4) into a flocculating agent (0.3% sulfuric acid solution) to perform flocculation demulsification at 80 ℃, separating solids from water by a centrifuge after demulsification, and drying to obtain MABS graft copolymer powder;

(6) And (3) carrying out melt blending extrusion granulation on 25 parts of the obtained MABS graft copolymer powder and 75 parts of MSAN resin at 220 ℃ to obtain the transparent ABS resin.

Example 2

(1) Adding 1 part of emulsifier fatty acid potassium soap, 1 part of oleic acid potassium soap, 0.2 part of molecular weight regulator tertiary dodecyl mercaptan and 100 parts of distilled water into a high-pressure polymerization reaction kettle, pumping 10 parts of butadiene monomer into the reaction kettle by using a pressure pump, 1 part of comonomer I methyl methacrylate, 1 part of comonomer II methacrylic acid and 0.3 part of initiator potassium persulfate, heating to 65 ℃ for initiating polymerization, and keeping the temperature for 3 hours to prepare hydrophilic small-particle-size polybutadiene latex;

(2) Continuously adding 10 parts of butadiene monomer, 1 part of comonomer I methyl methacrylate and 1 part of acrylonitrile into a high-pressure reaction kettle at constant speed, controlling the adding time to be 4 hours, and constructing a transition layer on the surface of the hydrophilic small-particle-size polybutadiene latex;

(3) Continuously adding 80 parts of butadiene into a high-pressure reaction kettle at a constant speed, controlling the adding time to be 14 hours, adding 0.05 part of initiator potassium persulfate after the dripping is finished, heating to 85 ℃, and preserving heat for 2 hours. Continuously adding 0.6 part of potassium hydroxide into the reaction kettle, and preserving heat for 2 hours to obtain the polybutadiene latex with large particle size and hollow structure;

(4) The preparation method comprises the following steps of taking the polybutadiene latex with the large particle size and the hollow structure as core layer latex, and preparing MABS grafted latex with the pomegranate structure through emulsion graft polymerization after monomer swelling, wherein the specific steps are as follows: (1) 100 parts (dry basis) of the polybutadiene latex with the hollow structure obtained above is placed in a reaction kettle, 1 part of emulsifier potassium oleate, 0.01 part of oil-soluble initiator benzoyl peroxide and 0.7 part of redox initiation system (the redox initiation system is configured according to the mass ratio of cumene hydroperoxide, ferrous sulfate, fructose and sodium pyrophosphate of 1:0.02:0.6:0.8), 0.5 part of comonomer I styrene, 1.5 parts of methyl methacrylate and swelling for 1 hour at normal temperature are added; (2) heating the system to 65 ℃, starting to initiate polymerization, and simultaneously dropwise adding 16 parts of styrene monomer into the system for 1 hour; (3) after the dripping is finished, 50 parts of methyl methacrylate monomer is continuously dripped for 2 hours, and the temperature is raised to 80 ℃ and kept for 1 hour after the dripping is finished, so that MABS graft copolymer latex can be obtained;

(5) Adding the MABS graft copolymer latex obtained in the step (4) into a flocculating agent (0.5% magnesium sulfate solution) to perform flocculation demulsification at 80 ℃, separating solids from water after demulsification, and drying to obtain MABS graft copolymer powder;

(6) And (3) carrying out melt blending extrusion granulation on 25 parts of the obtained MABS graft copolymer powder and 75 parts of MSAN resin at 220 ℃ to obtain the transparent ABS resin.

Example 3

(1) Adding 2 parts of emulsifier disproportionated potassium abietate soap, 0.1 part of molecular weight regulator tertiary dodecyl mercaptan and 80 parts of distilled water into a high-pressure polymerization reaction kettle, pumping 5 parts of butadiene monomer, 1 part of comonomer I styrene, 0.5 part of comonomer II acrylic acid and 0.25 part of initiator potassium persulfate into the reaction kettle by using a pressure pump, heating to 60 ℃ to initiate polymerization, and keeping the temperature for 5 hours to prepare the hydrophilic small-particle-size polybutadiene latex;

(2) Continuously adding 10 parts of butadiene monomer and 1 part of comonomer I styrene into a high-pressure reaction kettle at constant speed, controlling the adding time to be 5 hours, and constructing a transition layer on the surface of the hydrophilic small-particle-size polybutadiene latex;

(3) Continuously adding 80 parts of butadiene into a high-pressure reaction kettle at a constant speed, controlling the adding time to be 15 hours, adding 0.05 part of initiator potassium persulfate after the dripping is finished, heating to 85 ℃, and preserving heat for 3 hours. Continuously adding 0.4 part of sodium hydroxide into the reaction kettle, and preserving heat for 3 hours to obtain the polybutadiene latex with large particle size and hollow structure;

(4) The preparation method comprises the following steps of taking the polybutadiene latex with the large particle size and the hollow structure as core layer latex, and preparing MABS grafted latex with the pomegranate structure through emulsion graft polymerization after monomer swelling, wherein the specific steps are as follows: (1) 100 parts (dry basis) of the polybutadiene latex with the hollow structure obtained above is placed in a reaction kettle, 1 part of emulsifier fatty acid soap is added, 0.01 part of oil-soluble initiator azodiisobutyronitrile, 0.4 part of redox initiation system (the redox initiation system is configured according to the mass ratio of cumene hydroperoxide, ferrous sulfate, glucose and sodium pyrophosphate of 1:0.02:0.6:0.8), 0.5 part of comonomer I styrene is added, and swelling is carried out for 0.5 hour at normal temperature; (2) heating the system to 60 ℃, starting to initiate polymerization, and simultaneously dropwise adding 16 parts of styrene monomer into the system for 0.5 hour; (3) after the dripping is finished, 50 parts of methyl methacrylate monomer is continuously dripped for 1.5 hours, and the temperature is raised to 75 ℃ and kept for 1 hour after the dripping is finished, so that MABS graft copolymer latex can be obtained;

(5) Adding the MABS graft copolymer latex obtained in the step (4) into a flocculating agent (0.2% magnesium sulfate solution) to perform flocculation demulsification at 85 ℃, separating solids from water after demulsification, and drying to obtain MABS graft copolymer powder;

(6) And (3) carrying out melt blending extrusion granulation on 23 parts of the obtained MABS graft copolymer powder and 77 parts of MSAN resin at 200 ℃ to obtain the transparent ABS resin.

Example 4

(1) Adding 3 parts of emulsifier potassium oleate soap, 1 part of molecular weight regulator tertiary dodecyl mercaptan and 150 parts of distilled water into a high-pressure polymerization reaction kettle, pumping 15 parts of butadiene monomer, 5 parts of comonomer I methyl methacrylate, 3 parts of comonomer II methacrylic acid and 0.95 part of initiator potassium persulfate into the reaction kettle by using a pressure pump, heating and polymerizing to 80 ℃ to initiate polymerization, and keeping the temperature for 2 hours to prepare the hydrophilic small-particle-size polybutadiene latex;

(2) Continuously adding 20 parts of butadiene monomer and 3 parts of comonomer I methyl methacrylate into a high-pressure reaction kettle at constant speed, controlling the adding time to be 2 hours, and constructing a transition layer on the surface of the hydrophilic polybutadiene latex with small particle size;

(3) Continuously adding 80 parts of butadiene into a high-pressure reaction kettle at a constant speed, controlling the adding time to be 10 hours, adding 0.05 part of initiator potassium persulfate after the dripping is finished, heating to 80 ℃, and preserving heat for 1 hour. Continuously adding 1 part of potassium hydroxide into the reaction kettle, and preserving heat for 1 hour to obtain the polybutadiene latex with large particle size and hollow structure;

(4) The preparation method comprises the following steps of taking the polybutadiene latex with the large particle size and the hollow structure as core layer latex, and preparing MABS grafted latex with the pomegranate structure through emulsion graft polymerization after monomer swelling, wherein the specific steps are as follows: (1) 100 parts (dry basis) of polybutadiene latex with a hollow structure obtained in the above is placed in a reaction kettle, 2 parts of emulsifier fatty acid soap and 1 part of potassium oleate soap are added, 0.1 part of oil-soluble initiator azodiisobutyronitrile, 1 part of redox initiation system (the redox initiation system is configured according to the mass ratio of cumene hydroperoxide, ferrous sulfate, glucose and sodium pyrophosphate of 1:0.02:0.6:0.8), 5 parts of comonomer I methyl methacrylate and the mixture is swelled for 1 hour at normal temperature; (2) heating the system to 70 ℃, starting to initiate polymerization, and simultaneously dropwise adding 16 parts of styrene monomer into the system for 0.5 hour; (3) after the dripping is finished, 50 parts of methyl methacrylate monomer is continuously dripped for 1.5 hours, and the temperature is raised to 85 ℃ and kept for 0.5 hour after the dripping is finished, so that MABS graft copolymer latex can be obtained;

(5) Adding the MABS graft copolymer latex obtained in the step (4) into a flocculating agent (1% magnesium sulfate solution) to perform flocculation demulsification at 65 ℃, separating solids from water after demulsification, and drying to obtain MABS graft copolymer powder;

(6) And carrying out melt blending extrusion granulation on 27 parts of the obtained MABS graft copolymer powder and 73 parts of MSAN resin at 240 ℃ to obtain the transparent ABS resin.

Example 5

(1) Adding 2.5 parts of emulsifier fatty acid potassium soap, 0.55 part of molecular weight regulator tertiary dodecyl mercaptan and 115 parts of distilled water into a high-pressure polymerization reaction kettle, pumping 15 parts of butadiene monomer, 4 parts of comonomer I acrylonitrile, 1.75 parts of comonomer II itaconic acid and 0.6 part of initiator potassium persulfate into the reaction kettle by using a pressure pump, heating to 70 ℃ to initiate polymerization, and keeping the temperature for 3.5 hours to prepare the hydrophilic small-particle-size polybutadiene latex;

(2) Continuously adding 5 parts of butadiene monomer and 1 part of comonomer (I) acrylonitrile into a high-pressure reaction kettle at constant speed, controlling the adding time to be 3.5 hours, and constructing a transition layer on the surface of the hydrophilic polybutadiene latex with small particle size;

(3) Continuously adding 80 parts of butadiene into a high-pressure reaction kettle at a constant speed, controlling the adding time to be 12.5 hours, adding 0.05 part of initiator potassium persulfate after the dripping is finished, heating to 80 ℃, and preserving heat for 2 hours. Continuously adding 0.7 part of potassium hydroxide into the reaction kettle, and preserving heat for 2 hours to obtain the polybutadiene latex with large particle size and hollow structure;

(4) The preparation method comprises the following steps of taking the polybutadiene latex with the large particle size and the hollow structure as core layer latex, and preparing MABS grafted latex with the pomegranate structure through emulsion graft polymerization after monomer swelling, wherein the specific steps are as follows: (1) 100 parts (dry basis) of the polybutadiene latex with the hollow structure obtained above is placed in a reaction kettle, 2 parts of emulsifier disproportionated potassium abietate soap, 0.05 part of oil-soluble initiator azodiisobutyronitrile, 0.7 part of redox initiation system (the redox initiation system is configured according to the mass ratio of cumene hydroperoxide, ferrous sulfate, glucose and sodium pyrophosphate of 1:0.02:0.6:0.8), 2 parts of comonomer I styrene, 0.75 part of methyl methacrylate and swelling at normal temperature for 0.75 hours; (2) heating the system to 65 ℃ to start polymerization, and simultaneously dropwise adding 16 parts of styrene monomer into the system for 0.5 hour; (3) after the dripping is finished, 50 parts of methyl methacrylate monomer is continuously dripped for 1.5 hours, and the temperature is raised to 80 ℃ and kept for 0.75 hour after the dripping is finished, so that MABS graft copolymer latex can be obtained;

(5) Adding the MABS graft copolymer latex obtained in the step (4) into a flocculating agent (0.6% magnesium sulfate solution) to perform flocculation demulsification at 75 ℃, separating solid from water after demulsification, and drying to obtain MABS graft copolymer powder;

(6) And (3) carrying out melt blending extrusion granulation on 25 parts of the obtained MABS graft copolymer powder and 75 parts of MSAN resin at 220 ℃ to obtain the transparent ABS resin.

Comparative example 1

Based on the technical method reported in journal (2008, 36, 33-34) of new chemical materials, the preparation of large-particle-size styrene-butadiene latex by a one-step method comprises the specific steps of adding 2.3 parts of disproportionated potassium abietate soap as an emulsifier and 60 parts of water, 70 parts of butadiene monomer, 30 parts of styrene monomer and 0.6 part of initiator sodium persulfate into a high-pressure reaction kettle of 1L. Stirring is started, the stirring speed is set to 100rpm, the temperature is set to 65 ℃ for reaction for 18 hours, then the temperature is increased to 70 ℃ for continuous reaction for 12 hours, and the styrene-butadiene latex (SBR) can be obtained after the reaction is completed. Adding 55 parts of obtained SBR latex serving as a core layer latex dry basis into a reaction kettle, adding deionized water to adjust the solid content of the SBR latex in the reaction kettle to 30%, and then adding 0.8 part of sodium pyrophosphate, 0.6 part of glucose, 0.01 part of ferrous sulfate and 0.8 part of cumene hydroperoxide. 15 parts of styrene and 30 parts of methyl methacrylate were added dropwise to the reaction vessel over a period of 1 hour. Finally, heating to 75 ℃, and preserving heat for 1 hour to obtain the graft copolymer emulsion. Adding the obtained graft copolymer emulsion into 0.5wt% sulfuric acid water solution according to the volume ratio of 1/2 for flocculation demulsification, then carrying out solid-liquid separation, and drying the grafted powder to obtain the MBS high-gel powder. 25 parts of the obtained MBS high rubber powder and 75 parts of MSAN resin are subjected to melt extrusion blending at 220 ℃, so that transparent ABS resin can be obtained. It is worth emphasizing that the refractive index of the transparent ABS resin prepared in the paper is 1.534.

Comparative example 2

MABS graft copolymer latex was prepared based on the preparation method of transparent ABS resin disclosed in patent CN 105008406A, which was carried out by stirring 50 parts of water, 0.8 part of potassium fatty acid, 1.0 part of potassium rosin and 1.0 part of potassium carbonate, and then started at a stirring rate of 100rpm. Then, 30 parts of butadiene monomer, 0.3 part of tertiary dodecyl mercaptan, 0.8 part of polyethylene glycol diacrylate and 0.3 part of dicumyl hydroperoxide are added into the reaction kettle. The temperature was raised to 40℃and the reaction was carried out for 6 hours. Then 15 parts of butadiene were continuously added to the reaction vessel, and after the temperature of the reaction vessel was raised to 55 ℃, 55 parts of butadiene was continuously added dropwise into the reaction vessel over 8 hours. From the continuous addition of butadiene, an emulsion comprising 4 parts by weight of deionized water, 0.5 parts by weight of potassium abietate and 0.3 parts by weight of t-butyl hydroperoxide was added to the reactor over 6 hours. Next, 0.0003 parts by weight of ferrous sulfate, 0.05 parts by weight of glucose, 0.04 parts by weight of sodium pyrophosphate, and 0.3 parts by weight of t-butyl hydroperoxide were further added to the reactor. Polybutadiene latex after 2 hours of incubation. After the butadiene monomer is added dropwise, the temperature is raised to 75 ℃, and the polybutadiene latex can be obtained after 2 hours of heat preservation.

100 parts deionized water, 0.5 part reactive emulsifier C ₁₆ -C ₁₈ Dipotassium alkenylsuccinate, 27 parts of methyl methacrylate, 10 parts of styrene, 3 parts of acrylonitrile, 0.5 part of tertiary dodecyl mercaptan, 0.048 part of sodium formaldehyde sulfoxylate, 0.012 part of sodium ethylenediamine tetraacetate, 0.001 part of ferrous sulfate and 0.04 part of tertiary butyl hydroperoxide are continuously added to the prepared polybutadiene rubber latex for reaction at 75 ℃ for 5 hours. After the reaction, the reaction mixture was heated to 80℃and then maintained at that temperature for 1 hour, and then the reaction was terminated to obtain a graft copolymer latex. And (3) flocculating and demulsifying the obtained graft copolymer latex with sulfuric acid with the system ratio of 1/2 and the concentration of 0.5%, and drying to obtain the high-rubber powder. 25 parts of high rubber powder and 75 parts of MSAN resin are subjected to melt extrusion blending at 220 ℃ to obtain the transparent ABS resin.

Comparative example 3

The procedure for the non-addition of hydrophilic monomers in example 1, which does not constitute a polybutadiene latex with a hollow structure, is as follows:

(1) Adding 2 parts of emulsifier disproportionated potassium abietate soap, 0.5 part of fatty acid potassium soap, 0.1 part of molecular weight regulator tertiary dodecyl mercaptan and 150 parts of distilled water into a high-pressure polymerization reaction kettle, pumping 5 parts of butadiene monomer, 1 part of comonomer I styrene and 0.3 part of initiator potassium persulfate into the reaction kettle by using a pressure pump, heating to 65 ℃ for polymerization, and preparing small-particle-size polybutadiene latex at constant temperature for 3 hours;

(2) Continuously adding 10 parts of butadiene monomer and 2 parts of comonomer I methyl methacrylate into a high-pressure reaction kettle at constant speed, controlling the adding time to be 4 hours, and constructing a transition layer on the surface of the hydrophilic polybutadiene latex with small particle size;

(3) Continuously adding 85 parts of butadiene into a high-pressure reaction kettle at a constant speed, controlling the adding time to be 12 hours, adding 0.05 part of initiator potassium persulfate after the dripping is finished, and heating to 85 ℃. The polybutadiene latex with large particle diameter and hollow structure can be obtained after heat preservation for 2 hours;

(4) The preparation method comprises the following steps of taking the polybutadiene latex with the large particle size and the hollow structure as core layer latex, and preparing MABS grafted latex with the pomegranate structure through emulsion graft polymerization after monomer swelling, wherein the specific steps are as follows: (1) 100 parts (dry basis) of the polybutadiene latex obtained above is placed in a reaction kettle, 1 part of emulsifier disproportionated potassium abietate, 0.01 part of oil-soluble initiator azodiisobutyronitrile, 0.8 part of redox initiation system (the redox initiation system is configured according to the mass ratio of cumene hydroperoxide, ferrous sulfate, glucose and sodium pyrophosphate of 1:0.02:0.6:0.8), 0.5 part of comonomer I styrene, 1.5 parts of methyl methacrylate and swelling for 1 hour at normal temperature are added; (2) heating the system to 65 ℃ to start polymerization, and simultaneously dropwise adding 16 parts of styrene monomer into the system for 0.5 hour; (3) after the dripping is finished, 50 parts of methyl methacrylate monomer is continuously dripped for 1.5 hours, and the temperature is raised to 75 ℃ and kept for 1 hour after the dripping is finished, so that MABS graft copolymer latex can be obtained;

(5) Adding the MABS graft copolymer latex obtained in the step (4) into a flocculating agent (0.3% sulfuric acid solution) to perform flocculation demulsification at 80 ℃, separating solids from water by a centrifuge after demulsification, and drying to obtain MABS graft copolymer powder;

(6) And (3) carrying out melt blending extrusion granulation on 25 parts of the obtained MABS graft copolymer powder and 75 parts of MSAN resin at 220 ℃ to obtain the transparent ABS resin.

The transparent ABS resins prepared in examples 1 to 5 and comparative examples 1 to 3 were injected into standard bars under the same process conditions, and the impact strength, tensile strength and flexural strength test methods of the materials were respectively referred to ASTM D256-2006, ASTM D638-2000 and ASTM D790-2000 standards, the melt index test method was referred to ASTM D1238-2010 standard (210 ℃,10 KG), and the light transmittance and haze test samples were 3mm thick plaques, and were tested with reference to GB T2410-2008 standards. When the light transmittance test result is an average value of 5 test results, the light transmittance variance calculation method can calculate according to the following formula:

s in the formula ² I.e. variance, n represents the specific number of measurements, x _i For the actually measured transmittance values, x is the average of n measured transmittance values, and the performance is tested as shown in the following table:

the data in the comparative examples and comparative examples show that the impact strength and melt index of the transparent ABS resin prepared by the invention are higher than those of the comparative examples. In addition, the transparent ABS resin prepared by the invention has high light transmittance, low haze value and small variance value of test results, and can show that the sample prepared by the invention has good transparent uniformity and stable product quality. Comparative example 3 is a result of example 1 in which no hydrophilic monomer was added to prepare a polybutadiene latex, and the polybutadiene latex prepared without the hydrophilic monomer was not hollow, so that swelling of the monomer during subsequent grafting was hindered, and a pomegranate structure could not be formed, resulting in a decrease in performance.

The transparent ABS resins prepared in example 1 and comparative example 1 were ultrathin-sectioned under liquid nitrogen freezing conditions, then stained with osmium tetroxide, and their morphology was photographed by a transmission electron microscope, and the results thereof are shown in fig. 1 and 2. In the figure, the black part is a polybutadiene phase, i.e., a dispersed phase, and the bright part is a resin phase. It is clear from fig. 1 that the black rubber particles contain a resin structure of a bright color inside, and this structural morphology is similar to that of a garnet structure. The resin phase structure inside the rubber particles is caused by the adsorption of styrene and methyl methacrylate in the grafting process of hollow polybutadiene, so that the size of the rubber particles is increased, the cavitation process of the rubber particles is easier to initiate, and the mechanical property of the rubber particles is enhanced. In addition, the resin structure inside the rubber particles changes the chain aggregation state structure of the rubber particles, so that the acting force between molecular chains inside the butadiene rubber particles is reduced, the fluidity of the transparent ABS resin is improved, and the melt index is increased. In fig. 2, butadiene latex of a normal (solid) structure is used as a core layer structure, and thus a garnet structure does not appear.

Claims (10)

1. A method for preparing a high flow transparent ABS resin having a garnet structure by hollow polybutadiene latex, comprising the steps of:

(2) Adding an emulsifying agent and a molecular weight regulator in parts by weight, adding distilled water into a polymerization reaction kettle, adding a butadiene monomer, a comonomer I, a comonomer II and an initiator into the reaction kettle, heating to 60-80 ℃ to initiate polymerization, and keeping the temperature for 2-5 hours to prepare the hydrophilic small-particle-size polybutadiene latex;

(3) Continuously adding butadiene monomer and comonomer I into the reaction kettle at the same time, controlling the adding time to be 2-5 hours, and constructing a transition layer on the surface of the hydrophilic polybutadiene latex with small particle size;

(4) Continuously adding butadiene into the high-pressure reaction kettle at a constant speed, controlling the adding time to be 5-15 hours, adding an initiator after the dripping is finished, heating to 85-90 ℃, and preserving heat for 1-3 hours; continuously adding strong alkali into the reaction kettle, and preserving heat for 1-3 hours to obtain the polybutadiene latex with large particle diameter and hollow structure;

(5) The preparation method comprises the following steps of taking the polybutadiene latex with the large particle size and the hollow structure as core layer latex, and preparing MABS grafted latex with the pomegranate structure through emulsion graft polymerization after monomer swelling, wherein the specific steps are as follows: (1) the polybutadiene latex (dry basis) with the hollow structure is placed in a reaction kettle, and an emulsifier, an oil-soluble initiator, a redox initiation system, a comonomer I and swelling at normal temperature are added for 0.5 to 1 hour; (2) heating the system to 60-70 ℃, starting to initiate polymerization, and simultaneously dropwise adding a styrene monomer into the system for 0.5-1 hour; (3) continuously dripping methyl methacrylate monomer for 0.5-2 hours after finishing dripping, and heating to 75-85 ℃ after finishing dripping and preserving heat for 0.5 hour to obtain MABS graft copolymer latex;

(6) Adding the MABS graft copolymer latex obtained in the step (4) into a flocculating agent aqueous solution, performing flocculation demulsification at 65-85 ℃, and drying at 60-80 ℃ after separating solids from water after demulsification to obtain MABS graft copolymer powder;

(7) And carrying out melt blending extrusion granulation on the obtained MABS graft copolymer powder and MSAN resin to obtain the transparent ABS resin.

2. The method of claim 1, wherein the emulsifier in step (1) and step (4) is independently selected from one or more of disproportionated potassium rosin soap, potassium oleate soap, potassium fatty acid soap; and/or, the molecular weight regulator in the step (1) is tert-dodecyl mercaptan; and/or the comonomer I is one or a mixture of more of styrene, methyl methacrylate and acrylonitrile; and/or the comonomer II is one of acrylic acid, methacrylic acid and itaconic acid; and/or, the initiator is potassium persulfate.

3. The method according to claim 1 or 2, wherein the amount of the emulsifier in the step (1) is 2 to 3 parts by mass, the amount of the molecular weight modifier is 0.1 to 1 part by mass, the amount of distilled water is 80 to 150 parts by mass, the amount of the butadiene monomer is 5 to 10 parts by mass, the amount of the comonomer I is 0 to 3 parts by mass, the amount of the comonomer II is 0.5 to 3 parts by mass, and the amount of the initiator is 0.3 to 1 part by mass.

4. A method according to any one of claims 1 to 3, wherein in the step (2), the butadiene monomer is added in an amount of 10 to 20 parts by mass and the comonomer i is added in an amount of 2 to 5 parts by mass.

5. The method according to any one of claims 1 to 4, wherein in the step (3), the butadiene monomer is added in an amount of 70 to 85 parts by mass, the initiator is added in an amount of 0.03 to 0.06 part by mass, and the alkali is added in an amount of 0.2 to 1 part by mass, the alkali being one of potassium hydroxide or sodium hydroxide.

6. The method of any one of claims 1-5, wherein the oil-soluble initiator is one of azobisisobutyronitrile, benzoyl peroxide; the redox initiation system comprises a redox initiation system consisting of cumene hydroperoxide, ferrous sulfate, glucose or fructose and sodium pyrophosphate.

7. The method according to any one of claims 1 to 6, wherein in the step (4), the polybutadiene latex having a hollow structure is added in an amount of 100 parts by mass, the emulsifier is added in an amount of 1 to 3 parts by mass, the oil-soluble initiator is added in an amount of 0.01 to 1 part by mass, the redox initiator is added in an amount of 0.4 to 1 part by mass, the comonomer I is added in an amount of 0.5 to 5 parts by mass, the styrene monomer is added in an amount of 15 to 17 parts by mass, and the methyl methacrylate monomer is added in an amount of 45 to 51 parts by mass.

8. The method according to any one of claims 1 to 7, wherein the flocculant aqueous solution of step (5) is a sulfuric acid or magnesium sulfate aqueous solution with a concentration of 0.2 to 1%, preferably a sulfuric acid or magnesium sulfate aqueous solution with a concentration of 0.3 to 0.6%.

9. The method of any one of claims 1 to 8, wherein the MABS graft copolymer powder is used in an amount of 23 to 27 parts and the MSAN resin is used in an amount of 73 to 77 parts in step (6); the melt extrusion temperature is 200 to 240℃and preferably 210 to 225 ℃.

10. A high flow transparent ABS resin having a garnet structure prepared according to the method of any one of claims 1 to 8.

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