An impact modifier, its preparation method and use

Abstract

The application provides an impact modifier and a preparation method and application thereof, the impact modifier is a condensed particle with a core-shell structure; the condensed particle with the core-shell structure comprises a conjugated diene polymer inner core and a vinyl polymer outer shell; the average particle size of the conjugated diene polymer inner core is 180-320 nm; the unsaturation degree of the condensed particle is 17-105 g I2 / 100 g in terms of the mass of iodine consumed per 100 g of sample; the impact modifier contains calcium ions, and the content of the calcium ions in the impact modifier is 200-1800 ppm. In the application, the material prepared from the impact modifier has excellent low-temperature toughness, high impact performance retention rate after hygrothermal aging and thermal oxygen aging, small color change, and good color stability.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to an impact modifier, its preparation method, and its application. Background Technology

[0002] To improve the impact resistance of resin compositions containing aromatic polycarbonates, impact modifiers containing rubber components are typically added, such as butadiene-styrene-acrylonitrile copolymer (ABS), butadiene-methyl methacrylate-styrene-acrylonitrile copolymer (MABS), butadiene-methyl methacrylate-styrene copolymer (MBS), and acrylonitrile-styrene-acrylate monomer copolymer (ASA). However, in recent years, resin compositions containing aromatic polycarbonates have tended towards thinner walls. To improve flowability during molding, molding temperatures often need to be increased. However, in resin compositions containing aromatic polycarbonates with added impact modifiers containing rubber components, the rubber components are prone to deterioration at high temperatures, leading to poorer mechanical properties and appearance defects caused by discoloration. In particular, rubber polymerized with divinyl monomers is more prone to aging during high-temperature processing; further improvements are needed in the low-temperature toughness of commonly used impact modifiers.

[0003] Therefore, developing an impact modifier with excellent low-temperature toughness, high impact strength after damp heat aging and thermo-oxidative aging, and minimal color change is an urgent problem to be solved in this field. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide an impact modifier, its preparation method, and its application. Materials containing the impact modifier exhibit excellent low-temperature toughness, maintain high toughness even after damp heat aging and thermo-oxidative aging, and show minimal color change and good color stability.

[0005] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides an impact modifier, wherein the impact modifier is a coagulated particle with a core-shell structure; the coagulated particle with a core-shell structure comprises a conjugated diene polymer core and a vinyl polymer shell; the average particle size of the conjugated diene polymer core is 180~320 nm; the degree of unsaturation of the coagulated particle is 17~105 g I2 / 100 g, based on the mass of iodine consumed per 100 g sample; the impact modifier contains calcium ions, and the content of calcium ions in the impact modifier is 200~1800 ppm.

[0006] In this invention, "derived from" can be understood as "the raw material for preparation is", such as "the structural unit in the core of the conjugated diene polymer is derived from the conjugated diene", indicating that the raw material for preparing the core of the conjugated diene polymer contains the conjugated diene.

[0007] In this invention, an impact modifier with a core-shell structure is used, and the average particle size of the core of the impact modifier and the unsaturation of the aggregated particles are controlled within a specific range. At the same time, calcium ions are introduced into the impact modifier, and the calcium ion content is controlled within a specific range. This is beneficial to improving the low-temperature toughness, resistance to damp heat aging, and resistance to heat oxidation aging of the material. The material including the impact modifier still has high impact performance at -40℃, and the impact strength retention rate is high after damp heat aging and heat oxidation aging, with little color change.

[0008] In this invention, the calcium ions in the impact modifier exist in the form of organic calcium salts. Organic calcium salts can absorb acidic or alkaline substances generated during aging (especially significant in polymers such as polyesters), thereby inhibiting further aging and effectively improving the performance retention and color retention of the resin composition after aging. If the content of calcium ions is too low, the color change of the obtained resin composition after double 85 humid heat aging and thermo-oxidative aging will be increased; if it is too high, it will accelerate the aging process of the resin composition.

[0009] In this invention, the organic calcium salt can be formed by adding a water-soluble calcium-containing compound during the coagulation process, through calcium ions and an emulsifier.

[0010] In this invention, the average particle size of the conjugated diene polymer core is 180~320 nm, for example, it can be 190 nm, 200 nm, 210 nm, 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm, 280 nm, 290 nm, 300 nm, 310 nm, 318 nm or any of the above values, more preferably 200~300 nm, and particularly preferably 280~300 nm.

[0011] In this invention, the calcium ion content in the core-shell structured condensed particles is 200~1800 ppm, for example, it can be 220 ppm, 250 ppm, 280 ppm, 300 ppm, 350 ppm, 400 ppm, 450 ppm, 500 ppm, 550 ppm, 600 ppm, 650 ppm, 700 ppm, 750 ppm, 800 ppm, 850 ppm, 900 ppm, 950 ppm, 1000 ppm, 1100 ppm, 1200 ppm, 1300 ppm, 1400 ppm, 1500 ppm, 1600 ppm, 1700 ppm, 1750 ppm or any of the above values, more preferably 500~1400 ppm.

[0012] In this invention, based on the mass of iodine consumed per 100g sample, the unsaturation degree of the agglomerated particles is 17~105g I2 / 100g, for example, it can be 18 g I2 / 100g, 20 g I2 / 100g, 22 g I2 / 100g, 25 g I2 / 100g, 28 g I2 / 100g, 30 g I2 / 100g, 32 g I2 / 100g, 35 g I2 / 100g, 40 g I2 / 100g, 45 g I2 / 100g, 50 g I2 / 100g, 55 g I2 / 100g, 60 g I2 / 100g, 65 g I2 / 100g, 70 g I2 / 100g, 75 g I2 / 100g, 80 g I2 / 100g, 85 g I2 / 100g, 90 g I2 / 100g, etc. I2 / 100g, 95 g I2 / 100g, 100 g I2 / 100g, 105 g I2 / 100g or any of the above values, more preferably 30~90g I2 / 100g.

[0013] Preferably, the mass percentage of structural units derived from conjugated diene in the conjugated diene polymer core is 79-100%, for example, it can be 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or any of the above values, more preferably 89-100%.

[0014] In this invention, the mass percentage of the structural units involved is calculated as the percentage of the added mass of the corresponding monomer to the total added mass of the monomer. For example, if the mass percentage of the structural units derived from the conjugated diene in the core of the conjugated diene polymer is 79-100%, then the added mass of the conjugated diene monomer is 79-100% of the total added mass of the conjugated diene polymer core monomer.

[0015] Preferably, the conjugated diene polymer core further includes structural units derived from styrene compounds.

[0016] In this invention, the mass percentage of structural units derived from styrene compounds in the conjugated diene polymer core is 0-21%, more preferably 1-11%.

[0017] In this invention, the conjugated diene in the conjugated diene polymer core is a conjugated diene with ≥4 carbon atoms, exemplarily including butadiene, isoprene, hexadiene, heptaadiene, nonadiene, etc.; the styrene compound includes, but is not limited to, any one or a combination of at least two of styrene, α-ethylstyrene, α-methylstyrene, p-methylstyrene, o-tert-butylstyrene, bromostyrene, or chlorostyrene (such as trichlorostyrene); the same expressions below indicate the same meaning or are selected from the same range, but the two may be the same or different. For example, the styrene compound in the vinyl polymer shell is selected from the same limited range as the conjugated diene polymer core, but the styrene compounds used in the two may be the same or different.

[0018] Preferably, the vinyl polymer shell comprises at least one structural unit derived from styrene compounds, a structural unit derived from acrylonitrile compounds, or a structural unit derived from alkyl (meth)acrylates.

[0019] In this invention, the acrylonitrile compounds include, but are not limited to, at least one of acrylonitrile, methacrylonitrile, and fumaronitrile; the alkyl methacrylates include, but are not limited to, at least one of methyl methacrylate, methyl acrylate, butyl methacrylate, butyl acrylate, propyl methacrylate, and propyl acrylate.

[0020] Preferably, by weight, the vinyl polymer shell comprises 8 to 35 parts of structural units derived from styrene compounds and 8 to 36 parts of structural units derived from a second monomer; the structural units derived from the second monomer comprise 8 to 26 parts of structural units derived from acrylonitrile compounds and / or 24 to 36 parts of structural units derived from alkyl (meth)acrylates.

[0021] In this invention, 8 to 35 parts of structural units derived from styrene compounds can be, for example, 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, 20 parts, 22 parts, 24 parts, 26 parts, 28 parts, 30 parts, 32 parts, 34 parts, or any range of the above values.

[0022] In this invention, 8 to 26 parts of structural units derived from acrylonitrile compounds can be, for example, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, or any of the above values.

[0023] In this invention, 24 to 36 parts of structural units derived from (meth)acrylates can be, for example, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35 parts or any range of the above values.

[0024] In this invention, the mass percentage of structural units derived from styrene and similar compounds in the vinyl polymer shell is ≥20%, for example, it can be 40~70%.

[0025] In this invention, the content of each structural unit in the vinyl polymer shell is expressed as a percentage of monomer mass, for example... The vinyl polymer shell comprises 8-35 structural units derived from styrene compounds and 8-36 structural units derived from a second monomer, meaning that the monomers of the vinyl polymer shell comprise 8-35 styrene compounds and 8-36 second monomers.

[0026] Preferably, the mass ratio of the conjugated diene polymer core to the vinyl polymer shell is (39~72):(28~61), wherein the specific value of (39~72) can be, for example, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70 or any of the above values; the specific value of (28~61) can be, for example, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60 or any of the above values; more preferably, it is (49~62):(38~51).

[0027] In this invention, the total mass of the conjugated diene polymer core and the vinyl polymer shell is 100 parts; the mass ratio of the conjugated diene polymer core and the vinyl polymer shell is calculated as the ratio of the dry basis of the conjugated diene polymer core latex (i.e., the dry basis of the core layer rubber latex) to the total mass of the monomers of the vinyl polymer shell.

[0028] Preferably, the calcium ions are derived from water-soluble calcium-containing compounds.

[0029] Preferably, the water-soluble calcium-containing compound includes at least one of calcium chloride, calcium nitrate, calcium acetate, and calcium gluconate.

[0030] In a second aspect, the present invention provides a method for preparing the impact modifier according to the first aspect, the method comprising the following steps: (1) Mix latex with a core-shell structure, coagulant, and water, and coagulate to obtain the first slurry; (2) The first slurry is dehydrated, washed and dried to obtain the impact modifier.

[0031] The core-shell structured latex comprises a conjugated diene polymer core and a vinyl polymer shell; the coagulant is a water-soluble calcium-containing compound; the washing method includes: mixing the dehydrated solid with demineralized water to obtain a second slurry with a solid content of 15-25% (e.g., 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24% or any range of the above values); stirring and washing the slurry for 10-30 minutes (e.g., 12 minutes, 14 minutes, 16 minutes, 18 minutes, 20 minutes, 22 minutes, 24 minutes, 26 minutes, 28 minutes or any range of the above values); the drying is carried out under vacuum conditions or in the presence of a protective atmosphere.

[0032] In this invention, the calcium ion content in the impact modifier can be adjusted by adjusting the amount and type of water-soluble calcium-containing compound and the washing process (including the amount of desalinated water, washing time, etc.).

[0033] In this invention, the washing process further includes a centrifugation step.

[0034] In this invention, the washing method can also involve mixing the dehydrated solid with demineralized water to obtain a second slurry with a solid content of 15-25%, centrifuging the second slurry directly, repeating this step at least once, and then subjecting the obtained solid to the subsequent drying step.

[0035] In this invention, the core-shell structured latex can be commercially available or prepared using conventional methods in the art. Exemplarily, the core-shell structured latex is obtained by emulsion polymerization of a vinyl polymer grafted onto the surface of the core layer rubber, resulting in a core-shell structured latex formed by a conjugated diene polymer core and a vinyl polymer shell. Specific preparation methods include: The latex of the core-shell rubber, initiator, chain transfer agent, emulsifier, catalyst, solvent and graft monomer (graft monomer includes at least one of styrene and its derivatives, acrylonitrile and its derivatives, and alkyl (meth)acrylate) are mixed and reacted at 50-60°C for 1-6 h. Then, a surfactant is added and the reaction is continued for 0.5-3 h to obtain the latex with the core-shell structure.

[0036] In this invention, the degree of unsaturation of the core layer rubber is 30~130 g I2 / 100g, based on the mass of iodine consumed per 100g sample. For example, it can be 35 g I2 / 100g, 40 g I2 / 100g, 45 g I2 / 100g, 50 g I2 / 100g, 55 g I2 / 100g, 60 g I2 / 100g, 65 g I2 / 100g, 70 g I2 / 100g, 75 g I2 / 100g, 80 g I2 / 100g, 85 g I2 / 100g, 90 g I2 / 100g, 95 g I2 / 100g, 100 g I2 / 100g, 105 g I2 / 100g, 110 g I2 / 100g, 115 g I2 / 100g, 120 g I2 / 100g, etc. I2 / 100g, 125 g I2 / 100g, or any of the above values, preferably 60~100g I2 / 100g.

[0037] In the method for preparing the core-shell structured latex, based on 100 parts of the dry latex of the core layer rubber, the initiator, chain transfer agent, emulsifier, and surfactant each have a mass of 0.1 to 1 part; the catalyst can be selected from commonly used catalysts according to existing technology, including but not limited to tetramethylethylenediamine and / or sodium formaldehyde sulfoxylate; based on 100 parts of the dry latex of the core layer rubber, the catalyst has a mass of 0.2 to 2 parts, and the solvent has a mass of 100 to 140 parts.

[0038] In this invention, the latex of the core layer rubber can be commercially available or prepared using conventional methods in the art; exemplary, the latex of the core layer rubber is obtained by emulsion polymerization of conjugated diene and styrene and its derivatives; the specific preparation method includes: Solvent, initiator, chain transfer agent, electrolyte, emulsifier, and 15-25% surfactant (based on the formulation amount) are mixed uniformly at room temperature. Under a protective atmosphere, some or all of the monomer (based on the formulation amount) is added. The mixture is reacted at 50-60℃ and 100-110 rpm for 6-12 hours. The temperature is then increased to 64-75℃ and the rotation speed to 110-125 rpm, and the reaction continues for 3-13 hours. The temperature is then increased to 69-80℃ and the rotation speed to 125-135 rpm, and the reaction continues for another 3-13 hours. The reaction is then terminated. The remaining surfactant is added, and the mixture is stirred for 30-40 minutes. The mixture is then cooled and discharged to obtain the latex of the core layer rubber. If only some monomer is added, the remaining monomer is added during the third heating. The partial monomer accounts for 10-90% of the total monomer mass.

[0039] In the preparation method of the latex of the core layer rubber in this invention, based on 100 parts by mass of the polymer monomer of the core layer rubber, the mass of the solvent is 80-120 parts, the mass of the initiator is 0.1-1 parts, the mass of the chain transfer agent is 0.2-1.2 parts, the mass of the electrolyte is 0.1-1 parts, the mass of the emulsifier is 0.1-1 parts, and the total mass of the surfactant is 0.1-0.45 parts.

[0040] In this invention, the average particle size of the conjugated diene polymer core refers to the average particle size of the core layer rubber latex. The average particle size of the core layer rubber latex can be adjusted by adjusting the monomer composition, the amount of monomer fed during polymerization, and the polymerization process (such as reaction temperature, time, feeding method, etc.).

[0041] In this invention, the raw materials (such as initiators, chain transfer agents, surfactants, and emulsifiers) used to prepare the latex for core-layer rubber and the latex for preparing a core-shell structure may be the same or different.

[0042] The initiator includes, but is not limited to, water-soluble initiators, such as at least one of potassium persulfate, sodium persulfate, and ammonium persulfate; the initiator may also include a redox initiator; the redox initiator comprises a peroxide compound, a variable-valence transition metal salt, a chelating agent, and a reducing agent, wherein the peroxide compound includes, but is not limited to, benzoyl peroxide, dilauroyl peroxide, eicosanoyl peroxide, tert-butyl peroxide, tert-butyl peroxyvalerate, methyl ethyl ketone peroxide, cyclohexanone peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, di-tert-butyl peroxide, and dicumyl peroxide, or a mixture of at least two or more of these; the variable-valence transition metal salt includes iron salts and / or copper salts, further preferably... The ferric salt is selected, including but not limited to ferric sulfate, ferrous sulfate, ferric chloride, and ferrous chloride, and more preferably ferrous salts such as ferrous sulfate or ferrous chloride; the chelating agent includes but is not limited to: sodium pyrophosphate, ethylenediaminetetraacetic acid, disodium ethylenediaminetetraacetic acid, sodium ethylenediaminetetraethylenetetraacetic acid, sodium hydroxyethylethylenediaminetriacetic acid, N,N-bis(2-hydroxyethyl)glycine, diethylenetriaminepentaacetic acid, ethylene glycol bis(2-aminoethyl ether)tetraacetic acid, iminodiacetic acid, tetrasodium iminodisuccinate, sodium hydroxyethylethylenediaminetriacetic acid, and disodium hypocyanotriacetic acid; the reducing agent includes but is not limited to: glucose, lactose, sodium formaldehyde sulfoxylate, sodium sulfite, and sodium bisulfite, and at least one of hydroxyethyl mercaptan.

[0043] The chain transfer agent includes, but is not limited to, at least one of the following: n-octylthiol, n-dodecylthiol, cyclohexylthiol, tert-dodecylthiol, tert-nonylthiol, 1,8-dimercapto-3,6-dioxooctane, mercaptoacetic acid, methyl 3-thiopropionate, 2-ethylhexyl 3-hydropropionate, 3-methoxybutyl 3-thiopropionate, pentaerythritol tetra-3-mercaptopropionate, n-butyl thioglycolate, benzylthiol, furfuryl thiol, thiosalicylic acid, 4-mercaptopyridine, or 4-aminobenzylthiophenol.

[0044] The electrolytes mentioned include, but are not limited to, potassium carbonate.

[0045] The emulsifiers include, but are not limited to, one or more combinations of octanoate, caprylate, laurate, myristicate, palmitate, stearate, oleate, linoleate, linolenic acid salt, rosinate, betaine, castor oil sulfate, dodecylbenzene sulfonate, dodecyl sulfonate, dodecyl sulfate, and alkylnaphthalene sulfonate.

[0046] The surfactants include alkynyl alcohol surfactants, which can act as emulsifiers. Commonly used alkynyl alcohol surfactants can be selected according to existing technology, including but not limited to one or more of methylpentynyl alcohol, 2,4,7,9-tetramethyl-5-decyn-4,7-diol, and ethyl octynyl alcohol.

[0047] Preferably, based on 100 parts by weight of the dry basis of the latex with a core-shell structure, the mass of the water-soluble calcium-containing compound is 0.5 to 5.2 parts, for example, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 part, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, 2 parts, 2.1 parts, 2.2 parts, 2.3 parts, 2.4 parts, 2.5 parts, 2.6 parts, 2.7 parts, 2.8 parts, 2.9 parts, 3 parts, 3.1 parts, 3.2 parts, 3.3 parts, 3.4 parts, 3.5 parts, 3.6 parts, 3.8 parts, 4 parts, 4.2 parts, 4.4 parts, 4.6 parts, 4.8 parts, 5 parts, or any range of the above values.

[0048] Preferably, the coagulation includes steps of first heat preservation, heating, second heat preservation, and cooling.

[0049] Preferably, the temperature of the first heat preservation is 70~80℃, for example, it can be 70℃, 72℃, 74℃, 75℃, 76℃, 78℃, 80℃, etc.; the time is 1~10 min, for example, it can be 1 min, 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, etc.

[0050] Preferably, the heating rate is 3~7℃ / min, for example, it can be 3℃ / min, 4℃ / min, 5℃ / min, 6℃ / min, 7℃ / min, etc.

[0051] Preferably, the temperature of the second heat preservation is 90~100℃, for example, it can be 90℃, 91℃, 92℃, 93℃, 94℃, 95℃, 96℃, 97℃, 98℃, 99℃, 100℃, etc.; the time is 5~15 min, for example, it can be 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, etc.

[0052] Preferably, the cooling rate is 0.5~4℃ / min, for example, it can be 0.5℃ / min, 1℃ / min, 1.5℃ / min, 2℃ / min, 2.5℃ / min, 3℃ / min, 3.5℃ / min, 4℃ / min, etc.; until the temperature drops to room temperature.

[0053] Preferably, the pH value of the first slurry is 3 to 8, for example, it can be 4, 5, 6, 7, etc.

[0054] In this invention, the pH value of 3 to 8 can be obtained by adjusting a pH adjuster. Specifically, after coagulation is completed, a pH adjuster is added to adjust the pH value to 3 to 8. The pH adjuster can be an aqueous solution of sodium hydroxide or an aqueous solution of acetic acid.

[0055] In this invention, the dehydration method includes filtration, centrifugation, etc., and the filtration method can be mechanical filtration or vacuum and pressure filtration; dehydration is carried out until the moisture content is reduced to below 30%.

[0056] In this invention, the drying temperature is 50~95℃; the drying method can be hot air drying or vacuum drying; the drying is complete when the moisture content of the impact modifier is 0.1~0.25%.

[0057] In this invention, the impact modifier can also be prepared by adding calcium ions to condensed particles with a core-shell structure.

[0058] Thirdly, the present invention provides a resin composition comprising, by weight, 70 to 90 parts of a matrix resin (e.g., 72, 74, 76, 78, 80, 82, 84, 86, 88 parts or any range thereof) and 10 to 30 parts of an impact modifier as described in the first aspect (e.g., 12, 14, 16, 18, 20, 22, 24, 26, 28 parts or any range thereof).

[0059] In this invention, the mass percentage of the matrix resin in the resin composition is ≥50%, preferably ≥70%.

[0060] The impact modifier described in this invention can be incorporated into various thermoplastic resins. Examples of such thermoplastic resins include rigid, semi-rigid, and flexible chlorinated resins such as vinyl chloride resin (PVC), chlorinated polyethylene resin, chlorinated vinyl chloride resin, and vinylidene chloride resin; olefin resins such as polypropylene (PP) and polyethylene (PE); polystyrene (PS), high-impact polystyrene (HIPS), (meth)acrylate-styrene copolymer (MS), styrene-acrylonitrile copolymer (AS), styrene-maleic anhydride copolymer (SMA), acrylonitrile-butadiene-styrene resin (ABS), acrylate-styrene-acrylonitrile resin (ASA), and acrylonitrile... - Ethylene-propylene-styrene resin (AES) and other styrene-based resins (St-based resins); polymethyl methacrylate (PMMA) and other acrylic-based resins (Ac-based resins); polycarbonate-based resins (PC-based resins); polyamide-based resins (PA-based resins); polyethylene terephthalate (PET), polybutylene terephthalate (PBT) and other polyester-based resins (PE-based resins); polylactic acid resin, thermoplastic polyvinyl alcohol resin, polybutylene succinate, and environmentally adaptable resins derived from other biodegradable natural raw materials and petroleum raw materials (generally referred to as biodegradable resins); (Modified) Engineering plastics such as polyphenylene ether resins (PPE resins), polyoxymethylene resins (POM resins), polysulfone resins (PSO resins), polyarylate resins (PAr resins), polyphenylene oxide resins (PPS resins), and thermoplastic polyurethane resins (PU resins); styrene elastomers, olefin elastomers, vinyl chloride elastomers, polyurethane elastomers, polyester elastomers, polyamide elastomers, fluoropolymer elastomers, 1,2-polybutadiene, and trans-1,4-polyisoprene elastomers (TPE); PC / ABS and other PC / St resins. Polymer alloys including alloys of PVC / ABS and other PVC-based resins / St-based resins, PA / ABS and other PA-based resins / St-based resins, PA-based resins / TPE alloys, PA / PP and other PA-based resins / polyolefin resins, PBT-based resins / TPE, PC / PBT and other PC-based resins / PEs-based resins, polyolefin resins / TPE, PP / PE and other olefin resins, PPE / HIPS, PPE / PBT, PPE / PA and other PPE-based resins, PVC / PMMA and other PVC-based resins / Ac-based resins, etc. These can be used alone or in combination of two or more. The thermal stability of the rubber graft copolymers of the present invention is particularly evident when at least one selected from polycarbonate resins and polyester resins is used among these thermoplastic resins, and is therefore preferred.

[0061] Preferably, the resin composition further comprises 0.5 to 3 parts by weight of a second auxiliary agent, for example, 0.5 parts, 0.6 parts, 0.8 parts, 1 part, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2 parts, 2.2 parts, 2.5 parts, 2.8 parts, 3 parts or any range between the above values.

[0062] In this invention, additives with corresponding functions can be selected according to actual needs. The additives include, but are not limited to, at least one of antioxidants, lubricants, flame retardants, or compatibilizers.

[0063] In this invention, the antioxidant comprises a combination of a primary antioxidant and a secondary antioxidant.

[0064] In this invention, the primary antioxidant includes, but is not limited to, any one or a combination of at least two of the following: 2,6-di-tert-butyl-p-cresol (BHT), 2,2'-methylene-bis(4-ethyl-6-tert-butylphenol), 2,2'-methylene-bis(4-methyl-6-tert-butylphenol), 2,2'-methylene-bis(4-methyl-6-cyclohexylphenol), 2,2'-methylene-bis(4-methyl-6-nonylphenol), octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 1,1,3-tris(5-tert-butyl-4-hydroxy-2-methylphenyl)butane, and pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate).

[0065] In this invention, the auxiliary antioxidants include, but are not limited to, tri(nonylphenyl) phosphite and / or dilauryl thiodipropionate.

[0066] In this invention, the lubricant includes, but is not limited to, any one or a combination of at least two of the following: silicone oil, silicone powder, paraffin wax, stearic acid, magnesium stearate, butyl stearate, erucamide, oleamide, and ethylene bis-stearamide.

[0067] In this invention, the flame retardant includes, but is not limited to, melamine polyphosphate, melamine cyanurate, phosphate ester compounds, etc.; the compatibilizer includes, but is not limited to, maleic anhydride-grafted polyolefin elastomer, maleic anhydride-grafted polyethylene, etc.

[0068] In this invention, the additives include 0.1 to 1.5 parts by weight of antioxidant and 0.1 to 1.5 parts by weight of lubricant.

[0069] Preferably, the second additive includes at least one of antioxidants, lubricants, flame retardants, and compatibilizers.

[0070] In this invention, the method for preparing the resin composition includes: mixing a base resin with an impact modifier and optionally a second auxiliary agent, and extruding the mixture to obtain the resin composition. The extrusion temperature is 180~250℃.

[0071] Fourthly, the present invention provides an article comprising the impact modifier described in the first aspect or the resin composition described in the second aspect.

[0072] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0073] Compared with the prior art, the beneficial effects of the present invention are as follows: The impact modifier provided by this invention is a cohesive particle with a core-shell structure. By controlling the average particle size and unsaturation of the core of the impact modifier within a specific range, and by introducing calcium ions into the impact modifier and controlling the calcium ion content within a specific range, it is beneficial to improve the low-temperature toughness, resistance to damp heat aging, and resistance to heat oxidation aging of the material. The material including the impact modifier still has high impact performance at -40℃, and the impact strength retention rate is high after damp heat aging and heat oxidation aging, with little color change. Detailed Implementation

[0074] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0075] In this invention, the degree of unsaturation (iodine value) is determined according to the method specified in SH / T 1763-2020 "Determination of Residual Unsaturation in Hydrogenated Nitrile Butadiene Rubber (HNBR) - Iodine Value Method"; the specific test method is as follows: Unsaturation degree of core layer rubber: A certain amount of the test sample emulsion was dropped onto a clean glass plate and coated with a scraper. After natural air drying, a transparent film (200 micrometers thick) was formed. The film was then completely dried in a vacuum oven at 30°C to remove residual moisture, yielding the dried test film. 0.5 g of the film was weighed, dissolved, and dispersed in 50 g of chloroform. An excess of Widmanstätten reagent was added, and the mixture was allowed to stand in a 25°C water bath for 24 hours to allow the Widmanstätten reagent to react completely with any remaining unsaturated substances in the sample. Unreacted Widmanstätten reagent was neutralized with potassium iodide. Finally, the free iodine in the solution was titrated with sodium thiosulfate solution (0.1 mol / L), and the iodine value was calculated.

[0076] Unsaturation of condensed particles: The agglomerated particles were dried completely in a vacuum oven at 30°C to remove residual moisture. Then, 0.5g of the sample was weighed, dissolved, and dispersed in 50g of chloroform. An excess of Widmanstätten reagent was added, and the mixture was allowed to stand in a 25°C water bath for 24 hours to allow the Widmanstätten reagent to react completely with any remaining unsaturated matter in the sample. Unreacted Widmanstätten reagent was neutralized with potassium iodide. Finally, the free iodine in the solution was titrated with a 0.1 mol / L sodium thiosulfate solution, and the iodine value was calculated.

[0077] In this invention, the moisture content is determined according to method B specified in GB / T 2914-2008 "Determination of volatiles (including water) in homopolymer and copolymer resins of vinyl chloride".

[0078] In this invention, the average particle size was obtained by laser diffraction particle size analyzer (model Mastersizer 3000+), and the test method referred to GB / T 19077-2016 "Particle Size Distribution - Laser Diffraction Method". The specific test method is as follows: Take 0.5g of sample, stir and disperse it in 500g of water, and test the particle size of the sample dispersion using the variable volume semi-automatic wet sampler of the laser particle size analyzer.

[0079] In this invention, the calcium ion content can be determined by inductively coupled plasma atomic emission spectrometry (ICP-AES), and the test method refers to SH / T1829-2020 "Determination of Trace Element Content in Polyethylene and Polypropylene Resins by Inductively Coupled Plasma AES".

[0080] Preparation Example 1: Latex for preparing core layer rubber (A) The composition (by mass percentage), degree of unsaturation (iodine value), and average particle size of the core layer rubber A are shown in Table 1.

[0081] Table 1 The preparation method of the latex of the core layer rubber A1 includes: adding 100 parts of water, 0.4 parts of ammonium persulfate, 0.6 parts of n-dodecyl mercaptan, 0.4 parts of sodium carbonate, 0.4 parts of potassium stearate, and 0.08 parts of ethyl octyne alcohol to a reaction vessel and stirring at room temperature until completely dissolved and mixed evenly; purging nitrogen into the reaction vessel to replace the air, so that the oxygen content is lower than 10 ppm, and then adding 100 parts of butadiene monomer; heating the reaction vessel to 55°C and reacting at a constant temperature for 9 hours as the first stage of polymerization reaction, controlling the stirring speed at 105 rpm; after the first stage of polymerization reaction, heating the system to 70°C and reacting at a constant temperature for 12 hours as the second stage of polymerization reaction, controlling the stirring speed at 120 rpm; after the second stage of polymerization reaction, heating the system to 75°C and reacting at a constant temperature for 12 hours as the third stage of reaction, controlling the stirring speed at 130 rpm; and finally adding 0.32 parts of ethyl octyne alcohol at the end of the polymerization reaction, stirring for half an hour, cooling and discharging to obtain the latex of the core layer rubber A1.

[0082] The preparation method of the latex of core layer rubber A2 differs from that of A1 only in that 100 parts of butadiene monomer are replaced with 95 parts of butadiene and 5 parts of styrene. All other raw materials, dosages and process parameters are the same as those of A1.

[0083] The preparation method of the latex of core layer rubber A3 differs from that of A1 only in that 100 parts of butadiene monomer are replaced with 90 parts of butadiene and 10 parts of styrene. All other raw materials, dosages and process parameters are the same as those of A1.

[0084] The preparation method of the latex of core layer rubber A4 differs from that of A1 only in that 100 parts of butadiene monomer are replaced with 95 parts of hexadiene and 5 parts of α-methylstyrene. All other raw materials, dosages and process parameters are the same as those of A1.

[0085] The preparation method of the latex of core layer rubber A5 differs from that of A1 only in that the amount of potassium stearate added is increased to 0.5 parts, while the other raw materials, dosages and process parameters are the same as those of A1.

[0086] The preparation method of the latex of core layer rubber A6 differs from that of A1 only in that 100 parts of butadiene monomer are replaced with 80 parts of butadiene and 20 parts of styrene. All other raw materials, dosages and process parameters are the same as those of A1.

[0087] The preparation method of the latex of core layer rubber A7 differs from that of A1 only in that the process is adjusted so that the iodine value of the core layer rubber is 120g I2 / 100g. Specifically, the temperature of the second reaction stage is reduced to 65℃ and the temperature of the third reaction stage is reduced to 70℃. Other raw materials, dosages and process parameters are the same as those of A1.

[0088] The preparation method of the latex of core layer rubber Ad1 differs from that of A1 only in that the process is adjusted so that the average particle size of the core layer rubber is 85nm. Specifically, the amount of potassium stearate added is increased to 1.5 parts and the total amount of ethyl octyryl alcohol added is increased to 0.5 parts. Other raw materials, dosages and process parameters are the same as those of A1.

[0089] The preparation method of the latex of core layer rubber Ad2 differs from that of A1 only in that 5 parts of divinylbenzene are added. All other raw materials, dosages and process parameters are the same as those of A1.

[0090] The preparation method of Ad3 core layer rubber differs from that of A1 only in that the first stage reaction time is 8 hours and the second stage reaction time is 15 hours. After the second stage reaction is completed, the material is cooled and discharged. Other raw materials, dosages and process parameters are the same as those of A1.

[0091] Preparation Example 2: Preparation of a core-shell structured latex (B) formed from a conjugated diene polymer core and a vinyl polymer shell. The core-shell structured latex is prepared from a core layer rubber and vinyl polymer monomers. The types and contents of the core layer rubber, the composition of the vinyl polymer monomers, the degree of unsaturation of the core (i.e., iodine value) in the core-shell structured latex, and the solid content of the core-shell structured latex are shown in Tables 2 and 3.

[0092] Table 2 Table 3 The preparation method of latex B1 with a core-shell structure includes: heating the latex of the core layer rubber A1 to 55°C, adding 0.4 parts of ammonium persulfate, 0.6 parts of n-dodecyl mercaptan, 0.4 parts of potassium stearate, 1 part of tetramethylethylenediamine and 120 parts of water based on 100 parts of the dry basis of the latex of the core layer rubber A1, and adding the formulated amounts of acrylonitrile monomer and styrene monomer, continuously adding dropwise for 2 hours, continuing the reaction for 3 hours after heating is completed, then adding 0.4 parts of ethyl octyryne alcohol, and continuing the reaction for 2 hours to obtain the latex B1 with a core-shell structure (solid content of about 40%).

[0093] The preparation methods of latexes B2~B14 and Bd1~Bd3 with core-shell structures differ from those of B1 in that the type and content of the core layer rubber and the type and content of the outer shell monomer are adjusted according to the composition in Tables 2 and 3. Other raw materials, dosages, and preparation methods are the same as those for B1.

[0094] Example 1 This embodiment provides an impact modifier, the preparation method of which includes the following steps: Three parts of coagulant (calcium chloride) and 50 parts of water were thoroughly mixed at room temperature and then heated to 75°C. 100 parts (dry basis) of core-shell latex B1 were then slowly added to the mixture while stirring, maintaining a constant temperature throughout the addition. After addition, stirring and heating continued until the temperature reached 90°C. The pH of the mixture was then adjusted to 6-7 using a 30% acetic acid aqueous solution, and the mixture was stirred at 90°C for 15 minutes. After cooling to room temperature, the mixture was centrifuged to dehydrate and form a wet powder with a moisture content of 32%. A certain amount of desalinated water (prepared using a Milli-Q pure water system) was then added to prepare a slurry with a solid content of 20%, and the slurry was stirred and washed for 30 minutes. Following centrifugation and vacuum drying, impact modifier D1 with a moisture content of 0.12% was obtained. The calcium ion content of impact modifier D1 was 958 ppm.

[0095] Examples 2-20, Comparative Examples 1-7 Examples 2-20 and Comparative Examples 1-7 each provide an impact modifier, which differs from Example 1 in the type of latex with a core-shell structure, the type and content of the coagulant, the iodine value (degree of unsaturation), and the calcium ion content, as shown in Table 4. In Comparative Example 2, 98wt% concentrated sulfuric acid was used. The sulfuric acid content in Table 4 refers to the effective content.

[0096] Table 4 Unless otherwise specified, the preparation methods in Examples 2-20 and Comparative Examples 1-7 are the same as those in Example 1.

[0097] The difference between the preparation method of the impact modifier provided in Example 19 and Example 1 is that the washing process is adjusted. The wet powder obtained after centrifugation is mixed with water to form a slurry with a solid content of 20% and stirred and washed for 30 minutes. Then it is centrifuged and dehydrated. The washed wet powder is then mixed with water to form a slurry and washed twice more to make the calcium ion content 280 ppm. All other parameters are the same as in Example 1.

[0098] The difference between the preparation method of the impact modifier provided in Comparative Example 3 and Example 1 is that 2% sulfuric acid was used instead of 30% acetic acid when adjusting the pH, so that the calcium ion content was 4680 ppm. All other parameters were the same as in Example 1.

[0099] The difference between the preparation method of the impact modifier provided in Comparative Example 5 and Example 1 is that the washing process is adjusted so that the wet powder obtained after centrifugation is mixed with water to prepare a slurry with a solid content of 20%, the slurry is stirred for 30 minutes, centrifuged and dehydrated, and washed five times to make the calcium ion content 105 ppm. Other parameters are the same as in Example 1.

[0100] Application examples Application Examples 1-23 and Comparative Application Examples 1-7 each provide a resin composition, the formulation of which is shown in Tables 5 and 6 by weight. The preparation method of the resin composition includes: mixing each component in a mixer according to the formulation amount at 150 rpm for 5 min to obtain a premix; adding the premix to a twin-screw extruder for melt blending, and then extruding, granulating, drying and cooling to obtain the resin composition; wherein the temperature of the twin-screw extruder is 280°C and the screw speed is 130 rpm.

[0101] Among them, polycarbonate (PC): Wanhua CLARNATE® 2100. Copolymer of styrene and acrylonitrile (SAN resin): Liaoning Kingfa KFA-130.

[0102] The antioxidant is a compound antioxidant formed by combining the main antioxidant and the auxiliary antioxidant in a mass ratio of 1:1; the main antioxidant is pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate), commercially available; the auxiliary antioxidant is dilauryl thiodipropionate, commercially available; and the lubricant is ethylene bis-stearamide, commercially available.

[0103] The provided resin composition was subjected to the following performance tests.

[0104] (1) Low temperature toughness: Samples were prepared in accordance with the standard ASTM D256-2010 "Plastic cantilever beam notched impact test" with notch type A. The samples were placed in a standard environment (23±2℃, 50±10% humidity) for 40h, and then placed in a -40℃ low temperature chamber for 24h before testing.

[0105] (2) Retention rate of damp heat aging performance: The aging process of the resin composition is carried out in accordance with the standard number GB / T2423.27-2020 "Environmental testing - Part 2: Test methods - Test methods and guidelines: Temperature / low pressure or temperature / humidity / low pressure combined test", and the mechanical properties of the samples before and after aging are tested. The test standard is in accordance with GB / T1843-2008 "Determination of impact strength of plastic cantilever beam".

[0106] The specific method is as follows: The resin composition to be tested is injection molded into an ISO standard notched impact specimen (Type A notch), and its initial impact strength P0 is tested according to the aforementioned standard; then, the specimen is placed in a hot air oven at 80°C and kept for 800 hours, and the impact strength P1 after thermo-oxidative aging is tested. The impact strength retention rate after thermo-oxidative aging = P1 / P0×100%.

[0107] The sample was placed in a constant temperature and humidity chamber at 85 degrees Celsius and 85% humidity for 2000 hours, and its impact strength P2 after damp heat aging was tested. The impact strength retention rate after damp heat (double 85) aging = P2 / P0 × 100%.

[0108] The resin composition to be tested was injection molded into samples with dimensions of 50×35×2mm. The initial L, a, and b values ​​of the samples, as well as their L, a, and b values ​​after thermo-oxidative aging and damp-heat aging, were tested. To characterize the color retention rate after aging. Among them, .

[0109] The specific test results are shown in Tables 5 and 6.

[0110] Table 5 Table 6 As shown in Tables 5 and 6, the material prepared by the impact modifier, matrix resin, and additives provided by this invention exhibits a low-temperature impact performance of ≥221 J / m at -40℃ and an initial impact strength of ≥45 kJ / m. 2 The impact strength retention rate after aging of Double 85 is ≥76%. ≤29; Impact strength retention rate after thermo-oxidative aging ≥68%, ≤27.

[0111] A comparison of Application Example 2 and Comparative Application Examples 6-7 shows that when the unsaturation of the condensed particles is within a specific range, the material exhibits good toughness, low-temperature toughness, and resistance to damp heat aging and thermo-oxidative aging. When the unsaturation is too low, the low-temperature toughness is poor and the initial impact strength is low. When the unsaturation is too high, the mechanical properties are poorly retained after damp heat aging and thermo-oxidative aging, the color retention rate is low, and the color changes significantly.

[0112] As can be seen from Application Examples 1 and 9-10, when the mass ratio of the conjugated diene polymer core to the vinyl polymer shell in the impact modifier is within a specific range, the material achieves good toughness, low-temperature toughness, and resistance to damp heat aging and thermo-oxidative aging. When the mass ratio of the conjugated diene polymer core to the vinyl polymer shell is too low, the low-temperature toughness is poor and the initial impact strength is low. When the mass ratio of the conjugated diene polymer core to the vinyl polymer shell is too high, the mechanical property retention rate after damp heat aging and thermo-oxidative aging is low, the color retention rate is low, and the color change is large.

[0113] As can be seen from the comparison of application examples 1, 15, 16, 19, and 20 with comparative application examples 3 and 5, both low and high calcium ion content will lead to significant color changes after damp heat aging and thermo-oxidative aging. Moreover, within a certain range, the calcium ion content has little impact on the retention rate of mechanical properties after aging, but exceeding a certain range will lead to a significant deterioration in the retention rate of mechanical properties after aging.

[0114] As can be seen from the comparison between Application Example 1 and Comparative Application Examples 2 and 4, the impact modifier does not contain calcium ions or contains other metal ions, and the material undergoes significant color changes after wet heat aging and thermo-oxidative aging.

[0115] As can be seen from the comparison between Application Example 1 and Comparative Application Example 1, the average particle size of the conjugated diene polymer core is relatively low, and the toughness, low temperature toughness, resistance to damp heat aging and resistance to heat and oxygen aging are significantly worse.

[0116] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. An impact modifier, characterized in that, The impact modifier is a condensed particle with a core-shell structure; The core-shell structured condensed particles comprise a conjugated diene polymer core and a vinyl polymer shell; The average particle size of the conjugated diene polymer core is 180~320 nm; The degree of unsaturation of the aggregated particles is 17~105g I2 / 100g, based on the mass of iodine consumed per 100g sample. The impact modifier contains calcium ions, and the calcium ion content in the impact modifier is 200~1800ppm.

2. The impact modifier according to claim 1, characterized in that, The degree of unsaturation of the aggregated particles is 30~90g I2 / 100g, based on the mass of iodine consumed per 100g sample. Preferably, the mass percentage of structural units derived from conjugated dienes in the conjugated diene polymer core is 79-100%, more preferably 89-100%; Preferably, the conjugated diene polymer core further includes structural units derived from styrene compounds.

3. The impact modifier according to claim 1 or 2, characterized in that, The vinyl polymer shell comprises at least one structural unit derived from styrene compounds, a structural unit derived from acrylonitrile compounds, or a structural unit derived from alkyl (meth)acrylates; Preferably, by weight, the vinyl polymer shell comprises 8 to 35 parts of structural units derived from styrene compounds and 8 to 36 parts of structural units derived from a second monomer; the structural units derived from the second monomer comprise 8 to 26 parts of structural units derived from acrylonitrile compounds and / or 24 to 36 parts of structural units derived from alkyl (meth)acrylates.

4. The impact modifier according to any one of claims 1 to 3, characterized in that, The mass ratio of the conjugated diene polymer core to the vinyl polymer shell is (39~72):(28~61), more preferably (49~62):(38~51).

5. The impact modifier according to any one of claims 1 to 4, characterized in that, The calcium ion content in the core-shell structured condensed particles is 500~1400 ppm; Preferably, the calcium ions are derived from water-soluble calcium-containing compounds; Preferably, the water-soluble calcium-containing compound includes at least one of calcium chloride, calcium nitrate, calcium acetate, and calcium gluconate.

6. A method for preparing an impact modifier according to any one of claims 1 to 5, characterized in that, The preparation method includes the following steps: (1) Mix latex with a core-shell structure, coagulant, and water, and coagulate to obtain the first slurry; (2) The first slurry is dehydrated, washed and dried to obtain the impact modifier; The core-shell structured latex comprises a conjugated diene polymer core and a vinyl polymer shell; The coagulant is a water-soluble calcium-containing compound; The washing method includes: mixing the solid obtained from dehydration with deionized water to obtain a second slurry with a solid content of 15-25%, and stirring and washing the slurry for 10-30 minutes; The drying is carried out under vacuum conditions or in the presence of a protective atmosphere.

7. The preparation method according to claim 6, characterized in that, Based on 100 parts by weight of the dry basis of the latex with a core-shell structure, the mass of the water-soluble calcium-containing compound is 0.5 to 5.2 parts; Preferably, the coagulant further includes an acid and / or a second metal salt; Preferably, the coagulation includes coagulation through a first heat preservation, a heating, a second heat preservation, and a cooling process; Preferably, the first heat preservation temperature is 70~80℃, and the time is 1~10 min; the heating rate is 3~7℃ / min; the second heat preservation temperature is 90~100℃, and the time is 5~15 min; the cooling rate is 0.5~4℃ / min. Preferably, the pH value of the first slurry is 3 to 8.

8. A resin composition, characterized in that, The resin composition comprises, by weight, 70-90 parts of a matrix resin and 10-30 parts of an impact modifier as described in any one of claims 1-5.

9. The resin composition according to claim 8, characterized in that, The resin composition further includes 0.5 to 3 parts by weight of a second auxiliary agent; Preferably, the second additive includes at least one of antioxidants, lubricants, flame retardants, and compatibilizers.

10. An article characterized in that, The article comprises the impact modifier as described in any one of claims 1 to 5 or the resin composition as described in claim 8 or 9.

Images