A long-chain alkyl-modified silicone toughening agent and a method for preparing the same

Abstract

The application relates to the technical field of silicone toughening agents, in particular to a long-chain alkyl modified silicone toughening agent and a preparation method thereof. The long-chain alkyl modified silicone toughening agent is prepared by the thiol-double bond reaction between vinyl silicone oil and long-chain alkyl mercaptan to prepare long-chain alkyl silicone oil, then the long-chain alkyl silicone oil is hydrolyzed under certain temperature conditions to synthesize a silicone emulsion, and long-chain alkyl is preliminarily obtained; then a first mixed emulsion liquid, which is obtained by mixing acrylate soft monomers, octadecyl methacrylate, functional monomers, an emulsifier and an initiator, is added dropwise; a second mixed emulsion liquid, which is obtained by mixing acrylate hard monomers, functional monomers, an emulsifier and an initiator, is added dropwise; emulsion copolymerization reaction is carried out; long-chain alkyl is obtained again; an interpenetrating network system is formed; the weather resistance and temperature stability of the polymer are improved; the molecular weight of the polymer is greatly increased; the toughness of the polymer is good; the toughening effect on plastic materials is greatly improved; the low-temperature toughening property is particularly good; and the amount of the toughening agent in alloy materials can be reduced.

Description

Technical Field

[0001] This invention relates to the field of organosilicon toughening agents, specifically to a long-chain alkyl-modified organosilicon toughening agent and its preparation method. Background Technology

[0002] Currently, toughening agents are divided into two categories: active toughening agents and inactive toughening agents. Active toughening agents refer to those whose molecular chains contain active groups that can react with the matrix resin. They can form a network structure and increase some flexible chains, thereby improving the impact resistance of polymer materials. Inactive toughening agents, on the other hand, have good compatibility with the matrix resin but do not participate in chemical reactions.

[0003] There are many types of toughening agents available, and their toughening effects vary depending on the polymer. Among them, silicone toughening agents are one type, possessing excellent elasticity. However, most existing silicone toughening agents are made through emulsion polymerization. After being added to polymer plastic products, most silicone toughening agents still suffer from poor weather resistance, require large amounts, and have poor temperature stability, which indirectly leads to poor toughening effects. Summary of the Invention

[0004] To overcome the shortcomings and deficiencies of existing technologies, one of the objectives of this invention is to provide a method for preparing a long-chain alkyl-modified organosilicon toughening agent. Introducing long-chain alkyl groups into the organosilicon graft structure significantly increases the molecular weight of the organosilicon toughening agent, effectively reducing physical losses during the processing and use of toughened polycarbonate (PC) / acrylonitrile-butadiene-styrene (ABS) alloys (hereinafter referred to as PC / ABS alloys). Because the long branches in the silicon structure impart excellent elasticity to the material, the resulting organosilicon toughening agent exhibits excellent toughness, greatly improving the toughening effect on plastic materials, especially at low temperatures (below -30℃), and reducing the amount of toughening agent required in the alloy material. This preparation method is simple to operate, easy to control, has high production efficiency, and low production cost, making it suitable for large-scale production.

[0005] The second objective of this invention is to provide a long-chain alkyl-modified organosilicon toughening agent that can improve the weather resistance and low-temperature stability of materials and enhance the toughening effect with a lower dosage.

[0006] One of the objectives of this invention is achieved through the following technical solution: a method for preparing a long-chain alkyl-modified organosilicon toughening agent, comprising the following steps:

[0007] (S1) Take vinyl silicone oil, long-chain alkyl thiol, photoinitiator and tetrahydrofuran, stir and react under UV light for 2.5-4.5h, then remove the solvent by vacuum distillation, wash and purify, and then vacuum dry at 45-60℃ for 20-30h to obtain long-chain alkyl silicone oil.

[0008] (S2) Take water and dodecylbenzene sulfonic acid, stir evenly under the condition of keeping warm at 50-80℃, then take organosilicon mixed monomers and the long-chain alkyl silicone oil and mix them, react under the condition of keeping warm at 50-90℃ for 0.5-1h to synthesize seed emulsion.

[0009] (S3) Take water, dodecylbenzene sulfonic acid, emulsifier, organosilicon mixed monomer and the long-chain alkyl silicone oil and mix them evenly to obtain a uniform mixture;

[0010] (S4) While stirring, continuously add the uniformly mixed liquid dropwise to the seed emulsion for 3.5-8.5 hours at a temperature of 50-90°C. Continue the reaction for 4-10 hours, cool to room temperature, and then add sodium hydroxide solution to adjust the pH value to 7-7.5 to obtain a polysiloxane emulsion with long-chain alkyl groups.

[0011] (S5) Take water, acrylate soft monomers, octadecyl methacrylate, functional monomers, emulsifiers and initiators and mix them evenly to obtain the first mixed emulsion;

[0012] (S6) Take acrylate hard monomers, functional monomers, emulsifiers and initiators and mix them evenly to obtain a second mixed emulsion;

[0013] (S7) Under conditions of 65-85°C, the first mixed emulsion is added dropwise to the polysiloxane emulsion with long-chain alkyl groups while stirring for 2.5-4.5 h, and the reaction continues for 0.5-2.5 h. Then, the second mixed emulsion is added dropwise for another 1.5-2.5 h, and the reaction continues for another 1.5-2.5 h to obtain a copolymer emulsion.

[0014] (S8) Add magnesium sulfate solution to the copolymer emulsion to break the emulsion, wash with water and centrifuge, and then vacuum dry at 75-85℃ to obtain the long-chain alkyl modified organosilicon toughening agent.

[0015] The preparation method of this long-chain alkyl-modified organosilicon toughening agent involves reacting vinyl silicone oil with long-chain alkyl thiols via a thiol double bond reaction to prepare long-chain alkyl silicone oil. Then, the long-chain alkyl silicone oil is combined with dodecylbenzene sulfonic acid, organosilicon mixed monomers, emulsifiers, and water under specific temperature conditions to hydrolyze the organosilicon into a silicone emulsion. The prepared silicone emulsion exhibits good stability and initially yields long-chain alkyl groups. Subsequently, a first mixed emulsion consisting of acrylate soft monomers, octadecyl methacrylate, functional monomers, emulsifiers, and initiators is added dropwise. A second mixed emulsion consisting of acrylate hard monomers, functional monomers, emulsifiers, and initiators is then added dropwise to initiate an emulsion copolymerization reaction, again yielding long-chain alkyl groups. The resulting copolymer emulsion is then subjected to coagulation and demulsification, washed, and dried to obtain... The obtained long-chain alkyl-modified organosilicon toughening agent involves the double introduction of long-chain alkyl groups into the organosilicon graft structure. By introducing long-chain vinyl groups into the organosilicon macromolecule, a double-bonded organosilicon seed emulsion is obtained. This seed emulsion is then grafted and copolymerized with long-chain alkyl octadecyl ester to form an interpenetrating network system, improving the polymer's weather resistance and temperature stability, and significantly increasing its molecular weight. This effectively reduces physical losses during the processing and use of PC / ABS alloys. Because the long branches in the silicon structure impart excellent elasticity to the material, the resulting organosilicon toughening agent exhibits excellent toughness, significantly improving the toughening effect on plastic materials, especially at low temperatures (below -30°C), and reducing the amount of toughening agent required in the alloy material. In steps (S2) and (S3), dodecylbenzenesulfonic acid is used to hydrolyze the organosilicon mixed monomers to form a silicone emulsion. Further, in step (S5), the concentration of the sodium hydroxide solution is 5 wt%; and in step (S8), the concentration of the magnesium sulfate solution is 5 wt%.

[0016] Preferably, in step (S1), the washing and purification specifically involves washing with methanol 2-4 times, the molar mass ratio of long-chain alkyl thiols to vinyl silicone oil being 1-1.42:1, the photoinitiator mass accounting for 1.8wt%-3wt% of the total reactants, and the volume weight ratio (ml / g) of tetrahydrofuran to the total reactants being 2-4:1.

[0017] Preferably, the long-chain alkyl thiol is at least one of 1-pentanethiol, n-hexanethiol, and 1-heptanethiol; and the photoinitiator is at least one of 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, and p-methylbenzophenone.

[0018] Using the above technical solution, the long-chain alkyl thiol reacts with vinyl silicone oil under the action of photoinitiator and UV light to prepare long-chain alkyl silicone oil and introduce long-chain alkyl groups.

[0019] Preferably, in step (S2), the stirring speed is 150-250 r / min; in step (S4), the stirring speed is 150-250 r / min; and in step (S7), the stirring speed is 150-250 r / min.

[0020] Preferably, in step (S2), the weight parts of each component are 250-300 parts of water, 0.8-1.4 parts of dodecylbenzenesulfonic acid, 59.1-81 parts of organosilicon mixed monomers, and 8-15 parts of long-chain alkyl silicone oil, respectively; in step (S3), the weight parts of each component are 300-350 parts of water, 2.1-3.2 parts of dodecylbenzenesulfonic acid, 4.8-9.56 parts of emulsifier, 187.5-243 parts of organosilicon mixed monomers, and 24-45 parts of long-chain alkyl silicone oil, respectively; in step (S4), the weight ratio of seed emulsion to homogeneous mixture is 317.9-397.4:518.4-650.76.

[0021] Preferably, in step (S2), the organosilicon mixed monomers are octamethylcyclotetrasiloxane, γ-methacryloyloxypropyltrimethoxysilane, and vinyltriethoxysilane mixed in a weight ratio of 58-78:1-1.5:0.1-1.5; in step (S3), the organosilicon mixed monomers are octamethylcyclotetrasiloxane, γ-methacryloyloxypropyltrimethoxysilane, and vinyltriethoxysilane mixed in a weight ratio of 185-236:2.4-4.5:0.1-2.5.

[0022] Preferably, in step (S5), the weight parts of each component are 30-50 parts of water, 40-60 parts of acrylate soft monomers, 5-15 parts of octadecyl methacrylate, 1-2.5 parts of functional monomers, 1.5-3.5 parts of emulsifiers, and 0.45-1.16 parts of initiators, respectively; in step (S6), the weight parts of each component are 25-35 parts of acrylate hard monomers, 0.1-1.5 parts of functional monomers, 0.8-2.5 parts of emulsifiers, and 0.35-0.86 parts of initiators, respectively; in step (S7), the weight ratio of the polysiloxane emulsion with long-chain alkyl groups, the first mixed emulsion, and the second mixed emulsion is 15-45:77.95-132.16:26.25-39.86.

[0023] Preferably, in steps (S3), (S5), and (S6), the emulsifier is at least one of sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium hexadecyl sulfate, sodium octadecyl sulfate, sodium dodecyl sulfonate, and sodium tetradecyl sulfonate; and in steps (S5) and (S6), the initiator is at least one of ammonium persulfate, potassium persulfate, sodium persulfate, and hydrogen peroxide-L-ascorbic acid.

[0024] Preferably, the acrylate soft monomer is at least one of butyl acrylate, isooctyl acrylate, and ethyl acrylate; the functional monomer is at least one of acrylic acid, methacrylic acid, glycidyl methacrylate, ethylene glycol dimethacrylate, adipic acid, allyl methacrylate, and hydroxyethyl methacrylate; and the acrylate hard monomer is at least one of methyl methacrylate, styrene, and methyl acrylate.

[0025] Using the above technical solutions, the above-mentioned acrylate soft monomers can impart good flexibility and elasticity to the polymer, and the above-mentioned acrylate hard monomers can impart good hardness and strength to the polymer; the above-mentioned functional monomers, hydroxyethyl methacrylate and hydroxyethyl acrylate contain hydroxyl functional groups, which can react with a variety of compounds to form cross-linked structures, thereby improving the polymer's water resistance, solvent resistance and heat resistance; acrylic acid and methacrylic acid contain carboxyl functional groups, which can react with metal ions, alcohol compounds, etc., thereby improving the polymer's ion exchange performance, adsorption performance and dispersion performance.

[0026] The second objective of this invention is achieved through the following technical solution: a long-chain alkyl-modified organosilicon toughening agent, prepared by the method described above for preparing long-chain alkyl-modified organosilicon toughening agents.

[0027] The beneficial effects of this invention are as follows: The preparation method of the long-chain alkyl-modified organosilicon toughening agent of this invention involves preparing long-chain alkyl silicone oil through a mercapto double bond reaction between vinyl silicone oil and long-chain alkyl thiols. Then, the long-chain alkyl silicone oil is combined with dodecylbenzene sulfonic acid, organosilicon mixed monomers, emulsifiers, water, etc., and subjected to organosilicon hydrolysis under certain temperature conditions to synthesize a silicone emulsion. The prepared silicone emulsion has good stability and initially obtains long-chain alkyl groups. Subsequently, a first mixed emulsion consisting of acrylate soft monomers, octadecyl methacrylate, functional monomers, emulsifiers, and initiators is added dropwise. A second mixed emulsion consisting of acrylate hard monomers, functional monomers, emulsifiers, and initiators is then added dropwise to carry out an emulsion copolymerization reaction, again obtaining long-chain alkyl groups. The resulting copolymer emulsion undergoes coagulation and demulsification. The long-chain alkyl-modified organosilicon toughening agent, obtained by cleaning and drying, incorporates long-chain alkyl groups twice into the organosilicon graft structure. By introducing long-chain vinyl groups into the organosilicon macromolecule, a double-bonded organosilicon seed emulsion is obtained. This seed emulsion is then grafted and copolymerized with long-chain alkyl octadecyl ester to form an interpenetrating network system, which improves the polymer's weather resistance and temperature stability and significantly increases its molecular weight. This effectively reduces physical losses during the processing and use of PC / ABS alloys. Because the long branches in the silicon structure impart excellent elasticity to the material, the resulting organosilicon toughening agent exhibits excellent toughness, significantly improving the toughening effect on plastic materials, especially at low temperatures (below -30℃), and reducing the amount of toughening agent required in alloy materials.

[0028] The long-chain alkyl-modified organosilicon toughening agent of the present invention can improve the weather resistance and low-temperature stability of materials and enhance the toughening effect with a low dosage, and is particularly suitable for toughening modification of PC / ABS alloys. Detailed Implementation

[0029] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments. The content mentioned in the embodiments is not intended to limit the present invention.

[0030] Example 1

[0031] A method for preparing a long-chain alkyl-modified organosilicon toughening agent includes the following steps:

[0032] (S1) Add vinyl silicone oil, long-chain alkyl thiols, photoinitiators and tetrahydrofuran into a reaction vessel, stir and react for 3 hours under UV light with a power of 20W at 365nm, remove the solvent by vacuum distillation, wash with methanol 3 times for purification, and then dry under vacuum at 55℃ for 24 hours to obtain long-chain alkyl silicone oil.

[0033] (S2) Take 280 parts by weight of water and 1.2 parts by weight of dodecylbenzenesulfonic acid and add them to a four-necked flask equipped with a stirrer, thermometer and condenser. Stir evenly at 200 r / min under the condition of keeping warm at 65℃. Then take 68 parts of octamethylcyclotetrasiloxane, 1.2 parts of γ-methacryloyloxypropyltrimethoxysilane, 1 part of vinyltriethoxysilane and 12 parts of the long-chain alkyl silicone oil and mix them. React at a constant temperature of 70℃ for 0.8 h to synthesize seed emulsion.

[0034] (S3) Take 320 parts by weight of water, 2.6 parts by weight of dodecylbenzenesulfonic acid, 7.2 parts by weight of emulsifier, 208 parts by weight of octamethylcyclotetrasiloxane, 3.5 parts by weight of γ-methacryloyloxypropyltrimethoxysilane, 1.5 parts by weight of vinyltriethoxysilane and 35 parts by weight of the long-chain alkyl silicone oil and mix them evenly to obtain a uniform mixture.

[0035] (S4) The mixed liquid is continuously added dropwise to the seed emulsion at a stirring speed of 200 r / min using a Lange peristaltic pump (basic type BT100-2J1) for 6 h. The addition temperature is 70 °C. The reaction is continued for 6 h. After cooling to room temperature, 5 wt% sodium hydroxide solution is added to adjust the pH value to 7-7.5 to obtain a polysiloxane emulsion with long-chain alkyl groups.

[0036] (S5) Take 40 parts by weight of water, 50 parts by weight of acrylate soft monomer, 10 parts by weight of octadecyl methacrylate, 1.8 parts by weight of functional monomer, 2.5 parts by weight of emulsifier and 0.86 parts by weight of initiator and mix them evenly to obtain the first mixed emulsion.

[0037] (S6) Take 30 parts by weight of acrylate hard monomer, 1 part of functional monomer, 1.5 parts of emulsifier and 0.6 parts of initiator and mix them evenly to obtain a second mixed emulsion;

[0038] (S7) At 75°C, in a four-necked flask equipped with a stirrer, thermometer and condenser, the first mixed emulsion was added dropwise to the polysiloxane emulsion with long-chain alkyl groups at a stirring speed of 200 r / min for 3.5 h while stirring. The reaction continued for 1.5 h, and then the second mixed emulsion was added dropwise to the polysiloxane emulsion with a Lange peristaltic pump for 2 h. The reaction continued for 2 h to obtain a copolymer emulsion.

[0039] (S8) Add 5 wt% magnesium sulfate solution to the copolymer emulsion to break the emulsion, wash with water and centrifuge, and then vacuum dry at 80°C to obtain the long-chain alkyl modified organosilicon toughening agent.

[0040] In step (S1), the molar mass ratio of long-chain alkyl thiols to vinyl silicone oil is 1.2:1, the mass of photoinitiator accounts for 2.5 wt% of the total reactants, and the volume weight ratio (ml / g) of tetrahydrofuran to the total reactants is 3:1.

[0041] The long-chain alkyl thiol is 1-pentanethiol; the photoinitiator is 2,2-dimethoxy-2-phenylacetophenone.

[0042] In step (S4), the weight ratio of seed emulsion to homogeneous mixture is 357.4:618.4.

[0043] In step (S7), the weight ratio of the polysiloxane emulsion with long-chain alkyl groups, the first mixed emulsion, and the second mixed emulsion is 30:100.95:32.25.

[0044] In step (S3), the emulsifier is sodium tetradecyl sulfonate; in step (S5), the emulsifier is a mixture of sodium dodecyl sulfonate and sodium tetradecyl sulfonate in a weight ratio of 2:1; in step (S6), the emulsifier is a mixture of sodium dodecyl sulfonate and sodium tetradecyl sulfonate in a weight ratio of 2:1; in step (S5), the initiator is ammonium persulfate; in step (S6), the initiator is ammonium persulfate.

[0045] The acrylate soft monomer is a mixture of butyl acrylate and isooctyl acrylate in a weight ratio of 3:1; in step (S5), the functional monomer is allyl methacrylate; in step (S6), the functional monomer is glycidyl methacrylate; the acrylate hard monomer is methyl methacrylate.

[0046] Example 2

[0047] A method for preparing a long-chain alkyl-modified organosilicon toughening agent includes the following steps:

[0048] (S1) Add vinyl silicone oil, long-chain alkyl thiols, photoinitiators and tetrahydrofuran into a reaction vessel, stir and react for 2.5 h under UV light irradiation at 365 nm and power of 20 W, remove the solvent by vacuum distillation, wash with methanol 3 times for purification, and then vacuum dry at 45 °C for 24 h to obtain long-chain alkyl silicone oil.

[0049] (S2) Take 250 parts by weight of water and 0.8 parts by weight of dodecylbenzenesulfonic acid and add them to a four-necked flask equipped with a stirrer, thermometer and condenser. Stir evenly at 250 r / min under the condition of keeping warm at 50℃. Then take 58 parts of octamethylcyclotetrasiloxane, 1 part of γ-methacryloyloxypropyltrimethoxysilane, 0.1 part of vinyltriethoxysilane and 8 parts of the long-chain alkyl silicone oil and mix them. React at a constant temperature of 50℃ for 1 h to synthesize seed emulsion.

[0050] (S3) Take 300 parts by weight of water, 2.1 parts by weight of dodecylbenzenesulfonic acid, 4.8 parts by weight of emulsifier, 185 parts by weight of octamethylcyclotetrasiloxane, 2.4 parts by weight of γ-methacryloyloxypropyltrimethoxysilane, 0.1 parts by weight of vinyltriethoxysilane and 24 parts by weight of the long-chain alkyl silicone oil and mix them evenly to obtain a uniform mixture.

[0051] (S4) The mixed liquid is continuously added dropwise to the seed emulsion at a stirring speed of 150 r / min using a Lange peristaltic pump (basic type BT100-2J1) for 3.5 h. The addition temperature is 50 °C. The reaction is continued for 10 h. After cooling to room temperature, 5 wt% sodium hydroxide solution is added to adjust the pH value to 7-7.5 to obtain a polysiloxane emulsion with long-chain alkyl groups.

[0052] (S5) Take 30 parts by weight of water, 40 parts by weight of acrylate soft monomer, 5 parts by weight of octadecyl methacrylate, 1 part by weight of functional monomer, 1.5 parts by weight of emulsifier and 0.45 parts by weight of initiator and mix them evenly to obtain the first mixed emulsion.

[0053] (S6) Take 25 parts by weight of acrylate hard monomer, 0.1 parts by weight of functional monomer, 0.8 parts by weight of emulsifier and 0.35 parts by weight of initiator and mix them evenly to obtain a second mixed emulsion;

[0054] (S7) At 65°C, in a four-necked flask equipped with a stirrer, thermometer and condenser, the first mixed emulsion was added dropwise to the polysiloxane emulsion with long-chain alkyl groups at a stirring speed of 150 r / min using a Lange peristaltic pump (basic type BT100-2J1) for 2.5 h while stirring. The reaction was continued for 2.5 h, and then the second mixed emulsion was added dropwise using a Lange peristaltic pump (basic type BT100-2J1) for 1.5 h. The reaction was continued for 2.5 h to obtain a copolymer emulsion.

[0055] (S8) Add 5 wt% magnesium sulfate solution to the copolymer emulsion to break the emulsion, wash with water and centrifuge, and then vacuum dry at 75°C to obtain the long-chain alkyl modified organosilicon toughening agent.

[0056] In step (S1), the molar mass ratio of long-chain alkyl thiols and vinyl silicone oil is 1:1, the mass of photoinitiator accounts for 1.8 wt% of the total reactants, and the volume weight ratio (ml / g) of tetrahydrofuran to the total reactants is 2:1.

[0057] The long-chain alkyl thiol is 1-pentanethiol; the photoinitiator is 2,2-dimethoxy-2-phenylacetophenone.

[0058] In step (S4), the weight ratio of seed emulsion to homogeneous mixture is 317.9:518.4.

[0059] In step (S7), the weight ratio of the polysiloxane emulsion with long-chain alkyl groups, the first mixed emulsion, and the second mixed emulsion is 15:77.95:26.25.

[0060] In step (S3), the emulsifier is sodium tetradecyl sulfonate; in step (S5), the emulsifier is a mixture of sodium dodecyl sulfonate and sodium tetradecyl sulfonate in a weight ratio of 2:1; in step (S6), the emulsifier is a mixture of sodium dodecyl sulfonate and sodium tetradecyl sulfonate in a weight ratio of 2:1; in step (S5), the initiator is ammonium persulfate; in step (S6), the initiator is ammonium persulfate.

[0061] The acrylate soft monomer is a mixture of butyl acrylate and isooctyl acrylate in a weight ratio of 3:1; in step (S5), the functional monomer is allyl methacrylate; in step (S6), the functional monomer is glycidyl methacrylate; the acrylate hard monomer is methyl methacrylate.

[0062] Example 3

[0063] A method for preparing a long-chain alkyl-modified organosilicon toughening agent includes the following steps:

[0064] (S1) Add vinyl silicone oil, long-chain alkyl thiol, photoinitiator and tetrahydrofuran into the reaction vessel, stir and react for 4.5 h under UV light irradiation at 365 nm and power of 20 W, then remove the solvent by vacuum distillation, wash with methanol 3 times for purification, and then vacuum dry at 60 °C for 24 h to obtain long-chain alkyl silicone oil.

[0065] (S2) Take 300 parts by weight of water and 1.4 parts by weight of dodecylbenzenesulfonic acid and add them to a four-necked flask equipped with a stirrer, thermometer and condenser. Stir evenly at 250 r / min under the condition of keeping warm at 80℃. Then take 78 parts of octamethylcyclotetrasiloxane, 1.5 parts of γ-methacryloyloxypropyltrimethoxysilane, 1.5 parts of vinyltriethoxysilane and 15 parts of the long-chain alkyl silicone oil and mix them. React at a constant temperature of 90℃ for 0.5 h to synthesize seed emulsion.

[0066] (S3) Take 350 parts by weight of water, 3.2 parts by weight of dodecylbenzenesulfonic acid, 9.56 parts by weight of emulsifier, 236 parts by weight of octamethylcyclotetrasiloxane, 4.5 parts by weight of γ-methacryloyloxypropyltrimethoxysilane, 2.5 parts by weight of vinyltriethoxysilane and 45 parts by weight of the long-chain alkyl silicone oil and mix them evenly to obtain a uniform mixture.

[0067] (S4) The mixed liquid is continuously added dropwise to the seed emulsion at a stirring speed of 250 r / min using a Lange peristaltic pump (basic type BT100-2J1) for 8.5 h while stirring. The addition temperature is 50 °C. The reaction is continued for 10 h. After cooling to room temperature, 5 wt% sodium hydroxide solution is added to adjust the pH value to 7-7.5 to obtain a polysiloxane emulsion with long-chain alkyl groups.

[0068] (S5) Take 50 parts by weight of water, 60 parts by weight of acrylate soft monomer, 15 parts by weight of octadecyl methacrylate, 2.5 parts by weight of functional monomer, 3.5 parts by weight of emulsifier and 1.16 parts by weight of initiator and mix them evenly to obtain the first mixed emulsion.

[0069] (S6) Take 35 parts by weight of acrylate hard monomer, 1.5 parts by weight of functional monomer, 0.8-2.5 parts by weight of emulsifier and 0.86 parts by weight of initiator and mix them evenly to obtain a second mixed emulsion;

[0070] (S7) At 85°C, in a four-necked flask equipped with a stirrer, thermometer and condenser, the first mixed emulsion was added dropwise to the polysiloxane emulsion with long-chain alkyl groups at a stirring speed of 250 r / min for 4.5 h while stirring. The reaction continued for 2.5 h, and then the second mixed emulsion was added dropwise to the polysiloxane emulsion with a Lange peristaltic pump for 1.5 h. The reaction continued for 2.5 h to obtain a copolymer emulsion.

[0071] (S8) Add 5 wt% magnesium sulfate solution to the copolymer emulsion to break the emulsion, wash with water and centrifuge, and then vacuum dry at 85°C to obtain the long-chain alkyl modified organosilicon toughening agent.

[0072] In step (S1), the molar mass ratio of long-chain alkyl thiols to vinyl silicone oil is 1.42:1, the mass of photoinitiator accounts for 3 wt% of the total reactants, and the volume weight ratio (ml / g) of tetrahydrofuran to the total reactants is 4:1.

[0073] The long-chain alkyl thiol is 1-pentanethiol; the photoinitiator is 2,2-dimethoxy-2-phenylacetophenone.

[0074] In step (S4), the weight ratio of seed emulsion to homogeneous mixture is 397.4:650.76.

[0075] In step (S7), the weight ratio of the polysiloxane emulsion with long-chain alkyl groups, the first mixed emulsion, and the second mixed emulsion is 45:132.16:39.86.

[0076] In step (S3), the emulsifier is sodium tetradecyl sulfonate; in step (S5), the emulsifier is a mixture of sodium dodecyl sulfonate and sodium tetradecyl sulfonate in a weight ratio of 2:1; in step (S6), the emulsifier is a mixture of sodium dodecyl sulfonate and sodium tetradecyl sulfonate in a weight ratio of 2:1; in step (S5), the initiator is ammonium persulfate; in step (S6), the initiator is ammonium persulfate.

[0077] The acrylate soft monomer is a mixture of butyl acrylate and isooctyl acrylate in a weight ratio of 3:1; in step (S5), the functional monomer is allyl methacrylate; in step (S6), the functional monomer is glycidyl methacrylate; the acrylate hard monomer is methyl methacrylate.

[0078] Example 4

[0079] A method for preparing a long-chain alkyl-modified organosilicon toughening agent includes the following steps:

[0080] (S1) Add vinyl silicone oil, long-chain alkyl thiols, photoinitiators and tetrahydrofuran into a reaction vessel, stir and react for 3.5 h under UV light irradiation at 365 nm and power of 20 W, remove the solvent by vacuum distillation, wash with methanol 3 times for purification, and then vacuum dry at 50 °C for 24 h to obtain long-chain alkyl silicone oil.

[0081] (S2) Take 280 parts by weight of water and 1.2 parts by weight of dodecylbenzenesulfonic acid and add them to a four-necked flask equipped with a stirrer, thermometer and condenser. Stir evenly at 200 r / min under the condition of keeping warm at 70℃. Then take 65 parts of octamethylcyclotetrasiloxane, 1.2 parts of γ-methacryloyloxypropyltrimethoxysilane, 0.8 parts of vinyltriethoxysilane and 10 parts of the long-chain alkyl silicone oil and mix them. React at a constant temperature of 60℃ for 0.6 h to synthesize seed emulsion.

[0082] (S3) Take 320 parts by weight of water, 2.8 parts by weight of dodecylbenzenesulfonic acid, 6.56 parts by weight of emulsifier, 206 parts by weight of octamethylcyclotetrasiloxane, 3.5 parts by weight of γ-methacryloyloxypropyltrimethoxysilane, 1 part by weight of vinyltriethoxysilane and 34 parts by weight of the long-chain alkyl silicone oil and mix them evenly to obtain a uniform mixture.

[0083] (S4) The mixed liquid is continuously added dropwise to the seed emulsion at a stirring speed of 180 r / min using a Lange peristaltic pump (BT100-2J1) for 5.5 h. The addition temperature is 70 °C. The reaction is continued for 7 h. After cooling to room temperature, 5 wt% sodium hydroxide solution is added to adjust the pH value to 7-7.5 to obtain a polysiloxane emulsion with long-chain alkyl groups.

[0084] (S5) Take 35 parts by weight of water, 45 parts by weight of acrylate soft monomer, 8 parts by weight of octadecyl methacrylate, 1.5 parts by weight of functional monomer, 2.5 parts by weight of emulsifier and 0.9 parts by weight of initiator and mix them evenly to obtain the first mixed emulsion.

[0085] (S6) Take 29 parts by weight of acrylate hard monomer, 1 part of functional monomer, 1 part of emulsifier and 0.6 parts of initiator and mix them evenly to obtain the second mixed emulsion;

[0086] (S7) At 75°C, in a four-necked flask equipped with a stirrer, thermometer and condenser, the first mixed emulsion was added dropwise to the polysiloxane emulsion with long-chain alkyl groups at a stirring speed of 180 r / min using a Lange peristaltic pump (BT100-2J1) for 3.5 h while stirring. The reaction was continued for 1.5 h, and then the second mixed emulsion was added dropwise using a Lange peristaltic pump (BT100-2J1) for 2 h. The reaction was continued for 2 h to obtain a copolymer emulsion.

[0087] (S8) Add 5 wt% magnesium sulfate solution to the copolymer emulsion to break the emulsion, wash with water and centrifuge, and then vacuum dry at 80°C to obtain the long-chain alkyl modified organosilicon toughening agent.

[0088] In step (S1), the molar mass ratio of long-chain alkyl thiols to vinyl silicone oil is 1.2:1, the mass of photoinitiator accounts for 2 wt% of the total reactants, and the volume weight ratio (m1 / g) of tetrahydrofuran to the total reactants is 3:1.

[0089] The long-chain alkyl thiol is 1-pentanethiol; the photoinitiator is 2,2-dimethoxy-2-phenylacetophenone.

[0090] In step (S4), the weight ratio of seed emulsion to homogeneous mixture is 347.4:550.76.

[0091] In step (S7), the weight ratio of the polysiloxane emulsion with long-chain alkyl groups, the first mixed emulsion, and the second mixed emulsion is 25:92.16:28.86.

[0092] In step (S3), the emulsifier is sodium tetradecyl sulfonate; in step (S5), the emulsifier is a mixture of sodium dodecyl sulfonate and sodium tetradecyl sulfonate in a weight ratio of 2:1; in step (S6), the emulsifier is a mixture of sodium dodecyl sulfonate and sodium tetradecyl sulfonate in a weight ratio of 2:1; in step (S5), the initiator is ammonium persulfate; in step (S6), the initiator is ammonium persulfate.

[0093] The acrylate soft monomer is a mixture of butyl acrylate and isooctyl acrylate in a weight ratio of 3:1; in step (S5), the functional monomer is allyl methacrylate; in step (S6), the functional monomer is glycidyl methacrylate; the acrylate hard monomer is a mixture of methyl methacrylate and styrene in a weight ratio of 2:1.

[0094] Comparative Example 1

[0095] The difference between this comparative example and Example 1 is as follows:

[0096] The octadecyl methacrylate is replaced with ethyl methacrylate.

[0097] Comparative Example 2

[0098] An organosilicon toughening agent, selected from commercially available model ZS-3003.

[0099] Performance testing

[0100] A blank control group and a model group were established using PC / ABS alloy, and the tensile strength, elongation at break, flexural modulus and notched impact strength of each group were tested.

[0101] The blank control group was prepared into toughened modified PC / ABS alloy material using the following parts by weight of raw materials:

[0102] PC / ABS alloy C1200HF 99.6 parts

[0103] Antioxidant 1010 0.3 parts

[0104] Antioxidant 168 0.1 parts.

[0105] The toughened modified PC / ABS alloy material is prepared by the following steps: PC / ABS alloy C1200HF, antioxidant 1010 and antioxidant 168 are fed into a twin-screw granulator according to the above-mentioned weight parts for melting, extrusion and granulation to obtain PC / ABS alloy material. The temperature of each zone of the twin-screw granulator is set as follows: Zone 1 temperature 215-225℃, Zone 2 temperature 225-235℃, Zone 3 temperature 235-245℃, Zone 4 temperature 235-245℃, Zone 5 temperature 235-245℃, Zone 6 temperature 235-245℃, Zone 7 temperature 230-240℃, Zone 8 temperature 235-245℃, and die head temperature 245-260℃. The length-to-diameter ratio of the twin-screw granulator is 40:1, and the screw speed is 300 rpm. The test sample is then injection molded at a temperature of 250℃~280℃ on an injection molding machine.

[0106] The model group selected the following parts by weight of raw materials to prepare toughened and modified PC / ABS alloy materials:

[0107]

[0108] The silicone toughening agent was taken from the silicone toughening agents of Examples 1-4 and Comparative Examples 1-2;

[0109] The toughened modified PC / ABS alloy material is prepared by the following steps: PC / ABS alloy C1200HF, antioxidant 1010, antioxidant 168, and organosilicon toughening agent are fed into a twin-screw granulator according to the above-mentioned weight parts for melting, extrusion, and granulation to obtain the PC / ABS alloy material. The temperature settings for each zone of the twin-screw granulator are as follows: Zone 1 temperature 215-225℃, Zone 2 temperature 225-235℃, Zone 3 temperature... The test specimens were prepared by injection molding at temperatures of 235-245℃ in zones four, five, six, seven, and eight, with a die head temperature of 245-260℃. The length-to-diameter ratio of the twin-screw granulator was 40:1, and the screw speed was 300 rpm.

[0110] The test results are shown in the table below:

[0111]

[0112] As shown in the table above, the organosilicon toughening agent prepared by this invention, when applied to PC / ABS alloy materials, more effectively improves the low-temperature impact strength of PC / ABS alloy materials.

[0113] The above embodiments are preferred implementations of the present invention. In addition, the present invention can be implemented in other ways. Any obvious substitutions without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A method for preparing a long-chain alkyl-modified silicone toughening agent, characterized by, It comprises the following steps: S1, take vinyl silicone oil, long-chain alkyl mercaptan, photoinitiator and tetrahydrofuran, under the UV light irradiation, stirring reaction 2.5-4.5h, then distilled under reduced pressure to remove the solvent, washing and purification, then vacuum drying at 45-60℃ for 20-30h, to get long-chain alkyl silicone oil; S2, take water and dodecyl benzene sulfonic acid, stirring uniformly under the condition of 50-80℃, then take silicone mixed monomer and the long-chain alkyl silicone oil mixed, under the condition of constant temperature 50-90℃, reaction 0.5-1h, to synthesize seed emulsion; S3, take water, dodecyl benzene sulfonic acid, emulsifier, silicone mixed monomer and the long-chain alkyl silicone oil mixed uniformly, to get mixed uniform liquid; S4, to the seed emulsion, continuously drop the mixed uniform liquid under stirring for 3.5-8.5h, the drop temperature is 50-90℃, continue to react for 4-10h, cool to room temperature, then add sodium hydroxide solution to adjust the pH value to 7-7.5, to get polysiloxane emulsion with long-chain alkyl; S5, take water, acrylic ester soft monomer, methacrylic acid octadecyl ester, functional monomer, emulsifier and initiator mixed uniformly, to get first mixed emulsion; S6, take hard monomer, functional monomer, emulsifier and initiator mixed uniformly, to get second mixed emulsion; S7, under the condition of 65-85℃, to the polysiloxane emulsion with long-chain alkyl, continuously drop the first mixed emulsion under stirring for 2.5-4.5h, continue to react for 0.5-2.5h, then continuously drop the second mixed emulsion for 1.5-2.5h, continue to react for 1.5-2.5h, to get copolymerization emulsion; S8, to the copolymerization emulsion, add magnesium sulfate solution to break emulsion, washing and centrifugation, then vacuum drying at 75-85℃, to get long-chain alkyl modified silicone toughening agent; Wherein, the long-chain alkyl mercaptan is at least one of 1-pentane mercaptan, n-hexyl mercaptan and 1-heptyl mercaptan; In the step S2, the silicone mixed monomer is octamethylcyclotetrasiloxane, γ-methacryloyloxypropyltrimethoxysilane, vinyltriethoxysilane mixed by weight ratio 58-78:1-1.5:0.1-1.5; in the step S3, the silicone mixed monomer is octamethylcyclotetrasiloxane, γ-methacryloyloxypropyltrimethoxysilane, vinyltriethoxysilane mixed by weight ratio 185-236:2.4-4.5:0.1-2.5; The acrylic ester soft monomer is at least one of butyl acrylate, isooctyl acrylate, ethyl acrylate; the functional monomer is at least one of acrylic acid, methacrylic acid, glycidyl methacrylate, ethylene dimethacrylate, allyl methacrylate, hydroxyethyl methacrylate, hydroxyethyl acrylate; the hard monomer is at least one of methyl methacrylate, styrene, methyl acrylate.

2. The method for preparing a long-chain alkyl-modified organosilicon toughening agent according to claim 1, characterized in that: The step S1, the washing purification is specifically washing 2-4 times with methanol, the molar mass ratio of long chain alkyl mercaptan and vinyl silicone oil is 1-1.42:1, the mass of photoinitiator accounts for 1.8wt%-3wt% of the total reactants, the volume weight ratio of tetrahydrofuran to the total reactants is 2-4ml:1g.

3. The method for preparing a long-chain alkyl-modified organosilicon toughening agent according to claim 1, characterized in that: The photoinitiator is at least one of 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone and p-methyl benzophenone.

4. The method for preparing a long-chain alkyl-modified organosilicon toughening agent according to claim 1, characterized in that: The stirring speed in the step S2 is 150-250r / min; the stirring speed in the step S4 is 150-250r / min; the stirring speed in the step S7 is 150-250r / min.

5. The method for preparing a long-chain alkyl-modified organosilicon toughening agent according to claim 1, characterized in that: The weight amount of each component in the step S2 is respectively water 250-300 parts, dodecyl benzene sulfonic acid 0.8-1.4 parts, silicone mixed monomer 59.1-81 parts and long chain alkyl silicone oil 8-15 parts; the weight amount of each component in the step S3 is respectively water 300-350 parts, dodecyl benzene sulfonic acid 2.1-3.2 parts, emulsifier 4.8-9.56 parts, silicone mixed monomer 187.5-243 parts and long chain alkyl silicone oil 24-45 parts; the ratio of the weight amount of seed emulsion and mixed uniform liquid in the step S4 is 317.9-397.4:518.4-650.

76.

6. The method for preparing a long-chain alkyl-modified organosilicon toughening agent according to claim 1, characterized in that: The weight amount of each component in the step S5 is respectively water 30-50 parts, acrylate soft monomer 40-60 parts, methacrylic acid octadecyl ester 5-15 parts, functional monomer 1-2.5 parts, emulsifier 1.5-3.5 parts and initiator 0.45-1.16 parts; the weight amount of each component in the step S6 is respectively hard monomer 25-35 parts, functional monomer 0.1-1.5 parts, emulsifier 0.8-2.5 parts and initiator 0.35-0.86 parts; The ratio of the weight amount of polysiloxane emulsion with long chain alkyl, first mixed emulsion and second mixed emulsion in the step S7 is 15-45: 77.95-132.16：26.25-39.86。 7. The method for preparing a long-chain alkyl-modified organosilicon toughening agent according to claim 1, characterized in that: The emulsifier in the steps S3, S5, S6 is at least one of sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium hexadecyl sulfate, sodium octadecyl sulfate, sodium dodecyl sulfonate and sodium tetradecyl sulfonate; the initiator in the steps S5, S6 is at least one of ammonium persulfate, potassium persulfate, sodium persulfate and hydrogen peroxide-L-ascorbic acid.

8. A long chain alkyl-modified silicone toughening agent characterized by: The long chain alkyl modified silicone toughening agent is prepared by the method in any one of claims 1-7.

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