Long-chain alkyl modified organic silicon toughening agent and preparation method thereof

Abstract

The invention relates to the technical field of organic silicon toughening agents, in particular to a long-chain alkyl modified organic silicon toughening agent and a preparation method thereof.The long-chain alkyl modified organic silicon toughening agent is prepared through sulfydryl double-bond reaction of vinyl silicone oil and long-chain alkyl mercaptan, organic silicon hydrolysis is conducted under a certain temperature condition to synthesize silicon emulsion, long-chain alkyl is preliminarily obtained, and the long-chain alkyl modified organic silicon toughening agent is prepared. Then dropwise adding a first mixed emulsion obtained by mixing an acrylate soft monomer, octadecyl methacrylate, a functional monomer, an emulsifier and an initiator, dropwise adding a second mixed emulsion obtained by mixing an acrylate hard monomer, a functional monomer, an emulsifier and an initiator, and carrying out emulsion copolymerization reaction to obtain a long-chain alkyl group again to form an interpenetrating network system; compared with the prior art, the weather resistance and temperature stability of a polymer are improved, the molecular weight of the polymer is greatly improved, the polymer has good toughness, the toughening effect on a plastic material, especially the low-temperature toughening effect, is greatly improved, and the dosage of a toughening agent in an alloy material can be reduced.

Description

Technical Field

[0001] The invention relates to the technical field of organosilicon toughening agents, and in particular to a long-chain alkyl modified organosilicon toughening agent and a preparation method thereof. Background Art

[0002] At present, 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 a part of the flexible chain, thereby improving the impact resistance of the polymer material; while inactive toughening agents have good compatibility with the matrix resin but do not participate in chemical reactions.

[0003] There are many kinds of existing toughening agents, and the toughening effects on different polymers are also different. Among them, silicone toughening agent is one of them, which has excellent elasticity. However, most of the existing silicone toughening agents are made by emulsion polymerization. After adding and using most silicone toughening agents to prepare polymer plastic products, there are still problems such as poor weather resistance, large addition amount, and poor temperature stability, which will indirectly lead to the problem of poor toughening effect. Summary of the invention

[0004] In order to overcome the shortcomings and deficiencies in the prior art, one of the purposes of the present invention is to provide a method for preparing a long-chain alkyl modified organosilicon toughening agent, in which a long-chain alkyl group is introduced into the organosilicon graft structure, which greatly improves the molecular weight of the organosilicon toughening agent, and can effectively reduce the physical loss during the processing and use of toughened polycarbonate (PC) / acrylonitrile-butadiene-styrene plastic (ABS) alloy (referred to as PC / ABS alloy). Since the silicon structure contains long side chains, the material can be given good elasticity. The organosilicon toughening agent obtained after the reaction has good toughness, which greatly improves the toughening effect on plastic materials, especially the toughening at low temperature (below -30°C), and can reduce the amount of toughening agent added to the alloy material. The preparation method is simple to operate, convenient to control, high in production efficiency, low in production cost, and can be used for large-scale production.

[0005] The second object of the present invention is to provide a long-chain alkyl modified organosilicon toughening agent, which can improve the weather resistance and low-temperature stability of the material and enhance the toughening effect at a relatively low dosage.

[0006] One of the purposes of the present invention is achieved by the following technical solution: A method for preparing a long-chain alkyl modified organosilicon toughening agent comprises the following steps:

[0007] (S1), taking vinyl silicone oil, long-chain alkyl mercaptan, photoinitiator and tetrahydrofuran, stirring and reacting for 2.5-4.5 hours under UV light, then removing the solvent by reduced pressure distillation, washing and purifying, and vacuum drying at 45-60° C. for 20-30 hours to obtain long-chain alkyl silicone oil;

[0008] (S2), taking water and dodecylbenzene sulfonic acid, stirring them evenly at a temperature of 50-80° C., then taking the organosilicon mixed monomer and the long-chain alkyl silicone oil and mixing them, reacting them at a constant temperature of 50-90° C. for 0.5-1 h to synthesize a seed emulsion;

[0009] (S3), mixing water, dodecylbenzene sulfonic acid, emulsifier, organic silicon mixed monomer and the long-chain alkyl silicone oil to obtain a mixed uniform liquid;

[0010] (S4), adding the mixed uniform liquid to the seed emulsion while stirring for 3.5-8.5 hours, the dropping temperature is 50-90° C., the reaction is continued for 4-10 hours, cooled to room temperature, and then adding sodium hydroxide solution to adjust the pH value to 7-7.5 to obtain a polysiloxane emulsion with a long-chain alkyl group;

[0011] (S5), mixing water, acrylic soft monomer, octadecyl methacrylate, functional monomer, emulsifier and initiator to obtain a first mixed emulsion;

[0012] (S6), taking an acrylic ester hard monomer, a functional monomer, an emulsifier and an initiator and mixing them evenly to obtain a second mixed emulsion;

[0013] (S7), adding the first mixed emulsion dropwise to the polysiloxane emulsion having a long-chain alkyl group under stirring for 2.5-4.5 hours at 65-85° C., continuing the reaction for 0.5-2.5 hours, and then adding the second mixed emulsion dropwise for 1.5-2.5 hours, and continuing the reaction for 1.5-2.5 hours to obtain a copolymer emulsion;

[0014] (S8), adding magnesium sulfate solution to the copolymer emulsion to break the emulsion, washing with water and centrifuging, and then vacuum drying at a temperature of 75-85° C. to obtain a long-chain alkyl modified organosilicon toughening agent.

[0015] The preparation method of the long-chain alkyl modified organic silicon toughening agent comprises the following steps: preparing the long-chain alkyl silicone oil by reacting the vinyl silicone oil with the long-chain alkyl mercaptan to produce a mercapto double bond, then hydrolyzing the long-chain alkyl silicone oil with dodecylbenzenesulfonic acid, organic silicon mixed monomer, emulsifier, water and the like under certain temperature conditions to synthesize a silicone emulsion, wherein the prepared silicone emulsion has good stability and preliminarily obtains a long-chain alkyl group, then dripping a first mixed emulsion obtained by mixing an acrylate soft monomer, octadecyl methacrylate, a functional monomer, an emulsifier and an initiator, and dripping a second mixed emulsion obtained by mixing an acrylate hard monomer, a functional monomer, an emulsifier and an initiator, carrying out an emulsion copolymerization reaction, obtaining the long-chain alkyl group again, and performing coagulation and demulsification on the obtained copolymer emulsion, washing, and drying to obtain the obtained copolymer emulsion. The obtained long-chain alkyl modified organosilicon toughening agent introduces long-chain alkyl twice into the organosilicon graft structure, introduces long-chain vinyl into the organosilicon macromolecule, obtains organosilicon seed emulsion containing double bonds, and grafts emulsion copolymerization with long-chain alkyl octadecyl ester to form an interpenetrating network system, improves the weather resistance and temperature stability of the polymer, and greatly improves its molecular weight, which can effectively reduce the physical loss during the processing and use of PC / ABS alloy. Since the silicon structure contains long side chains, it can give the material good elasticity. The organosilicon toughening agent obtained after the reaction has good toughness, greatly improves the toughening effect on plastic materials, especially low-temperature (below -30°C) toughening, and can reduce the amount of toughening agent in the alloy material. In steps (S2) and (S3), dodecylbenzene sulfonic acid is hydrolyzed to form a silicon emulsion in order to form an organosilicon mixed monomer. Further, in the step (S5), the concentration of the sodium hydroxide solution is 5wt%; in the step (S8), the concentration of the magnesium sulfate solution is 5wt%.

[0016] Preferably, in the step (S1), the washing and purification is specifically performed by washing with methanol 2-4 times, the molar mass ratio of long-chain alkyl thiol and vinyl silicone oil is 1-1.42:1, the mass of the photoinitiator accounts for 1.8wt%-3wt% of the total reactants, and the volume weight (m1 / g) ratio of tetrahydrofuran to the total reactants is 2-4:1.

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

[0018] By adopting the above technical scheme, the above long-chain alkyl mercaptan reacts with vinyl silicone oil to form a thiol double bond reaction under the action of a photoinitiator and UV light to prepare long-chain alkyl silicone oil and introduce a long-chain alkyl group.

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

[0020] Preferably, in the step (S2), the weight amounts of the components are 250-300 parts of water, 0.8-1.4 parts of dodecylbenzene sulfonic acid, 59.1-81 parts of organosilicon mixed monomers and 8-15 parts of long-chain alkyl silicone oil; in the step (S3), the weight amounts of the components are 300-350 parts of water, 2.1-3.2 parts of dodecylbenzene sulfonic 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; in the step (S4), the weight ratio of the seed emulsion to the mixed uniform liquid is 317.9-397.4:518.4-650.76.

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

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

[0023] Preferably, in the 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; in the 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 acrylic 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, hydroxyethyl methacrylate, and hydroxyethyl acrylate; and the acrylic hard monomer is at least one of methyl methacrylate, styrene, and methyl acrylate.

[0025] By adopting the above technical scheme, the above-mentioned acrylic soft monomer can give the polymer good flexibility and elasticity, and the above-mentioned acrylic hard monomer can give the polymer good hardness and strength; the above-mentioned functional monomers, hydroxyethyl methacrylate and hydroxyethyl acrylate contain hydroxyl functional groups, which can react with various compounds to form a cross-linked structure, and can improve the water resistance, solvent resistance and heat resistance of the polymer; acrylic acid and methacrylic acid contain carboxyl functional groups, which can react with metal ions, alcohol compounds, etc., and can improve the ion exchange performance, adsorption performance and dispersion performance of the polymer.

[0026] The second object of the present invention is achieved by the following technical solution: a long-chain alkyl-modified organosilicon toughening agent is prepared by the preparation method of the long-chain alkyl-modified organosilicon toughening agent as described above.

[0027] The beneficial effects of the present invention are as follows: the preparation method of the long-chain alkyl modified silicone toughening agent of the present invention comprises the following steps: preparing the long-chain alkyl silicone oil by reacting the vinyl silicone oil with the long-chain alkyl mercaptan to produce a thiol double bond, and then hydrolyzing the long-chain alkyl silicone oil with dodecylbenzenesulfonic acid, silicone mixed monomer, emulsifier, water, etc. under certain temperature conditions to synthesize silicone emulsion, wherein the prepared silicone emulsion has good stability and preliminarily obtains the long-chain alkyl group, and then dripping a first mixed emulsion obtained by mixing an acrylate soft monomer, octadecyl methacrylate, a functional monomer, an emulsifier and an initiator, and dripping a second mixed emulsion obtained by mixing an acrylate hard monomer, a functional monomer, an emulsifier and an initiator, and performing an emulsion copolymerization reaction to obtain the long-chain alkyl group again, and performing coagulation and demulsification on the obtained copolymer emulsion, The long-chain alkyl modified organic silicon toughening agent is washed and dried, and the long-chain alkyl is introduced twice into the organic silicon graft structure, and the organic silicon seed emulsion containing double bonds is obtained by introducing the long-chain vinyl into the organic silicon macromolecule, and the graft emulsion copolymerization with the long-chain alkyl octadecyl ester is carried out to form an interpenetrating network system, thereby improving the weather resistance and temperature stability of the polymer, and greatly increasing its molecular weight, which can effectively reduce the physical loss during the processing and use of the PC / ABS alloy. Since the silicon structure contains long side chains, the material can be given good elasticity, and the organic silicon toughening agent obtained after the reaction has good toughness, which greatly improves the toughening effect on the plastic material, especially the toughening at low temperature (below -30°C), and can reduce the amount of the toughening agent in the alloy material.

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

[0029] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with embodiments, and the contents mentioned in the implementation modes are not intended to limit the present invention.

[0030] Example 1

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

[0032] (S1), adding vinyl silicone oil, long-chain alkyl mercaptan, photoinitiator and tetrahydrofuran into a reaction kettle, stirring and reacting for 3 hours under 365nm UV light with a power of 20W, then removing the solvent by reduced pressure distillation, washing with methanol for 3 times for purification, and then vacuum drying at 55°C for 24 hours to obtain long-chain alkyl silicone oil;

[0033] (S2), 280 parts of water and 1.2 parts of dodecylbenzenesulfonic acid were added to a four-necked flask equipped with a stirrer, a thermometer and a condenser, and stirred evenly at a stirring speed of 200 r / min under a heat preservation condition of 65° C., and then 68 parts of octamethylcyclotetrasiloxane, 1.2 parts of γ-methacryloxypropyltrimethoxysilane, 1 part of vinyltriethoxysilane and 12 parts of the long-chain alkyl silicone oil were mixed, and reacted at a constant temperature of 70° C. for 0.8 h to synthesize a seed emulsion;

[0034] (S3), 320 parts of water, 2.6 parts of dodecylbenzenesulfonic acid, 7.2 parts of emulsifier, 208 parts of octamethylcyclotetrasiloxane, 3.5 parts of Y-methacryloxypropyltrimethoxysilane, 1.5 parts of vinyltriethoxysilane and 35 parts of the long-chain alkyl silicone oil are mixed uniformly to obtain a mixed uniform liquid;

[0035] (S4), adding the mixed uniform liquid to the seed emulsion at a stirring speed of 200 r / min while stirring using a Lange peristaltic pump basic model BT100-2J1 for 6 hours, the dropping temperature is 70° C., the reaction is continued for 6 hours, cooled to room temperature, and then 5 wt % sodium hydroxide solution is added to adjust the pH value to 7-7.5 to obtain a polysiloxane emulsion with a long-chain alkyl group;

[0036] (S5), taking 40 parts of water, 50 parts of acrylic soft monomer, 10 parts of octadecyl methacrylate, 1.8 parts of functional monomer, 2.5 parts of emulsifier and 0.86 parts of initiator by weight and mixing them evenly to obtain a first mixed emulsion;

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

[0038] (S7), at 75°C, in a four-necked flask equipped with a stirrer, a thermometer and a condenser, the first mixed emulsion is added dropwise to the polysiloxane emulsion having a long-chain alkyl group at a stirring speed of 200 r / min for 3.5 hours using a Langer peristaltic pump basic model BT100-2J1, the reaction is continued for 1.5 hours, and the second mixed emulsion is added dropwise for 2 hours using a Langer peristaltic pump basic model BT100-2J1, and the reaction is continued for 2 hours to obtain a copolymer emulsion;

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

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

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

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

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

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

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

[0046] Example 2

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

[0048] (S1), adding vinyl silicone oil, long-chain alkyl mercaptan, photoinitiator and tetrahydrofuran into a reaction kettle, stirring and reacting for 2.5 hours under 365nm UV light with a power of 20W, and then removing the solvent by reduced pressure distillation, washing with methanol for 3 times for purification, and then vacuum drying at 45°C for 24 hours to obtain long-chain alkyl silicone oil;

[0049] (S2), adding 250 parts of water and 0.8 parts of dodecylbenzenesulfonic acid by weight into a four-necked flask equipped with a stirrer, a thermometer and a condenser, stirring evenly at a stirring speed of 250r / min under a heat preservation condition of 50°C, and then mixing 58 parts of octamethylcyclotetrasiloxane, 1 part of γ-methacryloxypropyltrimethoxysilane, 0.1 part of vinyltriethoxysilane and 8 parts of the long-chain alkyl silicone oil, reacting at a constant temperature of 50°C for 1h to synthesize a seed emulsion;

[0050] (S3), 300 parts by weight of water, 2.1 parts of dodecylbenzenesulfonic acid, 4.8 parts of emulsifier, 185 parts of octamethylcyclotetrasiloxane, 2.4 parts of γ-methacryloxypropyltrimethoxysilane, 0.1 parts of vinyltriethoxysilane and 24 parts of the long-chain alkyl silicone oil are mixed uniformly to obtain a mixed uniform liquid;

[0051] (S4), adding the mixed uniform liquid to the seed emulsion at a stirring speed of 150 r / min while stirring using a Lange peristaltic pump basic model BT100-2J1 for 3.5 hours, the dropping temperature is 50° C., the reaction is continued for 10 hours, cooled to room temperature, and then 5 wt % sodium hydroxide solution is added to adjust the pH value to 7-7.5 to obtain a polysiloxane emulsion with a long-chain alkyl group;

[0052] (S5), taking 30 parts of water, 40 parts of acrylic soft monomer, 5 parts of octadecyl methacrylate, 1 part of functional monomer, 1.5 parts of emulsifier and 0.45 parts of initiator by weight and mixing them evenly to obtain a first mixed emulsion;

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

[0054] (S7), at 65°C, in a four-necked flask equipped with a stirrer, a thermometer and a condenser, the first mixed emulsion is added dropwise to the polysiloxane emulsion having a long-chain alkyl group at a stirring speed of 150 r / min while stirring using a Langer peristaltic pump basic model BT100-2J1 for 2.5 hours, and the reaction is continued for 2.5 hours, and then the second mixed emulsion is added dropwise using a Langer peristaltic pump basic model BT100-2J1 for 1.5 hours, and the reaction is continued for 2.5 hours to obtain a copolymer emulsion;

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

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

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

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

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

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

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

[0062] Example 3

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

[0064] (S1), adding vinyl silicone oil, long-chain alkyl mercaptan, photoinitiator and tetrahydrofuran into a reaction kettle, stirring and reacting for 4.5 hours under 365nm UV light with a power of 20W, and then removing the solvent by reduced pressure distillation, washing with methanol for 3 times and then drying in vacuum at 60°C for 24 hours to obtain long-chain alkyl silicone oil;

[0065] (S2), 300 parts of water and 1.4 parts of dodecylbenzenesulfonic acid are added to a four-necked flask equipped with a stirrer, a thermometer and a condenser, and stirred evenly at a stirring speed of 250r / min under a heat preservation condition of 80°C, and then 78 parts of octamethylcyclotetrasiloxane, 1.5 parts of γ-methacryloxypropyltrimethoxysilane, 1.5 parts of vinyltriethoxysilane and 15 parts of the long-chain alkyl silicone oil are mixed, and reacted at a constant temperature of 90°C for 0.5h to synthesize a seed emulsion;

[0066] (S3), 350 parts of water, 3.2 parts of dodecylbenzenesulfonic acid, 9.56 parts of emulsifier, 236 parts of octamethylcyclotetrasiloxane, 4.5 parts of γ-methacryloxypropyltrimethoxysilane, 2.5 parts of vinyltriethoxysilane and 45 parts of the long-chain alkyl silicone oil are mixed uniformly to obtain a mixed uniform liquid;

[0067] (S4), adding the mixed uniform liquid to the seed emulsion at a stirring speed of 250 r / min while stirring using a Lange peristaltic pump basic model BT100-2J1 for 8.5 hours, the dropping temperature is 50° C., the reaction is continued for 10 hours, cooled to room temperature, and then 5 wt % sodium hydroxide solution is added to adjust the pH value to 7-7.5 to obtain a polysiloxane emulsion with a long-chain alkyl group;

[0068] (S5), taking 50 parts of water, 60 parts of acrylic soft monomer, 15 parts of octadecyl methacrylate, 2.5 parts of functional monomer, 3.5 parts of emulsifier and 1.16 parts of initiator by weight and mixing them evenly to obtain a first mixed emulsion;

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

[0070] (S7), at 85°C, in a four-necked flask equipped with a stirrer, a thermometer and a condenser, the first mixed emulsion is added dropwise to the polysiloxane emulsion having a long-chain alkyl group at a stirring speed of 250 r / min for 4.5 hours with a Langer peristaltic pump basic model BT100-2J1, the reaction is continued for 2.5 hours, and the second mixed emulsion is added dropwise for 1.5 hours with a Langer peristaltic pump basic model BT100-2J1, the reaction is continued for 2.5 hours, and a copolymer emulsion is obtained;

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

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

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

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

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

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

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

[0078] Example 4

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

[0080] (S1), vinyl silicone oil, long-chain alkyl mercaptan, photoinitiator and tetrahydrofuran were added to a reaction kettle, stirred and reacted for 3.5 hours under 365nm UV light with a power of 20W, and then the solvent was removed by reduced pressure distillation, washed with methanol for 3 times and purified, and then vacuum dried at 50°C for 24 hours to obtain long-chain alkyl silicone oil;

[0081] (S2), 280 parts of water and 1.2 parts of dodecylbenzenesulfonic acid were added to a four-necked flask equipped with a stirrer, a thermometer and a condenser, and stirred evenly at a stirring speed of 200 r / min under a heat preservation condition of 70° C., and then 65 parts of octamethylcyclotetrasiloxane, 1.2 parts of γ-methacryloxypropyltrimethoxysilane, 0.8 parts of vinyltriethoxysilane and 10 parts of the long-chain alkyl silicone oil were mixed, and reacted at a constant temperature of 60° C. for 0.6 h to synthesize a seed emulsion;

[0082] (S3), 320 parts of water, 2.8 parts of dodecylbenzenesulfonic acid, 6.56 parts of emulsifier, 206 parts of octamethylcyclotetrasiloxane, 3.5 parts of γ-methacryloxypropyltrimethoxysilane, 1 part of vinyltriethoxysilane and 34 parts of the long-chain alkyl silicone oil are mixed uniformly to obtain a mixed uniform liquid;

[0083] (S4), adding the mixed uniform liquid to the seed emulsion at a stirring speed of 180 r / min while stirring using a Lange peristaltic pump basic model BT100-2J1 for 5.5 hours, the dropping temperature is 70° C., the reaction is continued for 7 hours, cooled to room temperature, and then 5 wt % sodium hydroxide solution is added to adjust the pH value to 7-7.5 to obtain a polysiloxane emulsion with a long-chain alkyl group;

[0084] (S5), taking 35 parts of water, 45 parts of acrylic soft monomer, 8 parts of octadecyl methacrylate, 1.5 parts of functional monomer, 2.5 parts of emulsifier and 0.9 parts of initiator by weight and mixing them evenly to obtain a first mixed emulsion;

[0085] (S6), taking 29 parts by weight of an acrylic hard monomer, 1 part of a functional monomer, 1 part of an emulsifier and 0.6 parts of an initiator and mixing them evenly to obtain a second mixed emulsion;

[0086] (S7), at 75°C, in a four-necked flask equipped with a stirrer, a thermometer and a condenser, the first mixed emulsion is added dropwise to the polysiloxane emulsion having a long-chain alkyl group at a stirring speed of 180 r / min for 3.5 hours using a Langer peristaltic pump basic model BT100-2J1, the reaction is continued for 1.5 hours, and the second mixed emulsion is added dropwise for 2 hours using a Langer peristaltic pump basic model BT100-2J1, and the reaction is continued for 2 hours to obtain a copolymer emulsion;

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

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

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

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

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

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

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

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

[0097] Comparative Example 2

[0098] A silicone toughening agent is selected from commercially available model ZS-3003.

[0099] Performance Testing

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

[0101] The blank control group used the following raw materials in parts by weight to prepare toughened modified PC / ABS alloy material:

[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 weight parts for melting, extrusion and granulation to obtain the PC / ABS alloy material, wherein the temperature of each zone of the twin-screw granulator is set as follows: zone 1 temperature 215-225°C, zone 2 temperature 225-235°C, zone 3 temperature 235-245°C, zone 4 temperature 235-245°C, zone 5 temperature 235-245°C, zone 6 temperature 235-245°C, zone 7 temperature 230-240°C, zone 8 temperature 235-245°C and die head temperature 245-260°C, the aspect ratio of the twin-screw granulator is 40:1, the screw speed is 300 rpm, and then the test specimens are injection molded at a temperature of 250°C to 280°C on the injection molding machine to obtain the test specimens.

[0106] The model group uses the following raw materials in parts by weight to prepare toughened modified PC / ABS alloy material:

[0107]

[0108] The organosilicon toughening agent is taken from the organosilicon 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 silicone toughening agent are fed into a twin-screw granulator according to the above weight parts to be melted, extruded and granulated to obtain the PC / ABS alloy material, wherein the temperature of each zone of the twin-screw granulator is set as follows: the temperature of zone 1 is 215-225°C, the temperature of zone 2 is 225-235°C, and the temperature of zone 3 is 240-250°C. The temperature is 235-245°C, the temperature of zone four is 235-245°C, the temperature of zone five is 235-245°C, the temperature of zone six is ​​235-245°C, the temperature of zone seven is 230-240°C, the temperature of zone eight is 235-245°C, the temperature of the die head is 245-260°C, the aspect ratio of the twin-screw granulator is 40:1, the screw speed is 300 rpm, and then the test specimens are injection molded at a temperature of 250°C to 280°C on the injection molding machine.

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

[0111]

[0112] It can be seen from the above table that the organosilicon toughening agent prepared in the present invention is applied to PC / ABS alloy materials, which more effectively improves the low-temperature impact strength of the PC / ABS alloy materials.

[0113] The above embodiments are preferred implementation schemes of the present invention. In addition, the present invention may also be implemented in other ways. Any obvious replacement without departing from the concept of the present invention is within the protection scope of the present invention.

Claims

1. A method for preparing a long-chain alkyl modified organosilicon toughening agent, characterized in that: The steps include: (S1), taking vinyl silicone oil, long-chain alkyl mercaptan, photoinitiator and tetrahydrofuran, stirring and reacting for 2.5-4.5 hours under UV light, then removing the solvent by reduced pressure distillation, washing and purifying, and vacuum drying at 45-60° C. for 20-30 hours to obtain long-chain alkyl silicone oil; (S2), taking water and dodecylbenzene sulfonic acid, stirring them evenly at a temperature of 50-80° C., then taking the organosilicon mixed monomer and the long-chain alkyl silicone oil and mixing them, reacting them at a constant temperature of 50-90° C. for 0.5-1 h to synthesize a seed emulsion; (S3), mixing water, dodecylbenzene sulfonic acid, emulsifier, organic silicon mixed monomer and the long-chain alkyl silicone oil to obtain a mixed uniform liquid; (S4), adding the mixed uniform liquid to the seed emulsion while stirring for 3.5-8.5 hours, the dropping temperature is 50-90° C., the reaction is continued for 4-10 hours, cooled to room temperature, and then adding sodium hydroxide solution to adjust the pH value to 7-7.5 to obtain a polysiloxane emulsion with a long-chain alkyl group; (S5), mixing water, acrylic soft monomer, octadecyl methacrylate, functional monomer, emulsifier and initiator to obtain a first mixed emulsion; (S6), taking an acrylic ester hard monomer, a functional monomer, an emulsifier and an initiator and mixing them evenly to obtain a second mixed emulsion; (S7), adding the first mixed emulsion dropwise to the polysiloxane emulsion having a long-chain alkyl group under stirring for 2.5-4.5 hours at 65-85° C., continuing the reaction for 0.5-2.5 hours, and then adding the second mixed emulsion dropwise for 1.5-2.5 hours, and continuing the reaction for 1.5-2.5 hours to obtain a copolymer emulsion; (S8), adding magnesium sulfate solution to the copolymer emulsion to break the emulsion, washing with water and centrifuging, and then vacuum drying at a temperature of 75-85° C. to obtain a long-chain alkyl modified organosilicon toughening agent.

2. The method for preparing a long-chain alkyl modified organosilicon toughening agent according to claim 1, characterized in that: In the step (S1), the washing and purification is specifically performed by washing with methanol 2-4 times, the molar mass ratio of long-chain alkyl mercaptan to vinyl silicone oil is 1-1.42:1, the mass of the photoinitiator accounts for 1.8wt%-3wt% of the total reactants, and the volume weight (m1 / g) ratio of tetrahydrofuran to the total reactants is 2-4:

1.

3. The method for preparing a long-chain alkyl modified organosilicon toughening agent according to claim 1, characterized in that: The long-chain alkyl mercaptan is at least one of 1-pentanethiol, n-hexylthiol and 1-heptylthiol; the photoinitiator is at least one of 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone and p-methylbenzophenone.

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

5. The method for preparing a long-chain alkyl modified organosilicon toughening agent according to claim 1, characterized in that: In the step (S2), the weight amounts of the components are 250-300 parts of water, 0.8-1.4 parts of dodecylbenzene sulfonic acid, 59.1-81 parts of organic silicon mixed monomers and 8-15 parts of long-chain alkyl silicone oil; in the step (S3), the weight amounts of the components are 300-350 parts of water, 2.1-3.2 parts of dodecylbenzene sulfonic acid, 4.8-9.56 parts of emulsifier, 187.5-243 parts of organic silicon mixed monomers and 24-45 parts of long-chain alkyl silicone oil; in the step (S4), the weight ratio of the seed emulsion to the mixed uniform liquid 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 5, characterized in that: In the step (S2), the organic silicon mixed monomer is octamethylcyclotetrasiloxane, γ-methacryloxypropyltrimethoxysilane, and vinyltriethoxysilane mixed in a weight ratio of 58-78: 1-1.5: 0.1-1.5; in the step (S3), the organic silicon mixed monomer is octamethylcyclotetrasiloxane, γ-methacryloxypropyltrimethoxysilane, and vinyltriethoxysilane mixed in a weight ratio of 185-236: 2.4-4.5: 0.1-2.

5.

7. The method for preparing a long-chain alkyl modified organosilicon toughening agent according to claim 1, characterized in that: In the step (S5), the weight portions of the components are 30-50 parts of water, 40-60 parts of acrylate soft monomers, 5-15 parts of methacrylate octadecyl, 1-2.5 parts of functional monomers, 1.5-3.5 parts of emulsifiers, and 0.45-1.16 parts of initiators; in the step (S6), the weight portions of the components 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; In the step (S7), the weight ratio of the polysiloxane emulsion with a long-chain alkyl group, the first mixed emulsion and the second mixed emulsion is 15-45:77.95-132.16:26.25-39.

86.

8. The method for preparing a long-chain alkyl modified organosilicon toughening agent according to claim 1, characterized in that: In the 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; in the steps (S5) and (S6), the initiator is at least one of ammonium persulfate, potassium persulfate, sodium persulfate and hydrogen peroxide-L-ascorbic acid.

9. The method for preparing a long-chain alkyl modified organosilicon toughening agent according to claim 1, characterized in that: The acrylic 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, hydroxyethyl methacrylate, and hydroxyethyl acrylate; the acrylic hard monomer is at least one of methyl methacrylate, styrene, and methyl acrylate.

10. A long-chain alkyl-modified organosilicon toughening agent, characterized in that: The long-chain alkyl modified organosilicon toughening agent is prepared by the preparation method of any one of claims 1 to 9.

Images