An impact-resistant ACR additive for transparent PVC products and its preparation method

Abstract

An impact-resistant ACR additive for transparent PVC products and a preparation method thereof belong to the technical field of polymer materials. The preparation method of the impact-resistant ACR additive for transparent PVC products comprises five steps: preparing a seed emulsion, preparing a core, preparing a transition layer, preparing an outer shell, and spray drying. The impact-resistant ACR additive for transparent PVC products is pressed to obtain a sheet with a thickness of 3 mm, and its notched impact strength at 23°C is 17.1 to 18.9 kJ / m 2 The notched impact strength at -10°C is 11.7~13.6 kJ / m 2 The transmittance is 94.6~96.3%, and the haze is 1.8~3.1%.

Description

Technical Field

[0001] The invention relates to an impact-resistant ACR additive for transparent PVC products and a preparation method thereof, belonging to the technical field of polymer materials. Background Art

[0002] Core-shell acrylates (ACRs), as impact modifiers for polyvinyl chloride (PVC), possess excellent impact resistance and good processing properties. However, ACR impact modifiers also suffer from less-than-ideal transparency. This is particularly true when used in transparent PVC products, where the addition of ACR impact modifiers can negatively impact the product's light transmittance, particularly in thicker PVC sheets. Furthermore, PVC modified with ACR impact modifiers exhibits poor low-temperature resistance. Therefore, developing an ACR impact modifier with excellent low-temperature resistance, high light transmittance, and suitability for transparent PVC products is a product development strategy that meets the real needs of the PVC industry.

[0003] Chinese patent CN115232262A discloses an acrylate impact modifier for transparent PVC products and its preparation method. Specifically, the preparation comprises raw materials including reactive monomers, surfactants, crosslinking agents, oxidants, reducing agents, chain transfer agents, additives, and deionized water. The preparation process includes the following steps: seed latex synthesis, acrylic elastomer synthesis, core-shell graft copolymer synthesis, and acrylate impact modifier preparation. The acrylate impact modifier prepared in this patent achieves a maximum light transmittance of 86.5% for modified PVC products, which is not particularly ideal.

[0004] Chinese patent CN103613713A discloses a method for preparing an impact-resistant ACR additive for transparent PVC products. The method comprises preparing a core layer of ACR particles and then coating the core layer of the ACR particles with a shell layer. The process of the present invention is simple to operate, has low energy consumption, and does not cause significant pollution to the environment. A high-rubber phase ACR particles are prepared by first preparing a highly cross-linked nano-scale microsphere and then coating the outer surface thereof with a hard shell having a high glass transition temperature, thereby ensuring excellent impact resistance. The impact-resistant ACR additive for transparent PVC products obtained in this patent has a very high light transmittance of PVC products, which is above 92%. However, the room temperature impact resistance of PVC products is not good, and the patent does not pay attention to the impact resistance at low temperatures.

[0005] From the above, it can be seen that the impact-resistant ACR additives used in transparent PVC products still have poor light transmittance and low-temperature impact resistance. Therefore, the development of an impact-resistant ACR additive for transparent PVC products with high light transmittance and good impact resistance at low temperatures is of great practical value to the PVC industry. Summary of the Invention

[0006] In view of the shortcomings of the above-mentioned prior art, the present invention provides an impact-resistant ACR additive for transparent PVC products and a preparation method thereof, to achieve the following invention objectives: to prepare an impact-resistant ACR additive for transparent PVC products with high light transmittance and good impact resistance at low temperatures.

[0007] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0008] An impact-resistant ACR additive for transparent PVC products and a preparation method thereof, the preparation method comprising five steps: preparing a seed emulsion, preparing a core, preparing a transition layer, preparing an outer shell, and spray drying;

[0009] The impact-resistant ACR additive for transparent PVC products is pressed to obtain a sheet with a thickness of 3 mm, and its notched impact strength at 23° C. is 17.1-18.9 kJ / m 2 The notched impact strength at -10°C is 11.7~13.6 kJ / m 2 , light transmittance is 94.6~96.3%, haze is 1.8~3.1%;

[0010] The following are further improvements to the above technical solution:

[0011] Step 1: Prepare seed emulsion

[0012] Deionized water, seed monomer mixture, and emulsifier are added to the reactor, and stirred and emulsified under nitrogen protection. Sodium bicarbonate is added to adjust the pH value. After stirring and emulsification into a uniform and stable emulsion, a seed crosslinker is added, and the temperature is raised and kept constant to the reaction temperature. Then, an initiator is added and the reaction is continued at a constant temperature. After the reaction is completed, a seed emulsion is obtained;

[0013] The seed monomer mixture is formed by mixing one or two of an organic silicon monomer or an acrylic ester substance in any mass ratio, 5-vinyl-2-pyrrolidone, and 4-hydroxy-cyclopent-2-enone;

[0014] The organosilicon monomer is one of 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, diallyltetramethyldisiloxane, acryloxytriisopropylsilane, vinyltriethoxysilane, methacryloxymethyltriethoxysilane, vinyltrimethoxysilane, vinyltriisopropoxysilane, and methylvinyldimethoxysilane;

[0015] The acrylic acid ester substance is one of butyl acrylate and isooctyl acrylate or a mixture of the two in any mass ratio;

[0016] The mass ratio of a mixture of one or two of the organosilicon monomers or acrylate substances in any mass ratio, 5-vinyl-2-pyrrolidone, and 4-hydroxy-cyclopent-2-enone is 90-220:0.1-2:0.1-1.5;

[0017] The seed crosslinking agent is one or a mixture of two or more of triallyl isocyanurate, 1,3-diallyl-2-thiourea, N,N-dimethylallylamine, diallylisopropylamine, methyltriallylsilane, diallyltetramethyldisiloxane, diallylamine, allyl acrylate, ethylene glycol diallyl ether, allyl oxalate, diallyl maleate, 1,3,5-triallylcyanurate, divinylbenzene, vinylidene chloride, glycidyl methacrylate, and allyl phthalate in any mass ratio;

[0018] The emulsifier is one of sodium lauryl sulfate, sodium dodecylbenzene sulfonate, nonylphenol polyoxyethylene ether, sodium dodecyl diphenyl ether disulfonate, sodium fatty alcohol polyoxyethylene ether sulfate, and dodecylphenol polyoxyethylene ether;

[0019] The initiator is one of potassium persulfate and ammonium persulfate;

[0020] The mass ratio of the deionized water, seed monomer mixture, emulsifier, seed crosslinking agent, and initiator is 90-160:20-50:2-8:4-9:0.3-1;

[0021] Sodium bicarbonate is added to adjust the pH value to 8.5-10;

[0022] The stirring emulsification has a stirring rate of 800 to 1800 rpm;

[0023] The reaction temperature is 65-85°C;

[0024] The constant temperature reaction has a reaction time of 0.5 to 1 hour.

[0025] Step 2: Prepare the kernel

[0026] The core monomer mixture, deionized water, and emulsifier are added to an emulsifier, and stirred under nitrogen protection to form a uniform and stable emulsion to obtain a core monomer emulsion. Subsequently, the core monomer emulsion, initiator, and core cross-linking agent are added to the seed emulsion, and the temperature is raised and kept constant to the reaction temperature. After the constant temperature reaction is completed, the core emulsion is obtained;

[0027] The core monomer mixture is formed by mixing one or two of an organic silicon monomer or an acrylic ester substance in any mass ratio, 5-vinyl-2-pyrrolidone, and 4-hydroxy-cyclopent-2-enone;

[0028] The organosilicon monomer is one of 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, diallyltetramethyldisiloxane, acryloxytriisopropylsilane, vinyltriethoxysilane, methacryloxymethyltriethoxysilane, vinyltrimethoxysilane, vinyltriisopropoxysilane, and methylvinyldimethoxysilane;

[0029] The acrylic acid ester substance is one of butyl acrylate and isooctyl acrylate or a mixture of the two in any mass ratio;

[0030] The mass ratio of a mixture of one or two of the organosilicon monomers or acrylate substances in any mass ratio, 5-vinyl-2-pyrrolidone, and 4-hydroxy-cyclopent-2-enone is 100-250:0.2-2:0.3-1.5;

[0031] The core crosslinking agent is one or a mixture of two or more of triallyl isocyanurate, 1,3-diallyl-2-thiourea, N,N-dimethylallylamine, diallylisopropylamine, methyltriallylsilane, diallyltetramethyldisiloxane, diallylamine, allyl acrylate, ethylene glycol diallyl ether, allyl oxalate, diallyl maleate, 1,3,5-triallylcyanurate, divinylbenzene, vinylidene chloride, glycidyl methacrylate, and allyl phthalate in any mass ratio;

[0032] The emulsifier is one of sodium lauryl sulfate, sodium dodecylbenzene sulfonate, nonylphenol polyoxyethylene ether, sodium dodecyl diphenyl ether disulfonate, sodium fatty alcohol polyoxyethylene ether sulfate, and dodecylphenol polyoxyethylene ether;

[0033] The initiator is one of potassium persulfate and ammonium persulfate;

[0034] The mass ratio of the core monomer mixture, deionized water, and emulsifier is 20-50: 90-160: 2-8;

[0035] The mass ratio of the core monomer emulsion, initiator, core crosslinking agent and seed emulsion is 80-200:0.3-1.2:5-12:15-60;

[0036] The reaction temperature is 65-85°C;

[0037] The constant temperature reaction has a reaction time of 3 to 6 hours.

[0038] Step 3: Prepare the transition layer

[0039] Adding the transition layer monomer mixture, deionized water, and emulsifier into an emulsifying kettle, stirring and emulsifying under nitrogen protection to form a uniform and stable emulsion to obtain a transition layer monomer emulsion, then adding the transition layer monomer emulsion, initiator, and transition layer crosslinker to the core emulsion, heating and maintaining the temperature to the reaction temperature, and obtaining a transition layer emulsion after the isothermal reaction is completed;

[0040] The transition layer monomer mixture is prepared by mixing butyl acrylate and styrene;

[0041] The mass ratio of butyl acrylate to styrene is 60-170:25-100;

[0042] The emulsifier is one of sodium lauryl sulfate, sodium dodecylbenzene sulfonate, nonylphenol polyoxyethylene ether, sodium dodecyl diphenyl ether disulfonate, sodium fatty alcohol polyoxyethylene ether sulfate, and dodecylphenol polyoxyethylene ether;

[0043] The initiator is one of potassium persulfate and ammonium persulfate;

[0044] The mass ratio of the transition layer monomer mixture, deionized water, and emulsifier is 30-70:100-190:3-9;

[0045] The mass ratio of the transition layer monomer emulsion, initiator, transition layer crosslinking agent, and core emulsion is 20-80:0.1-0.6:1-10:125-260;

[0046] The transition layer crosslinking agent is bisphenol A dimethacrylate;

[0047] The reaction temperature is 65-85°C;

[0048] The constant temperature reaction has a reaction time of 1 to 2 hours.

[0049] Step 4: Prepare the shell

[0050] The shell monomer mixture, deionized water, and emulsifier are added to an emulsifier, and stirred under nitrogen protection to form a uniform and stable emulsion to obtain a shell monomer emulsion. Subsequently, the shell monomer emulsion, initiator, and shell crosslinker are added to the transition layer emulsion, and the temperature is increased and kept constant to the reaction temperature. After the constant temperature reaction is completed, the core-shell structure ACR emulsion is obtained;

[0051] The shell monomer mixture is prepared by mixing styrene, methyl methacrylate, acrylic acid derivatives, fumaramide, and acryloyl glycinamide;

[0052] The acrylic acid derivative is one of methacrylic acid, acrylic acid, and hydroxyethyl acrylate;

[0053] The emulsifier is one of sodium lauryl sulfate, sodium dodecylbenzene sulfonate, nonylphenol polyoxyethylene ether, sodium dodecyl diphenyl ether disulfonate, sodium fatty alcohol polyoxyethylene ether sulfate, and dodecylphenol polyoxyethylene ether;

[0054] The mass ratio of styrene, methyl methacrylate, acrylic acid derivative, fumaramide and acryloylglycinamide is 80-180:25-45:3-10:0.3-1:0.1-0.6;

[0055] The mass ratio of the shell monomer mixture, deionized water, and emulsifier is 40-100:130-210:4-9;

[0056] The mass ratio of the shell monomer emulsion, initiator, shell crosslinking agent and transition layer emulsion is 40-100:0.2-0.8:1-8:145-250;

[0057] The initiator is one of potassium persulfate and ammonium persulfate;

[0058] The shell crosslinking agent is one or a mixture of two or more of triallyl isocyanurate, 1,3-diallyl-2-thiourea, N,N-dimethylallylamine, diallylisopropylamine, methyltriallylsilane, diallyltetramethyldisiloxane, diallylamine, allyl acrylate, ethylene glycol diallyl ether, allyl oxalate, diallyl maleate, 1,3,5-triallylcyanurate, divinylbenzene, vinylidene chloride, glycidyl methacrylate, and allyl phthalate in any mass ratio;

[0059] The reaction temperature is 65-85°C;

[0060] The constant temperature reaction has a reaction time of 1.5 to 3 hours.

[0061] Step 5: Spray drying

[0062] The core-shell structured ACR emulsion was fed into the centrifugal spray drying system by a feed pump for spray drying. The inlet temperature of the drying system was controlled between 160 and 165°C, the outlet temperature was controlled between 60 and 65°C, and the drying air volume was controlled between 46 and 55 m 3 / min, and after drying, a powdery impact-resistant ACR additive for transparent PVC products is obtained.

[0063] Compared with the prior art, the present invention achieves the following beneficial effects:

[0064] 1. The impact-resistant ACR additive for transparent PVC products obtained by the present invention comprises, in addition to conventional organosilicon monomers and butyl acrylate, 5-vinyl-2-pyrrolidone and 4-hydroxy-cyclopent-2-enone as seed monomers and core monomers. Both substances contain ketone carbonyl groups. The carbon-oxygen double bond structure of the ketone carbonyl group exhibits a dipole moment effect, which can enhance the polymerization density of the ACR additive seed and core. This makes it easier for the ACR additive to buffer the stress concentration caused by the silver shear band effect when toughening PVC, thereby significantly improving the impact resistance of the PVC sheet.

[0065] 2. The impact-resistant ACR additive obtained by the present invention has a transition layer designed between the core and the shell. The transition layer is cross-linked with bisphenol A dimethacrylate, which has a very high cross-linking strength. This transition layer can provide a certain cross-linked network buffer structure between the rubber-phase polymer core and the plastic shell, making it easier to maintain good overall consistency at low temperatures, thereby enhancing the ACR additive's toughening performance on PVC materials at low temperatures.

[0066] 3. The impact-resistant ACR additive prepared by the present invention has fumaramide and acryl glycinamide added to the shell monomer. The amino groups contained in these two monomers can greatly improve the compatibility of the ACR additive with the PVC matrix material, and can reduce the interfacial effect between the ACR additive and PVC to a very low level, thereby ensuring the high light transmittance of thick PVC sheets. In addition, the reduction of this interfacial effect will also promote the toughening effect of the ACR additive on the PVC substrate, which ultimately manifests as an improvement in notched impact strength.

[0067] 4. The impact-resistant ACR additive for transparent PVC products prepared by the present invention is pressed to obtain a sheet with a thickness of 3 mm, and its notched impact strength at 23°C is 17.1~18.9 kJ / m 2 The notched impact strength at -10°C is 11.7~13.6 kJ / m 2 The transmittance is 94.6~96.3%, and the haze is 1.8~3.1%. DETAILED DESCRIPTION

[0068] The preferred embodiments of the present invention are described below. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0069] Example 1: Preparation method of impact-resistant ACR additive for transparent PVC products

[0070] Step 1: Prepare seed emulsion

[0071] Deionized water, seed monomer mixture, and emulsifier are added to the reactor, and stirred and emulsified under nitrogen protection. Sodium bicarbonate is added to adjust the pH value. After stirring and emulsification into a uniform and stable emulsion, a seed crosslinker is added, and the temperature is raised and kept constant to the reaction temperature. Then, an initiator is added and the reaction is continued at a constant temperature. After the reaction is completed, a seed emulsion is obtained;

[0072] The seed monomer mixture is prepared by mixing acrylic acid esters, 5-vinyl-2-pyrrolidone, and 4-hydroxy-cyclopent-2-enone;

[0073] The acrylic acid ester substance is butyl acrylate;

[0074] The mass ratio of the acrylic acid ester substance, 5-vinyl-2-pyrrolidone, and 4-hydroxy-cyclopent-2-enone is 130:0.8:0.9;

[0075] The seed cross-linking agent is triallyl isocyanurate;

[0076] The emulsifier is sodium lauryl sulfate;

[0077] The initiator is potassium persulfate;

[0078] The mass ratio of the deionized water, seed monomer mixture, emulsifier, seed crosslinking agent, and initiator is 130:40:5:7:0.6;

[0079] Said adding of sodium bicarbonate to adjust the pH value to 9;

[0080] The stirring emulsification has a stirring rate of 1300 rpm;

[0081] The reaction temperature is 75°C;

[0082] The isothermal reaction had a reaction time of 0.8 h.

[0083] Step 2: Prepare the kernel

[0084] The core monomer mixture, deionized water, and emulsifier are added to an emulsifier, and stirred under nitrogen protection to form a uniform and stable emulsion to obtain a core monomer emulsion. Subsequently, the core monomer emulsion, initiator, and core cross-linking agent are added to the seed emulsion, and the temperature is raised and kept constant to the reaction temperature. After the constant temperature reaction is completed, the core emulsion is obtained;

[0085] The core monomer mixture is prepared by mixing acrylic acid esters, 5-vinyl-2-pyrrolidone, and 4-hydroxy-cyclopent-2-enone;

[0086] The acrylic acid ester substance is butyl acrylate;

[0087] The mass ratio of the acrylic acid ester substance, 5-vinyl-2-pyrrolidone, and 4-hydroxy-cyclopent-2-enone is 200:0.8:0.9;

[0088] The core cross-linking agent is triallyl isocyanurate;

[0089] The emulsifier is sodium lauryl sulfate;

[0090] The initiator is potassium persulfate;

[0091] The mass ratio of the core monomer mixture, deionized water, and emulsifier is 40:120:7;

[0092] The mass ratio of the core monomer emulsion, initiator, core crosslinking agent, and seed emulsion is 140:1:6:40;

[0093] The reaction temperature is 75°C;

[0094] The constant temperature reaction has a reaction time of 4 hours.

[0095] Step 3: Prepare the transition layer

[0096] Adding the transition layer monomer mixture, deionized water, and emulsifier into an emulsifying kettle, stirring and emulsifying under nitrogen protection to form a uniform and stable emulsion to obtain a transition layer monomer emulsion, then adding the transition layer monomer emulsion, initiator, and transition layer crosslinker to the core emulsion, heating and maintaining the temperature to the reaction temperature, and obtaining a transition layer emulsion after the isothermal reaction is completed;

[0097] The transition layer monomer mixture is prepared by mixing butyl acrylate and styrene;

[0098] The mass ratio of butyl acrylate to styrene is 130:75;

[0099] The emulsifier is sodium lauryl sulfate;

[0100] The initiator is potassium persulfate;

[0101] The mass ratio of the transition layer monomer mixture, deionized water, and emulsifier is 60:140:7;

[0102] The mass ratio of the transition layer monomer emulsion, initiator, transition layer crosslinker, and core emulsion is 50:0.5:7:180;

[0103] The transition layer crosslinking agent is bisphenol A dimethacrylate;

[0104] The reaction temperature is 75°C;

[0105] The isothermal reaction had a reaction time of 1.4 h.

[0106] Step 4: Prepare the shell

[0107] The shell monomer mixture, deionized water, and emulsifier are added to an emulsifier, and stirred under nitrogen protection to form a uniform and stable emulsion to obtain a shell monomer emulsion. Subsequently, the shell monomer emulsion, initiator, and shell crosslinker are added to the transition layer emulsion, and the temperature is increased and kept constant to the reaction temperature. After the constant temperature reaction is completed, the core-shell structure ACR emulsion is obtained;

[0108] The shell monomer mixture is prepared by mixing styrene, methyl methacrylate, acrylic acid derivatives, fumaramide, and acryloyl glycinamide;

[0109] The acrylic acid derivative is methacrylic acid;

[0110] The emulsifier is sodium lauryl sulfate;

[0111] The mass ratio of styrene, methyl methacrylate, acrylic acid derivative, fumaramide and acryloyl glycinamide is 130:30:7:0.6:0.4;

[0112] The mass ratio of the shell monomer mixture, deionized water, and emulsifier is 70:180:8;

[0113] The mass ratio of the shell monomer emulsion, initiator, shell crosslinking agent, and transition layer emulsion is 70:0.5:6:230;

[0114] The initiator is potassium persulfate;

[0115] The shell cross-linking agent is triallyl isocyanurate;

[0116] The reaction temperature is 75°C;

[0117] The constant temperature reaction has a reaction time of 2 hours.

[0118] Step 5: Spray drying

[0119] The core-shell structured ACR emulsion was fed into the centrifugal spray drying system by a feed pump for spray drying. The inlet temperature of the drying system was controlled at 163°C, the outlet temperature at 63°C, and the drying air volume was controlled at 48m 3 / min, and after drying, a powdery impact-resistant ACR additive for transparent PVC products is obtained.

[0120] Example 2: Preparation method of impact-resistant ACR additive for transparent PVC products

[0121] Step 1: Prepare seed emulsion

[0122] Deionized water, seed monomer mixture, and emulsifier are added to the reactor, and stirred and emulsified under nitrogen protection. Sodium bicarbonate is added to adjust the pH value. After stirring and emulsification into a uniform and stable emulsion, a seed crosslinker is added, and the temperature is raised and kept constant to the reaction temperature. Then, an initiator is added and the reaction is continued at a constant temperature. After the reaction is completed, a seed emulsion is obtained;

[0123] The seed monomer mixture is formed by mixing a mixture of an organosilicon monomer and an acrylic ester substance, 5-vinyl-2-pyrrolidone, and 4-hydroxy-cyclopent-2-enone;

[0124] The mass ratio of the silicone monomer to the acrylic ester substance is 1:1;

[0125] The organosilicon monomer is a mixture of methacryloxypropyltrimethoxysilane and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane in a mass ratio of 1:1;

[0126] The acrylic acid ester substance is isooctyl acrylate;

[0127] The mass ratio of the mixture of the organosilicon monomer and the acrylic ester substance, 5-vinyl-2-pyrrolidone, and 4-hydroxy-cyclopent-2-enone is 90:0.1:0.1;

[0128] The seed crosslinking agent is 1,3-diallyl-2-thiourea;

[0129] The emulsifier is sodium dodecylbenzenesulfonate;

[0130] The initiator is ammonium persulfate;

[0131] The mass ratio of the deionized water, seed monomer mixture, emulsifier, seed crosslinking agent, and initiator is 90:20:2:4:0.3;

[0132] Sodium bicarbonate was added to adjust the pH value to 8.5;

[0133] The stirring emulsification has a stirring rate of 800 rpm;

[0134] The reaction temperature is 65°C;

[0135] The reaction time of the isothermal reaction is 0.5 h.

[0136] Step 2: Prepare the kernel

[0137] The core monomer mixture, deionized water, and emulsifier are added to an emulsifier, and stirred under nitrogen protection to form a uniform and stable emulsion to obtain a core monomer emulsion. Subsequently, the core monomer emulsion, initiator, and core cross-linking agent are added to the seed emulsion, and the temperature is raised and kept constant to the reaction temperature. After the constant temperature reaction is completed, the core emulsion is obtained;

[0138] The core monomer mixture is formed by mixing a mixture of an organic silicon monomer and an acrylic acid ester substance, 5-vinyl-2-pyrrolidone, and 4-hydroxy-cyclopent-2-enone;

[0139] The mass ratio of the silicone monomer to the acrylic ester substance is 1:1;

[0140] The organosilicon monomer is a mixture of methacryloxypropyltrimethoxysilane and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane in a mass ratio of 1:1;

[0141] The acrylic acid ester substance is isooctyl acrylate;

[0142] The mass ratio of the mixture of the organosilicon monomer and the acrylic ester substance, 5-vinyl-2-pyrrolidone, and 4-hydroxy-cyclopent-2-enone is 100:0.2:0.3;

[0143] The core cross-linking agent is 1,3-diallyl-2-thiourea;

[0144] The emulsifier is sodium dodecylbenzenesulfonate;

[0145] The initiator is ammonium persulfate;

[0146] The mass ratio of the core monomer mixture, deionized water, and emulsifier is 20:90:2;

[0147] The mass ratio of the core monomer emulsion, initiator, core crosslinking agent, and seed emulsion is 80:0.3:5:15;

[0148] The reaction temperature is 65°C;

[0149] The constant temperature reaction has a reaction time of 3 hours.

[0150] Step 3: Prepare the transition layer

[0151] Adding the transition layer monomer mixture, deionized water, and emulsifier into an emulsifying kettle, stirring and emulsifying under nitrogen protection to form a uniform and stable emulsion to obtain a transition layer monomer emulsion, then adding the transition layer monomer emulsion, initiator, and transition layer crosslinker to the core emulsion, heating and maintaining the temperature to the reaction temperature, and obtaining a transition layer emulsion after the isothermal reaction is completed;

[0152] The transition layer monomer mixture is prepared by mixing butyl acrylate and styrene;

[0153] The mass ratio of butyl acrylate to styrene is 60:25;

[0154] The emulsifier is sodium dodecylbenzenesulfonate;

[0155] The initiator is ammonium persulfate;

[0156] The mass ratio of the transition layer monomer mixture, deionized water, and emulsifier is 30:100:3;

[0157] The mass ratio of the transition layer monomer emulsion, initiator, transition layer crosslinker, and core emulsion is 20:0.1:1:125;

[0158] The transition layer crosslinking agent is bisphenol A dimethacrylate;

[0159] The reaction temperature is 65°C;

[0160] The reaction time of the isothermal reaction is 1 h.

[0161] Step 4: Prepare the shell

[0162] The shell monomer mixture, deionized water, and emulsifier are added to an emulsifier, and stirred under nitrogen protection to form a uniform and stable emulsion to obtain a shell monomer emulsion. Subsequently, the shell monomer emulsion, initiator, and shell crosslinker are added to the transition layer emulsion, and the temperature is increased and kept constant to the reaction temperature. After the constant temperature reaction is completed, the core-shell structure ACR emulsion is obtained;

[0163] The shell monomer mixture is prepared by mixing styrene, methyl methacrylate, acrylic acid derivatives, fumaramide, and acryloyl glycinamide;

[0164] The acrylic acid derivative is acrylic acid;

[0165] The emulsifier is sodium dodecylbenzenesulfonate;

[0166] The mass ratio of styrene, methyl methacrylate, acrylic acid derivative, fumaramide and acryloyl glycinamide is 80:25:3:0.3:0.1;

[0167] The mass ratio of the shell monomer mixture, deionized water, and emulsifier is 40:130:4;

[0168] The mass ratio of the shell monomer emulsion, initiator, shell crosslinking agent, and transition layer emulsion is 40:0.2:1:145;

[0169] The initiator is ammonium persulfate;

[0170] The shell crosslinking agent is 1,3-diallyl-2-thiourea;

[0171] The reaction temperature is 65°C;

[0172] The isothermal reaction has a reaction time of 1.5 h.

[0173] Step 5: Spray drying

[0174] The core-shell structured ACR emulsion was fed into the centrifugal spray drying system by a feed pump for spray drying. The inlet temperature of the drying system was controlled at 160°C, the outlet temperature at 60°C, and the drying air volume was controlled at 46m3. 3 / min, and after drying, a powdery impact-resistant ACR additive for transparent PVC products is obtained.

[0175] Example 3: Preparation method of impact-resistant ACR additive for transparent PVC products

[0176] Step 1: Prepare seed emulsion

[0177] Deionized water, seed monomer mixture, and emulsifier are added to the reactor, and stirred and emulsified under nitrogen protection. Sodium bicarbonate is added to adjust the pH value. After stirring and emulsification into a uniform and stable emulsion, a seed crosslinker is added, and the temperature is raised and kept constant to the reaction temperature. Then, an initiator is added and the reaction is continued at a constant temperature. After the reaction is completed, a seed emulsion is obtained;

[0178] The seed monomer mixture is prepared by mixing organosilicon monomer, 5-vinyl-2-pyrrolidone and 4-hydroxy-cyclopent-2-enone;

[0179] The organosilicon monomer is vinyl triacetoxysilane;

[0180] The mass ratio of the organosilicon monomer, 5-vinyl-2-pyrrolidone, and 4-hydroxy-cyclopent-2-enone is 220:2:1.5;

[0181] The seed cross-linking agent is diallyl isopropylamine;

[0182] The emulsifier is nonylphenol polyoxyethylene ether;

[0183] The initiator is potassium persulfate;

[0184] The mass ratio of the deionized water, seed monomer mixture, emulsifier, seed crosslinking agent, and initiator is 160:50:8:9:1;

[0185] Said adding of sodium bicarbonate to adjust the pH value to 10;

[0186] The stirring emulsification has a stirring rate of 1800 rpm;

[0187] The reaction temperature is 85°C;

[0188] The reaction time of the isothermal reaction is 1 h.

[0189] Step 2: Prepare the kernel

[0190] The core monomer mixture, deionized water, and emulsifier are added to an emulsifier, and stirred under nitrogen protection to form a uniform and stable emulsion to obtain a core monomer emulsion. Subsequently, the core monomer emulsion, initiator, and core cross-linking agent are added to the seed emulsion, and the temperature is raised and kept constant to the reaction temperature. After the constant temperature reaction is completed, the core emulsion is obtained;

[0191] The core monomer mixture is prepared by mixing organosilicon monomer, 5-vinyl-2-pyrrolidone and 4-hydroxy-cyclopent-2-enone;

[0192] The organosilicon monomer is vinyl triacetoxysilane;

[0193] The mass ratio of the organosilicon monomer, 5-vinyl-2-pyrrolidone, and 4-hydroxy-cyclopent-2-enone is 250:2:1.5;

[0194] The core cross-linking agent is N,N-dimethylallylamine;

[0195] The emulsifier is nonylphenol polyoxyethylene ether;

[0196] The initiator is potassium persulfate;

[0197] The mass ratio of the core monomer mixture, deionized water, and emulsifier is 50:160:8;

[0198] The mass ratio of the core monomer emulsion, initiator, core crosslinking agent, and seed emulsion is 200:1.2:12:60;

[0199] The reaction temperature is 85°C;

[0200] The constant temperature reaction has a reaction time of 6 hours.

[0201] Step 3: Prepare the transition layer

[0202] Adding the transition layer monomer mixture, deionized water, and emulsifier into an emulsifying kettle, stirring and emulsifying under nitrogen protection to form a uniform and stable emulsion to obtain a transition layer monomer emulsion, then adding the transition layer monomer emulsion, initiator, and transition layer crosslinker to the core emulsion, heating and maintaining the temperature to the reaction temperature, and obtaining a transition layer emulsion after the isothermal reaction is completed;

[0203] The transition layer monomer mixture is prepared by mixing butyl acrylate and styrene;

[0204] The mass ratio of butyl acrylate to styrene is 170:100;

[0205] The emulsifier is nonylphenol polyoxyethylene ether;

[0206] The initiator is potassium persulfate;

[0207] The mass ratio of the transition layer monomer mixture, deionized water, and emulsifier is 70:190:9;

[0208] The mass ratio of the transition layer monomer emulsion, initiator, transition layer crosslinker, and core emulsion is 80:0.6:10:260;

[0209] The transition layer crosslinking agent is bisphenol A dimethacrylate;

[0210] The reaction temperature is 85°C;

[0211] The constant temperature reaction has a reaction time of 2 hours.

[0212] Step 4: Prepare the shell

[0213] The shell monomer mixture, deionized water, and emulsifier are added to an emulsifier, and stirred under nitrogen protection to form a uniform and stable emulsion to obtain a shell monomer emulsion. Subsequently, the shell monomer emulsion, initiator, and shell crosslinker are added to the transition layer emulsion, and the temperature is increased and kept constant to the reaction temperature. After the constant temperature reaction is completed, the core-shell structure ACR emulsion is obtained;

[0214] The shell monomer mixture is prepared by mixing styrene, methyl methacrylate, acrylic acid derivatives, fumaramide, and acryloyl glycinamide;

[0215] The acrylic acid derivative is hydroxyethyl acrylate;

[0216] The emulsifier is nonylphenol polyoxyethylene ether;

[0217] The mass ratio of styrene, methyl methacrylate, acrylic acid derivative, fumaramide and acryloyl glycinamide is 180:45:10:1:0.6;

[0218] The mass ratio of the shell monomer mixture, deionized water, and emulsifier is 100:210:9;

[0219] The mass ratio of the shell monomer emulsion, initiator, shell crosslinking agent, and transition layer emulsion is 100:0.8:8:250;

[0220] The initiator is potassium persulfate;

[0221] The shell cross-linking agent is N,N-dimethylallylamine;

[0222] The reaction temperature is 85°C;

[0223] The constant temperature reaction has a reaction time of 3 hours.

[0224] Step 5: Spray drying

[0225] The core-shell structured ACR emulsion was fed into the centrifugal spray drying system by a feed pump for spray drying. The inlet temperature of the drying system was controlled at 165°C, the outlet temperature at 65°C, and the drying air volume was controlled at 55m 3 / min, and after drying, a powdery impact-resistant ACR additive for transparent PVC products is obtained.

[0226] Example 4: Preparation method of impact-resistant ACR additive for transparent PVC products

[0227] Step 1: Prepare seed emulsion

[0228] The organosilicon monomer is diallyltetramethyldisiloxane;

[0229] The seed crosslinking agent is methyl triallylsilane;

[0230] The emulsifier is sodium dodecyl diphenyl ether disulfonate;

[0231] Other operations are the same as in Example 1.

[0232] Step 2: Prepare the kernel

[0233] The organosilicon monomer is diallyltetramethyldisiloxane;

[0234] The core cross-linking agent is diallyl isopropylamine;

[0235] The emulsifier is sodium dodecyl diphenyl ether disulfonate;

[0236] Other operations are the same as in Example 1.

[0237] Step 3: Prepare the transition layer

[0238] The emulsifier is sodium dodecyl diphenyl ether disulfonate;

[0239] Other operations are the same as in Example 1.

[0240] Step 4: Prepare the shell

[0241] The emulsifier is sodium dodecyl diphenyl ether disulfonate;

[0242] The shell cross-linking agent is diallyl isopropylamine;

[0243] Other operations are the same as in Example 1.

[0244] The operation of step 5 is the same as that of embodiment 1.

[0245] Example 5: Preparation method of impact-resistant ACR additive for transparent PVC products

[0246] Step 1: Prepare seed emulsion

[0247] The organosilicon monomer is acryloxytriisopropylsilane;

[0248] The seed crosslinking agent is methyl triallylsilane;

[0249] The emulsifier is sodium fatty alcohol polyoxyethylene ether sulfate;

[0250] Other operations are the same as in Example 1.

[0251] Step 2: Prepare the kernel

[0252] The organosilicon monomer is acryloxytriisopropylsilane;

[0253] The core crosslinking agent is methyl triallylsilane;

[0254] The emulsifier is sodium fatty alcohol polyoxyethylene ether sulfate;

[0255] Other operations are the same as in Example 1.

[0256] Step 3: Prepare the transition layer

[0257] The emulsifier is sodium fatty alcohol polyoxyethylene ether sulfate;

[0258] Other operations are the same as in Example 1.

[0259] Step 4: Prepare the shell

[0260] The emulsifier is sodium fatty alcohol polyoxyethylene ether sulfate;

[0261] The shell crosslinking agent is methyl triallylsilane;

[0262] Other operations are the same as in Example 1.

[0263] The operation of step 5 is the same as that of embodiment 1.

[0264] Example 6: Preparation method of impact-resistant ACR additive for transparent PVC products

[0265] Step 1: Prepare seed emulsion

[0266] The organosilicon monomer is vinyltriethoxysilane;

[0267] The seed crosslinking agent is diallyltetramethyldisiloxane;

[0268] The emulsifier is dodecylphenol polyoxyethylene ether;

[0269] Other operations are the same as in Example 1.

[0270] Step 2: Prepare the kernel

[0271] The organosilicon monomer is vinyltriethoxysilane;

[0272] The core crosslinking agent is diallyltetramethyldisiloxane;

[0273] The emulsifier is dodecylphenol polyoxyethylene ether;

[0274] Other operations are the same as in Example 1.

[0275] Step 3: Prepare the transition layer

[0276] The emulsifier is dodecylphenol polyoxyethylene ether;

[0277] Other operations are the same as in Example 1.

[0278] Step 4: Prepare the shell

[0279] The emulsifier is dodecylphenol polyoxyethylene ether;

[0280] The shell crosslinking agent is diallyltetramethyldisiloxane;

[0281] Other operations are the same as in Example 1.

[0282] The operation of step 5 is the same as that of embodiment 1.

[0283] Example 7: Preparation method of impact-resistant ACR additive for transparent PVC products

[0284] Step 1: Prepare seed emulsion

[0285] The organosilicon monomer is methacryloxymethyltriethoxysilane;

[0286] The seed cross-linking agent is diallylamine;

[0287] Other operations are the same as in Example 1.

[0288] Step 2: Prepare the kernel

[0289] The organosilicon monomer is methacryloxymethyltriethoxysilane;

[0290] The core cross-linking agent is diallylamine;

[0291] Other operations are the same as in Example 1.

[0292] The operation of step 3 is the same as that of embodiment 1.

[0293] Step 4: Prepare the shell

[0294] The shell cross-linking agent is diallylamine;

[0295] Other operations are the same as in Example 1.

[0296] The operation of step 5 is the same as that of embodiment 1.

[0297] Example 8: Preparation method of impact-resistant ACR additive for transparent PVC products

[0298] Step 1: Prepare seed emulsion

[0299] The organosilicon monomer is vinyltrimethoxysilane;

[0300] The seed cross-linking agent is allyl acrylate;

[0301] Other operations are the same as in Example 1.

[0302] Step 2: Prepare the kernel

[0303] The organosilicon monomer is vinyltrimethoxysilane;

[0304] The core cross-linking agent is allyl acrylate;

[0305] Other operations are the same as in Example 1.

[0306] The operation of step 3 is the same as that of embodiment 1.

[0307] Step 4: Prepare the shell

[0308] The shell cross-linking agent is allyl acrylate;

[0309] Other operations are the same as in Example 1.

[0310] The operation of step 5 is the same as that of embodiment 1.

[0311] Example 9: Preparation method of impact-resistant ACR additive for transparent PVC products

[0312] Step 1: Prepare seed emulsion

[0313] The organosilicon monomer is vinyl triisopropoxy silane;

[0314] The seed cross-linking agent is ethylene glycol diallyl ether;

[0315] Other operations are the same as in Example 1.

[0316] Step 2: Prepare the kernel

[0317] The organosilicon monomer is vinyl triisopropoxy silane;

[0318] The core cross-linking agent is ethylene glycol diallyl ether;

[0319] Other operations are the same as in Example 1.

[0320] The operation of step 3 is the same as that of embodiment 1.

[0321] Step 4: Prepare the shell

[0322] The shell cross-linking agent is ethylene glycol diallyl ether;

[0323] Other operations are the same as in Example 1.

[0324] The operation of step 5 is the same as that of embodiment 1.

[0325] Example 10: Preparation method of impact-resistant ACR additive for transparent PVC products

[0326] Step 1: Prepare seed emulsion

[0327] The organosilicon monomer is methylvinyldimethoxysilane;

[0328] The seed cross-linking agent is allyl oxalate;

[0329] Other operations are the same as in Example 1.

[0330] Step 2: Prepare the kernel

[0331] The organosilicon monomer is methylvinyldimethoxysilane;

[0332] The core cross-linking agent is allyl oxalate;

[0333] Other operations are the same as in Example 1.

[0334] The operation of step 3 is the same as that of embodiment 1.

[0335] Step 4: Prepare the shell

[0336] The shell cross-linking agent is allyl oxalate;

[0337] Other operations are the same as in Example 1.

[0338] The operation of step 5 is the same as that of embodiment 1.

[0339] Example 11: Preparation method of impact-resistant ACR additive for transparent PVC products

[0340] Step 1: Prepare seed emulsion

[0341] The seed cross-linking agent is diallyl maleate;

[0342] Other operations are the same as in Example 1.

[0343] Step 2: Prepare the kernel

[0344] The core cross-linking agent is diallyl maleate;

[0345] Other operations are the same as in Example 1.

[0346] The operation of step 3 is the same as that of embodiment 1.

[0347] Step 4: Prepare the shell

[0348] The shell cross-linking agent is diallyl maleate;

[0349] Other operations are the same as in Example 1.

[0350] The operation of step 5 is the same as that of embodiment 1.

[0351] Example 12: Preparation method of impact-resistant ACR additive for transparent PVC products

[0352] Step 1: Prepare seed emulsion

[0353] The seed cross-linking agent is 1,3,5-triallyl cyanurate;

[0354] Other operations are the same as in Example 1.

[0355] Step 2: Prepare the kernel

[0356] The core cross-linking agent is 1,3,5-triallyl cyanurate;

[0357] Other operations are the same as in Example 1.

[0358] The operation of step 3 is the same as that of embodiment 1.

[0359] Step 4: Prepare the shell

[0360] The shell cross-linking agent is 1,3,5-triallyl cyanurate;

[0361] Other operations are the same as in Example 1.

[0362] The operation of step 5 is the same as that of embodiment 1.

[0363] Example 13: Preparation method of impact-resistant ACR additive for transparent PVC products

[0364] Step 1: Prepare seed emulsion

[0365] The seed cross-linking agent is divinylbenzene;

[0366] Other operations are the same as in Example 1.

[0367] Step 2: Prepare the kernel

[0368] The core cross-linking agent is divinylbenzene;

[0369] Other operations are the same as in Example 1.

[0370] The operation of step 3 is the same as that of embodiment 1.

[0371] Step 4: Prepare the shell

[0372] The shell cross-linking agent is divinylbenzene;

[0373] Other operations are the same as in Example 1.

[0374] The operation of step 5 is the same as that of embodiment 1.

[0375] Example 14: Preparation method of impact-resistant ACR additive for transparent PVC products

[0376] Step 1: Prepare seed emulsion

[0377] The seed cross-linking agent is vinylidene chloride;

[0378] Other operations are the same as in Example 1.

[0379] Step 2: Prepare the kernel

[0380] The core cross-linking agent is vinylidene chloride;

[0381] Other operations are the same as in Example 1.

[0382] The operation of step 3 is the same as that of embodiment 1.

[0383] Step 4: Prepare the shell

[0384] The shell cross-linking agent is vinylidene chloride;

[0385] Other operations are the same as in Example 1.

[0386] The operation of step 5 is the same as that of embodiment 1.

[0387] Example 15: Preparation method of impact-resistant ACR additive for transparent PVC products

[0388] Step 1: Prepare seed emulsion

[0389] The seed cross-linking agent is glycidyl methacrylate;

[0390] Other operations are the same as in Example 1.

[0391] Step 2: Prepare the kernel

[0392] The core cross-linking agent is glycidyl methacrylate;

[0393] Other operations are the same as in Example 1.

[0394] The operation of step 3 is the same as that of embodiment 1.

[0395] Step 4: Prepare the shell

[0396] The shell cross-linking agent is glycidyl methacrylate;

[0397] Other operations are the same as in Example 1.

[0398] The operation of step 5 is the same as that of embodiment 1.

[0399] Example 16: Preparation method of impact-resistant ACR additive for transparent PVC products

[0400] Step 1: Prepare seed emulsion

[0401] The seed cross-linking agent is allyl phthalate;

[0402] Other operations are the same as in Example 1.

[0403] Step 2: Prepare the kernel

[0404] The core cross-linking agent is allyl phthalate;

[0405] Other operations are the same as in Example 1.

[0406] The operation of step 3 is the same as that of embodiment 1.

[0407] Step 4: Prepare the shell

[0408] The shell cross-linking agent is allyl phthalate;

[0409] Other operations are the same as in Example 1.

[0410] The operation of step 5 is the same as that of embodiment 1.

[0411] Comparative Example 1: Based on Example 1, in step 1, preparing the seed emulsion and step 2, preparing the core, neither 5-vinyl-2-pyrrolidone nor 4-hydroxy-cyclopent-2-enone was added to the seed monomer mixture nor the core monomer mixture. Instead, 5-vinyl-2-pyrrolidone and 4-hydroxy-cyclopent-2-enone were replaced with butyl acrylate in equal amounts. The specific operation was as follows:

[0412] Step 1: Prepare seed emulsion

[0413] The seed monomer mixture is butyl acrylate, and the other operations are the same as in Example 1;

[0414] Step 2: Prepare the kernel

[0415] The core monomer mixture is butyl acrylate, and the other operations are the same as in Example 1;

[0416] The operations of steps 3, 4, and 5 are the same as those in Example 1.

[0417] Comparative Example 2: Based on Example 1, step 3, preparing the transition layer, is omitted. The specific operations are as follows:

[0418] The operations of steps 1 and 2 are the same as those in Example 1;

[0419] Step 3, preparing the transition layer, is not performed;

[0420] Step 4: Prepare the shell

[0421] The shell monomer mixture, deionized water, and emulsifier are added to an emulsifier, and stirred under nitrogen protection to form a uniform and stable emulsion to obtain a shell monomer emulsion. Then, the shell monomer emulsion, initiator, and shell crosslinker are added to the core emulsion, and the temperature is increased and kept constant to the reaction temperature. After the isothermal reaction is completed, the core-shell structure ACR emulsion is obtained;

[0422] The shell monomer mixture is prepared by mixing styrene, methyl methacrylate, acrylic acid derivatives, fumaramide, and acryloyl glycinamide;

[0423] The acrylic acid derivative is methacrylic acid;

[0424] The emulsifier is sodium lauryl sulfate;

[0425] The mass ratio of styrene, methyl methacrylate, acrylic acid derivative, fumaramide and acryloyl glycinamide is 130:30:7:0.6:0.4;

[0426] The mass ratio of the shell monomer mixture, deionized water, and emulsifier is 70:180:8;

[0427] The mass ratio of the shell monomer emulsion, initiator, shell crosslinker, and core emulsion is 70:0.5:6:230;

[0428] The initiator is potassium persulfate;

[0429] The shell cross-linking agent is triallyl isocyanurate;

[0430] The reaction temperature is 75°C;

[0431] The isothermal reaction has a reaction time of 2 hours;

[0432] The operation of step 5 is the same as that of embodiment 1.

[0433] Comparative Example 3: Based on Example 1, in step 4, preparing the shell, fumaramide and acryloyl glycinamide were not added to the shell monomer mixture, and fumaramide and acryloyl glycinamide were replaced with styrene in equal amounts. The specific operation was as follows:

[0434] The operations of steps 1, 2, and 3 are the same as those in Example 1;

[0435] Step 4: Prepare the shell

[0436] The shell monomer mixture is prepared by mixing styrene, methyl methacrylate and acrylic acid derivatives;

[0437] The mass ratio of styrene, methyl methacrylate and acrylic acid derivative is 131:30:7, and the other operations are the same as in Example 1;

[0438] The operation of step 5 is the same as that of embodiment 1.

[0439] Performance testing:

[0440] The impact-resistant ACR additives for transparent PVC products prepared in Examples 1-16 and Comparative Examples 1-3 were formulated in parts by weight as follows: 100 parts of polyvinyl chloride, 4 parts of ACR additive, 3 parts of calcium zinc stabilizer, 4 parts of calcium carbonate, 2 parts of titanium dioxide, and 0.8 parts of polyethylene wax. The mixture was put into a mixer at a temperature of 110° C., a mixing speed of 500 rpm, and a high-speed mixing time of 20 min. After mixing, the mixture was cooled to room temperature to obtain a masterbatch. The masterbatch was then placed in a tablet press and pressed into a 3 mm thick sheet at a set temperature of 180° C. After the sheet was cooled to room temperature, the notched impact strength was tested according to GB / T 1043.1-2008, and the transmittance and haze were tested according to GB / T 2410-2008. The results are shown in Table 1:

[0441] Table 1

[0442] From the data in Table 1, we can see that the notched impact strength of Examples 1-12 at 23°C is all 17 kJ / m 2 Above, the notched impact strength at -10℃ is 11.7 kJ / m 2The above results show that the transmittance is above 94% and the haze is below 3.1%, which shows that the impact-resistant ACR additive for transparent PVC products obtained by the present invention has the advantages of high transmittance and good impact resistance at low temperatures. In Comparative Example 1, neither 5-vinyl-2-pyrrolidone nor 4-hydroxy-cyclopent-2-enone is added to the seed monomer mixture and the core monomer mixture. The notched impact strength of Comparative Example 1 at 23°C and -10°C is greatly reduced, while the transmittance and haze do not change. This shows that 5-vinyl-2-pyrrolidone and 4-hydroxy-cyclopent-2-enone are very important for improving the impact resistance of the ACR additive, which may be due to the fact that 5-vinyl-2-pyrrolidone The ketone carbonyl contained in alkenyl-2-pyrrolidone and 4-hydroxy-cyclopent-2-enone, and the dipole moment effect of the carbon-oxygen double bond structure thereof can enhance the polymerization density of the ACR additive seed and the core, making it easier for the ACR additive to buffer the stress concentration caused by the silver shear band effect when toughening PVC, thereby significantly improving the impact resistance of the PVC sheet; in Comparative Example 2, no transition layer was prepared between the core and the shell layer. The notched impact strength of Comparative Example 2 at 23°C and -10°C decreased significantly, especially the notched impact strength at -10°C, which decreased by more than 50%, while the transmittance and haze did not change, which indicates that The transition layer between the core and the shell can greatly improve the impact resistance of the ACR additive at low temperatures. This may be because the core of the ACR additive is mainly a rubber phase polymer, while the physical properties of the shell are mainly plastic properties. The transition layer can provide a certain cross-linked network buffer structure between the core of the rubber phase polymer and the shell of plastic properties, making it easier to maintain good overall consistency at low temperatures, thereby improving the toughening performance of the ACR additive on PVC materials at low temperatures; in Comparative Example 3, no fumaramide and acrylamide are added to the shell monomer mixture. The notched impact strength of Comparative Example 3 at 23°C and -10°C is significantly reduced, and the penetration The light index dropped significantly, while the haze increased significantly. This shows that the two monomers, fumaramide and acrylyl glycinamide, used in the shell polymer play a vital role in improving the light transmittance of the ACR additive-modified PVC. This may be because the amino groups contained in the two monomers, fumaramide and acrylyl glycinamide, can greatly improve the compatibility of the ACR additive with the PVC matrix material, and can reduce the interface effect between the ACR additive and PVC to a very low level, thereby ensuring the high light transmittance of the thick PVC sheet. In addition, the reduction of this interface effect will also promote the toughening effect of the ACR additive on the PVC substrate, which is ultimately manifested as an improvement in the notched impact strength.

[0443] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for preparing an impact-resistant ACR additive for transparent PVC products, characterized in that: The preparation method comprises five steps: preparing seed emulsion, preparing core, preparing transition layer, preparing shell, and spray drying; The seed emulsion is prepared by adding deionized water, a seed monomer mixture, and an emulsifier into a reactor, stirring and emulsifying under nitrogen protection, and adding sodium bicarbonate to adjust the pH value. After stirring and emulsifying into a uniform and stable emulsion, a seed crosslinking agent is added, the temperature is raised and kept constant at the reaction temperature, and then an initiator is added. After the constant temperature reaction is completed, the seed emulsion is obtained; The core is prepared by mixing a core monomer mixture, deionized water, and an emulsifier, emulsifying to obtain a core monomer emulsion, then adding the core monomer emulsion, an initiator, and a core cross-linking agent to the seed emulsion, heating and maintaining the temperature to a reaction temperature, and obtaining a core emulsion after the isothermal reaction is completed; The seed monomer mixture and the core monomer mixture are both prepared by mixing one or two of an organosilicon monomer or an acrylate substance in any mass ratio, 5-vinyl-2-pyrrolidone, and 4-hydroxy-cyclopent-2-enone; The transition layer is prepared by adding a transition layer monomer mixture, deionized water, and an emulsifier into an emulsifying kettle, stirring and emulsifying the mixture under nitrogen protection to form a uniform and stable emulsion to obtain a transition layer monomer emulsion, then adding the transition layer monomer emulsion, an initiator, and a transition layer crosslinking agent to the core emulsion, heating the mixture to a reaction temperature, and maintaining the temperature constant to obtain a transition layer emulsion after the constant temperature reaction is completed; The transition layer monomer mixture is prepared by mixing butyl acrylate and styrene; The transition layer crosslinking agent is bisphenol A dimethacrylate; The shell is prepared by adding a shell monomer mixture, deionized water, and an emulsifier into an emulsifier, stirring and emulsifying the mixture into a uniform and stable emulsion under nitrogen protection to obtain a shell monomer emulsion, then adding the shell monomer emulsion, an initiator, and a shell cross-linking agent into the transition layer emulsion, heating and maintaining the temperature to the reaction temperature, and obtaining a core-shell structured ACR emulsion after the isothermal reaction is completed; The shell monomer mixed liquid is prepared by mixing styrene, methyl methacrylate, acrylic acid derivatives, fumaramide and acryloyl glycinamide.

2. The method for preparing an impact-resistant ACR additive for transparent PVC products according to claim 1, characterized in that: The spray drying process uses a pump to deliver the core-shell structured ACR emulsion into a centrifugal spray drying system for spray drying. The inlet temperature of the drying system is controlled between 160 and 165°C, the outlet temperature is controlled between 60 and 65°C, and the drying air volume is controlled between 46 and 55m 3 / min, and after drying, a powdery impact-resistant ACR additive for transparent PVC products is obtained.

3. The method for preparing the impact-resistant ACR additive for transparent PVC products according to claim 1, characterized in that: The organosilicon monomer is one of 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, diallyltetramethyldisiloxane, acryloxytriisopropylsilane, vinyltriethoxysilane, methacryloxymethyltriethoxysilane, vinyltrimethoxysilane, vinyltriisopropoxysilane, and methylvinyldimethoxysilane; The acrylic acid ester substance is one of butyl acrylate and isooctyl acrylate or a mixture of the two in any mass ratio.

4. The method for preparing an impact-resistant ACR additive for transparent PVC products according to claim 1, characterized in that: The seed crosslinking agent is one or a mixture of two or more of triallyl isocyanurate, 1,3-diallyl-2-thiourea, N,N-dimethylallylamine, diallylisopropylamine, methyltriallylsilane, diallyltetramethyldisiloxane, diallylamine, allyl acrylate, ethylene glycol diallyl ether, allyl oxalate, diallyl maleate, 1,3,5-triallylcyanurate, divinylbenzene, and allyl phthalate in any mass ratio; The emulsifier is one of sodium lauryl sulfate, sodium dodecylbenzene sulfonate, nonylphenol polyoxyethylene ether, sodium dodecyl diphenyl ether disulfonate, sodium fatty alcohol polyoxyethylene ether sulfate, and dodecylphenol polyoxyethylene ether; The initiator is one of potassium persulfate and ammonium persulfate.

5. The method for preparing an impact-resistant ACR additive for transparent PVC products according to claim 1, characterized in that: The core crosslinking agent is one or a mixture of two or more of triallyl isocyanurate, 1,3-diallyl-2-thiourea, N,N-dimethylallylamine, diallylisopropylamine, methyltriallylsilane, diallyltetramethyldisiloxane, diallylamine, allyl acrylate, ethylene glycol diallyl ether, allyl oxalate, diallyl maleate, 1,3,5-triallylcyanurate, divinylbenzene, and allyl phthalate in any mass ratio.

6. The method for preparing the impact-resistant ACR additive for transparent PVC products according to claim 1, characterized in that: The acrylic acid derivative is one of methacrylic acid, acrylic acid, and hydroxyethyl acrylate.

7. The impact-resistant ACR additive for transparent PVC products prepared according to the preparation method of any one of claims 1 to 6, characterized in that: The impact-resistant ACR additive for transparent PVC products is pressed to obtain a sheet with a thickness of 3 mm, and its notched impact strength at 23° C. is 17.1-18.9 kJ / m 2 The notched impact strength at -10°C is 11.7~13.6 kJ / m 2 The transmittance is 94.6~96.3%, and the haze is 1.8~3.1%.

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