A graft copolymerized polyvinyl chloride and its preparation method

Abstract

The present invention discloses a graft copolymerized polyvinyl chloride and a preparation method thereof, belonging to the technical field of polymer polymerization and material preparation. The raw materials of the graft copolymerized polyvinyl chloride include seeds and vinyl chloride; wherein, the raw materials of the seeds include mixed monomers, or the raw materials of the seeds include a resin or an elastomer obtained by a polymerization reaction using mixed monomers as raw materials; the mixed monomers are obtained by mixing two or more of a substituted monoene containing a C n H 2n structure and a substituted diene containing a C n H (2n‑2) structure. The present invention adopts the method of first preparing seeds and then graft copolymerizing with vinyl chloride. By adjusting the feeding mode and reaction conditions, the prepared polyvinyl chloride resin has a tensile strength of 10-30 MPa and an elongation at break of 100-500% when no plasticizer is added. In subsequent production, polyvinyl chloride-based soft products can be prepared without adding a plasticizer.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer polymerization and material preparation, and specifically relates to a graft copolymerized polyvinyl chloride and a preparation method thereof. Background Art

[0002] The glass transition temperature of polyvinyl chloride resin is 80 - 90°C. To prepare polyvinyl chloride products with different application scenarios and a wide range of softness and hardness, such as polyvinyl chloride hoses, polyvinyl chloride medical catheters, polyvinyl chloride films, polyvinyl chloride sealing strips, polyvinyl chloride cable sheaths, etc., mainly by adding different amounts of plasticizers. The plasticizers are mainly phthalate small molecule substances. As the use time of these products prolongs, the plasticizers therein migrate and precipitate. These precipitates enter the human body and can cause abnormalities in the reproductive system, and even cause birth defects, cancer and other hazards. Therefore, plasticizers are currently under global control and restriction. At present, non-phthalate plasticizers, as substitutes for phthalate plasticizers, are also widely used in various plastic production and processing processes. Compared with phthalate plasticizers, non-phthalate plasticizers have lower toxicity, and their safety, processability, and stability can all meet the safety and environmental protection requirements of regulations such as the EU REACH regulation and the US CPSIA for plasticizer products. With the increase in the use range and amount of non-phthalate plasticizers, their compliance risks have gradually emerged. In the first half of 2022, in the notifications of the Rapid Alert System for Food and Feed (RASFF) of the European Union, there were 16 notifications of the migration risk of plasticizers, involving environmental protection plasticizers such as bis(2-ethylhexyl) phthalate (DEHP), bis(2-ethylhexyl) terephthalate (DOTP), epoxidized soybean oil (ESBO), dibutyl sebacate (DBS), bis(2-ethylhexyl) adipate (DEHA), tributyl 2-(vinyloxy)-1,2,3-propanetricarboxylate (ATBC), bisphenol F diglycidyl ether (BFDGE), etc. In addition, the migration and precipitation of plasticizers will cause the material to become brittle and lose its flexibility, thereby reducing the overall performance of the product.

[0003] Currently, to solve the problem of adding plasticizers to polyvinyl chloride resin, during vinyl chloride polymerization, internal plasticized polyvinyl chloride resin is prepared by adding all at once or dropwise adding a second monomer during the polymerization process. However, considering the copolymerization reactivity ratios of different monomers with vinyl chloride, the selectable second monomers are limited, and during the polymerization process, a mixture of vinyl chloride homopolymer and second monomer homopolymer is easily formed, thus a polyvinyl chloride with excellent physical properties, without adding plasticizers, and capable of preparing soft products cannot be prepared. Summary of the Invention

[0004] Aiming at the deficiencies of the above prior art, the present invention provides a graft copolymerized polyvinyl chloride and a preparation method thereof, which can obtain polyvinyl chloride with excellent physical properties. In subsequent production, polyvinyl chloride-based soft products can be prepared without adding plasticizers.

[0005] To achieve the above object, the specific technical solution of the present invention is as follows:

[0006] A graft copolymerized polyvinyl chloride, the raw materials of which include seeds and vinyl chloride; wherein, the raw materials of the seeds include mixed monomers; or, the raw materials of the seeds include a resin or an elastomer obtained by a polymerization reaction using mixed monomers as raw materials;

[0007] The mixed monomers are obtained by mixing two or more of a substituted monoene containing a C n H 2n structure and a substituted diene containing a C n H (2n-2) structure.

[0008] Preferably, the substituted monoene containing a C n H 2n structure includes but is not limited to ethylene, propylene, vinyl acetate, styrene; the substituted diene containing a C n H (2n-2) structure includes but is not limited to butadiene, octadiene, norbornene, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, ethyl acrylate, n-butyl acrylate.

[0009] Preferably, the preparation method of the seeds is one of the following three methods:

[0010] Method I: (1) Mix water, emulsifier I, catalyst, chelating agent, and reducing agent I evenly and heat to 40 - 90 °C; (2) Add the mixed monomers and react for 5 - 30 min; then add oxidizing agent I and react for 30 - 90 min; (3) Homogenize the monomers and emulsifier I and start dropping them into the reaction system simultaneously with oxidizing agent I, and react at 40 - 90 °C for 20 - 40 min after dropping is completed; (4) Cool the reaction system to 25 - 35 °C, and then add emulsifier I, reducing agent I, chelating agent, and catalyst to obtain the seeds; the particle size of the seeds is 0.02 - 0.15 μm;

[0011] In step (1), the addition amount of water is 100 phr, the addition amount of emulsifier is 0.1 - 2.0 phr, the addition amount of catalyst is 0.001 - 0.1 phr, the addition amount of chelating agent is 0.01 - 0.2 phr, and the addition amount of reducing agent is 0.0 - 0.3 phr; in step (2), the addition amount of monomer is 1 - 5 phr, and the addition amount of oxidizing agent is 0.1 - 0.2 phr; in step (3), the addition amount of monomer is 100 phr, the addition amount of emulsifier is 0.5 - 2.5 phr, and the addition amount of oxidizing agent is 0.1 - 0.2 phr; in step (4), the addition amount of emulsifier is 0.2 - 1.0 phr, the addition amount of reducing agent is 0.0 - 0.3 phr, the addition amount of chelating agent is 0.01 - 0.2 phr, and the addition amount of catalyst is 0.001 - 0.1 phr.

[0012] Method II: Mix water, emulsifier I, monomer, inhibitor, and initiator evenly; then, through homogenization treatment, make the cumulative homogenization amount 1 - 10 times the feeding amount, and raise the temperature to 40 - 70 °C and react for 240 - 1200 min to obtain seeds; the particle size of the seeds is 0.4 - 2.0 μm;

[0013] The addition amount of water is 100 phr, the addition amount of emulsifier I is 0.2 - 2.5 phr, the addition amount of polymerization monomer is 50 - 100 phr, the addition amount of inhibitor is 0 - 0.001 phr, and the addition amount of initiator is 0.03 - 0.2 phr.

[0014] Method III: Use emulsifier I to emulsify resin or elastomer through high-speed shearing to obtain microparticle seeds; the particle size of the microparticle seeds is 0.7 - 2.5 μm.

[0015] Further preferably, the specific operation of Method III is: Heat the resin or elastomer to the molten state, then add deionized water under slow stirring, and then add emulsifier I; the molten raw material undergoes high-speed shearing in the presence of the emulsifier to obtain dispersed emulsion seeds; these emulsion seeds can be used directly, or after spray drying, the obtained fine particles can be used as seeds.

[0016] Preferably, the weight ratio of the resin or elastomer to emulsifier I is 100:(0.5 - 10).

[0017] Preferably, the emulsifier I is one or more of fatty acid salts with 12 to 18 carbon atoms, sulfonates with 10 to 18 carbon atoms, and sulfosuccinate salts with 8 to 10 carbon atoms on the alcohol group; alternatively, the emulsifier I is prepared by mixing an anionic surfactant and a nonionic surfactant in a proportion and then subjecting them to an emulsification reaction for 1 to 2 hours, and the weight ratio of the anionic surfactant to the nonionic surfactant is (0 to 20):(80 to 100).

[0018] More preferably, the fatty acid salts with 12 to 18 carbon atoms include but are not limited to sodium tetradecanoate and sodium palmitate; the sulfonates with 10 to 18 carbon atoms include but are not limited to sodium dodecyl sulfonate, sodium heptadecyl sulfonate, sodium carboxymethyl sulfonate, sodium dodecylbenzenesulfonate, and sodium octylbenzenesulfonate; the sulfosuccinate salts with 8 to 10 carbon atoms on the alcohol group include but are not limited to sodium dihexyl sulfosuccinate and sodium didodecyl sulfosuccinate.

[0019] More preferably, the hydrophilic-lipophilic balance (HLB) value of the anionic surfactant is 1.8 to 18, and it is selected from one or more of sodium fatty alcohol alkyl sulfonate (RSAS80), alkyl amine ester (OTE), lauryl alcohol phosphate (MAE), detergent 6503, sodium ethoxylated alkyl sulfate (AES), dispersant NNF, dispersant NOF, sulfonic acid, polyoxyethylene lauryl ether NM-9, and AEC alcohol ether carboxylate; the HLB value of the nonionic surfactant is 1.2 to 26, and it is selected from one or more of nonylphenol polyoxyethylene ether, polyoxyethylene sorbitan monolaurate (Tween 21), polyoxyethylene sorbitan monostearate (Tween60), polyoxyethylene sorbitan monooleate (Tween 80), and polyether P65 (Plurnoic P65).

[0020] More preferably, the emulsifier I is prepared by mixing an anionic surfactant and a nonionic surfactant in a proportion, adding deionized water in 3 portions, and then subjecting them to an emulsification reaction for 1 to 2 hours.

[0021] Preferably, the catalyst is copper sulfate and / or copper chloride.

[0022] Preferably, the chelating agent is ethylenediaminetetraacetic acid and / or diethylenetriaminepentaacetic acid.

[0023] Preferably, the reducing agent I is selected from one or more of sodium formaldehyde sulfoxylate, disodium hydroxymethanesulfinate, ascorbic acid, sodium bisulfite, sodium sulfite, and sodium thiosulfate.

[0024] Preferably, the oxidizing agent I is selected from one or more of inorganic peroxides such as ammonium persulfate and potassium persulfate; and organic peroxides such as hydrogen peroxide.

[0025] Preferably, the rotation speed of the high-speed shearing is 6000 - 25000 rpm.

[0026] More preferably, the rotation speed of the high-speed shearing is 10000 - 20000 rpm.

[0027] Even more preferably, the rotation speed of the high-speed shearing is 12000 - 18000 rpm.

[0028] The present invention also provides a method for preparing the graft copolymerized polyvinyl chloride, comprising the following steps:

[0029] S1. Mix the seeds, water, buffer, and vinyl chloride uniformly and heat to 40 - 70 °C;

[0030] S2. Dropwise add oxidant II and reductant II to the system, and continuously dropwise add for 20 - 120 min;

[0031] S3. Simultaneously start to dropwise add vinyl chloride, emulsifier II, oxidant II, and reductant II to the system, and end the reaction after the pressure drop reaches 1 - 5 bar, and obtain the graft copolymerized polyvinyl chloride through drying.

[0032] Preferably, after the reaction ends, a demulsifier needs to be added to the system, and the graft copolymerized polyvinyl chloride is obtained through drying.

[0033] Preferably, in step S1, the addition amount of the seeds is 1 - 15 phr, the addition amount of the water is 100 phr, the addition amount of the buffer is 0.002 - 0.01 phr, and the addition amount of the vinyl chloride is 5 - 15 phr; in step S2, the addition amount of the oxidant is 0.1 - 0.2 phr, and the addition amount of the reductant is 0.0 - 0.3 phr; in step S3, the addition amount of the vinyl chloride is 35 - 45 phr, the addition amount of the emulsifier is 0.1 - 0.5 phr, the addition amount of the oxidant is 0.05 - 0.1 phr, and the addition amount of the reductant is 0.0 - 0.15 phr.

[0034] Preferably, the buffer is selected from one or more of sodium bicarbonate, sodium carbonate, disodium hydrogen phosphate, sodium dihydrogen phosphate, and ammonia water.

[0035] Preferably, the oxidant II is selected from organic peroxides, such as dicyclohexyl peroxydicarbonate, di-n-butyl peroxydicarbonate, dilauroyl peroxide, dibenzoyl peroxide, dipropionyl peroxide, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxybenzoate, cumene hydroperoxide, and tert-butyl hydroperoxide.

[0036] Preferably, the reducing agent II is selected from one or more of sodium formaldehyde sulfoxylate, disodium hydroxymethanesulfinate, ascorbic acid, sodium bisulfite, sodium sulfite, and sodium thiosulfate.

[0037] Preferably, the emulsifier II is selected from one or more of fatty acid salts with 12 - 18 carbon atoms, sulfonates with 10 - 18 carbon atoms, and sulfosuccinate esters with 8 - 10 carbon atoms in the alcohol group.

[0038] More preferably, the fatty acid salts with 12 - 18 carbon atoms include but are not limited to sodium tetradecanoate and sodium palmitate; the sulfonates with 10 - 18 carbon atoms include but are not limited to sodium dodecylsulfonate, sodium heptadecylsulfonate, sodium carboxymethylsulfonate, sodium dodecylbenzenesulfonate, and sodium octylbenzenesulfonate; the sulfosuccinate esters with 8 - 10 carbon atoms in the alcohol group include but are not limited to sodium dihexyl sulfosuccinate and sodium didodecyl sulfosuccinate.

[0039] The present invention also provides a flexible product prepared by using the graft copolymerized polyvinyl chloride.

[0040] The present invention prepares polyvinyl chloride by first preparing seeds and then graft copolymerizing with vinyl chloride. Its tensile strength can reach 10 - 30 MPa, and the elongation at break can reach 100 - 500%. There are three options for the seed preparation method of the present invention. Among them, Method III prepares seeds by melt emulsification of vinyl resin or elastomer that is difficult to physically break according to the concept of "particle design"; the seeds prepared by the three methods can all be graft copolymerized with vinyl chloride to prepare polyvinyl chloride for flexible products without adding plasticizers.

[0041] The present invention first prepares seeds and then realizes the internal plasticization of polyvinyl chloride by grafting vinyl chloride. First, the seed polymerization method is an effective method for preparing highly monodisperse microspheres. Its principle is to use the seeds of the polymer core as the initial reaction system. In subsequent polymerization reactions, the seeds serve as the reaction centers to guide the reaction direction of the polymer; by controlling the particle size of the polymer core and reaction conditions, the purpose of preparing monodisperse large - particle - size polymer microspheres can be achieved. Second, compared with other preparation methods, the seed polymerization method has a higher yield and controllability of polymer microspheres. The emulsion polymerization method is a typical method for preparing seed particles. The polymers obtained by emulsion seed polymerization are generally homopolymers or copolymers; the micro - suspension method can be used to prepare seeds with larger particle sizes, and then emulsion intermediates with even larger particle sizes can be prepared, which can reduce the viscosity of the prepared emulsion and is beneficial to improving product performance after subsequent drying. By precisely controlling the reaction conditions and subsequent treatments, seed particles with specific sizes and properties can be obtained, and then different seeds can be selected according to different material requirements for subsequent polymerization reactions to obtain polyvinyl chloride products that meet the requirements.

[0042] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0043] (1) When the graft copolymerized polyvinyl chloride prepared by the present invention does not contain a plasticizer, its tensile strength is 10-30 MPa and its elongation at break is 100-500%. In subsequent production, polyvinyl chloride-based flexible products can be prepared without adding a plasticizer.

[0044] (2) The surface of the seeds of the present invention has graftable active groups. Polyvinyl chloride is obtained by graft copolymerization reaction with vinyl chloride. Different raw materials or methods can be selected to prepare the seeds according to different needs. By first preparing the seeds and then carrying out graft copolymerization with vinyl chloride, product diversification can be achieved.

[0045] (3) One of the methods for preparing the seeds of the present invention is to obtain them by melting and emulsifying a high molecular resin or elastomer. Its outer layer has active structural groups of the raw material itself and can be used as a seed to continue grafting and growing. In addition, since the raw material of the microparticles is difficult to pulverize itself, it is difficult to obtain fine particles by ordinary physical methods. After directly spray-drying the microparticles, fine particle products of the resin can be obtained, which broadens the uses of the raw material products and can be used in special fields with high requirements for particle size. Brief Description of the Drawings

[0046] Figure 1 It is the particle size distribution diagram of the seeds prepared in Example 1;

[0047] Figure 2 It is the particle size distribution diagram of the seeds prepared in Example 2;

[0048] Figure 3 It is the particle size distribution diagram of the seeds prepared in Example 3;

[0049] Figure 4 It is the double-notch specimen diagram for the impact performance test in the example. Detailed Embodiments

[0050] The technical solutions of the present invention will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0051] The present invention provides a graft copolymerized polyvinyl chloride, the raw materials of which include seeds and vinyl chloride; wherein, the raw materials of the seeds include mixed monomers; or, the raw materials of the seeds include a resin or elastomer obtained by a polymerization reaction using mixed monomers as raw materials;

[0052] The mixed monomers contain Cn H 2n Substituted monoenes of the structure and containing C n H (2n-2) Two or more of the substituted dienes of the structure are mixed to obtain.

[0053] In some examples, the substituted monoenes containing C n H 2n Substituted monoenes of the structure include but are not limited to ethylene, propylene, vinyl acetate, styrene; the substituted dienes containing C n H (2n-2) Substituted dienes of the structure include but are not limited to butadiene, octadiene, norbornene, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, ethyl acrylate, n-butyl acrylate.

[0054] In some examples, the method for preparing the seeds is one of the following three methods:

[0055] Method I: (1) Mix water, emulsifier I, catalyst, chelating agent, reducing agent I evenly and heat up to 40 - 90 °C; (2) Add the mixed monomers and react for 5 - 30 min; then add oxidizing agent I and react for 30 - 90 min; (3) Homogenize the monomers and emulsifier I and start dropping them into the reaction system simultaneously with oxidizing agent I, and react at 40 - 90 °C for 20 - 40 min after dropping is completed; (4) Cool the reaction system to 25 - 35 °C, and then add emulsifier I, reducing agent I, chelating agent, catalyst to obtain the seeds;

[0056] Method II: Mix water, emulsifier I, monomers, inhibitor, initiator evenly; then through homogenization treatment, make the cumulative homogenization amount 1 - 10 times of the feeding amount, and heat up to 40 - 70 °C and react for 240 - 1200 min to obtain the seeds;

[0057] Method III: Use emulsifier I to emulsify resin or elastomer by high-speed shearing to obtain microparticle seeds.

[0058] In some examples, the weight ratio of the resin or elastomer to emulsifier I is 100:(0.5 - 10).

[0059] In some examples, the emulsifier I is one or more of fatty acid salts with 12 to 18 carbon atoms, sulfonates with 10 to 18 carbon atoms, and sulfosuccinate salts with 8 to 10 carbon atoms on the alcohol group. The fatty acid salts with 12 to 18 carbon atoms include but are not limited to sodium tetradecanoate and sodium palmitate; the sulfonates with 10 to 18 carbon atoms include but are not limited to sodium dodecylsulfonate, sodium heptadecylsulfonate, sodium carboxymethylsulfonate, sodium dodecylbenzenesulfonate, and sodium octylbenzenesulfonate; the sulfosuccinate salts with 8 to 10 carbon atoms on the alcohol group include but are not limited to sodium dihexyl sulfosuccinate and sodium didodecyl sulfosuccinate; or, the emulsifier I is prepared by mixing an anionic surfactant and a nonionic surfactant in proportion and then subjecting them to an emulsification reaction for 1 to 2 hours. The weight ratio of the anionic surfactant to the nonionic surfactant is (0 to 20):(80 to 100); the hydrophilic-lipophilic balance value (HLB) of the anionic surfactant is 1.8 to 18, and it is selected from one or more of sodium alkylsulfonate of fatty alcohol (RSAS80), alkyl amine ester (OTE), lauryl alcohol phosphate ester (MAE), detergent 6503, sodium ethoxylated alkyl sulfate (AES), dispersant NNF, dispersant NOF, sulfonic acid, polyoxyethylene lauryl ether NM-9, and AEC alcohol ether carboxylate; the HLB value of the nonionic surfactant is 1.2 to 26, and it is selected from one or more of nonylphenol polyoxyethylene ether, polyoxyethylene sorbitan monolaurate (Tween 21), polyoxyethylene sorbitan monostearate (Tween 60), polyoxyethylene sorbitan monooleate (Tween 80), and polyether P65 (Plurnoic P65).

[0060] In some examples, the catalyst is copper sulfate and / or copper chloride.

[0061] In some examples, the chelating agent is ethylenediaminetetraacetic acid and / or diethylenetriaminepentaacetic acid.

[0062] In some examples, the reducing agent I is selected from one or more of sodium formaldehyde sulfoxylate, disodium hydroxymethanesulfinate, ascorbic acid, sodium bisulfite, sodium sulfite, and sodium thiosulfate.

[0063] In some examples, the oxidizing agent I is selected from one or more of inorganic peroxides such as ammonium persulfate and potassium persulfate; and organic peroxides such as hydrogen peroxide.

[0064] In some examples, the rotation speed of the high-speed shearing is 6000 to 25000 rpm.

[0065] The present invention also provides a method for preparing the graft copolymerized polyvinyl chloride, comprising the following steps:

[0066] S1. Mix the seeds, water, buffer, and vinyl chloride evenly and heat to 40 - 70 °C;

[0067] S2. Dropwise add Oxidizer II and Reducing Agent II to the system, and continuously add dropwise for 20 - 120 min;

[0068] S3. Start to simultaneously dropwise add vinyl chloride, Emulsifier II, Oxidizer II, and Reducing Agent II to the system. After the pressure drop reaches 1 - 5 bar, end the reaction, and obtain graft copolymerized polyvinyl chloride through drying.

[0069] In some examples, in step S1, the addition amount of the seeds is 1 - 15 phr, the addition amount of the water is 100 phr, the addition amount of the buffer is 0.002 - 0.01 phr, and the addition amount of the vinyl chloride is 5 - 15 phr; in step S2, the addition amount of the oxidizer is 0.1 - 0.2 phr, and the addition amount of the reducing agent is 0.0 - 0.3 phr; in step S3, the addition amount of the vinyl chloride is 35 - 45 phr, the addition amount of the emulsifier is 0.1 - 0.5 phr, the addition amount of the oxidizer is 0.05 - 0.1 phr, and the addition amount of the reducing agent is 0.0 - 0.15 phr.

[0070] In some examples, the buffer is selected from one or more of sodium bicarbonate, sodium carbonate, disodium hydrogen phosphate, sodium dihydrogen phosphate, and ammonia water.

[0071] In some examples, the Oxidizer II is selected from organic peroxides, such as dicyclohexyl peroxydicarbonate, di - n - butyl peroxydicarbonate, dilauroyl peroxide, dibenzoyl peroxide, dipropionyl peroxide, tert - butyl peroxy - 2 - ethylhexanoate, tert - butyl peroxybenzoate, cumene hydroperoxide, and tert - butyl hydroperoxide.

[0072] In some examples, the Reducing Agent II is selected from one or more of sodium formaldehyde sulfoxylate, disodium hydroxymethanesulfinate, ascorbic acid, sodium bisulfite, sodium sulfite, and sodium thiosulfate.

[0073] In some examples, the Emulsifier II is selected from one or more of fatty acid salts with 12 - 18 carbon atoms, sulfonates with 10 - 18 carbon atoms, and sulfosuccinate salts with 8 - 10 carbon atoms on the alcohol group; the fatty acid salts with 12 - 18 carbon atoms include but are not limited to sodium myristate and sodium palmitate; the sulfonates with 10 - 18 carbon atoms include but are not limited to sodium dodecylsulfonate, sodium heptadecylsulfonate, sodium carboxymethylsulfonate, sodium dodecylbenzenesulfonate, and sodium octylbenzenesulfonate; the sulfosuccinate salts with 8 - 10 carbon atoms on the alcohol group include but are not limited to sodium dihexyl sulfosuccinate and sodium bis - dodecyl sulfosuccinate.

[0074] In the following specific embodiments, unless otherwise specified, in the preparation method of the seeds, the mixed monomers are a mixture of n-butyl acrylate and vinyl acetate, and the ratio of n-butyl acrylate to vinyl acetate is 5:1.

[0075] Example 1

[0076] A graft copolymerized polyvinyl chloride, the preparation method is as follows:

[0077] Preparation of seeds: (1) Add 100 phr of deionized water to the seed reactor, then add 0.1 phr of sodium dodecyl sulfate, 0.001 phr of copper sulfate, 0.01 phr of ethylenediaminetetraacetic acid, and 0.11 phr of sodium bisulfite, stir evenly and heat up to 40 °C; (2) Then add 1 phr of the mixed monomers, stir for 5 min, add 0.1 phr of sodium persulfate, and react for 30 min; (3) Homogenize 100 phr of the mixed monomers and 0.5 phr of sodium dodecyl sulfate with a high-speed homogenizer and simultaneously start dropping them into the reactor together with 0.1 phr of sodium persulfate. After the dropping is completed in 100 min, stir at 40 °C for 30 min; (4) Cool the reaction system to 30 °C, add 0.2 phr of sodium dodecyl sulfate, 0.3 phr of sodium bisulfite, 0.01 phr of ethylenediaminetetraacetic acid, and 0.001 phr of copper sulfate to obtain the seeds. Figure 1 This is the particle size distribution diagram of the seeds prepared in this example.

[0078] Preparation of graft copolymerized polyvinyl chloride: S1. Add 1 phr of seeds, 100 phr of deionized water, 0.002 phr of sodium bicarbonate, and 5 phr of vinyl chloride to the graft reactor, stir evenly and heat up to 42 °C; S2. Drop 0.1 phr of sodium persulfate and 0.12 phr of sodium bisulfite into the system, and continuously drop for 20 min; S3. Simultaneously start dropping 45 phr of vinyl chloride, 0.1 phr of sodium dodecylbenzenesulfonate, 0.05 phr of sodium persulfate, and 0.15 phr of sodium bisulfite into the system. After the pressure drop reaches 1 bar, end the reaction to obtain a polymer emulsion. Add 2 phr of calcium chloride to the polymer emulsion for demulsification, and dry to obtain graft copolymerized polyvinyl chloride.

[0079] Example 2

[0080] A graft copolymerized polyvinyl chloride, the preparation method is as follows:

[0081] Preparation of seeds: Add 100 phr of deionized water to the seed reactor, then add 0.2 phr of sodium dodecyl sulfate, 50 phr of n-butyl acrylate and vinyl acetate, 0.0001 phr of copper chloride, and 0.03 phr of dilauroyl peroxide, and stir evenly; then use a homogenizer with a linear velocity of 10 m / s to homogenize the cumulative homogenization amount 1 time the feeding amount, heat up to 42 °C and react for 1200 min to obtain seeds. Figure 2 This is the particle size distribution diagram of the seeds prepared in this example.

[0082] Preparation of graft copolymerized polyvinyl chloride: S1. Add 1 phr of seeds, 100 phr of deionized water, 0.002 phr of sodium bicarbonate, and 5 phr of vinyl chloride to the graft reactor, stir evenly and heat up to 42 °C; S2. Dropwise add 0.1 phr of sodium persulfate and 0.12 phr of sodium bisulfite to the system, and continuously dropwise add for 20 min; S3. Start to dropwise add 45 phr of vinyl chloride, 0.1 phr of sodium dodecylbenzenesulfonate, 0.05 phr of sodium persulfate, and 0.15 phr of sodium bisulfite to the system at the same time. After the pressure drop reaches 1 bar, end the reaction to obtain a polymer emulsion. Add 2 phr of calcium chloride to the polymer emulsion for demulsification, and dry to obtain graft copolymerized polyvinyl chloride.

[0083] Example 3

[0084] A graft copolymerized polyvinyl chloride, the preparation method is as follows:

[0085] Preparation of seeds: (1) Add 100 parts of EVA resin to the seed reactor, heat up to its softening and melting (about 60 - 90 °C), then add 20 parts of deionized water, stir slowly at 1000 rpm for 10 min, add a composite emulsifier of 7 parts of nonylphenol polyoxyethylene ether and 1 part of sodium dodecylbenzenesulfonate, continue to stir for 10 min, then adjust the stirring speed to 10000 rpm, add 20 parts of deionized water and continue to stir and emulsify for 20 min; adjust the stirring speed to 12000 rpm, continue to stir and emulsify for 40 min, then add 20 parts of deionized water as needed, increase the rotation speed to 15000 rpm and continue to emulsify for 2 h to obtain uniformly dispersed resin microparticle seeds. Figure 3 This is the particle size distribution diagram of the seeds prepared in this example.

[0086] Preparation of graft copolymerized polyvinyl chloride: S1. Add 1 phr of resin microparticle seeds, 100 phr of deionized water, 0.002 phr of sodium bicarbonate, and 5 phr of vinyl chloride into the grafting reactor, stir evenly and heat up to 42 °C; S2. Dropwise add 0.1 phr of sodium persulfate and 0.12 phr of sodium bisulfite into the system, and continuously dropwise add for 20 min; S3. Start to dropwise add 45 phr of vinyl chloride, 0.1 phr of sodium dodecylbenzenesulfonate, 0.05 phr of sodium persulfate, and 0.15 phr of sodium bisulfite into the system at the same time. After the pressure drop reaches 1 bar, end the reaction to obtain a polymer emulsion. Add 2 phr of calcium chloride to the polymer emulsion for demulsification, and dry to obtain graft copolymerized polyvinyl chloride.

[0087] Example 4

[0088] A graft copolymerized polyvinyl chloride, the preparation method is as follows:

[0089] Preparation of seeds: (1) Add 100 phr of deionized water into the seed reactor, then add 2.0 phr of sodium dodecyl sulfate, 0.1 phr of copper sulfate, 0.2 phr of ethylenediaminetetraacetic acid, and 0.0 phr of sodium bisulfite, stir evenly and heat up to 85 °C; (2) Then add 1 phr of n-butyl acrylate and vinyl acetate, stir for 5 min, add 0.1 phr of sodium persulfate, and react for 30 min; (3) Homogenize 100 phr of mixed monomers and 2.5 phr of sodium dodecyl sulfate with a high-speed homogenizer and start to dropwise add them into the reactor at the same time with 0.2 phr of sodium persulfate. After the dropping is completed in 300 min, stir at 85 °C for 30 min; (4) Cool the reaction system to 35 °C, add 1.0 phr of sodium dodecyl sulfate, 0.3 phr of sodium bisulfite, 0.2 phr of ethylenediaminetetraacetic acid, and 0.1 phr of copper sulfate to obtain the seeds.

[0090] Preparation of graft copolymerized polyvinyl chloride: S1. Add 15 phr of seeds, 100 phr of deionized water, 0.01 phr of sodium bicarbonate, and 15 phr of vinyl chloride into the grafting reactor, stir evenly and heat up to 70 °C; S2. Dropwise add 0.2 phr of sodium persulfate and 0.3 phr of sodium bisulfite into the system, and continuously dropwise add for 120 min; S3. Start to dropwise add 35 phr of vinyl chloride, 0.1 phr of sodium dodecylbenzenesulfonate, 0.1 phr of sodium persulfate, and 0.15 phr of sodium bisulfite into the system at the same time. After the pressure drop reaches 5 bar, end the reaction to obtain a polymer emulsion. Add 2 phr of calcium chloride to the polymer emulsion for demulsification, and dry to obtain graft copolymerized polyvinyl chloride.

[0091] Example 5

[0092] A graft copolymerized polyvinyl chloride, and the preparation method is as follows:

[0093] Prepare seeds: Add 100 phr of deionized water to the seed reactor, then add 2.5 phr of sodium dodecyl sulfate, 100 phr of n-butyl acrylate and vinyl acetate, 0.001 phr of inhibitor, 0.2 phr of dilauroyl peroxide, and stir evenly; then use a homogenizer with a linear velocity of 48 m / s for cumulative homogenization with a homogenization amount of 10 times the feeding amount, and heat up to 70 °C and react for 240 min to obtain seeds.

[0094] Prepare graft copolymerized polyvinyl chloride: S1. Add 15 phr of seeds, 100 phr of deionized water, 0.01 phr of sodium bicarbonate, and 15 phr of vinyl chloride to the graft reactor, stir evenly and heat up to 70 °C; S2. Dropwise add 0.2 phr of sodium persulfate and 0.3 phr of sodium bisulfite to the system, and continue dropping for 120 min; S3. Start dropping 35 phr of vinyl chloride, 0.1 phr of sodium dodecylbenzenesulfonate, 0.1 phr of sodium persulfate, and 0.15 phr of sodium bisulfite into the system at the same time, and end the reaction after the pressure drop reaches 5 bar to obtain a polymer emulsion. Add 2 phr of calcium chloride to the polymer emulsion for demulsification, and dry to obtain graft copolymerized polyvinyl chloride.

[0095] Example 6

[0096] A graft copolymerized polyvinyl chloride, the preparation method of this example is basically the same as that of Example 4, the difference is that in the seed preparation, an equal amount of 2-ethylhexyl acrylate is used to replace n-butyl acrylate.

[0097] Example 7

[0098] A graft copolymerized polyvinyl chloride, the preparation method of this example is basically the same as that of Example 5, the difference is that in the monomers of the seed preparation, an equal amount of 2-ethylhexyl acrylate is used to replace n-butyl acrylate.

[0099] Example 8

[0100] A graft copolymerized polyvinyl chloride, the preparation method of this example is basically the same as that of Example 4, the difference is that in the emulsifier of the seed preparation, an equal amount of sodium dodecylbenzenesulfonate is used to replace sodium dodecyl sulfate.

[0101] Example 9

[0102] A graft copolymerized polyvinyl chloride, the preparation method of this example is basically the same as that of Example 5, the difference is that in the emulsifier of the seed preparation, an equal amount of sodium dodecylbenzenesulfonate is used to replace sodium dodecyl sulfate.

[0103] Example 10

[0104] A graft copolymerized polyvinyl chloride, the preparation method is as follows:

[0105] Preparation of seeds: (1) Add 100 phr of deionized water to the seed reactor, then add 2.0 phr of sodium dodecyl sulfate, 0.1 phr of copper sulfate, 0.2 phr of ethylenediaminetetraacetic acid, 0.0 phr of sodium formaldehyde sulfoxylate, and stir evenly and heat up to 85 °C; (2) Then add 1 phr of n-butyl acrylate and vinyl acetate, stir for 5 min, add 0.1 phr of hydrogen peroxide, and react for 30 min; (3) Homogenize 100 phr of the mixed monomers and 2.5 phr of sodium dodecyl sulfate with a high-speed homogenizer and then start dropping them into the reactor simultaneously with 0.2 phr of hydrogen peroxide. After 300 min of dropping, stir at 85 °C for 30 min; (4) Cool the reaction system to 35 °C, add 1.0 phr of sodium dodecyl sulfate, 0.3 phr of sodium formaldehyde sulfoxylate, 0.2 phr of ethylenediaminetetraacetic acid, and 0.1 phr of copper sulfate to obtain the seeds.

[0106] Preparation of graft copolymerized polyvinyl chloride: S1. Add 15 phr of seeds, 100 phr of deionized water, 0.01 phr of sodium bicarbonate, and 15 phr of vinyl chloride to the graft reactor, stir evenly and heat up to 70 °C; S2. Drop 0.2 phr of hydrogen peroxide and 0.3 phr of sodium formaldehyde sulfoxylate into the system, and continuously drop for 120 min; S3. Start dropping 35 phr of vinyl chloride, 0.1 phr of sodium dodecylbenzenesulfonate, 0.1 phr of hydrogen peroxide, and 0.15 phr of sodium formaldehyde sulfoxylate into the system simultaneously. After the pressure drop reaches 5 bar, end the reaction to obtain a polymer emulsion. Add 2 phr of calcium chloride to the polymer emulsion for demulsification, and dry to obtain graft copolymerized polyvinyl chloride.

[0107] Example 11

[0108] A graft copolymerized polyvinyl chloride, the preparation method of this example is basically the same as that of Example 5, the difference is that in the preparation of seeds, the initiator is replaced with an equal amount of tert-butyl hydroperoxide instead of dilauroyl peroxide.

[0109] Example 12

[0110] A graft copolymerized polyvinyl chloride, the preparation method of this example is basically the same as that of Example 3, the difference is that in the preparation of seeds, an equal amount of EVM elastomer is used to replace the EVA resin.

[0111] Example 13

[0112] A graft copolymerized polyvinyl chloride, the preparation method in this example is basically the same as that in Example 3, except that in the preparation of the seed, an equal amount of EPDM elastomer is used to replace the EVA resin.

[0113] Example 14

[0114] A graft copolymerized polyvinyl chloride, the preparation method in this example is basically the same as that in Example 5, except that in step S3 of preparing the graft copolymerized polyvinyl chloride, 35 phr of vinyl chloride, 0.1 phr of sodium dodecylbenzenesulfonate, 0.1 phr of sodium persulfate, and 0.15 phr of sodium bisulfite are simultaneously added dropwise to the system. After the pressure drop reaches 5 bar, the reaction is terminated to obtain a polymer emulsion, and the graft copolymerized polyvinyl chloride is obtained after being spray-dried by a cyclone at an outlet air temperature of 50°C.

[0115] Comparative Example 1

[0116] 100 phr of pure water, 90 phr of vinyl chloride, 0.1 phr of polyvinyl alcohol, 0.05 phr of tert-butyl peroxyneodecanoate, 0.05 phr of cumyl peroxyneodecanoate, and 0.002 phr of sodium bicarbonate are added to the reaction kettle, and the temperature is raised to 57°C under stirring for 240 min. After discharging and drying, a polyvinyl chloride homopolymer resin with a degree of polymerization of 1000 is obtained.

[0117] Comparative Example 2

[0118] A graft copolymerized polyvinyl chloride, the preparation method is as follows:

[0119] Preparation of seeds: (1) Add 100 phr of deionized water to the seed reaction kettle, and then add 0.1 phr of sodium dodecyl sulfate, 0.001 phr of copper sulfate, 0.01 phr of ethylenediaminetetraacetic acid, 0.11 phr of sodium bisulfite, 1 phr of mixed monomers, and 0.1 phr of sodium persulfate, and stir evenly and heat up to 40°C; (2) Homogenize 100 phr of mixed monomers and 0.5 phr of sodium dodecyl sulfate with a high-speed homogenizer and simultaneously start dropping them into the reaction kettle together with 0.1 phr of sodium persulfate. After the dropping is completed in 100 min, stir at 40°C for 30 min; (3) Cool the reaction system to 30°C, and add 0.2 phr of sodium dodecyl sulfate, 0.3 phr of sodium bisulfite, 0.01 phr of ethylenediaminetetraacetic acid, and 0.001 phr of copper sulfate to obtain the seeds.

[0120] Preparation of graft copolymerized polyvinyl chloride: S1. Add 1 phr of seeds, 100 phr of deionized water, 0.002 phr of sodium bicarbonate, and 5 phr of vinyl chloride into the grafting reactor, stir evenly and heat up to 42 °C; S2. Dropwise add 0.1 phr of sodium persulfate and 0.12 phr of sodium bisulfite into the system, and continuously dropwise add for 20 min; S3. Start to dropwise add 45 phr of vinyl chloride, 0.1 phr of sodium dodecylbenzenesulfonate, 0.05 phr of sodium persulfate, and 0.15 phr of sodium bisulfite into the system at the same time. After the pressure drop reaches 1 bar, end the reaction to obtain a polymer emulsion. Add 2 phr of calcium chloride to the polymer emulsion for demulsification, and dry to obtain graft copolymerized polyvinyl chloride.

[0121] Comparative Example 3

[0122] A graft copolymerized polyvinyl chloride, the preparation method of which is basically the same as that of Example 1, except that in the preparation of the seeds, n-butyl acrylate is used to replace the mixed monomers in equal amounts.

[0123] Perform softness performance tests on the polyvinyl chloride prepared in Examples 1 to 14 and Comparative Example 1. For Examples 1 to 14, use a formulation of 100 phr of resin, 2 phr of organotin, 5 phr of epoxidized soybean oil, 0.1 phr of stearic acid, and 0.1 phr of lignite wax. After mixing evenly, knead on a two-roll mill at 145 °C for 6 min to form a sheet for softness performance testing; for Comparative Example 1, use a formulation of 100 phr of resin, 2 phr of organotin, 5 phr of epoxidized soybean oil, 0.1 phr of stearic acid, and 0.1 phr of lignite wax. After mixing evenly, knead on a two-roll mill at 185 °C for 6 min to form a sheet for softness performance testing. The softness performance test results are shown in Table 1. Control 1 in Table 1 is polyvinyl chloride with a polymerization degree of 1000 purchased from the market; Control 2 is polyvinyl chloride with a polymerization degree of 1300 purchased from the market. Controls 1 to 2 use a formulation of 100 phr of resin, 2 phr of organotin, 5 phr of epoxidized soybean oil, 60 phr of dioctyl phthalate (plasticizer), 0.1 phr of stearic acid, and 0.1 phr of lignite wax. After mixing evenly, knead on a two-roll mill at 155 °C for 6 min to form a sheet for softness performance testing.

[0124] Table 1: Softness performance of Examples 1 to 14 and Comparative Examples 1 to 3

[0125]

[0126] The rigid impact performance of the polyvinyl chloride resins prepared in Example 1, 3, 14 and Comparative Example 1 was tested, and the results are shown in Table 2. Impact strength test formulation: 100 phr resin, 4 phr calcium-zinc stabilizer, 0.2 phr PE wax, 0.1 phr calcium stearate, 15 phr 2500-mesh calcium powder, 0 - 4.5 phr toughening agent. Impact strength test sample preparation process: Kneading at 185 °C for 8 min. Molding of 2.5 mm thick sample: First step: 185 °C / 10 bar / 300 s; Second step: 185 °C / 200 bar / 300 s; Third step: 40 °C / 200 bar / 360 s. The sample was cut into a 1fA double-notch sample in ISO 179-1 Plastics - Determination of Charpy impact properties, as Figure 4 shown.

[0127] Table 2: Rigid properties of Example 1, 3, 14 and Comparative Example 1

[0128]

[0129] In summary, the present invention uses a mixed monomer as a raw material to prepare seeds, or purchases a resin or elastomer obtained by polymerization reaction using a mixed monomer as a raw material to prepare seeds. The mixed monomer is obtained by mixing two or more of a substituted monoene containing a C n H 2n structure and a substituted diene containing a C n H (2n-2) structure; by the method of first preparing seeds and then graft copolymerizing with vinyl chloride, by adjusting the preparation conditions of the seeds and the preparation conditions of the graft copolymerized polyvinyl chloride, when no plasticizer is added, the prepared polyvinyl chloride has a tensile strength of 10 - 30 MPa and an elongation at break of 100 - 500%; in subsequent production, polyvinyl chloride-based flexible products can be prepared without adding plasticizers; the present invention provides three different methods to prepare seeds, and different raw materials or methods can be selected to prepare seeds according to different needs, realizing the diversification of polyvinyl chloride products.

[0130] The above specific embodiments have described the implementation of the present invention in detail. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the claims and technical concept of the present invention, various simple modifications and changes can be made to the technical solution of the present invention, and these simple variations all belong to the protection scope of the present invention.

Claims

1. A graft copolymer polyvinyl chloride, characterized in that: The raw materials include seeds and vinyl chloride; wherein the raw materials of the seeds include mixed monomers; The mixed monomer is obtained by mixing two or more of ethylene, propylene, vinyl acetate, styrene, butadiene, octadiene, norbornene, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, ethyl acrylate, and n-butyl acrylate; The preparation method of the seeds is as follows: (1) Mix water, emulsifier I, catalyst, chelating agent and reducing agent I and heat them to 40-90°C; (2) Add the mixed monomer and react for 5-30 min; then add the oxidizing agent I and react for 30-90 min; (3) After homogenizing the mixed monomer and emulsifier I, add them dropwise to the reaction system at the same time as the oxidizing agent I. After the addition is completed, react at 40-90°C for 20-40 min; (4) Cool the reaction system to 25-35°C, then add the emulsifier I, reducing agent I, chelating agent and catalyst to obtain seeds; In the step (1), the amount of water added is 100 phr, the amount of emulsifier added is 0.1-2.0 phr, the amount of catalyst added is 0.001-0.1 phr, the amount of chelating agent added is 0.01-0.2 phr, and the amount of reducing agent added is 0.0-0.3 phr; in the step (2), the amount of monomer added is 1-5 phr, and the amount of oxidant added is 0.1-0.2 phr; in the step (3), the amount of monomer added is 100 phr, the amount of emulsifier added is 0.5-2.5 phr, and the amount of oxidant added is 0.1-0.2 phr; in the step (4), the amount of emulsifier added is 0.2-1.0 phr, the amount of reducing agent added is 0.0-0.3 phr, the amount of chelating agent added is 0.01-0.2 phr, and the amount of catalyst added is 0.001-0.1 phr; The preparation method of the graft copolymer polyvinyl chloride comprises the following steps: S1. Mix seeds, water, buffer and a small amount of vinyl chloride evenly and heat to 40-70℃; S2, add oxidant II and reducing agent II to the system, and continue to add for 20-120 minutes; S3. Start to drop vinyl chloride, emulsifier II, oxidant II and reducing agent II into the system simultaneously. The reaction is terminated when the pressure drop reaches 1-5 bar. The graft copolymerized polyvinyl chloride is obtained after drying.

2. A graft copolymer polyvinyl chloride according to claim 1, characterized in that: The emulsifier I is one or more of a fatty acid salt with 12 to 18 carbon atoms, a sulfonate with 10 to 18 carbon atoms, and a sulfosuccinate salt with 8 to 10 carbon atoms on the alcohol group; or, the emulsifier I is prepared by mixing an anionic surfactant and a nonionic surfactant in proportion, and then emulsifying and reacting for 1 to 2 hours, and the weight ratio of the anionic surfactant to the nonionic surfactant is (0 to 20): (80 to 100).

3. The graft copolymer polyvinyl chloride according to claim 1, characterized in that: In step S1, the amount of vinyl chloride added is 5-15 phr; in step S3, the amount of vinyl chloride added is 35-45 phr.

4. A soft product prepared by using the graft copolymerized polyvinyl chloride as claimed in claim 1 or 2.

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