A chlorine-containing acrylate rubber with excellent processability and its preparation method

Abstract

The present invention discloses a chlorine-containing acrylate rubber and a preparation method thereof. The chlorine-containing acrylate rubber is prepared by polymerizing the following components calculated by weight percentage: 65-85% of alkyl acrylate, 15-30% of chloroprene rubber latex, 2-5% of hydroxy acrylate, 0.5-3% of ethylenically unsaturated monomer containing carboxyl group, and 0.5-2% of octadecyl acrylate. Among them, the chloroprene rubber latex is one or a combination of several of Bayer C84, Bayer C-2325, Bayer C-2694 or CR-244. By grafting the monomers of chloroprene rubber latex onto acrylate monomers in the present invention and synergistically acting with hydroxy acrylate, ethylenically unsaturated monomer containing carboxyl group and octadecyl acrylate as functional monomers, the rubber has excellent processing properties such as suitable vulcanization speed, not easy to scorch, non-sticking to the roll during mixing, not easy to stick during demolding, small extrusion swelling ratio, and little pollution and corrosion to the mold; at the same time, its rubber products have the advantages of low compression set rate, oil resistance, heat resistance, high tensile strength, smooth surface, etc.

Description

Technical Field

[0001] The present invention relates to an acrylate rubber (ACM), and particularly to a chlorine-containing acrylate rubber with excellent processing performance and a preparation method thereof. Background Art

[0002] Acrylate rubber (ACM) is an elastomer copolymerized mainly from acrylate monomers, and has advantages such as heat resistance, aging resistance, oil resistance, and ultraviolet resistance. In developed countries such as Europe and the United States, it has been widely used in hydraulic hoses, cylinder gaskets, valve stems, crankshafts, etc. of automobiles and locomotives, which can significantly improve the driving conditions of automobiles, reduce failures and pollution, protect the environment, and extend the service life of automobiles.

[0003] The comonomers of acrylate rubber can be classified into main monomers, low-temperature oil-resistant monomers, and vulcanization point monomers according to their functions. Commonly used main monomers include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, etc. As the number of carbon atoms in the ester group of the main monomer increases, the cold resistance improves while the oil resistance deteriorates. Therefore, in order to keep the product with good oil resistance, some low-temperature oil-resistant monomers with polar groups, such as alkoxy ether acrylate, methoxyethyl acrylate, polyethylene glycol methoxy acrylate, dimethoxyethyl maleate, etc., must be added to improve its low-temperature performance. To make the product easy to vulcanize, a certain amount of vulcanization point monomers, such as chloroethyl vinyl ether, glycidyl methacrylate, allyl glycidyl ether, acrylic acid, maleic acid, and maleic acid monoester, etc., must also be added. According to different vulcanization mechanisms, it can be divided into epoxy type, chlorine type, carboxylic acid type, etc.

[0004] At present, the most widely used and largest consumption amount in China is chlorine-containing acrylate rubber. Chlorine-containing acrylate rubber can obtain good compression set performance and physical and mechanical properties. Patents CN101445575A and CN101812180A disclose adding chlorine-containing functional monomers to acrylate rubber, but there are a series of processing disadvantages in the processing process, such as slow vulcanization speed leading to easy scorching, easy sticking to the roll during mixing, easy sticking during demolding and ejection, insufficient extrusion volume, large and uneven die swell at the outlet, and easy pollution and corrosion of the mold. In practical applications, it can be improved by adding fatty paraffin, phosphate esters, etc. during mixing, but it will also bring consequences such as blooming and poor vulcanization characteristics. Patent CN104558999A discloses that by using a specific environmentally friendly vulcanizing agent to slow down the crosslinking speed, the rubber compound has very good scorch resistance, but does not mention the problems of sticking to the roll, demolding, and die swell at the extrusion outlet.

[0005] In the prior art, the processing problems of chlorine-containing acrylate rubber result in the still inability to mass-produce chlorine-containing acrylate rubber. Therefore, there is an urgent need to develop a chlorine-containing acrylate rubber with excellent processing performance. Summary of the Invention

[0006] The object of the present invention is to overcome the processing problems existing in the existing chlorine-containing acrylate rubber, such as slow vulcanization speed, easy scorching, sticking to the roll during mixing, easy sticking during demolding, extrusion swelling and non-smoothness, and easy pollution and corrosion of the mold, and to provide a chlorine-containing acrylate rubber with excellent processing performance. The chlorine-containing acrylate rubber of the present invention grafts a special chloroprene rubber latex monomer onto the acrylate monomer and synergistically acts with acrylic hydroxy ester, an ethylenically unsaturated monomer containing a carboxyl group, and octadecyl acrylate as functional monomers. It has excellent processing performance such as a suitable vulcanization speed, not easy to scorch, not sticking to the roll during mixing, not easy to stick during demolding, small extrusion swelling rate, and small pollution and corrosion to the mold; at the same time, its rubber products have the advantages of low compression set rate, oil resistance, heat resistance, high tensile strength, and smooth surface.

[0007] Another object of the present invention is to provide a preparation method for the chlorine-containing acrylate rubber with excellent processing performance.

[0008] Another object of the present invention is to provide a rubber product processed from the chlorine-containing acrylate rubber.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] The chlorine-containing acrylate rubber is prepared by polymerizing the following monomers calculated by weight percentage:

[0011]

[0012] Among them, the chloroprene rubber latex is one or a combination of several of Bayer C84, Bayer C-2325, Bayer C-2694, or CR-244.

[0013] The chlorine-containing acrylate rubber is prepared by graft copolymerization of chloroprene rubber latex and acrylate monomer, using acrylic hydroxy ester, an ethylenically unsaturated monomer containing a carboxyl group, and octadecyl acrylate as functional monomers.

[0014] The processing performance is better after the hydroxy acrylate monomer is combined with chloroprene in the chloroprene rubber latex. The processing performance is better, the vulcanization crosslinking is sufficient, the vulcanization speed is moderate, the extrusion performance is improved and the dynamic performance is improved. On the basis of retaining the low compression set rate, oil resistance and heat resistance of the carboxylic acid type acrylate rubber, the mechanical properties such as the tensile strength of its vulcanizate and the surface smoothness are improved; since a certain amount of chlorine element will be released during the vulcanization process, it will cause a certain degree of pollution and corrosion to the mold. The chlorine element in the chloroprene rubber latex is more difficult to release than the small molecule chlorine-containing compound. Therefore, compared with other chlorine-containing acrylate rubbers, the chlorine-containing acrylate rubber prepared by using the chloroprene rubber latex will reduce the pollution and corrosion of the mold. Due to the different reaction activities and molecular weights of chloroprene rubber, not all chloroprene rubbers can successfully prepare chlorine-containing acrylate rubbers with excellent processing performance. Preferably, the chloroprene rubber latex is Bayer C84, Bayer C-2325, Bayer C-2694 or CR-244.

[0015] Preferably, the solid content in the chloroprene rubber latex is 45%.

[0016] As the number of carbon atoms in the ester group of the alkyl acrylate monomer increases, the cold resistance of the rubber improves and the oil resistance deteriorates. Therefore, in order to keep the product with good oil resistance, the number of carbon atoms of the alkyl acrylate is preferably 1-8. Further preferably, the alkyl acrylate is one or a combination of several of methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate or isooctyl acrylate.

[0017] Further preferably, the alkyl acrylate is one or a combination of several of methyl acrylate, ethyl acrylate or n-butyl acrylate.

[0018] The chlorine-containing acrylate rubber may further contain a monomer derivative copolymerizable with the alkyl acrylate and the chloroprene rubber latex as a comonomer. Preferably, the comonomer is a monomer such as a conjugated diene, a non-conjugated diene, an aromatic vinyl, an unsaturated nitrile, an unsaturated amide, a polyfunctional acrylate, etc.

[0019] The chlorine-containing acrylate rubber uses hydroxy acrylate, an ethylenically unsaturated monomer containing a carboxyl group, and octadecyl acrylate as functional monomers, so that on the basis of retaining the low compression set, oil resistance and heat resistance of acrylate rubber, its mechanical properties and processability are improved. Among them, hydroxy acrylate can play an auxiliary vulcanization role; the content of the ethylenically unsaturated monomer containing a carboxyl group can be used to regulate the vulcanization speed, so that the rubber has a suitable vulcanization time and avoids scorching during the vulcanization process; octadecyl acrylate can play a lubricant role, and coordinated with the chloroprene rubber emulsion, it can reduce the phenomena of sticking to the roller and sticking to the film, and helps to improve the processing performance.

[0020] Preferably, the hydroxy acrylate is one or a combination of several of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate or hydroxypropyl methacrylate.

[0021] Preferably, the ethylenically unsaturated monomer containing a carboxyl group is one or a combination of several of organic acids, monoalkyl maleates or acid anhydrides; the organic acids are acrylic acid, methacrylic acid, ethylacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid; the monoalkyl maleates are monomethyl maleate, monoethyl maleate, monobutyl maleate, monomethyl fumarate, monoethyl fumarate, monobutyl fumarate; the acid anhydrides are maleic anhydride and fumaric anhydride.

[0022] More preferably, the ethylenically unsaturated monomer containing a carboxyl group is one or a combination of several of acrylic acid, maleic acid, and methacrylic acid.

[0023] Preferably, the octadecyl acrylate is one or a combination of several of octadecyl methacrylate or octadecyl acrylate.

[0024] The chlorine-containing acrylate rubber is obtained by free radical graft polymerization and can be prepared by methods such as emulsion polymerization, suspension polymerization, bulk polymerization, and solution polymerization. Considering the stability of the process, emulsion polymerization is preferably used, and the specific preparation method is as follows:

[0025] S1. Deionized water, an emulsifier, and a chloroprene rubber emulsion are mixed to form a mixed solution A, so that the solid content of the chloroprene rubber in the mixed solution A is 30-40%;

[0026] S2. An alkyl acrylate, a hydroxy acrylate, an ethylenically unsaturated monomer containing a carboxyl group, an octadecyl acrylate, and a molecular weight regulator are mixed to form a mixed solution B, and an initiator is added to the mixed solution A or the mixed solution B;

[0027] S3. The mixed solution B is added to the mixed solution A for emulsification to obtain an emulsion C;

[0028] S4. Under an inert atmosphere, add deionized water and an emulsifier into the reaction kettle, and heat up to 20 - 80 °C;

[0029] S5. Transfer 1 / 6 - 1 / 3 parts by weight of Emulsion C to the reaction kettle completed in Step S4, and initiate the reaction under an inert atmosphere;

[0030] S6. After the reaction in S5 is sufficient, drop the remaining Emulsion C into the system in S5. After the dropping is completed, continue the reaction for 2 - 5 h, and obtain the chlorine - containing acrylate rubber emulsion through post - treatment.

[0031] Preferably, the total amount of deionized water in the emulsion polymerization is 1.5 - 3 times the total mass of the polymerization monomers.

[0032] Preferably, the emulsifier is one or a combination of polyoxyethylene alkyl ether, polyoxyethylene alkylphenol ether, polyoxyethylene sorbitan alkyl ester, dodecyl sulfonate, dodecyl benzene sulfonate.

[0033] The total amount of the emulsifier is preferably 0.5 - 4% of the total mass of the polymerization monomers.

[0034] Preferably, the initiator is an azo initiator, an organic peroxide or an inorganic persulfate. The azo initiator is 2,2 - azobisisobutyronitrile, 2,2 - azo - 2 - methylbutyronitrile, 2,2 - azo - 2,4 - dimethylvaleronitrile, 2,2 - azo - 4 - methoxy - 2,4 - dimethylvaleronitrile, 2,2 - azobis(methyl 2 - methylpropionate), 2,2 - azobis(2 - methylpropionamidine) - 2 - hydrochloride; the organic peroxide is cumene hydroperoxide (CHP), di - tert - butyl peroxide, dicumyl peroxide, benzoyl peroxide (BPO), lauroyl peroxide (LPO), 2,5 - dimethylhexane - 2,5 - di - tert - butylperoxide, 3,3,6,6 - tetramethyl - 1,2 - bis(tert - butylperoxy)hexane, 1,3 - bis(tert - butylperoxyisopropyl)benzene, 2,5 - dimethyl - 2,5 - bis(tert - butylperoxy)hexane, tert - butyl peroxy - 2 - ethylhexanoate, benzoyl peroxide, terpinyl hydroperoxide or tert - butyl peroxybenzoate; the inorganic persulfate is ammonium persulfate, potassium persulfate or sodium persulfate.

[0035] The above - mentioned initiators can be used alone respectively, or two or more of them can be used in combination. Among them, the peroxide initiator can also be used in combination with a reducing agent to form an oxidation - reduction system. The reducing agent is ferrous sulfate, copper naphthenate, sodium formaldehyde sulfoxylate. The amount of the initiator is preferably 0.1 - 0.5% of the total mass of the polymerization monomers.

[0036] The molecular weight regulator can be added as needed. Preferably, the molecular weight regulator is one or a combination of more of n-dodecyl mercaptan, tert-dodecyl mercaptan, and methylstyrene dimer. The dosage of the molecular weight regulator is preferably 0.01-0.2% of the total mass of the polymerization monomers.

[0037] Preferably, in order to better maintain the emulsion state of emulsion C, emulsion C is stored at a low temperature. More preferably, the storage temperature is below 0 °C, and more preferably, it is stored at -20 ± 0.5 °C.

[0038] Preferably, in step S4, the inert atmosphere generally refers to carrying out the reaction in an environment filled with an inert gas, and the inert gas can be nitrogen, etc.

[0039] In step S4, the temperature for heating up is determined according to the initiator selected for the system.

[0040] Preferably, in step S5, 1 / 5 weight part of emulsion C is transferred to the reaction kettle.

[0041] Preferably, the post-treatment is to add the prepared chlorinated acrylate rubber emulsion to an aqueous solution composed of a coagulant and a flocculant with a mass percentage of 5-20% for demulsification, and then obtain the chlorinated acrylate rubber through washing and drying.

[0042] Preferably, the coagulant is a metal salt such as sodium chloride, calcium chloride, aluminum chloride, or sodium sulfate, and can also form an acid-inorganic salt system with hydrochloric acid, sulfuric acid, etc. for use as a coagulant.

[0043] The flocculant is added to prevent the rubber from agglomerating and being difficult to coagulate. Preferably, the flocculant is sodium polyacrylate or polyvinyl alcohol.

[0044] A rubber product is obtained by processing the chlorinated acrylate rubber.

[0045] The processing method of the rubber product can be as follows: adding the raw rubber of the chlorinated acrylate rubber to a two-roll open mill, batchwise adding a mixture of a reinforcing filler, an inert filler, stearic acid, an antioxidant, etc. After all the powders are mixed into the rubber, finally add a mixture of a vulcanizing agent and a vulcanization accelerator, make 4 triangular bales and then take off the sheet to obtain a mixed rubber, and let it stand at room temperature for 8 hours. Then vulcanize the mixed rubber under certain conditions to obtain a vulcanized rubber. The primary vulcanization conditions are: vulcanization temperature is 180 °C, vulcanization pressure is 15 MPa, and vulcanization time is 10 minutes; the secondary vulcanization conditions are: vulcanization temperature is 180 °C, and vulcanization time is 4 hours.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] The chlorine-containing acrylate rubber of the present invention is obtained by grafting a chloroprene rubber emulsion monomer onto an acrylate monomer and synergistically acting with a hydroxy acrylate, an ethylenically unsaturated monomer containing a carboxyl group, and octadecyl acrylate as functional monomers, so that it has excellent processing properties such as a suitable vulcanization rate, not being prone to scorching, not sticking to the roll during mixing, not sticking easily during demolding, a small extrusion swelling rate, and little pollution and corrosion to the mold; at the same time, its rubber products have the advantages of a low compression set rate, oil resistance, heat resistance, high tensile strength, and a smooth surface. Detailed Embodiments

[0048] The present invention will be further described below in conjunction with specific embodiments, but the embodiments do not limit the present invention in any form. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the technical field.

[0049] The chloroprene rubber C84 emulsion was purchased from Changzhou Modeng Chemical Co., Ltd.;

[0050] The chloroprene rubber CR244 emulsion was purchased from Guangzhou Qianyiyuan Synthetic Materials Technology Co., Ltd.;

[0051] The chloroprene rubber LDJ241 emulsion was purchased from Sichuan Changshou Chemical Plant;

[0052] The chloroprene rubber CR120 emulsion was purchased from LANXESS Germany;

[0053] The chloroprene rubber AR-840 emulsion was purchased from Shanghai Sendi Chemical Co., Ltd.

[0054] Example 1

[0055] This example provides a chlorine-containing acrylate rubber with excellent processing properties. The specific formula and preparation method are as follows:

[0056] S1. Emulsion A is composed of 50 parts of deionized water, 2 parts of emulsifier sodium dodecyl sulfonate, 34 parts of chloroprene rubber C84 emulsion, and 0.3 part of initiator ammonium persulfate;

[0057] S2. Emulsion B is composed of 60 parts of ethyl acrylate, 20 parts of butyl acrylate, 4 parts of hydroxyethyl acrylate, 0.5 part of acrylic acid, 0.5 part of octadecyl acrylate, and 0.1 part of molecular weight regulator n-dodecyl mercaptan;

[0058] S3. Emulsion B is added to emulsion A, and emulsification is carried out for 30 min at normal temperature under nitrogen protection to obtain emulsion C;

[0059] S4. In an inert atmosphere, 100 parts of deionized water and 1 part of sodium dodecyl sulfonate are added to the reaction kettle, and the temperature is raised to 60 °C;

[0060] S5. Transfer 1 / 5 part by weight of emulsion C to a reaction kettle and carry out the reaction under an inert atmosphere at 60 °C;

[0061] S6. After 20 min, transfer the remaining mixture of emulsion C to a dropping kettle and drop it into the reaction system of step S5. After dropping for 1.5 h under an inert atmosphere at 60 °C, the dropping is completed, and continue to react for 4 h to obtain a chlorine-containing acrylate rubber emulsion;

[0062] S7. At 80 °C, add the chlorine-containing acrylate rubber emulsion obtained in step S6 to 500 parts of an aqueous solution containing 20 parts of calcium chloride and 2 parts of sodium polyacrylate for demulsification, and then wash and dry until the water content is less than 0.5%, thus obtaining the raw rubber product ACM-Cl-1 of the chlorine-containing acrylate rubber.

[0063] Example 2

[0064] This example provides a chlorine-containing acrylate rubber with excellent processing performance. The specific formula and preparation method are as follows:

[0065] S1. Emulsion A is composed of 80 parts of deionized water, 1 part of emulsifier sodium dodecyl sulfonate, 66 parts of chloroprene rubber C84 emulsion, and 0.3 part of initiator ammonium persulfate;

[0066] S2. Emulsion B is composed of 5 parts of methyl acrylate, 45 parts of ethyl acrylate, 15 parts of butyl acrylate, 2 parts of 2-hydroxyethyl acrylate, 2 parts of acrylic acid, 1 part of octadecyl acrylate, and 0.05 part of molecular weight regulator n-dodecyl mercaptan;

[0067] S3. Add emulsion B to emulsion A and carry out emulsification for 30 min under normal temperature and nitrogen protection to obtain emulsion C;

[0068] S4. Under an inert atmosphere, add 120 parts of deionized water and 0.5 part of sodium dodecyl sulfonate to a reaction kettle and heat up to 70 °C;

[0069] S5. Transfer 1 / 5 part by weight of emulsion C to a reaction kettle and carry out the reaction under an inert atmosphere at 70 °C;

[0070] S6. After 30 min, transfer the remaining mixture of emulsion C to a dropping kettle and drop it into the reaction system of step S5. After dropping for 2 h under an inert atmosphere at 70 °C, the dropping is completed, and continue to react for 4 h to obtain a chlorine-containing acrylate rubber emulsion;

[0071] S7. At 80 °C, the chlorine-containing acrylate rubber emulsion obtained in step S6 is added to 600 parts of an aqueous solution containing 15 parts of aluminum chloride and 2 parts of sodium polyacrylate for demulsification, and then washed and dried until the water content is less than 0.5%, thus obtaining the raw rubber product ACM-Cl-2 of the chlorine-containing acrylate rubber.

[0072] Example 3

[0073] This example provides a chlorine-containing acrylate rubber with excellent processing performance. The specific formulation and preparation method are as follows:

[0074] S1. Emulsion A is composed of 80 parts of deionized water, 1 part of emulsifier sodium dodecylsulfonate, 49 parts of chloroprene rubber C84 emulsion, and 0.3 part of initiator potassium persulfate;

[0075] S2. Emulsion B is composed of 9.5 parts of methoxyethyl acrylate, 45 parts of ethyl acrylate, 20 parts of butyl acrylate, 2.5 parts of 2-hydroxyethyl acrylate, 0.5 part of acrylic acid, 1 part of octadecyl acrylate, and 0.05 part of molecular weight regulator n-dodecyl mercaptan;

[0076] S3. Emulsion B is added to emulsion A, and emulsification is carried out for 30 min under normal temperature and nitrogen protection to obtain emulsion C;

[0077] S4. In an inert atmosphere, 220 parts of deionized water and 1 part of sodium dodecylsulfonate are added to the reaction kettle, and the temperature is raised to 75 °C;

[0078] S5. 1 / 5 weight part of emulsion C is transferred to the reaction kettle, and the reaction is carried out at 75 °C in an inert atmosphere;

[0079] S6. After 30 min, the remaining mixture emulsion C is transferred to the dropping kettle and dropped into the reaction system of step S5. The dropping is completed after 3 h of dropping at 75 °C in an inert atmosphere, and the reaction is continued for 5 h to obtain the chlorine-containing acrylate rubber emulsion;

[0080] S7. At 80 °C, the chlorine-containing acrylate rubber emulsion obtained in step S6 is added to 800 parts of an aqueous solution containing 40 parts of sodium chloride and 4 parts of polyvinyl alcohol for demulsification, and then washed and dried until the water content is less than 0.5%, thus obtaining the raw rubber product ACM-Cl-3 of the chlorine-containing acrylate rubber.

[0081] Example 4

[0082] This example provides a chlorine-containing acrylate rubber with excellent processing performance. The specific formulation and preparation method are as follows:

[0083] S1. 60 parts of deionized water, 0.5 part of emulsifier sodium dodecyl sulfonate, 2 parts of emulsifier polyoxyethylene alkylphenol ether, and 38 parts of chloroprene rubber C84 emulsion form emulsion A;

[0084] S2. 10 parts of methyl acrylate, 45 parts of ethyl acrylate, 15 parts of butyl acrylate, 5 parts of ethoxyethyl acrylate, 5 parts of hydroxypropyl acrylate, 1 part of acrylic acid, 1 part of octadecyl acrylate, and 0.2 part of initiator diisopropylbenzene peroxide form emulsion B;

[0085] S3. Emulsion B is added to emulsion A, and emulsification is carried out for 30 min under normal temperature and nitrogen protection to obtain emulsion C;

[0086] S4. Under an inert atmosphere, 140 parts of deionized water, 0.005 part of ferrous sulfate, 0.2 part of sodium formaldehyde sulfoxylate, and 0.5 part of sodium dodecyl sulfonate are added to the reaction kettle, and the temperature is raised to 40 °C;

[0087] S5. 1 / 5 weight part of emulsion C is transferred to the reaction kettle, and the reaction is carried out at 40 °C under an inert atmosphere;

[0088] S6. After 20 min, the remaining mixture of emulsion C is transferred to the dropping kettle and dropped into the reaction system of step S5. Under an inert atmosphere, the dropping is completed after 1.5 h of dropping at 40 °C, and the reaction is continued for 4 h to obtain the chlorine-containing acrylate rubber emulsion;

[0089] S7. At 80 °C, the chlorine-containing acrylate rubber emulsion obtained in step S6 is added to an aqueous solution containing 20 parts of calcium chloride, 15 parts of hydrochloric acid, and 2 parts of sodium polyacrylate for demulsification, and then washed and dried until the water content is less than 0.5%, thus obtaining the chlorine-containing acrylate rubber raw rubber product ACM-Cl-4.

[0090] Example 5

[0091] This example provides a chlorine-containing acrylate rubber with excellent processing performance. The specific formula and preparation method are as follows:

[0092] S1. 80 parts of deionized water, 1 part of emulsifier sodium dodecyl sulfonate, 1 part of emulsifier polyoxyethylene sorbitan alkyl ester, and 55 parts of chloroprene rubber C84 emulsion form emulsion A;

[0093] S2. 15 parts of methyl acrylate, 40 parts of ethyl acrylate, 15 parts of butyl acrylate, 2 parts of 2-hydroxyethyl methacrylate, 1 part of methacrylic acid, 2 parts of octadecyl acrylate, and 0.1 part of initiator diisopropylbenzene peroxide form emulsion B;

[0094] S3. Emulsion B is added to emulsion A, and emulsification is carried out for 30 min under normal temperature and nitrogen protection to obtain emulsion C;

[0095] S4. Under an inert atmosphere, add 220 parts of deionized water, 0.003 parts of ferrous sulfate, 0.15 parts of sodium formaldehyde sulfoxylate, 0.5 parts of sodium dodecylbenzenesulfonate, and 0.5 parts of polyoxyethylene sorbitan fatty acid ester into the reaction kettle, and heat up to 50 °C;

[0096] S5. Transfer 1 / 5 weight part of emulsion C to the reaction kettle, and carry out the reaction at 50 °C under an inert atmosphere;

[0097] S6. After 20 min, transfer the remaining mixture of emulsion C to the dropping kettle, and drop it into the reaction system of step S5. Under an inert atmosphere, after dropping for 2.5 h at 50 °C, the dropping is completed, and continue to react for 3 h to obtain the chlorine-containing acrylate rubber emulsion;

[0098] S7. Under the condition of 80 °C, add the chlorine-containing acrylate rubber emulsion obtained in step S6 into 900 parts of an aqueous solution containing 30 parts of calcium chloride and 3 parts of sodium polyacrylate for demulsification, and then wash and dry until the water content is less than 0.5%, thus obtaining the raw rubber product ACM-Cl-5 of the chlorine-containing acrylate rubber.

[0099] Example 6

[0100] This example provides a chlorine-containing acrylate rubber with excellent processing performance. The specific formula and preparation method are as follows:

[0101] S1. 100 parts of deionized water, 1 part of emulsifier sodium dodecylsulfonate, 1 part of emulsifier polyoxyethylene alkylphenol ether, and 48 parts of chloroprene rubber C84 emulsion form emulsion A;

[0102] S2. 55 parts of ethyl acrylate, 5 parts of butyl acrylate, 15 parts of ethoxyethyl acrylate, 2 parts of hydroxyethyl acrylate, 0.5 parts of maleic anhydride, 0.5 parts of octadecyl acrylate, 0.2 parts of initiator tert-butyl peroxide, and 0.01 part of molecular weight regulator methylstyrene dimer form emulsion B;

[0103] S3. Add emulsion B to emulsion A, and carry out emulsification for 30 min at room temperature under nitrogen protection to obtain emulsion C;

[0104] S4. Under an inert atmosphere, add 200 parts of deionized water, 0.005 parts of ferrous sulfate, 0.2 parts of sodium formaldehyde sulfoxylate, and 2 parts of sodium dodecylsulfonate into the reaction kettle, and heat up to 40 °C;

[0105] S5. Transfer 1 / 5 weight part of emulsion C to the reaction kettle, and carry out the reaction at 60 °C under an inert atmosphere;

[0106] S6. After 30 min, transfer the remaining mixture emulsion C to a dropping kettle, and drop it into the reaction system of step S5. Under an inert atmosphere, after dropping for 2 h at 60 °C, the dropping is completed, and continue to react for 4 h to obtain a chlorine-containing acrylate rubber emulsion;

[0107] S7. Under the condition of 80 °C, add the chlorine-containing acrylate rubber emulsion obtained in step S6 to an aqueous solution containing 800 parts of water, 30 parts of calcium chloride, 10 parts of hydrochloric acid, and 2 parts of sodium polyacrylate for demulsification, and then wash and dry until the water content is less than 0.5%, to obtain the raw rubber product ACM-Cl-6 of the chlorine-containing acrylate rubber.

[0108] Example 7

[0109] This example provides a chlorine-containing acrylate rubber with excellent processing performance. The specific formula and preparation method are as follows:

[0110] S1. Emulsion A is composed of 100 parts of deionized water, 1 part of emulsifier sodium dodecyl sulfonate, 1 part of emulsifier polyoxyethylene alkylphenol ether, and 48 parts of chloroprene rubber CR244 emulsion;

[0111] S2. Emulsion B is composed of 55 parts of ethyl acrylate, 5 parts of butyl acrylate, 15 parts of ethoxyethyl acrylate, 2 parts of hydroxyethyl acrylate, 0.5 part of maleic anhydride, 0.5 part of octadecyl acrylate, 0.2 part of initiator tert-butyl peroxide, and 0.01 part of molecular weight regulator methylstyrene dimer;

[0112] S3. Add emulsion B to emulsion A, and carry out emulsification for 30 min under normal temperature and nitrogen protection to obtain emulsion C;

[0113] S4. Under an inert atmosphere, add 200 parts of deionized water, 0.005 ferrous sulfate, 0.2 part of sodium formaldehyde sulfoxylate, and 2 parts of sodium dodecyl sulfonate to the reaction kettle, and heat up to 40 °C;

[0114] S5. Transfer 1 / 5 part by weight of emulsion C to the reaction kettle, and carry out the reaction at 60 °C under an inert atmosphere;

[0115] S6. After 30 min, transfer the remaining mixture emulsion C to a dropping kettle, and drop it into the reaction system of step S5. Under an inert atmosphere, after dropping for 2 h at 60 °C, the dropping is completed, and continue to react for 4 h to obtain a chlorine-containing acrylate rubber emulsion;

[0116] S7. At 80 °C, the chlorine-containing acrylate rubber emulsion obtained in step S6 was added to an aqueous solution containing 30 parts of calcium chloride, 10 parts of hydrochloric acid, and 2 parts of sodium polyacrylate for demulsification, and then washed and dried until the water content was less than 0.5%, thus obtaining the chlorine-containing acrylate rubber raw rubber product ACM-Cl-7.

[0117] Comparative Example 1

[0118] Compared with the above-mentioned examples, no functional monomer was added in this comparative example. The specific formulation and preparation method are as follows:

[0119] S1. 100 parts of deionized water, 1 part of emulsifier sodium dodecyl sulfonate, 1 part of emulsifier polyoxyethylene alkylphenol ether, and 50 parts of chloroprene rubber C84 emulsion formed emulsion A;

[0120] S2. 56 parts of ethyl acrylate, 6 parts of butyl acrylate, 15 parts of ethoxyethyl acrylate, 0.2 part of initiator di-tert-butyl peroxide, and 0.01 part of molecular weight regulator methylstyrene dimer formed emulsion B;

[0121] S3. Emulsion B was added to emulsion A, and emulsification was carried out for 30 min at normal temperature under nitrogen protection to obtain emulsion C;

[0122] S4. In an inert atmosphere, 200 parts of deionized water, 0.005 ferrous sulfate, 0.2 part of sodium formaldehyde sulfoxylate, and 2 parts of sodium dodecyl sulfonate were added to the reaction kettle, and the temperature was raised to 40 °C;

[0123] S5. 1 / 5 weight part of emulsion C was transferred to the reaction kettle, and the reaction was carried out at 60 °C in an inert atmosphere;

[0124] S6. After 30 min, the remaining mixture emulsion C was transferred to the dropping kettle and dropped into the reaction system of step S5. The dropping was completed after 2 h of dropping at 60 °C in an inert atmosphere, and the reaction was continued for 4 h to obtain the chlorine-containing acrylate rubber emulsion;

[0125] S7. At 80 °C, the chlorine-containing acrylate rubber emulsion obtained in step S6 was added to an aqueous solution containing 30 parts of calcium chloride, 10 parts of hydrochloric acid, and 2 parts of sodium polyacrylate for demulsification, and then washed and dried until the water content was less than 0.5%, thus obtaining the chlorine-containing acrylate rubber raw rubber product ACM-Cl-D1.

[0126] Comparative Example 2

[0127] Compared with the above-mentioned examples, chloroprene rubber LDJ241 was selected in this comparative example, and other steps were the same as those in Example 1, and the chlorine-containing acrylate rubber raw rubber product ACM-Cl-D2 was prepared.

[0128] Comparative Example 3

[0129] Compared with the above-mentioned examples, chloroprene rubber CR120 was selected in this comparative example, and the other steps were the same as those in Example 1, and the chlorinated acrylate rubber raw rubber product ACM-Cl-D3 was prepared.

[0130] Comparative Example 4

[0131] The acrylate rubber raw rubber in this comparative example was commercially available AR-840.

[0132] The properties of the chlorinated acrylate rubber described in the present invention can only be reflected in the vulcanized rubber after vulcanization. Vulcanization requires a suitable vulcanization formula. The chlorinated acrylate rubber composition provided by the present invention includes: chlorinated acrylate rubber, vulcanizing agent, vulcanization accelerator, reinforcing agent, antioxidant, and mold release agent.

[0133] According to the rubber processing formula shown in Table 1, the chlorinated acrylate rubber raw rubber prepared in the above examples and comparative examples was added to a two-roll mill, and the reinforcing filler, inert filler, stearic acid, antioxidant and other mixtures were added in batches. After all the powders were mixed into the rubber, the mixture of vulcanizing agent and vulcanization accelerator was finally added. After rolling 4 triangle bales, the sheet was taken out to obtain the mixed rubber, which was parked at room temperature for 8 hours. Then the mixed rubber was vulcanized under certain conditions to obtain vulcanized rubber. The primary vulcanization conditions were: vulcanization temperature 180°C, vulcanization pressure 15 MPa, vulcanization time 10 minutes; the secondary vulcanization conditions were: vulcanization temperature 180°C, vulcanization time 4 hours.

[0134] Table 1 Rubber processing formula

[0135]

[0136]

[0137] The properties of the chlorinated acrylate rubber prepared in the above examples and comparative examples were tested. The specific test items and test methods are as follows:

[0138] 1. Mooney viscosity test

[0139] Test sample: The mixed rubber obtained by mixing the chlorinated acrylate rubber obtained in each example and comparative example.

[0140] Test method: Test according to the determination of Mooney viscosity in the first part of GB / T 1232.1-2000. The experimental temperature is 100°C, the preheating time is 1 min, and the test time is 4 min.

[0141] The test results are shown in Table 2.

[0142] 2. Mooney scorch time t5 test

[0143] Test samples: The kneaded rubber compounds obtained by kneading the chlorine-containing acrylate rubbers from each example and comparative example.

[0144] Test method: Test according to GB / T1233-92, and test the scorch time t5 and the optimum cure time t90 of the rubber compound at 120 °C.

[0145] The test results are shown in Table 2.

[0146] 3. Hardness test

[0147] Test samples: The vulcanized rubbers obtained by vulcanizing the chlorine-containing acrylate rubbers from each example and comparative example.

[0148] Test method: Test according to GB / T 531.1-2008 Part 1: Shore hardness tester method (Shore hardness).

[0149] The test results are shown in Table 2.

[0150] 4. Mechanical property test

[0151] Test samples: The vulcanized rubbers obtained by vulcanizing the chlorine-containing acrylate rubbers from each example and comparative example.

[0152] Test instrument: Universal material testing machine (Shenzhen New SANS Metrology Technology Co., Ltd.)

[0153] Test method:

[0154] 4.1 Test the tensile properties of vulcanized rubber according to GB / T 528-2009;

[0155] 4.2 Test the tear strength of vulcanized rubber according to GB / T 529-2008, and the specimen is rectangular;

[0156] 4.3 Test the compression set value of vulcanized rubber according to GB / T 7759-1996 (Method B), and the test conditions are: test temperature 150 °C, placement time 70 h, and pre-compression ratio 25%.

[0157] The test results are shown in Table 2.

[0158] 5. Adhesion to roll test and evaluation

[0159] Test samples: Each formulation in Table 1.

[0160] Test method: Roller speed 20 r / min, roller gap 2 mm, roller diameter 8 mm, roller temperature 50 °C

[0161] Evaluation criteria: 5 - Excellent processing performance, 4 - Good processing performance, 3 - Slightly sticky, 2 - Highly sticky, 1 - Unable to knead.

[0162] The test results are shown in Table 2.

[0163] 6. Mold Pollution and Corrosion Performance Test

[0164] Test Samples: Each formulation in Table 1.

[0165] Test Method: Test according to the GM method

[0166] Evaluation Criteria: 0 - No pollution, 1 - Very slight pollution, 2 - Slight pollution, 3 - Moderate pollution, 4 - Severe pollution, 5 - Extreme pollution.

[0167] The test results are shown in Table 3.

[0168] 7. Demolding Performance Test

[0169] Test Samples: The mixed rubbers obtained by mixing the chlorine - containing acrylate rubbers from each example and comparative example.

[0170] Test Method: After laminating the raw rubber on a metal plate and vulcanizing at 180 °C for 3 min, measure the peel strength (90° peel).

[0171] The test results are shown in Table 2.

[0172] 8. Extrusion Performance Test

[0173] Test Samples: The mixed rubbers obtained by mixing the chlorine - containing acrylate rubbers from each example and comparative example.

[0174] Test Method: Extrude with an extruder, the barrel temperature is 60 °C, the head temperature is 80 °C, the rotation speed is 30 r / min, measure the extrusion amount, extrusion speed, and extrusion swelling ratio.

[0175] The test results are shown in Table 2.

[0176] Table 2 Processing Performance Test Results

[0177]

[0178]

[0179] Table 3 Test Results of Different Mold Pollution and Corrosion Performances

[0180]

[0181] Among them, no functional monomer was added in Comparative Example 1. Therefore, the processed chlorinated acrylate rubber prepared in Comparative Example 1 is prone to sticking to the roll and die, has a slow vulcanization speed, and is prone to scorching; the vulcanized rubbers prepared by adding other chloroprene rubber emulsions in Comparative Examples 2 and 3 have poor mechanical properties and cannot meet the use requirements; Comparative Example 4 is a commercially available ordinary acrylate rubber, which has poor processing mechanical properties, is prone to sticking to the roll, and is prone to corroding the die.

[0182] The Mooney viscosity has a great influence on the sticking phenomenon of the milled rubber during open milling. A lower Mooney viscosity is more likely to cause sticking to the roll, while a higher Mooney viscosity is prone to elastic roll-off. From the above test results, it can be seen that the Mooney viscosity of the milled rubber obtained from each example is higher than that of the milled rubber obtained from each comparative example, indicating that the chlorinated acrylate rubber of the present invention improves the sticking phenomenon during the processing.

[0183] The scorch time t5 of the vulcanized rubber of each example is above 10 min, longer than that of the comparative examples, with strong scorch resistance and good processing stability. At the same time, the optimum vulcanization time t90 of the vulcanized rubber of each example is about 6 - 7.5 min, indicating a moderate vulcanization speed and good basic mechanical properties.

[0184] From the test results in Table 2, it can be seen that the processing performance of the rubber of each example is better than that of each comparative example.

[0185] From the test results in Table 3, it can be seen that the pollution of the rubber of each example to the die is significantly less than that of the rubber of each comparative example.

[0186] The specific embodiments described above further elaborate on the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only the specific embodiments of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A chlorine-containing acrylate rubber, characterized in that It is made by polymerizing monomers calculated by weight percentage as follows: Among them, the chloroprene rubber emulsion is one or a combination of two of Bayer C84 and CR-244.

2. The chlorine-containing acrylate rubber according to claim 1, wherein The solid content of the chloroprene rubber emulsion is 45%.

3. The chlorine-containing acrylate rubber according to claim 1, wherein The alkyl acrylate is one or a combination of several of methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, and isooctyl acrylate.

4. The chlorine-containing acrylate rubber according to claim 1, wherein The hydroxy acrylate is one or a combination of several of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate.

5. The chlorine-containing acrylate rubber according to claim 1, wherein The ethylenically unsaturated monomer containing a carboxyl group is one or a combination of several of acrylic acid, methacrylic acid, ethylacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, monomethyl maleate, monoethyl maleate, monobutyl maleate, monomethyl fumarate, monoethyl fumarate, monobutyl fumarate, maleic anhydride, and fumaric anhydride.

6. The chlorine-containing acrylate rubber according to claim 1, wherein The octadecyl acrylate is one or a combination of several of octadecyl methacrylate and octadecyl acrylate.

7. The preparation method of the chlorine-containing acrylate rubber according to any one of claims 1 to 6, characterized in that, It includes the following steps: S1. Deionized water, an emulsifier, and a chloroprene rubber emulsion are mixed to form a mixed solution A, so that the solid content of chloroprene rubber in the mixed solution A is 30-40%; S2. The alkyl acrylate, hydroxy acrylate, ethylenically unsaturated monomer containing a carboxyl group, octadecyl acrylate, and a molecular weight regulator are mixed to form a mixed solution B, and an initiator is added to the mixed solution A or the mixed solution B; S3. The mixed solution B is added to the mixed solution A for emulsification to obtain an emulsion C; S4. Under an inert atmosphere, deionized water and an emulsifier are added to the reaction kettle and heated to 20-80 °C; S5. 1 / 6-1 / 3 parts by weight of the emulsion C is transferred to the reaction kettle that has completed step S4, and the reaction is initiated under an inert atmosphere; S6. After the reaction in S5 is sufficient, the remaining emulsion C is added dropwise to the system in S5. After the addition is completed, the reaction continues for 2-5 h, and after post-treatment, a chlorine-containing acrylate rubber emulsion is obtained.

8. The preparation method of the chlorine-containing acrylate rubber according to claim 7, wherein, The emulsifier is one or a combination of several of polyoxyethylene alkyl ether, polyoxyethylene alkylphenol ether, polyoxyethylene sorbitan alkyl ester, dodecyl sulfonate, and dodecyl benzene sulfonate.

9. The preparation method of the chlorine-containing acrylate rubber according to claim 7, characterized in that, The total amount of the emulsifier used is 0.5-4% of the total mass of the polymerization monomers.

10. A rubber product is processed from the chlorine-containing acrylate rubber according to any one of claims 1 to 6.

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