CN1200021C - Preparation method of carboxy-nitril latex with high strong action for impregnating product - Google Patents

Abstract

The present invention belongs to the preparation of carboxylic acrylonitrile butadiene rubber latex for manufacturing a pair of oil resistant industrial gloves without linings. 80 to 150 portions of deineralized water, 2.5 to 4.0 portions of emulsifying agent, 0.7 to 1.5 portions of molecular weight regulator, 0.1 to 0.6 portion of pH buffer, 50 to 65 portions of polymerization monomer butadiene, 35 to 45 portions of acrylonitrile, 3 to 10 portions of unsaturated carboxylic acid C, 1 to 8 portions of unsaturated carboxylic ether C or 1 to 4 portions of ethenyl carboxylate D are added, and finally, 0.1 to 1.0 protion of initiating agent is added. The temperature of the first stage is from 20 to 30 DEG C, 0 to 10 portions of acrylonitrile, 1 to 2 portions of unsaturated acid C, 0.5 to 1 portion of unsaturated carboxylic ether C and 0.5 to 1 portion of ethenyl carboxylate are added, and residual monomers continuously react. A primary emulsifying agent, a reducer and additional liquid are added and react for 12 hours, additional liquid is added for the second time and the third time, and the carboxylic acrylonitrile butadiene rubber latex is prepared when reaction is carried out till a conversion rate reaches more than 97%. The preparation ameliorates the softness of a latex product, gel generation is prevented, the prior period speed of the reaction is reduced, the physicochemical performance of latex is improved, and obvious performance change is not generated in a storage period.

Description

A kind of dipped goods of extra-high-speed brute force preparation method of carboxylic acrylonitrile butadiene rubber latex

The invention belongs to make linerless in the synthetic latex technology of oil resistant industrial gloves, be the preparation method of a kind of dipped goods of extra-high-speed brute force with carboxylic acrylonitrile butadiene rubber latex

Industrial gloves is the appliances for labor protection of field of petrochemical industry in linerless, is divided into light expert cover, suede expert cover, and this gloves require oil resistant, tear fracture brute force 〉=25MPa.Its used raw material mainly is the principal element of modified carboxyl nitrile rubber.This modified carboxyl butadiene-acrylonitrile rubber lactonitrile content is higher, in conjunction with nitrile between 35-38%.The latex product of high-nitrile, oil-proofness is good, and tear fracture is powerful high.But the weak point of high-nitrile is goods hardens, and the wearing comfort is poor.In order to improve the deficiency of this respect, just to use the 4th, the 5th monomer modifiedly, the 4th, the 5th monomer is used esters of unsaturated carboxylic acids more.As methyl methacrylate, the polysubstituted thing of hydroxyl esters of unsaturated carboxylic acids or unsaturated carboxylic acid ester group etc. can improve the flexibility of superpolymer, the brute force that can not lose superpolymer again.Four, the 5th monomeric consumption and all monomer adding modes are the keys of modification.Especially the actual of nitrile is the gordian technique that this latex is produced in conjunction with situation.Nitrile rubber, especially high nitrile rubber breast, the exothermic heat of reaction fierceness, the mechanical stability of latex is relatively poor, selects suitable emulsification system extremely important.Emulsification system should keep pH value vary stable and certain mechanical stability in reaction process, have the characteristics to the susceptibility (unstable) of dipping calcium ion again.Emulsification system adopts the polynary compound system of nonionic emulsifying agent and anionic emulsifier more.Initiator system mainly adopts the elevated temperature heat initiator system and the oxidation-reduction low temperature polymerization of persulphate.How the method that removes residual monomer also has method with chemical method and usefulness with decompression gas formulation.Degassing equipment is the support condition of this technology.Rerum natura for the product that guarantees latex adds auxiliary agents such as anti-aging agent in latex, add the stability of alkali with pH value in the maintenance system.For this reason, the U.S., Germany, Japanese firm innovate at monomer system, emulsification system, initiator system, processing condition, the aspects such as method of deviating from residual monomer, have independently formed unique technique.

The object of the invention is to provide a kind of latex product flexibility of improving, prevent that gel from producing, reduce the speed in early stage of reaction, improve the physical and chemical performance of latex product, make latex the dipped goods of extra-high-speed brute force of tangible performance variation not take place with the preparation method of carboxylic acrylonitrile butadiene rubber latex in storage period.

The present invention adopts following technical scheme:

1) monomer divides three addings, adds the semi-continuous emulsion polymerizing method of emulsifying agent and reductive agent three times.Initiator system is an oxidation-reduction system.Temperature is controlled to be the ladder temperature control.Temperature range 20-65 ℃.

2) synthetic set of dispense ratio: divinyl 40-60 part, vinyl cyanide 35-45 part, unsaturated carboxylic acid C3-8 part, esters of unsaturated carboxylic acids C0-8 part, vinyl carboxyl ester D0--3-4 part, emulsifying agent is sodium lauryl sulphate, OP, Sodium dodecylbenzene sulfonate, diffusant.The emulsifying agent consumption is 1.2-5.4 part, initiator 0.09-0.55 part, and molecular weight regulator 0.1-3.5 part, pH value buffer reagent is 0.3-0.5 part, and inorganic salt are 0.05-0.40 part, and de-salted water is 80-150 part, and terminator is 45-390ppm.

3) technological process:

Under vacuum, drop into soft water, partial emulsifier, molecular weight regulator, pH buffer reagent, partial monosomy in proportion, add initiator and partial reduction agent at last.By three sections temperature of reaction requirement temperature controls, by adding some an adding emulsifying agent and a reductive agent, partial monosomy.Transformation efficiency reaches more than 45.0%, the processing that outgases, and pH reaches between the 7-8 with alkali lye impregnation breast, adds terminator at last.

The present invention improves the latex product flexibility.Prevent that gel from producing, reduce the speed in early stage of reaction, the different monomer of reactivity ratio relatively is evenly distributed on the polymer key, improve the physical and chemical performance of latex product, improve processing performance.Make latex that tangible performance variation not take place in storage period.The latex that uses the present invention to produce, during auxiliary agents such as interpolation vulcanizing agent, precipitation precipitate≤0.5%.Film forming speed is fast, but 10s film forming 0.45-0.55mm.Glued membrane is easy to take off from fingerprint, yield rate 〉=95%.Before aging, elongation 〉=580%, tensile strength at yield 30MPa.After aging, elongation 〉=500%, tensile strength at yield 〉=25MPa.

Accompanying drawing of the present invention is a process flow diagram.

The embodiment of the invention is as follows:

Example one:

1. latex production

1) process that feeds intake: at first polymeric kettle is vacuumized, use nitrogen replacement again, vacuum tightness reaches-during 0.10Mpa, drop into 115 parts of de-salted waters successively, 1.0 parts of sodium alkyl sulfates, the ninth of the ten Heavenly Stems, phenolic group Soxylat A 25-7-10 was 0.8 part, 0.8 part of Sodium dodecylbenzene sulfonate, diffusion agent N F0.2 part, 0.3 part in inorganic salt, 0.30 part of pH buffer agent solution, 30 parts of vinyl cyanide, 1.0 parts of molecular weight regulators, 4.0 parts of unsaturated carboxylic acid C (vinyl carboxylic acid), esters of unsaturated carboxylic acids C3.0 part, esters of unsaturated carboxylic acids D1.0 part stops to vacuumize.Add 50 parts of divinyl, add 0.40 part of initiator solution at last.

2) reaction is controlled and is added: 25 ± 2 ℃ of controlled temperature, keep reaction 6 hours, and add residual monomer (10 parts of vinyl cyanide, unsaturated carboxylic acid C1.0 part, esters of unsaturated carboxylic acids C0.5 part, esters of unsaturated carboxylic acids D0.5 part), continue to keep being reacted to 9 hours, adding is added liquid for the first time, and (wherein de-salted water is 5 parts, 0.05 part of sodium lauryl sulphate, OP0.04 part, 0.04 part of Sodium dodecylbenzene sulfonate, 0.001 part of diffusant, 0.15 part of reductive agent).Put temperature in 40 minutes to 40 ± 1 ℃.Keep reaction 3 hours.Add and add liquid (wherein de-salted water is 5 parts, 0.05 part of sodium lauryl sulphate, OP0.04 part, 0.04 part of Sodium dodecylbenzene sulfonate, diffusion agent N F0.001 part, 0.1 part of reductive agent) for the second time, put temperature in 40 minutes to 55 ± 1 ℃.Keep and be reacted to end.

3) remove residual monomer and aftertreatment: transformation efficiency reaches 45% when above, and stopped reaction in degassing still vacuum tightness be-during 0.10MPa, change latex over to degassing still and outgas, and removes residual monomer, and the degassing time is 1.5 hours.The back slowly adds alkali lye and regulates the pH value to 7-8, adds terminator 200ppm again, filters and packages at last.

2. the physical index of latex

(1) total solid substance＞＞45%, (2) pH value 7-8 (3) viscosity≤100mPas (4) surface tension≤50mN/m (5) density 0.98 ± 0.03g/cm ³(6) particle diameter 140-160nm (7) structural gel≤35% (8) macroscopical gel≤0.01% (9) is in conjunction with nitrile 34-36%, (10) combined acid 35-45%.

3. application performance

1) Technological adaptability is good, curing temperature 110-120 ℃.

Good stability when 2) adding vulcanization aid, precipitation precipitate≤0.5%.

3) glued membrane is bright and clean bright in vain.

4) film forming speed is fast, but 10s film forming 0.45-0.55mm.Glued membrane is easy to take off from fingerprint, yield rate 〉=95%.

5) mechanical property of aging front and back: before aging, elongation 〉=580%, tensile strength at yield 35MPa.After aging, elongation 〉=500%, tensile strength at yield 〉=35MPa.

Example two: if esters of unsaturated carboxylic acids C does not use, only use esters of unsaturated carboxylic acids D, total consumption is 3.0 parts, originally add 2.0 parts, add 1.0 parts in batches, 52 parts of divinyl, the consumption of other monomer and auxiliary agent is constant, technology is identical, and then reaction gradient, the physical index of being produced, application indexes are all in example one scope.

Example three: if without esters of unsaturated carboxylic acids D, the total amount of esters of unsaturated carboxylic acids C is 5.0 parts, originally adds 4.0 parts, divide and add 1.0 parts, the consumption of other monomer and auxiliary agent is constant, and technological process is identical with example one, and the physical index of the latex of producing with this example and application indexes are still in the scope of example one.

Example four: if do not take the mode that adds in batches, monomeric kind, proportioning and example one or example two, example three are identical, and the consumption of initiator should be 0.30 part, and originally temperature of reaction is controlled at 25 ± 1 ℃.Other auxiliary dosage and technology are identical with example one, and the latex of being produced is identical with example one.

Example five: if reduce de-salted water consumption total amount is 110 parts, originally adds 102 parts, when adding for twice with each 4 parts of de-salted waters, and 0.3 part of the consumption of initiator.The consumption of various emulsifying agents reduces by 3%, and the latex of producing by this example is identical with example one.

Example six: if reduce the consumption to 37 part (originally add 30 parts, divide and add 7 parts) of vinyl cyanide, the divinyl consumption increases to 53 parts, and the consumption of initiator is reduced to 0.30 part, and other monomer and auxiliary dosage, technology are identical with example one.The physical index of the latex of producing by this example and application indexes are still in example one scope.

Example seven: if the vinyl cyanide consumption is 37 parts, 53 parts of divinyl, initiator are 0.25 part, and other monomer, auxiliary dosage, processing condition are identical with example four, and the physical index of the latex of being produced and application indexes are still in the scope of example one.

Example eight: if emulsifying agent and reductive agent that cancellation is added for the second time, other component, technology are with example one.

Physical Property Analysis index: particle diameter 160-180nm, surface tension≤40mN/m, structural gel＞60%, viscosity＞100mPas.

Application result: the film-forming properties of latex is poor, can not satisfy the requirement of process industry gloves.

Claims (2)

1. the dipped goods of an extra-high-speed brute force is characterized in that adopting the intermittent type emulsion polymerization technique with the preparation method of carboxylic acrylonitrile butadiene rubber latex, and initiator system is the oxidation-reduction system; Specific embodiment is as follows: polymeric kettle vacuumizes, use nitrogen replacement, add de-salted water 80-150 part then by weight ratio successively, emulsifying agent 2.5-4.0 part, molecular weight regulator 0.7-1.5 part, pH buffer reagent 0.1-0.6 part, add polymerization single polymerization monomer divinyl 50-65 part again, vinyl cyanide 35-45 part, vinylcarboxylic acid 3-10 part, vinyl carboxylate 1-4 part, add initiator 0.1-1.0 part at last, three periods ladder temperature control fs are 20-30 ℃, keep reaction 6 hours, add vinyl cyanide 0-10 part, vinylcarboxylic acid 1-2 part, vinyl carboxylate 0.5-1 part residual monomer continues to keep and is reacted to 9 hours, add and add liquid, wherein emulsifying agent for the first time, reductive agent accounts for the 3-7% of its gross weight, is warmed up to 30-40 ℃, keep and be reacted to 12 hours, add and add liquid, wherein emulsifying agent for the second time, reductive agent accounts for the 3-6% of its gross weight, is warmed up to 40-55 ℃, keep and be reacted to 14 hours, add and add liquid, wherein emulsifying agent for the third time, reductive agent accounts for the 3-6% of its gross weight, keeps to be reacted to transformation efficiency and to reach 45% when above, stopped reaction removes residual monomer and aftertreatment then.

2. the dipped goods of a kind of extra-high-speed brute force according to claim 1 preparation method of carboxylic acrylonitrile butadiene rubber latex, it is characterized in that: obtaining the carboxylic acrylonitrile butadiene rubber latex performance is: total solid substance 〉=45%, pH7-8, viscosity≤100mPa.S, surface tension≤50mN/m, density=0.98-1.01g/cm ³, particle diameter 130-160nm, structural gel≤30%, macroscopical gel≤0.01%, its product properties: tensile strength at yield is greater than 30Mpa, and elongation is greater than 400%.