+

WO1997042017A1 - Procede d'obtention d'articles enduits au trempe - Google Patents

Procede d'obtention d'articles enduits au trempe Download PDF

Info

Publication number
WO1997042017A1
WO1997042017A1 PCT/EP1997/002096 EP9702096W WO9742017A1 WO 1997042017 A1 WO1997042017 A1 WO 1997042017A1 EP 9702096 W EP9702096 W EP 9702096W WO 9742017 A1 WO9742017 A1 WO 9742017A1
Authority
WO
WIPO (PCT)
Prior art keywords
weight
monomers
aqueous
emulsion polymerization
monomer
Prior art date
Application number
PCT/EP1997/002096
Other languages
German (de)
English (en)
Inventor
Peter Claassen
Onno Graalmann
Wolfgang Alois Hormuth
Klaus Joachim MÜLLER-ENGEL
Original Assignee
Basf Aktiengesellschaft
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Basf Aktiengesellschaft filed Critical Basf Aktiengesellschaft
Priority to EP97921741A priority Critical patent/EP0904184A1/fr
Priority to CA002253909A priority patent/CA2253909A1/fr
Priority to AU27699/97A priority patent/AU2769997A/en
Priority to BR9709136A priority patent/BR9709136A/pt
Priority to JP9539481A priority patent/JP2000509421A/ja
Publication of WO1997042017A1 publication Critical patent/WO1997042017A1/fr
Priority to NO985119A priority patent/NO985119D0/no

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C41/00—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor
    • B29C41/02—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor for making articles of definite length, i.e. discrete articles
    • B29C41/14—Dipping a core
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08C—TREATMENT OR CHEMICAL MODIFICATION OF RUBBERS
    • C08C1/00—Treatment of rubber latex
    • C08C1/14—Coagulation
    • C08C1/145—Heat-sensitising agents
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F36/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds
    • C08F36/02—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds
    • C08F36/04—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds conjugated
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/02—Direct processing of dispersions, e.g. latex, to articles
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L9/00—Compositions of homopolymers or copolymers of conjugated diene hydrocarbons
    • C08L9/10—Latex
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2321/00—Characterised by the use of unspecified rubbers

Definitions

  • the present invention relates to a process for the production of immersion articles, in which a molded body is immersed in an aqueous latex immersion preparation in order to form a continuous polymer film on the surface of the molded body.
  • Aqueous latices (aqueous polymer dispersions) are generally known. These are fluid systems which contain, as a disperse phase in an aqueous dispersion medium, polymer balls consisting of a plurality of intertwined polymer chains (so-called polymer particles) in a disperse distribution.
  • aqueous polymer dispersions have the potential to form a coherent polymer matrix when the dispersant is deactivated in a controlled manner by partially or completely fusing the dispersed polymer particles.
  • radical aqueous emulsion polymerization 5 takes place at temperatures which are not too high and, if appropriate, with the use of substances which regulate the molecular weight, such as mercaptans (for example tert-dodecyl mercaptan or n-dodecyl mercaptan), only one of the two conjugated ethylenically takes substantially unsaturated double bonds 10 in the polymerization reaction.
  • mercaptans for example tert-dodecyl mercaptan or n-dodecyl mercaptan
  • aqueous latex preparations activated in association with elevated temperature and targeted to form a reaction with the formation of intramolecular crosslinking
  • Typical aqueous latex dipping preparations contain (see e.g. rubber handbook, volume 4, Berlin Union Verlag, Stuttgart, 30 1961, p. 247):
  • vulcanization accelerators are necessary because of the inertness of the sulfur and the second olefinically unsaturated group of the polymerized conjugated diene.
  • the most important accelerators are thiazoles (also called mercapto accelerators) like 2-mercaptobenzothiazole, whose Zinc salt and dibenzothiazyl disulfide, sulfenamides such as benzothiazyl-2-cyclohexylsulfenamide, benzothiazyl -2-tert.
  • guanidines such as diphenylguanidine, di-orthotolyl-guanidine and ortho-tolylbiguanidine
  • thiurams such as tetramethyl, thiuram disulfide and zinc tetramethylthiamidithiamidithiamidithiamidithiamidithi, such as tetramethyldithamidithiamidithiamidithi, such as tetramethyldimidate and tetraulfidylamidithi N-diethyl dithiocarbamate, zinc-N-dibutyl dithiocarbamate, zinc N-ethylphenyldithiocarbamat and zinc N-pentamethylendithiocarbamat, Thiolenstoffe lenthioharnstoff as ethylene, cloth
  • the vulcanization accelerators In order to develop their optimal effectiveness, the vulcanization accelerators normally require the addition of zinc oxide as an activator.
  • the unsaturated groups still present in the latex dipping preparation which on the one hand enable vulcanization due to their reactivity with sulfur, on the other hand cause sensitivity to reactive influences such as 0 2 or UV radiation.
  • the latex can harden and become brittle (age).
  • Bacterial attack on the organic polymer is an additional source of aging.
  • anti-aging agents such as Wingstay L are normally added to the latex dipping preparation.
  • a shaped body is now immersed in the aqueous latex immersion preparation and a coherent polymer film is deposited on the surface of the shaped body as a polymer matrix by controlled coagulation.
  • the molded body is then removed from the aqueous latex dipping preparation, dried, the polymer film enveloping the molded body is vulcanized by the action of heat, and then the vulcanized diving article (for example suction cups, condoms, medical gloves, surgical gloves, industrial gloves, housewife gloves, fingers, balloons or special goods for medical purposes) is stripped from the molded body and optionally washed, dried and optionally powdered or chlorinated.
  • the vulcanized diving article for example suction cups, condoms, medical gloves, surgical gloves, industrial gloves, housewife gloves, fingers, balloons or special goods for medical purposes
  • An aqueous latex dipping preparation is used for the electrolyte coagulation, the aqueous latex of which is mainly stabilized with regard to its disperse distribution by suitable anionic emulsifiers.
  • surfactant here simply means an amphiphilic substance that, when dissolved in water (at 25 ° C and 1 atm), can reduce the surface tension of the pure water.
  • amphiphilic means that surfactants have both hydrophilic and hydrophobic groups.
  • Anionic emulsifiers are those in which the hydrophilic groups in the aqueous medium carrying a negative charge, face wherein these hydrophilic groups small, the boundary surface-active properties of the anionic emulsifier ion little be ⁇ inflow end monovalent cations such as alkali metal or ammonium.
  • Oriented adsorption of the anionic emulsifier on the essentially non-polar surface of the dispersed polymer particles gives polymer particles which have a negative surface charge and whose mutual charge repulsion stabilizes their disperse distribution.
  • nonionic emulsifiers have no ionic charge in the aqueous medium.
  • the hydrophilicity of their hydrophilic grouping is generally determined by the polarity of an increased number of covalently bound oxygen atoms.
  • electrolyte coagulation is based on the fact that a molded body is immersed in the aqueous latex dipping preparation, the surface of which is an electrolyte (sub- punch, which dissociates in the presence of water in anion and cation), the cation of which interacts with the anionic emulsifier group in such a way that its stabilizing effect is reduced in a controlled manner and the desired coagulation is triggered.
  • electrolyte sub- punch, which dissociates in the presence of water in anion and cation
  • thermocoagulation While an aqueous latex immersion preparation which is sensitive to the addition of electrolyte is used for the electrolyte coagulation, an aqueous latex immersion preparation which is sensitive to an increase in temperature is required for the thermocoagulation.
  • coagulants are added to the aqueous latex dipping preparation which only become effective above a certain temperature, the coagulation temperature. If one immerses a shaped body having an elevated temperature in such a heat-sensitized aqueous latex immersion preparation, coagulation occurs on its surface which continues until the surface temperature of the shaped body is permanently below the set coagulation temperature of the aqueous latex immersion preparation.
  • a disadvantage of the above-mentioned procedure is that moldings with a very narrow range of uniform heat capacity and temperature are required for uniform thicknesses of the immersion article. Furthermore, particularly high removal speeds are necessary in order to achieve a uniform film thickness along the shaped body. Furthermore, the mechanical property profile of the resulting diving article is often not fully satisfactory.
  • a disadvantage is the increased immersion time required for a given film thickness, which is due to the fact that the coagulation electrolyte requires a certain time to diffuse through the gradually thicker film and to bring other parts of the aqueous latex immersion composition to coagulation .
  • the object of the present invention was to provide a process for the production of immersion articles, in which a molded body is immersed in an aqueous latex immersion preparation, which has both the advantages of electrolyte coagulation and the advantages of thermocoagulation.
  • a process has been found for the production of diving articles in which, normally at a pressure of 1 atm, a molded body having a temperature T, the surface of which has an electrolyte adsorbed as a coagulant, is immersed in an aqueous latex dipping preparation which is an aqueous polymer dispersion, the monomers having at least 30% by weight of two conjugated ethylenically unsaturated monomers having double bonds have been obtained by the method of free radical aqueous emulsion polymerization and have, based on the weight of the dispersed polymer, monomers ,
  • the electrolyte adsorbed on the molded body surface is a Bronsted acid and / or a salt
  • the free radical aqueous emulsion polymerization takes place in the presence of dispersants which consist of at least 50% by weight of water-soluble alkali metal and / or ammonium salts of the monosulfonic acids of C ⁇ o to C 2 o "hydrocarbons,
  • the aqueous latex dipping preparation contains, as a thermal coagulant, a nonionic, polyether group-containing, organosilicon surfactant with a cloud point in the range from 20 to 60, preferably 30 to 40 ° C. and
  • T is above the cloud point of the organosilicon surfactant.
  • T is> 40 to ⁇ 150 ° C.
  • T is preferably 60 to 90 ° C.
  • the cloud point is the temperature at which the aqueous solution of the polyether-modified organosilicon compound, which is clear at 20 ° C., decomposes into two phases when the temperature rises (usually the cloud point is based on a 4% strength by weight aqueous solution of the surfactant ).
  • the effect of the above-mentioned organosilicon surfactants according to the invention is presumably based on the fact that at low temperature they are able to dissolve in an aqueous medium with hydration.
  • surfactants in which the polyether-modified organosilicon compound is grafted as a hydrophilic part onto the polymer of a conjugated diene, preferably 1,2-polybutadiene, as a hydrophobic part, as described e.g. in DE-A 3218676, DE-A 2321557 and DE-3718588 Cl are disclosed by way of example.
  • Suitable modifying polyether groups are homopolymers and copolymers of alkylene oxides such as ethylene oxide, propylene oxide or isobutylene oxide. Homopolymers of are preferred Ethylene oxide.
  • the number average relative molecular weight of the nonionic polyether-modified organosilicon surfactants to be used according to the invention is> 1000 and ⁇ 50000.
  • Preferred inventive use poly- ether-modified organosilicon surfactants are the commercial products Basensol ® HA 5 (cloud point: 38 ° C) from BASF AG and Coagulant WS (cloud point: 32 ° C) of Bayer AG.
  • the amount of polyether-modified organosilicon compound required according to the invention is generally 0.1 to 5% by weight.
  • alkali metal and / or ammonium salts of the radi ⁇ -earth aqueous emulsion according to the invention preferably the sodium salts to be used with Cio * to C 2 o "are hydrocarbyl.
  • Examples include sodium dodecyl sulfonate, sodium myristyl sulfonate and sodium stearyl sulfonate as representatives of the sulfonates of aliphatic Cio to C 2 o "hydrocarbons, and sodium Dodecylbenzenesulfonate as representatives of alkylaryl sulfonates.
  • sodium dodecyl sulfonate, sodium myristyl sulfonate and sodium stearyl sulfonate as representatives of the sulfonates of aliphatic Cio to C 2 o "hydrocarbons
  • sodium Dodecylbenzenesulfonate as representatives of alkylaryl sulfonates.
  • mixtures of such sulfonates of C ⁇ o- to C 2 " can also be used are how they are commercially available (eg Cicr, C ⁇ 2 - and C ⁇ 3 alkylbenzenesulfonate mixtures or
  • radical aqueous emulsion polymerization based on the amount of the resulting dispersed emulsion polymer, usually 0.1 to 5% by weight, usually 0.5 to 2% by weight, of the water-soluble alkali metal and / or ammonium salts of the monosulfonic acids from Cio to C 2 o-hydrocarbons used.
  • the total amount of dispersing agent used for the free radical aqueous emulsion may contain up to 50% of their weight contain other dispersants.
  • anionic and / or nonionic emulsifiers and / or surfactants such as ethoxylated mono-, di- and tri-alkylphenols (EO degree: 3 to 100, alkyl radical: C 4 to C 2 ), ethoxylated fatty alcohols are suitable as such (EO grade: 3 to 100, alkyl radical: C B to C ⁇ 8 ), alkali and ammonium salts of alkyl sulfates (alkyl radical: Ce to Ci ⁇ ), of sulfuric acid half-esters O 97/42017 PC17EP97 / 02096
  • ethoxylated alkanols (EO degree: from 1 to 70, alkyl radical: C ⁇ 2 to Ci ⁇ ) of aryl and of alkylaryl sulfates (alkyl radical: C 9 to C ⁇ 8) and of C 8 - to Ci ⁇ -fatty acids and disproportionier ⁇ th resin acids from Rosin (Dresinate).
  • Protective colloids such as polyvinyl alcohols, cellulose derivatives, copolymers containing vinylpyrrolidone or polycondensates of naphthalenesulfonic acid and formaldehyde are of course also suitable as such further dispersants.
  • emulsifiers and surfactants In contrast to emulsifiers and surfactants, they are unable to form micelles in the aqueous polymerization medium and generally have relative molecular weights of> 1000. Furthermore, they hardly influence the surface tension of water. Suitable polycondensates of naphthalenesulfonic acid and formaldehyde (or their water-soluble salts) have, for example, a relative molecular weight of 4,000 to 8,000.
  • a combination of emulsifiers and protective colloids will often be used when aqueous polymer dispersions whose dispersed polymer particles are chemically as uniform as possible are aimed at for monomers to be polymerized with markedly different water solubility.
  • the diameter of the resulting emulsion polymer particles is usually determined via the absolute amount of emulsifier used. Its weight-average value is preferably 80 to 300, particularly preferably 100 to 250 and very particularly preferably 100 to 200 nm.
  • the amount of other dispersants is advantageously not more than 25% or not more than 10% of their weight.
  • Favorable embodiments according to the invention are those in which no further dispersants are used.
  • the monomer mixture to be polymerized by the free-radical aqueous emulsion polymerization method can contain only two conjugated ethylenically unsaturated groups (monomers A), or else additionally from the monomers A include various comonomers having at least one ethylenically unsaturated group.
  • the proportion of the monomers A in the monomer mixture to be polymerized according to the invention is frequently 30 to 90% by weight, often 40 to 70% by weight and in many cases 50 to 70% by weight.
  • Examples of possible monomers A are butadiene, 2-methyl-butadiene, 2,3-dimethylbutadiene, pentadiene 1.3 or pentadiene 2.4 or mixtures of these monomers.
  • Mono-ethylenically unsaturated comonomers which, at normal pressure (1 atm) and 25 ° C, have an increased molar water solubility (> that of Acrylonitrile) (monomers B), are usually contained in the monomer mixture to be polymerized in amounts of up to 10% by weight, often in amounts of 3 to 8% by weight.
  • Customary monomers B are, for example, ⁇ , ⁇ -monoethylenically unsaturated mono- and dicarboxylic acids having 3 to 6 carbon atoms, such as acrylic acid, methacrylic acid, maleic acid, fumaric acid and itaconic acid, the salts of these carboxylic acids (in particular the alkali metal salts and the ammonium salt), the amides the abovementioned ⁇ , ⁇ -monoethylenically unsaturated carboxylic acids, such as, for example, acrylamide and methacrylamide, also vinylsulfonic acid and its water-soluble salts (in particular the alkali metal salts and the ammonium salt) and N-vinylpyrrolidone.
  • the monomers B can of course also be used in a mixture. While butadiene is the preferred monomer A, methacrylic acid is the preferred monomer B.
  • the proportion of other copolymerizable monomers (monomers C) having an ethylenically unsaturated group can be up to 70% by weight.
  • the proportion of the monomers C is frequently 10 to 70, often 30 to 60 and in many cases 30 to 50% by weight.
  • Suitable monomers C are e.g. vinyl aromatic monomers such as styrene, vinyl toluene or o-chlorostyrene, acrylonitrile, methacrylonitrile and esters from acrylic or methacrylic acid with alkanols having 1 to 8 carbon atoms, and the mixtures of these monomers among which styrene, acrylonitrile and methyl methacrylate and mixtures thereof are particularly suitable Are monomers C.
  • aqueous dispersions of free-radical aqueous emulsion polymers of monomer mixtures consisting of are suitable
  • radical aqueous emulsion polymers of monomer mixtures consisting of
  • the free-radical aqueous emulsion polymerization is generally carried out in the presence of so-called molecular weight regulators (chain transfer agents), such as mercaptans (alkanethiols), which advantageously have 3 to 15 carbon atoms. Regularly are tert. -Dodecyl mercaptan and / or n-dodecyl mercaptan used as a molecular weight regulator.
  • the free-radical aqueous emulsion polymerization is typically carried out in the presence of from 0.1 to 3% by weight, frequently from 0.5 to 1.5% by weight, based on the monomers to be polymerized, of such molecular weight regulators.
  • Radical polymerization initiators which can be used to carry out the free radical aqueous emulsion polymerization are in principle all those which are capable of triggering a free radical aqueous emulsion polymerization. Both peroxides and azo compounds can be involved. To limit the degree of crosslinking of the resulting emulsion polymer, those initiator systems are preferred whose decomposition temperature is ⁇ 55 ° C. In other words, preference is given to using combined systems which are composed of at least one reducing agent and at least one peroxide and / or hydroperoxide, since the reducing agents activate the formation of free radicals and thus enable the free-radical aqueous emulsion polymerization according to the invention to be started at low temperatures .
  • Suitable reducing agents are, for example, ascorbic acid, acetone bisulfite, the sodium salt of hydroxymethanesulfinic acid, sodium sulfite, sodium hydrogen sulfite or sodium dithionite.
  • the aforementioned combined (redox initiator) systems very particularly preferably additionally comprise a small amount of a metal compound which is soluble in the polymerization medium and whose metallic component can occur in several valence stages.
  • iron (II) salts such as iron (II) sulfate.
  • a water-soluble iron (II) salt a combination of water-soluble Fe / V salts is often used.
  • Such redox initiator systems containing such a metal compound are advantageous in that they enable the free-radical aqueous emulsion polymerization according to the invention to be started at even lower temperatures.
  • redox initiator systems examples include ascorbic acid / iron (II) sulfate / hydrogen peroxide or sodium dithionite and / or sodium formaldehyde sulfoxylate / iron (II) sulfate / para-menthane hydroperoxide or diisopropylbenzene hydroperoxide or cumene hydroperoxide.
  • a chelating agent is added to such redox initiator systems containing a metal compound in order to ensure that the metallic component is in solution and not e.g. is withdrawn by a precipitation reaction.
  • the sodium salts of ethylenediaminetetraacetic acid may be mentioned as an example of such a chelating agent.
  • the metallic component is often added directly as a chelate complex.
  • the amount of initiator to be used is generally from 0.01 to 5%, usually from 0.01 to 1% by weight.
  • Sodium dithionite is also suitable as a scavenger for residual amounts of oxygen.
  • pH buffers such as alkali metal phosphate can be added to stabilize the pH of the aqueous dispersing medium during the emulsion polymerization.
  • strong electrolytes such as potassium sulfate, potassium chloride and / or sodium sulfate makes it easier, in a manner known per se, to set the desired polymer particle diameter by means of a controlling influence in the polymer particle formation phase.
  • the polymerization temperature, type and amount of molecular weight regulator and polymerization conversion are advantageously coordinated with one another in such a way that aqueous polymer dispersions result, the crosslinking density of which is such that the transverse nuclear magnetic relaxation time of the protons chemically bound to the polymer ( 1H T 2 ) 2, 5 to 4.5 ms.
  • These values relate to a sample of the respective aqueous polymer dispersion, which was filmed at 25 ° C. and then dried for 2 hours at 80 ° C., at a sample temperature of 140 ° C. and a ⁇ resonance frequency of 20 MHz.
  • the relationship between 1H T 2 and the crosslinking density is shown, for example, in Macromolecule 1994,27,2111-2119.
  • the transversal nuclear magnetic relaxation time of an atomic nucleus having a magnetic moment is on the one hand a measure of its mobility in an external magnetic field and a crosslinking of different polymer chains limits its mobility on the other hand.
  • the polymerization conversion of the free radical aqueous emulsion polymerization is stopped as required as a rule by adding polymerization inhibitors such as dimethylhydroxylamine and then unreacted monomers are removed in a manner known per se by deodorization (preferably stripping and / or steam distillation).
  • DE-A 19545096 discloses the implementation of a free-radical aqueous emulsion polymerization as described above.
  • the radical aqueous emulsion polymerization can be carried out in the simplest manner by placing the total amount of the polymerization batch, namely part of the polymerization initiator, in the polymerization vessel. triggering the polymerization by heating to the polymerization temperature and, with the successive addition of the remaining radical polymerization initiator and maintaining the polymerization temperature, continuing the radical aqueous emulsion polymerization until the desired polymerization conversion.
  • the residual monomers of which remain after the end of the free-radical aqueous emulsion polymerization eg acrylonitrile
  • the relative proportion of relatively easily removable residual monomers eg butadiene
  • Another possibility of realizing the free radical aqueous emulsion polymerization is the method of the continuous monomer feed process. Only a small part of the monomers to be polymerized is placed in the polymerization vessel, expediently polymerized in the presence of an added seed latex, and the remaining amount of the monomers to be polymerized is then fed continuously to the polymerization vessel in accordance with their consumption while maintaining the free radical aqueous emulsion polymerization.
  • the aqueous polymer dispersions to be used according to the invention are produced with a solids volume fraction of 30 to 70% by volume, usually 40 to 50% by volume.
  • the required vulcanization system, optionally further auxiliaries and the nonionic polyether-modified silicon-organic surfactant are usually incorporated into the aqueous polymer dispersion obtained by the free-radical aqueous emulsion polymerization method.
  • the thermal sensitizer is expediently incorporated last.
  • the remaining substances to be incorporated are essentially solids which must be incorporated in the finest possible form in order to develop their effect. Powdery substances generally have a high from ⁇ sorption capacity for water and therefore can be in trok- kenem state with difficulty in aqueous polymerizate dispersions incorporated as they escape the latex serum, thereby causing partial coagulation. Other finely divided solids act without having a particularly high absorption capacity, coagulating in that they have a high positive surface charge. The powdery solids must therefore, be prepared before incorporating them into the latex in such a way that they cannot cause coagulation for either reason.
  • the aqueous Ante Trent more thickeners are often added (eg Collatex ® AS / RK, Collatex A / RN or Collatex A / RE of the Kelco; it is these compounds are ammonium alginate, wt their 1 -% aqueous solution.. preferably has a viscosity of 350 to 650 mPa-s (20 ° C., Brookfield viscometer, Model LV, 60 revolutions / min, spindle 3) in order to achieve a paste-like consistency of the paste. Both water-soluble and water-insoluble can be used as vulcanization accelerators Water-insoluble accelerators are preferred because they are not absorbed by porous dipping forms.
  • the ultra-accelerators of the dithiocarbamate group eg zinc-N-diethyldithiocarbamate, zinc-N-dimethyldithiocarbamate, zinc-N-dibutyldithiocarbamate
  • the ultra-accelerators of the dithiocarbamate group are of particular importance or zinc N-phenyl-ethyl-dithiocarbamate
  • the less strongly accelerating compounds of the mercapto-benzothiazole class eg zinc merca ptobenzothiazole.
  • These solid vulcanization accelerators are also expediently incorporated in an aqueous, pasted form.
  • the emulsifiers and / or surfactants used are preferably those which would also be suitable for carrying out the free-radical aqueous emulsion polymerization and which have a particularly high affinity for the emulsified Show liquid.
  • Other anti-aging agents are Naugawhite and Proxel ® XL2 (bactericide).
  • Possible mineral fillers which are insoluble in the aqueous medium are, for example, quartz powder and calcium or aluminum silicates.
  • the vulcanosol dyes and the Halizarin ® pigments from BASF AG are particularly suitable as dyes.
  • Possible plasticizers are oils such as mineral oil, paraffinol or dibenzyl ether, which were also incorporated as an aqueous emulsion.
  • suitable electrolytes which are adsorbed on the surface of the molded body are, according to the character of the anionic sulfonate group, u.a. Salts of monovalent or polyvalent cations such as calcium nitrate, calcium chloride, aluminum sulfate, magnesium nitrate or zinc nitrate, which are preferably good
  • the electrolyte adsorbate is expediently applied to the surface of the shaped body by dipping the shaped body into a solution of the electrolyte and subsequent drying.
  • Lower alcohols such as methyl and ethyl alcohol, water and / or a mixture thereof, are suitable as solvents.
  • the pre-immersion solution In order to prevent the coagulant solution from contracting and not wetting evenly when the molded article runs out, the pre-immersion solution generally contains a wetting agent in a manner known per se (for example ethoxylated alkylphenols such as Lutensol * 'AP 10 in aqueous pre-immersion solutions) ).
  • a wetting agent for example ethoxylated alkylphenols such as Lutensol * 'AP 10 in aqueous pre-immersion solutions.
  • Glass, porcelain, ceramic or light metal which, however, must be free of Cu and Mn, has proven itself as the material for the molded body to be immersed. Often these materials are also covered with a textile fiber fabric, which serves as the basis for the later diving article.
  • Dver ⁇ course also heated moldings are suitable.
  • the temperature of the aqueous latex dipping preparation into which the molded body is immersed in the process according to the invention is generally 10 to 40, usually 10 to 30 ° C. It is normally below the cloud point of the nonionic organosilicon surfactant.
  • the polymer film deposited on the surface of the molded body is generally washed in water, dried, vulcanized in hot air and finally stripped, if necessary washed again in water and, if necessary, powdered or chlorinated.
  • dipping can also be carried out several times in succession in order to achieve particularly high film thicknesses.
  • the process according to the invention ensures films with increased thickness and improved reproducibility as well as a quality corresponding to electrolyte immersion with a shorter immersion time.
  • the resulting films show an improved grip, as is required in particular with medical gloves.
  • the dipping time required for a certain film thickness can be additionally influenced by varying the polymer content of the aqueous latex dipping preparation. Higher polymer contents generally require shorter dipping times.
  • the aqueous latex dipping preparation is often made alkaline using NH 3 and left to stand for a long time before dipping (maturing time). During this period, part of the ZnO dissolves, which often proves to be advantageous in the case of carboxylated polymers.
  • alkali metal hydroxide such as NaOH is used instead of NH 3 .
  • the method according to the invention is suitable, for example, for producing diving articles with a film thickness of 0.04 mm to 2 mm.
  • Suitable diving articles are those known per se, ie gloves, condoms, suction cups, balloons, finger cots etc.
  • a mixture was placed in a polymerization vessel (stirred pressure reactor made of V2A steel)
  • NN 4501 corresponding naphthalene-sulfonic acid-formaldehyde condensate (number average relative molecular weight: 6500)), 86 g of sodium sulfate and 40 g of a 40 wt. -% aqueous solution of the sodium salt of ethylenediaminetetraacetic acid
  • aqueous cumene hydroperoxide solution 90.5% by weight aqueous cumene hydroperoxide solution was added all at once and then polymerized while maintaining the 8 ° C. up to a polymerization conversion of 40 mol%. Then a mixture was suddenly formed
  • the polymerization temperature was then increased to 10 ° C. and the polymerization was continued at this temperature until a polymerization conversion of 75 mol% had been reached.
  • the polymerization was stopped at the aforementioned conversion.
  • the solids content of the aqueous polymer dispersion obtained was 45.5% by weight.
  • the resulting aqueous polymer dispersion had a solids content of 44.7% by weight.
  • the weight-average polymer particle diameter d w was 110 nm and the filming had a 1H T 2 value of 4.1 ms.
  • an inlet I consisting of
  • an inlet II consisting of
  • a mixture was made in a polymerization vessel (stirred pressure reactor made of V2A steel) 12.9 g of disodium salt of ethylenediaminetetraacetic acid,
  • the solids content of the aqueous polymer dispersion obtained was 49.8% by weight.
  • the resulting aqueous polymer dispersion had a solids content of 48.6% by weight.
  • the weight-average polymer particle diameter d w was 180 nm and the filming had a 1H T 2 value of 2.6 ms.
  • the preparation was then diluted to a solids content of 40% by weight and left to stand at 25 ° C. for 24 hours (ripening time). Then a mixture was made
  • VLTI Like LTI, but no base sol HA 5 was added.
  • LTII The following was incorporated into the total amount of aqueous polymer dispersion LII obtained as protection against aging:
  • aqueous ZnO preparation instead of 7 g of the aqueous ZnO preparation, however, only 2 g of the aqueous ZnO preparation were added. Furthermore, 2 g of the aqueous sulfur preparation were added in place of the 1.6 g of the aqueous sulfur preparation. Furthermore, the amount of base sol HA 5 added was not 0.2 g but 0.8 g (dissolved in 7.2 g water) and the dilution was carried out to a solids content of 25% by weight. The resulting coagulation temperature was 41 ° C.
  • VLTII Like LTII, but no base sol HA 5 was added.
  • LTIII Like LTII, but the amount of Basensol HA 5 added was 0.9 g (dissolved in 8.1 g water). Furthermore, only 1 g of aqueous sulfur preparation, but 5 g of aqueous ZnO
  • VLTIII Like LTIII, but no base sol HA 5 was added.
  • the immersion bodies VKH1, KH2 and KH3 were immersed in the aqueous latex immersion preparations, which had a temperature of 25 ° C. (with pure thermo-coagulation, the immersion speed was 50 mm / sec and the removal speed was 65 mm / sec; otherwise the immersion speed was 65 mm / sec and the removal speed 10 mm / sec). After a certain dwell time, the immersion bodies were removed again and left to stand at 25 ° C. for 5 minutes. Thereafter, the immersion body having the film deposited during immersion was immersed in 40 ° C. for 5 minutes to wash the films. The mixture was then dried at 70 ° C. for 30 minutes and then vulcanized for a further 30 minutes at 120 ° C.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Dispersion Chemistry (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • General Chemical & Material Sciences (AREA)
  • Polymerisation Methods In General (AREA)
  • Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
  • Moulding By Coating Moulds (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
  • Compositions Of Macromolecular Compounds (AREA)

Abstract

Procédé d'obtention d'articles enduits au trempé, dans lequel on immerge un corps moulé présentant, à la fois, une température élevée et une surface adsorbant des électrolytes, dans une préparation aqueuse de trempage renfermant du latex, dont le latex est, d'une part, stabilisé sensiblement par des émulsionnants présentant des groupes sulfonates anioniques et, d'autre part, thermosensibilisé par un agent tensioactif organosilicique présentant des groupes polyéthers non ioniques, d'une température de trouble comprise entre 30 et 40 °C.
PCT/EP1997/002096 1996-05-04 1997-04-24 Procede d'obtention d'articles enduits au trempe WO1997042017A1 (fr)

Priority Applications (6)

Application Number Priority Date Filing Date Title
EP97921741A EP0904184A1 (fr) 1996-05-04 1997-04-24 Procede d'obtention d'articles enduits au trempe
CA002253909A CA2253909A1 (fr) 1996-05-04 1997-04-24 Procede d'obtention d'articles enduits au trempe
AU27699/97A AU2769997A (en) 1996-05-04 1997-04-24 Process for producing dip-coated articles
BR9709136A BR9709136A (pt) 1996-05-04 1997-04-24 Processo para obtenção de artigos revestidos por imersão
JP9539481A JP2000509421A (ja) 1996-05-04 1997-04-24 浸漬被覆品の製造方法
NO985119A NO985119D0 (no) 1996-05-04 1998-11-03 FremgangsmÕte for fremstilling av dypp-belagte artikler

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19618006.6 1996-05-04
DE19618006A DE19618006A1 (de) 1996-05-04 1996-05-04 Verfahren zur Herstellung von Tauchartikeln

Publications (1)

Publication Number Publication Date
WO1997042017A1 true WO1997042017A1 (fr) 1997-11-13

Family

ID=7793383

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP1997/002096 WO1997042017A1 (fr) 1996-05-04 1997-04-24 Procede d'obtention d'articles enduits au trempe

Country Status (12)

Country Link
EP (1) EP0904184A1 (fr)
JP (1) JP2000509421A (fr)
KR (1) KR20000010757A (fr)
CN (1) CN1211210A (fr)
AU (1) AU2769997A (fr)
BR (1) BR9709136A (fr)
CA (1) CA2253909A1 (fr)
DE (1) DE19618006A1 (fr)
ID (1) ID17625A (fr)
MX (1) MX9806234A (fr)
NO (1) NO985119D0 (fr)
WO (1) WO1997042017A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9353243B2 (en) 2012-01-18 2016-05-31 Lg Chem, Ltd. Latex composition for dip-forming

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19803239C2 (de) * 1997-12-17 2002-01-17 Muench Chemie Labor Gmbh Vorrichtung und Verfahren zur Herstellung von puderfreien, proteinarmen Tauchartikeln, insbesondere von Operations- und Untersuchungshandschuhen
GB9822358D0 (en) * 1998-10-13 1998-12-09 Lrc Products Elastomeric gloves
US7052642B2 (en) * 2003-06-11 2006-05-30 Kimberly-Clark Worldwide, Inc. Composition for forming an elastomeric article
CN101836660B (zh) * 2010-04-06 2012-11-28 青岛科技大学 复合纳米抗菌剂及抗菌nl乳胶和抗菌tpi橡胶的制备方法
CN102371687B (zh) * 2011-08-07 2014-08-06 镇江苏惠乳胶制品有限公司 一种双色橡胶手套的加工方法
WO2020243899A1 (fr) * 2019-06-04 2020-12-10 Dow Global Technologies Llc Dispersion aqueuse de polyuréthane sensible à la chaleur et son procédé de préparation
KR20220081635A (ko) 2020-12-09 2022-06-16 현대자동차주식회사 차량용 손소독 장치 및 방법

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3714101A (en) * 1970-10-21 1973-01-30 Goodrich Co B F Heat sensitive latices containing silicone polyether
EP0456333A1 (fr) * 1990-05-11 1991-11-13 Tillotson Corporation Matériau de recouvrement élastomère et gant fabriqué avec ce matériau
US5096641A (en) * 1986-07-08 1992-03-17 Basf Corporation Continuous process of making a gelled rubber foam product
EP0524836A1 (fr) * 1991-07-26 1993-01-27 Ortho Pharmaceutical Corporation Film élastomère ayant une meilleure résistance chimique

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE634556A (fr) * 1962-07-06

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3714101A (en) * 1970-10-21 1973-01-30 Goodrich Co B F Heat sensitive latices containing silicone polyether
US5096641A (en) * 1986-07-08 1992-03-17 Basf Corporation Continuous process of making a gelled rubber foam product
EP0456333A1 (fr) * 1990-05-11 1991-11-13 Tillotson Corporation Matériau de recouvrement élastomère et gant fabriqué avec ce matériau
EP0524836A1 (fr) * 1991-07-26 1993-01-27 Ortho Pharmaceutical Corporation Film élastomère ayant une meilleure résistance chimique

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
J.P. COHEN-ADDAD: "NMR and Viscoelastic Investigations into the Structure and Dynamics of Emulsion Copolymer Gels", MACROMOLECULES, vol. 27, no. 8, 1994, EASTON US, pages 2111 - 2119, XP002037842 *
K. BERGHUS U.A.: "Handbuch für die Gummi-Industrie", 1991, BAYER AG, LEVERKUSEN, XP002037843 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9353243B2 (en) 2012-01-18 2016-05-31 Lg Chem, Ltd. Latex composition for dip-forming

Also Published As

Publication number Publication date
AU2769997A (en) 1997-11-26
ID17625A (id) 1998-01-15
NO985119L (no) 1998-11-03
CN1211210A (zh) 1999-03-17
DE19618006A1 (de) 1997-11-06
EP0904184A1 (fr) 1999-03-31
JP2000509421A (ja) 2000-07-25
CA2253909A1 (fr) 1997-11-13
NO985119D0 (no) 1998-11-03
KR20000010757A (ko) 2000-02-25
BR9709136A (pt) 1999-08-03
MX9806234A (es) 1998-11-29

Similar Documents

Publication Publication Date Title
DE60130372T2 (de) Tauchformen, zusammensetzung für das tauchformen und verfahren zur herstellung von tauchformen
US4102844A (en) Dipped articles of rubber
DE102007024010A1 (de) Nitrilkautschuke
DE102007024008A1 (de) Nitrilkautschuke
DE60030134T2 (de) Latex für tauchformen und geformter gegenstand, der durch tauchformen erhalten wird
EP0814103A2 (fr) Préparation de dispersions aqueuses de polymères à faible viscosité contenant une concentration volumique de polymère d'au moins 50%
WO1997042017A1 (fr) Procede d'obtention d'articles enduits au trempe
US4169086A (en) Aqueous dispersion paint having a high wet adhesion and process for preparing same
WO2010105805A1 (fr) Procédé de préparation de matières solides polymères
EP0778288B1 (fr) Procédé de préparation d'une dispersion aqueuse de polymères
DE2644776C2 (de) Verfahren zur Herstellung stabiler Polymeremulsionen
EP0007044B1 (fr) Procédé de préparation de latex de caoutchouc exempts de matons et présentant une tension superficielle élevée
EP0240697B1 (fr) Latex d'un polymère caoutchouteux contenant un groupe nitrile et à saturation élevée, et son procédé de préparation
EP1217028A1 (fr) Dispersion aqueuse de polymère contenant des particules de caoutchouc et des particules polymériques de renforcement
US4189567A (en) Process for preparing powdered rubber
DE2219708A1 (de) Formmassen auf der Basis von kautschukmodifizierten Nitril-Copolymerisaten, Verfahren zu deren Herstellung und deren Verwendung zur Herstellung von Verpackungsmaterialien für Lebensmittel
DE1122259B (de) Verfahren zur Herstellung stabiler Latices
DE1269360B (de) Verfahren zur Herstellung von thermoplastisch-elastischen Formmassen
FR2534591A1 (fr) Procede perfectionne de coagulation d'un latex de polymere
EP0744418B1 (fr) Caoutchuk en mousse de latex
US2548757A (en) Preparation of synthetic rubbercarbon black mixtures
DE2618695C2 (de) Verfahren zur Herstellung von Polychloropren in Teilchenform
DE1720897B2 (de) Verfahren zum Polymerisieren von äthylenisch ungesättigten Monomeren in wäßriger Emulsion
EP0926160A1 (fr) Procédé de préparation de mousses polymères en dispersion
EP0192151A2 (fr) Masses à mouler contenant des particules de dimension uniforme et de stabilité thermique

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 97192369.8

Country of ref document: CN

AK Designated states

Kind code of ref document: A1

Designated state(s): AU BG BR CA CN CZ GE HU IL JP KR LV MX NO NZ PL RO SG SI SK TR UA US AM AZ BY KG KZ MD RU TJ TM

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 1997921741

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: PA/a/1998/006234

Country of ref document: MX

ENP Entry into the national phase

Ref document number: 2253909

Country of ref document: CA

Ref document number: 2253909

Country of ref document: CA

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 1019980708874

Country of ref document: KR

WWP Wipo information: published in national office

Ref document number: 1997921741

Country of ref document: EP

WWR Wipo information: refused in national office

Ref document number: 1997921741

Country of ref document: EP

WWW Wipo information: withdrawn in national office

Ref document number: 1997921741

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 1019980708874

Country of ref document: KR

WWW Wipo information: withdrawn in national office

Ref document number: 1019980708874

Country of ref document: KR

点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载