AT500557B1 - DIVING ITEMS - Google Patents

Abstract

The invention describes a process for the production of dipping articles from latex by peroxidic crosslinking, in which a dipping mold (8) is immersed in a dipping bath in which a mixture of the latex and a peroxide is initially introduced, and thereby on the dipping mold (8). a carrier layer (2) is formed from the latex, whereupon the dip mold (8) with the carrier layer (2) is removed from the dipping bath and the carrier layer (2) is crosslinked at elevated temperature, wherein after removal of the dip mold (8) the dip bath and before crosslinking to the carrier layer (2) a barrier layer (3) made of a polymer selected from a group comprising polyurethane, polyacrylates, polymetacrylates, epoxies, silicones, polyesters, polyamides, rubbers, thermoplastic elastomers and mixtures thereof, against Radical scavenger, in particular oxygen, is applied, wherein the carrier layer (2) is made sulfur and accelerator free.

Description

Austrian Patent Office AT500 557B1 2011-08-15

Description: The invention relates to a process for the production of dipping articles from latex by peroxidic crosslinking, in which a dipping form is immersed in a dipping bath in which a mixture of the latex and a peroxide, and optionally at least one further auxiliary or coagent, a carrier layer of the latex is thereby formed on the dip mold, whereupon the dip mold with the carrier layer is removed from the dip bath and the carrier layer is crosslinked at elevated temperature, wherein after removing the dip mold from the dip bath and before crosslinking the backing layer is a barrier layer of a polymer selected from a group comprising polyurethane, polyacrylates, polymethacrylates, epoxies, silicones, polyesters, polyamides, rubbers, such as carboxylated nitrile-butadiene rubber, thermoplastic elastomers, e.g. Vinyl-based thermoplastic elastomers, thermoplastic polyurethane elastomers, olefin-based thermoplastic elastomers, polystyrene-based thermoplastic elastomers, thermoplastic polyester elastomers, thermoplastic polyamide elastomers and mixtures thereof, against radical scavengers, in particular oxygen, and a dipping article with a latex support layer having an inner and an outer surface, wherein on at least the inner surface a barrier layer of a polymer selected from a group comprising polyurethane, polyacrylates, polymetacrylates, epoxies, silicones, polyesters, polyamides, rubbers, such as carboxylated nitrile-butadiene rubber, thermoplastic elastomers, e.g. vinyl-based thermoplastic elastomers, thermoplastic polyurethane elastomers, olefin-based thermoplastic elastomers, polystyrene-based thermoplastic elastomers, thermoplastic polyester elastomers, thermoplastic polyamide elastomers, and mixtures thereof, against radical scavengers, especially oxygen. Due to the increasing number of viral diseases, e.g. HIV has experienced a significant increase in demand for latex gloves in recent years. These gloves, e.g. Surgery gloves or examination gloves are largely made from natural latex. The problem is the use of this material in the glove area whenever the wearer is allergic to natural latex, i. proteins contained therein or chemicals left in the latex from the manufacturing process, e.g. Sulfur for crosslinking. For this reason, the prior art has already described a wide variety of options for replacing natural rubber as a raw material either with synthetic latices or, with regard to the sulfur problem, finding other types of crosslinking.

For example, it is has long been known to crosslink latices peroxide. For example, US Pat. No. 6,569,375 B1 and US 2003/0142633 A1 describe a process for the production of non-porous rubber articles by a dipping process in which a reagent for vulcanization is initially introduced in the dipping bath. To create a film, a dip mold is immersed in this dipping bath. The vulcanization of the film thus formed is then carried out after removing the dip form from the dip in a heated bath, which is chemically inert with respect to the film formed. As baths, molten inorganic salts are used for heat transfer.

Furthermore, it is described in the prior art to use instead of molten salt baths hot oil baths, baths of molten lead or even baths with fluidized sand particles.

Also in US 6,329,444 B1 a peroxidic crosslinking of cis-1,4-polyisoprene is described. As peroxide, dicumyl peroxide can be used inter alia, as in the two aforementioned US documents. The peroxide causes a free-radical reaction in the latex, which cross-links the latter. In order to prevent oxygen access to the latex film to be crosslinked during the crosslinking reaction, a molten salt bath is also used after the latter US-B1. If the peroxidic crosslinking were carried out under an oxygen atmosphere, the crosslinking reaction by the oxygen molecules which react with the peroxide prematurely breaks, so that the vulcanization as a whole is ineffective and non-crosslinked latex layers are formed , which has a sticky surface and significantly reduced mechanical properties, such as in US 6,569,375 B1, arise.

WO 00/09590 A1 describes a dipping method for the production of a solvent-resistant glove comprising an elastomeric substrate and a fluorinated elastomeric coating. As an advantage it is stated that it is not necessary to use organic solvents. It can be applied for the fluorinated, elastomeric coating from an aqueous dispersion. This avoids the use of expensive organic solvents, provides a substantially safe manufacturing process and eliminates the need to dispose of or recycle solvents. As a crosslinking agent, i.a. also disclosed peroxides, preferably a piperazine is used. A further disclosure regarding the implementation of the peroxidic crosslinking does not contain this document.

US 6,051,320 A describes inter alia. a natural latex glove which is cured with an oxygen donor and contains a curing agent, e.g. Silicic acid, organic compounds, e.g. monomeric or polymeric acrylates. In particular, it is described that natural latex aggregates and products produced therefrom are mostly free of active chemical components, for example, sulfur, zinc, etc. In addition, the at least partial freedom of nitrosamines and similar harmful or undesirable chemicals is also set forth. The latex emulsion may contain microcrystalline waxes as an oxygen barrier. In addition, the latex material is protected from heat or water by protective layers that prevent the transfer of latex proteins to the environment while increasing lubricity.

From WO 96/23428 A1 discloses a glove for examination or surgical use, which has a polymeric coating on its inner surface for better attractability and on the outside has an elastomeric coating which acts bacterial and virus blocking. The hydrophilic inner coating is i.a. moisture-absorbing and has antimicrobial or antiviral components and is called skin-friendly. On the outside of the glove are fluoroelastomers, which act as effective barriers against viruses and their hydrophobicity against body fluids, etc.

WO 2004/033177 A1 describes a process for producing a thin-walled rubber article from an aqueous latex comprising a vulcanizable rubber, a sulfur-containing vulcanizing agent, a cross-linking agent which forms carbon-carbon compounds, avoiding vulcanization accelerators with secondary amino groups. As the crosslinking agent, among others, an organic peroxide can be used. In order to avoid contact with molecular oxygen during vulcanization, on the one hand in various baths, e.g. molten salt baths or in closed molds, in an oxygen-free atmosphere and with barrier coatings. The barrier coating can be applied by dipping or spraying. As effective barrier materials, inter alia polyvinyl alcohol, as well as acrylic or methacrylic coatings, both conventional and hydrogel type are described.

The object of the invention is now to provide a method for producing a dipping article made of latex by peroxide crosslinking, which has a low allergy potential.

This object of the invention is achieved in that the carrier layer is prepared and is free of sulfur and accelerator.

The advantage here is that can be used by the arrangement of a barrier layer on the support layer on conventional means, as they may be used anyway for the production of dipping articles, and not additional devices, such as the salt baths indicated in the prior art must be provided in the production line of such dipping articles 2/19 Austrian Patent Office AT500 557 B1 2011-08-15. It is thus possible to shorten the changeover times of production lines, at best, only the immersion bath must be replaced. Furthermore, according to the process of the invention, the cross-linking can be carried out in conventional hot-air ovens, so that no additional heating elements, e.g. for salt baths, are required. Furthermore, it is thus possible to further modify the product produced by the process in terms of its properties, without additional layers would have to be applied. It is also advantageous that the applied barrier layer not only acts against radical scavengers during crosslinking, but also continues to develop its effectiveness during storage or use of the dipping articles.

The barrier layer is formed of a polymer, so that this layer in addition to its functionality during crosslinking on the finished product can take over a function, for example in the form of a sliding layer to the attractability of the diving articles, e.g. if these are designed in the form of gloves to improve, so that, if necessary, on the additional attachment of such functional layers, as are common in diving articles, no longer required.

Characterized in that the carrier layer is sulfur and / or accelerator free, the dipping article has a low allergy potential.

By the polymer selected from the group mentioned, the properties of the dipping article can be varied within wide limits, for example, in terms of the hardness of the surface layer, the elongation, etc.

It is advantageous if an unsaturated polymer is used as the polymer, whereby the functionality can be further increased as a barrier layer.

In the case that an unsaturated polymer is used for the barrier layer, it is further advantageous if covalent bonds are formed between the polymer of the barrier layer and the latex of the carrier layer, because it can improve the adhesion of the barrier layer to the elastomer ,

It is also possible that the barrier layer is surfaced or sprayed, whereby very uniform films can be produced from this barrier layer, and also the equipment required for this purpose are usually present anyway in productions of diving articles.

It is further possible that the barrier layer is dried after application and before the crosslinking of the carrier layer in a separate process, whereby their effectiveness can be further improved.

According to one embodiment, it is provided that the barrier layer has a permeation coefficient under standard conditions for oxygen of not more than 20 × 10'8 cm 2 / (bar), preferably of at most 15 × 10'8 cm 2 / (bar), in particular of a maximum of 4 × 10 '. 8 cm 2 / (s bar), for example of at most 0.15 × 10'8 cm 2 / (bar), which ensures that the oxygen permeation is reduced to a negligible value both during crosslinking and thereafter.

By the peroxidic crosslinking, the polymer chains of the support layer can be connected to each other via carbon-carbon bonds, whereby a dipping article with improved mechanical properties can be provided. In addition, it is possible in this way to vary the properties of the dive article within certain limits on the number of carbon-carbon bonds.

It is advantageous if the peroxide selected from a group comprising Ditertiärbutylperoxid, Tertiärbutylcumylperoxid, bis (tertiärbutylperoxisiopropyl) benzene, dicumyl peroxide, 4,4-Ditertiärbutylperoxi- n-butylvalerate, 1,1 -ditertiärbutylperoxi-3, 3,5-trimethylcyclohexyl, Tertiärbutylperbenzoat, benzoyl peroxide, bis (2,4-dichlorobenzoyl) peroxide, bis (p-chlorobenzoyl) peroxide or mixtures thereof, because the cross-linking of the latex of the support layer by the formation of stable radicals due to the Charge distribution in the molecule of peroxides 3/19 Austrian Patent Office AT500 557 B1 2011-08-15 very reliable.

It is possible that the peroxide is present in a dipping bath in a concentration selected from a range with a lower limit of 0.2%, preferably 0.4%, in particular 1% and an upper limit of 5.8% , in particular 4.5%, preferably 3%, whereby it can be ensured that the crosslinking of the latex of the carrier layer takes place over the entire range.

It is also possible that the carrier layer of a latex selected from a group comprising natural rubber, enzymatically deproteinized natural rubber, isoprene rubber, Polychloroprenkautschuk, polyurethane, nitrile rubber, isobutene-isoprene rubber, styrene-butadiene rubber, copolymers of ethyl acrylate or others Acrylates with a proportion of a monomer that facilitates vulcanization, such as Chloromethyl acrylate, further terpolymers of ethylene, propylene and with an unsaturated diene, such as. 5-ethylidene-2-norbornene, cyclopentadiene, ethylene / propylene copolymers, further polyester urethanes and mixtures thereof, is formed because on the one hand according to the current state of knowledge diving products can be provided that have no or low allergy potential and on the other hand, the carrier layer elastomeric properties can be imparted, which can be varied within a wide range.

It is also advantageous if the crosslinking is carried out at a temperature of at least 85 ° C, in particular at least 90 ° C, preferably at least 150 ° C depending on the selected peroxide, as a result, a concentration of free radicals for crosslinking available, which enables rapid networking.

The barrier layer can be roughened after crosslinking and / or have a rough surface, whereby the attractability of the dive article after the barrier layer is disposed after a turning operation on the inside of the dive article, improves. The dipping article itself may be a glove, e.g. an examination glove, a surgical glove or a condom.

It is further advantageous if crosslinking by irradiation, e.g. with electron beams, microwaves, IR or UV rays or gamma rays or is supported by irradiation, whereby on the one hand, the speed of crosslinking can be increased and on the other hand, the crosslinking result can be improved insofar as the proportion of possibly not injured parts the carrier layer can be lowered.

The barrier layer may have a thickness selected from a range with a lower limit of 2 gm, in particular 5 gm, preferably 10 pm, and an upper limit of 80 pm, in particular 65 pm, preferably 30 pm, wherein it according to another Embodiment is advantageous if the barrier layer has an elongation selected from a range with a lower limit of 20%, in particular 40%, preferably 55%, and an upper limit of 500%, in particular 350%, preferably 200%, so that the elastomeric, mechanical properties of the base material of the carrier layer are not negatively influenced by the barrier layer.

For a better understanding of the invention, this will be explained in more detail with reference to the following figures.

In a schematic simplified representation: [0030] FIG. 1 shows a diving article according to the invention in a sectional view; Fig. 2 shows a variant of the method according to the invention in the manner of a flow scheme.

Introductoryly it should be noted that in the differently described embodiments, the same parts are provided with the same reference numerals or identical component names, wherein the disclosures contained in the entire description can be mutatis mutandis to the same parts with the same reference numerals or the same component names. Also, the location information chosen in the description, such as above, 4/19 Austrian Patent Office AT500 557 B1 2011-08-15 referred to the directly described and illustrated figure and are to be transferred to the new situation in a change in position mutatis mutandis.

Fig. 1 shows a dipping article according to the invention in the form of a glove 1 in cross section with a carrier layer 2 and a barrier layer 3, which is arranged on an inner surface 4 of the carrier layer 2. In addition, on the inner surface 4 opposite outer surface 5 of the support layer 2 is also a layer 6 attached, which, however, does not necessarily have to be present in the diving article according to the invention.

This layer 6 is e.g. intended to reduce the possibly existing lubricity of the outer surface 5 of the carrier layer 2, in order to form with the glove 1, for example, tools, such as e.g. Surgical instruments to be able to better grip and work better. Of course, this layer 6 can also be given other functions by having this layer 2 e.g. is equipped with an antibacterial agent, if this is not already present in the carrier layer.

Of course, it is also possible on the outer surface 5 to arrange a barrier layer 3, or it is generally possible that further layers 6 are attached to both the inner surface 4 and the outer surface 5. So it is e.g. it is conceivable to provide a layer 6 on the barrier layer 3, formed on the inner surface 4, which contains a lotion, e.g. with aloe vera or the like., In order to avoid the drying of the skin of the wearer, or to provide an appropriate antibacterial equipment in the interior of the glove 1.

To explain, it should be noted that the inner surface 4 is that surface in the embodiment of the invention as glove 1, which points towards the skin of the wearer of the glove 1, and is accordingly the outer surface 5 of these opposite.

The carrier layer 2 is made of an elastomer, i. a polymer with soft-elastic properties at service temperature, which can be chemically crosslinked with peroxide crosslinking agents. As a result, gloves 1 or generally immersion articles can be produced, which at least do not trigger any sulfur and / or accelerator allergy or contact allergy, as can occur with conventional latex gloves whose crosslinking takes place via sulfur and accelerators. Preferably, the backing layer 2 is selected from a group comprising natural rubber, enzymatically deproteinated natural rubber to further lower the allergy potential, isoprene rubber, polychloroprene rubber, polyurethane, nitrile rubber, isobutene-isoprene rubber, styrene-butadiene rubber, copolymers of ethyl acrylate or other acrylates having a proportion of a monomer facilitating vulcanization, such as Chloromethyl acrylate, further terpolymers of ethylene, propylene and with an unsaturated diene, such as. 5-ethylidene-2-norbornene, cyclopentadiene, ethylene / propylene copolymers, further polyester urethanes and mixtures thereof formed. The latices may thus be of both natural and synthetic origin, depending on whether type I and / or type IV allergies are to be excluded.

As already mentioned, a peroxide is used to crosslink the elastomer of the carrier layer 2. This peroxide may be selected from a group comprising di-tert-butyl peroxide, tertiary butyl cumyl peroxide, bis (tertiary butyl peroxi isopropyl) benzene, dicumyl peroxide, 4,4-di-tertiary butyl peroxy-n-butyl valerate, 1,1-di-tert-butyl peroxy-3,3,5-trimethyl cyclohexane, Tertiary butyl perbenzoate, benzoyl peroxide, bis (2,4-dichlorobenzoyl) peroxide, bis (p-chlorobenzoyl) peroxide or mixtures thereof. However, it is also possible to use other peroxides, for example dialkyl peroxides, for example 2,5-dimethyl-di (tert-butylperoxy) hexane, 2,5-bis (tert-butylperoxy) -2,5-dimethylhexane, 2,5-bis (tertiarybutylperoxy) -2,5-dimethyl-3-hexane, tertiarybutyl-3-iso-propenylcumylperoxide, bis (3-isopropenylcumyl) peroxide, and peroxyketals, but it would go too far at this point because of the principle of peroxide crosslinking Anyway, it is known from the state of the art to list all possible peroxides here, and if the person skilled in the art is referred to the pertinent literature in this regard (eg from "Röthemey Technology / AT500 557 B1 2011-08-15 er / Sommer- Kautschuk Technologie , 2001, Hanser-Verlag (ISBN 3-446-16169-4) ").

However, it is advantageous if a peroxide is used which has a peroxide group content in the molecule content of at least 35%, in particular at least 40%, preferably at least 50%.

The barrier layer 3 is formed of a polymer. Examples of these are polyurethane, polyacrylates, polymethacrylates, epoxies, silicones, polyesters, polyamides, rubbers, e.g. carboxylated nitrile-butadiene rubber, thermoplastic elastomers, e.g. Vinyl-based thermoplastic elastomers, thermoplastic polyurethane elastomers, olefin-based thermoplastic elastomers, polystyrene-based thermoplastic elastomers, thermoplastic polyester elastomers, thermoplastic polyamide elastomers and mixtures thereof.

The barrier layer 3 has the function of externally penetrating substances, which intercept the radicals formed during the crosslinking of the peroxide, for example oxygen, at least in those areas at least largely away from the carrier layer 2, which in direct contact with the surrounding atmosphere stand, so in the present embodiment of the inner surface 4, since this surface is outside after the dipping process, and only after the removal of the glove 1 comes to rest from the dipping shape by turning inside.

The polymer for the barrier layer 3 can advantageously have a permeation coefficient at standard conditions (20 ° C., 1013 mbar) for oxygen of not more than 20 × 10 -8 cm 2 / (s bar), preferably of not more than 15 × 10 -8 cm 2 / ( s bar), in particular of not more than 4 × 10'8 cm 2 / (bar), for example of not more than 0.15 × 10'8 cm 2 / (bar).

The barrier layer 3 can be obtained by spraying the polymer onto the carrier layer 2, by immersing the dip mold provided with the emerging carrier layer 2 in a further immersion bath containing the polymer, by brushing on a corresponding polymer solution, e.g. in the form of a lacquer, or be applied by other coating methods, as will be explained in more detail below.

The compound of the barrier layer 3 with the carrier layer 2 can be made via adhesion forces. However, it is advantageous if, instead of or in addition to this, covalent, ie chemical bonds, are formed between the polymer of the barrier layer 3 and the elastomer of the carrier layer 2, since this results in "adhesion". the barrier layer 3 on the carrier layer 2 can be improved. In order to achieve this, an unsaturated polymer may be used for the barrier layer 3.

The preparation of the dipping article according to the invention in the embodiment of glove 1 essentially follows those process steps for glove-dipping processes which are known from the prior art.

In Fig. 2, a possible process flow is shown for this purpose.

To produce, for example, powder-free gloves 1 made of an elastomer, a plurality of immersion molds 8, e.g. made of porcelain, plastic, metal, aluminum or the like., In the form of a glove 1 is arranged. These forms of immersion 8 may have a smooth surface for the subsequent outer side, or may be provided with grooves, as is described, for example, in US Pat. in EP 0 856 294 B1 of the Applicant, the content of which is included in the present application, is described.

In the usual way, the dipping forms 8 are cleaned prior to use in the production process of possibly remaining residues from previous productions, e.g. to ensure powder-free.

Powder freedom means that no separate sliding powder to improve the attractability of the glove 1, are applied. However, powdery substances which are used in the dipping process, e.g. Coagulants, be present in small quantities on the glove 1. The purified dipping forms 8 can subsequently be dipped optionally into a first dip tank 10, in which an aqueous coagulation solution 9 is located. This may contain, for example, calcium nitrate, polyethylene glycol and a water-soluble silicone type or chalk. However, any other compositions known in the art for this purpose, e.g. Alcohol solutions of potassium or calcium salts, which may also contain release agents, e.g. Talc or calcium carbonate which, if acid soluble, can be dissolved out of the surface layers of the glove 1 in subsequent acid treatment steps.

As indicated by the arrow 11, arranged on the mold carrier 7 Tauchformen 8 are immersed in the dip tank 9, then taken out of this according to arrow 12 and optionally after an intermediate drying with a drying device - as symbolically by a hot air blower 13 and the heated air for drying schematically representing arrows 14 indicated - spent according to the dotted lines 15 to a second dip tank 16.

Of course, it is within the scope of this inventive method to those skilled in the decision whether the immersion of the dipping molds 8 always takes place in the same dip tank 9 and this via an inlet 17 and a drain 18, e.g. via a schematically illustrated conveyor 19, for example, a pump, alternately with the coagulation solution 10 or any other liquids or media that are needed for the manufacturing process, is filled or whether several consecutively arranged basin are provided for diving. It is also possible that the immersion of the dipping forms 8 by a relative movement of any kind between the mold carrier 7 and the dip tank 9, 16 takes place. Of course, it is also possible that especially those treatment or process steps in which the diving articles or gloves 1 are already removed from the dipping forms 8, in rotating containers, such as drums or the like., As in conventional washing and drying machines be used to move them during the treatment by continuous rotation of the drum, for example, to prevent sticking of the diving products or gloves 1 during production.

Since all these different possibilities for carrying out the method are known to the person skilled in the art, the description of the different apparatuses for carrying out the individual method steps is omitted and this is explained only with reference to the purely schematic representations in FIG ,

After this optionally completed intermediate drying of the coagulant or the coagulation solution 10, the immersion molds 8 are immersed in the dip tank 16, so that the immersion molds 8 immerse completely under a liquid level 20. In this dip tank 16 there is a dispersion of at least one above-mentioned elastomer for the carrier layer 2. This dispersion may contain further auxiliaries or compounding substances, such as e.g. Zinc oxide, accelerators, stabilizers, waxes, anti-aging agents, antioxidants, viscosity regulators, plasticizers, e.g. Dioctyl phthalate or diisononyl phthalate, fillers, dyes, etc., as known to those skilled in the art, e.g. from "Röthemeyer / Summer - Rubber Technology, 2001, Hanser-Verlag (ISBN 3-446-16169-4) " are known contain. Furthermore, this dispersion contains at least one peroxide used for the peroxidic crosslinking and / or at least one adjuvant or coagent, as stated above.

The immersion molds 6 remain in the dip tank 16 until a desired layer thickness of the liquid elastomer or latex has formed on the surface of the immersion molds 8 or the layer of the coagulation solution 10. For this purpose, it is also possible that the immersion molds 8 are repeatedly pulled out of the dip tank 16 and dipped again in accordance with the arrows 12, 11.

The dipping bath with the elastomer may e.g. as the following components: EXAMPLE 1: 100 parts of carboxylated nitrile-butadiene rubber, 0.25 part of sodium dodecylbenzenesulfonate, 0.7 part of potassium hydroxide, 4 parts of titanium dioxide , 3.0 parts of wax wax emulsion, 2.0 parts of polyether-polysiloxane coagulant, 0.7 parts of pigment, 4 parts of dicumyl peroxide. Example 2: 100 parts of carboxylated nitrile-butadiene gum, 0.25 part of sodium dodecylbenzenesulfonate, 0.7 part of potassium hydroxide, 4 parts of titanium dioxide, 3.0 parts of paraffin wax emulsion, 2.0 parts of polyether-polysiloxane coagulant, 0 , 7 parts of pigment, 4 parts of dicumyl peroxide, 2 parts of EDMA (ethylene glycol dimethacrylate). Example 3: A compounded dispersion of natural rubber latex with 60 wt.% Solids and 1.5% diester butyl peroxide. Example 4: A compounded dispersion of 60% by weight of natural rubber latex and 1.5% di-tert-butyl peroxide, 1.5 parts triallyl cyanurate (TAC). Example 5: A compounded dispersion of polychloroprene latex containing 60% by weight of solids and an amount of an emulsion of 100 parts of dicumyl peroxide with 35 parts of toluene, 5.6 parts of oleic acid, 101 parts of water and 2.6 parts of 30% aqueous potassium hydroxide in that the dispersion contains 0.5 part of dicumyl peroxide per hundred parts of latex. Example 6: 15% by weight of polyurethane, 85% by weight of tetrahydrofuran and 0.5 part of dicumyl peroxide per hundred parts of latex in the form of the emulsion given in Example 3.

As advantageous, the use of the following peroxides (also in the above examples) has been found, the use of a water-soluble peroxide or peroxide mixture with respect to the environment and the associated requirements by the legislature is given preference, but this is not means that other, non-water-soluble peroxides are also usable, especially even if the legal situation for this contains no special requirements: 1) cumyl hydroperoxide (liquid, water-soluble): was dropped directly into the latex dispersion and delivered in the investigations of the Applicant best result.

2) Di-tert-butyl peroxide (liquid, not water-soluble): was dropped into the latex dispersion and stirred for 1-2 hours to allow diffusion into the latex particles. Pre-emulsification of the peroxide might be helpful.

3) Dibenzoyl peroxide (solid, not water-soluble): was pre-dissolved in acetone and in the

Dropped latex dispersion to obtain a fine precipitate. Subsequently, it was also stirred.

The abovementioned immersion bath compositions are only to be understood as possible examples, and these may vary both with regard to the stated amounts and with regard to the components used.

Thereafter, according to the dotted line 15, a brief intermediate drying of the elastomeric film on the dipping molds 8, for example with hot air from a further drying device 13, e.g. a hot air blower, made, for which the air may have a temperature of 70 ° C to 140 ° C, preferably 90 ° C to 110 ° C, and the dipping forms 8 of this hot air 15 sec. To 60 sec. Can be exposed. The duration of the Heißluftbeaufschlagung and the temperature of the hot air may be controlled so that the layer of the liquid elastomer on the surface passes from the liquid to the gel or solid state. The 8/19 Austrian Patent Office AT500 557 B1 2011-08-15

However, intermediate drying can be omitted if the elastomer film already has sufficient strength. By applying a temperature that is not too high, it is also possible to prevent the crosslinking of the elastomer of the carrier layer 2 from already beginning before the barrier layer 3 according to the invention has been arranged on the carrier layer 2.

Then, the mold carrier 7 is immersed with the immersion molds 8 as indicated by arrow 11 in the dip tank 21, in which the polymeric raw material 22 for producing the barrier layer 3 is located. This may be in the form of a suspension.

At this point, it should be mentioned for the sake of keeping in mind that one or more viscosity regulators known to the person skilled in the art in various embodiments may be added to the polymeric raw material 22 or the elastomer or the coagulation solution 10 in order to apply the dipping baths to the to adapt to desired flow properties. This makes it possible to adjust the viscosity of the usual manner as dispersions present products or materials to the particular desired applications to achieve appropriate thicknesses during dipping or uniform deposition of the various materials on a surface of the dipping molds 8.

For the sake of order, it should also be mentioned at this point that in the present description the term " elastomer " or "latex" regardless of whether it is a dispersion or the cured, dry, crosslinked layer or solid phase of this material, even though such as e.g. in natural latex is commonly referred to as rubber. It would therefore also be possible to designate the layers formed from the individual aforementioned materials as rubber layers.

The dipping bath with the polymeric raw material 22 may e.g. may be composed as follows, the information relating to the composition in the right-hand column being based on the dry matter content:

Example 1: 41.2 parts 0.2 part 0.1 part 58.5 parts

Acralen (BS) (styrene-acrylonitrile-butadiene copolymer latex,

Polymer latex, TSC = 48%)

Coagulant AW (Organopolysiloxane, Bayer)

Acetic acid 98%

water

Example 2:, 20.7 parts 0.1 parts 0.2 parts 79 parts

Rhoplex AC-33 (acrylic containing latex, dry content 46 c Fa. Rohm + Haas)

Coagulant AW (Organopolysiloxane, Fa.

Bayer)

Acetic acid 98%

water

Example 3: Polyurethane 8-18 parts polyacrylate 5-15 parts filler 5-10 parts Example 4: polyurethane 17-26 parts polyacrylate 5-11 parts filler 0-4 parts As polyurethane, a dispersion of an aliphatic polyurethane can be used. The acrylate used was an aqueous dispersion of a self-crosslinking acrylic polymer. The above examples, or in general, can also be a dispersion of an amino-functional polysiloxane in an amount of 4 parts to 15 parts, again based on the dry content, are added ,

After lifting the mold carrier 7 with the immersion molds 8 from the dispersion of the polymeric raw material 22 for the preparation of the barrier layer 3, the latter can, as indicated schematically, if necessary, also with hot air, for example at a temperature between 70 ° C and 140 ° C, preferably 90 ° C to 110 ° C, over a period of 15 sec. To 60 sec. Dried. Preferably, the temperature and the duration of the hot air treatment is adjusted so that at least the surface of the barrier layer 3, but preferably the entire barrier layer, solidifies.

Instead of or in addition to this, in particular if the barrier layer 3 is likewise formed from an elastomeric material, the immersion molds 8 with the semi-finished products of the immersion articles or gloves 1 located thereon can be immersed in a further immersion basin 23, in which the barrier layer 3 hot water 24 is sprayed or rinsed. For this purpose, this can by means of a pump 25 by a boiler or a heat exchanger 26, by which it is maintained at a desired temperature between 40 ° C and 95 ° C, preferably 70 ° C to 90 ° C, circulated through the dip tank 23 become.

By this treatment with hot water 52, the chemical reaction in the barrier layer 3 and the carrier layer 3 can be initiated or assisted, so that there is a start or complete solidification or coagulation in this layer.

After this optional hot water treatment, which can last between 15 seconds and 8 minutes, preferably 30 seconds and 4 minutes, the gloves 1 are removed in their mounted on the dipping molds 8 position from the dip tank 23, so that the remaining water 24 can drain.

The gloves 1 removed from the water 24 are left outdoors or exposed to predrying by means of hot air over a period of 10 seconds to 180 seconds, preferably 20 seconds to 50 seconds, which serves as dewatering time, before being exposed to hot air the "dip tank 27", in this case a heating cabinet or a heating oven, be acted upon by heat and / or infrared radiation. As a result, the peroxidic crosslinking of the carrier layer 3, if it has not already been triggered in a preceding method step, is started.

Instead of or in addition to this heat treatment, the crosslinking may also be effected by means of radiation, e.g. Electron beams, ultraviolet rays, gamma rays, microwaves.

The preferably designed as tile surfaces radiating surfaces 28 for the infrared radiation may have a temperature that the crosslinking in a temperature range with a lower limit of at least 85 ° C, in particular at least 90 ° C, preferably at least 150 ° C and an upper limit of 180 ° C, in particular 190 ° C, preferably 195 ° C, takes place. The respective crosslinking temperature should be adapted to the peroxide used. The dipping articles or gloves 1 can be exposed over a period of time between 1 min and 5 min to this infrared radiation schematically indicated by arrows 29. In this case, ambient air can be blown through the heat chamber or the dryer or the dip tank 27 through the plunge pool 27 or a corresponding drying device by means of a fan 30 according to the schematically indicated arrows 31.

It is also possible that the crosslinking of the elastomer of the carrier layer 2 takes place only via a hot air blower.

After the dipping articles or gloves 1 are dried, as shown in FIG. 2, the immersion molds 8 are immersed in a dip tank 32 containing a release agent 33, for example a powder such as talc, chalk or corn starch powder or a silicone emulsion which is to prevent the subsequent stripping of the gloves 1 of the dipping forms and simultaneous turning a sticking together of now turned outward surfaces of the gloves 1 8/19 Austrian Patent Office AT500 557 B1 2011-08-15.

After stripping the gloves 1, for example, in a transport basket 34, which may also be provided with lattice-shaped or perforations filled, and this transport basket 34 is placed in a dip tank 35, in which a bleaching agent 36 in one of the prior Technique known composition is located. For example, 0.5% sodium hypochlorite can be used mixed with about 0.2% hydrochloric acid.

Following treatment with the bleaching agent 36, the gloves 1 are washed at least once, but preferably several times, in liquids or liquids known in the art to remove the residues of bleaching agents or acids of e.g. separate treatments with acids and bleach.

When this washing process is completed, the gloves 1 are transported to the transport basket 34 in a dip tank 37 or in a drying chamber, in which either by in the drying chamber or in an air intake air for air drying heater 38 may be arranged so that the drying takes place by means of the air indicated schematically by arrows 39, which can be passed through a fan 40 or a blower through the interior of the drying chamber.

Of course, any other form of drying is possible. Thus, for example, using drums or the like .. It is preferably possible when using such a drying chamber, via an additional line 41 to inject a silicone emulsion in the air stream at the end of the drying process or at the end of the drying process, for example, the outside and optionally To coat the inner sides of the glove 1 forming surfaces with silicone and thus to improve the Anziehbar-speed of the gloves 1. Of course, it is also possible to perform this Sil-konbeschichtung in a known manner by immersion in emulsions or by spray application in certain areas of the gloves 1.

After the drying process carried out in the dip tank 37, the gloves 1 are paired together and the other processing operations, such as sterilization and packaging supplied.

In order to improve the lubricity of the gloves 1 on the one hand and the attractability of the gloves 1 on the other hand, their outer or inner surface can be roughened.

The simplest method for roughening gloves 1 is to feed the dip mold 8 coated with the still soft elastomer for the carrier layer 2 or the polymer for the barrier layer 3, for example, through a sandblasting chamber or through a fluidized bed with fine glass beads. Excess particles from the blasting process usually have to be completely removed in subsequent process steps.

In addition, partial surfaces can be roughened via the glass beads or corresponding pressing dies.

These partial surfaces extend, for example, only over part of the horizontal contact surfaces of the glove 1 on the user's hand. Thus, without the entire article is weakened too much, a sufficient wet lubricity achieved because often only on those surfaces on which a bias for tight fit of the glove 1 acts on a body part of the user, a high lubricity must be achieved.

Of course, the use of a sliding layer or a lubricant, as they are known from the prior art, possible.

For the production of a dive article according to the invention, it is not absolutely necessary that all individual steps of the illustrated process sequence are carried out. Thus, e.g. to dispense with individual water treatments. However, according to the invention, the method necessarily comprises the steps of applying a support layer 2 and subsequently the barrier layer 3, in order to prevent the penetration of radical scavengers during the peroxidic crosslinking, e.g. Oxygen, in the carrier layer 2 and the associated "Abbruch " to avoid networking.

The carrier layer 2 may have a thickness between 100 pm and 300 pm.

By contrast, the barrier layer 3 arranged on this carrier layer 2, for example, has a thickness of 2 μm to 80 μm, preferably 2 μm to 30 μm.

It is advantageous if, for the process for the preparation of the glove 1 or of the dipping article, the peroxide is present in a concentration in the latex suspension to be absorbed, which is selected from a range with a lower limit of 0.2% and an upper one Limit of 4%.

But it is also possible to submit the peroxide in a concentration selected from a range of 0.4% to 4.5% or in a concentration of 1% to 5.8%. Of course, all concentrations in the range of 0.2% to 5.8% with respect to the invention are possible or are also concentrations above 5.8%, depending on which peroxide is used for the crosslinking conceivable.

The peroxide can, as already mentioned, be contained directly in the latex suspension or it is likewise possible to use the peroxide in a separate process, for example by dipping, spraying or the like, on an already formed film of the latex suspension on the dip mold 8 apply.

The polymer for the barrier layer 3 preferably forms a dense, rather hard film, which is preferably formed at room temperature. If the latter is not the case, as described in the above method, the crosslinking of the polymer for the barrier layer 3 can take place before the crosslinking of the elastomer via the carrier layer 2.

It is also advantageous if a polymer is selected for the barrier layer 2, which has both an unsaturated and a saturated part in the polymer threads, since it is possible, on the one hand via the unsaturated moiety by radical reaction over the To form peroxides covalent bonds to the carrier layer and thus to improve the adhesion of the barrier layer 3 on the carrier layer 2 accordingly.

In order not to adversely affect the elastomeric properties of the dipping article or glove 1 through the barrier layer 3, the barrier layer 3 may have an elongation selected from a range with a lower limit of 20%, in particular 40%, preferably 55%, and one upper limit of 500%, in particular 350%, preferably 200%. The elongation is determined according to DIN 53 504.

The polymer or the polymer mixture can have a Shore D hardness selected from a range with a lower limit of 30, preferably 40, in particular 50, and an upper limit of 90, preferably 80, in particular 70, or a microhardness IRHD -M according to ISO 48 selected from a range with a lower limit of 30, preferably 50, in particular 70, and an upper limit of 100, preferably 90, in particular 80, having.

As polymer mixtures, compositions of a polyacrylate with polyurethane in a ratio selected from a range of 1: 2 to 2: 1 can be used. For example, it is possible Plextol®, an aqueous dispersion of a thermoplastic u. self-crosslinking acrylic polymer from Rohm GmbH and NeoRex, e.g. NeoRex R-967, an aqueous dispersion of an aromatic polyurethane or Neoxil from Composite Resins Italia Sri. To use. Also conceivable is the use of aliphatic polyester polyurethanes (e.g., Dispercoll U-42), other aromatic polyurethanes (e.g., Witcobond 160 and 170), and aliphatic polyurethanes (e.g., NeoRez R960, R962).

A mixture of 1 part of plextol and 2 parts of Neorex has, for example, a microhardness IRHD-M according to ISO 48 of 72 or a hardness according to Shore-D of 50. 12/19 Austrian Patent Office AT500 557 B1 2011-08-15 The IRHD-M hardness was determined on 2 mm thick layers in glass dishes.

Instead of peroxides which develop radicals by increasing the temperature, it is also possible to use peroxides in which the formation of radicals by redox reaction takes place. An example of this is the system FeS04, Na4P207, hydroxyacetone and sodium oleate.

The embodiments show possible embodiments of the dive article according to the invention, which should be noted at this point that the invention is not limited to the specifically illustrated embodiments thereof, but also various combinations of the individual embodiments are mutually possible and this variation possibility due to the teaching technical action by objective invention in the skill of working in this technical field expert.

For the sake of order, it should finally be pointed out that, for a better understanding of the structure of the dipping article or the dipping process, these or their constituent parts have been shown in the figures partially unevenly and / or enlarged and / or reduced in size.

Reference Number 1 Glove 26 Heat Exchanger 2 Carrier Layer 27 Dip Basin 3 Barrier Layer 28 Radiation Surface 4 Inner Surface 29 Arrow 5 Outer Surface 30 Fan 6 Layer 31 Arrow 7 Mold Carrier 32 Plunge Pool 8 T Shape 33 Release Agent 9 Dip Basin 34 Transport Basket 10 Coagulation Solution 35 Dip Basin 11 Arrow 36 Bleach 12 Line 37 Plunge pool 13 Plunge pool 38 Radiator 14 Inlet 39 Arrow 15 Outlet 40 Fan 16 Conveyor 41 Line 17 Liquid level 18 Plunge pool 19 Raw material 20 Plunge pool 21 Water 22 Raw material 23 Plunge pool 24 Water 25 Pump 13/19

Claims (23)

Austrian Patent Office AT500 557B1 2011-08-15 Claims 1. A process for the preparation of dipping articles made of latex by peroxidic crosslinking, in which a dip mold (8) is immersed in a dip bath in which a mixture of the latex and a peroxide, and optionally at least a further excipient or coagent, is submitted, and thereby on the dip mold (8) a carrier layer (2) is formed from the latex, whereupon the dip mold (8) with the carrier layer (2) is removed from the dipping bath and the carrier layer ( 2) is crosslinked at elevated temperature, wherein after removal of the dip mold (8) from the dip bath and before crosslinking to the carrier layer (2) a barrier layer (3) made of a polymer is selected from a group comprising polyurethane, polyacrylates, polymetacrylates , Epoxies, silicones, polyesters, polyamides, rubbers, such as carboxylated nitrile-butadiene rubber, thermoplastic elastomers, e.g. vinyl-based thermoplastic elastomers, thermoplastic polyurethane elastomers, olefin-based thermoplastic elastomers, polystyrene-based thermoplastic elastomers, thermoplastic polyester elastomers, thermoplastic polyamide elastomers and mixtures thereof, against radical scavengers, in particular oxygen, characterized in that the carrier layer (2 ) is produced sulfur-free and accelerator-free. 2. The method according to claim 1, characterized in that an unsaturated polymer or polymer mixture is used as the polymer. 3. The method according to claim 1 or 2, characterized in that between the polymer or polymer mixture of the barrier layer (3) and the latex of the carrier layer (2) covalent bonds are formed. 4. The method according to any one of the preceding claims, characterized in that the barrier layer (3) emerges and / or sprayed. 5. The method according to any one of the preceding claims, characterized in that the barrier layer (3) after the application and before the crosslinking of the carrier layer (2) is dried. 6. The method according to any one of the preceding claims, characterized in that the polymer chains of the carrier layer (2) via carbon-carbon bonds are interconnected. 7. The method according to any one of the preceding claims, characterized in that the peroxide is selected from a group comprising Ditertiärbutylperoxid, Tertiarbu- tylcumylperoxid, bis (tertiärbutylperoxisiopropyl) benzene, dicumyl peroxide, 4,4-Ditertiärbutyl-peroxy-n-butylvalerate, 1, 1 di-tert-butyl peroxy-3,3,5-trimethylcyclohexane, tert-butyl perbenzoate, benzoyl peroxide, bis (2,4-dichlorobenzoyl) peroxide, bis (p-chlorobenzoyl) peroxide or mixtures thereof. 8. The method according to any one of the preceding claims, characterized in that the peroxide is present in the dipping bath in a concentration selected from a range having a lower limit of 0.2%, preferably 0.4%, in particular 1%, and an upper limit of 5.8%, especially 4.5%, preferably 3%. 9. The method according to any one of the preceding claims, characterized in that the carrier layer (2) by a latex selected from a group comprising natural rubber, enzymatically deproteinated natural rubber, isoprene rubber, Polychlo-roprenkautschuk, polyurethane, nitrile rubber, isobutene-isoprene rubber, styrene Butadiene rubber, copolymers of ethyl acrylate or other acrylates, such as Chloromethyl acrylate, further terpolymers of ethylene, propylene and with an unsaturated diene, such as. 5-ethylidene-2-norbornene, cyclopentadiene, ethylene / propylene copolymers, further polyester urethanes and mixtures thereof is formed. 14/19 Austrian Patent Office AT500 557 B1 2011-08-15 10. The method according to any one of the preceding claims, characterized in that the crosslinking in dependence of the selected peroxide at a temperature of at least 85 ° C, in particular at least 90 ° C, preferably at least 150 ° C is performed. 11. The method according to any one of the preceding claims, characterized in that as a diving article, a glove, e.g. an examination glove, a surgical glove or a condom is made. 12. The method according to any one of the preceding claims, characterized in that the crosslinking by irradiation, e.g. with electron beams, microwaves, IR or UV rays or gamma rays. 13. Submersible article comprising a backing layer (2) of latex having an inner and an outer surface, wherein at least the inner surface of a barrier layer (3) made of a polymer selected from a group comprising polyurethane, polyacrylates, polymethacrylates, epoxies , Silicones, polyesters, polyamides, rubbers, such as carboxylated nitrile-butadiene rubber, thermoplastic elastomers, e.g. vinyl-based thermoplastic elastomers, thermoplastic polyurethane elastomers, olefin-based thermoplastic elastomers, polystyrene-based thermoplastic elastomers, thermoplastic polyester elastomers, thermoplastic polyamide elastomers and mixtures thereof, against free-radical scavengers, in particular oxygen, characterized in that the carrier layer (2 ) Is sulfur and accelerator free. 14. Dipping article according to claim 13, characterized in that the polymer is an unsaturated polymer. 15. Dipping article according to claim 13 or 14, characterized in that between the polymer of the barrier layer (3) and the latex of the carrier layer (2) covalent bonds are formed. 16. Dipping article according to one of claims 13 to 15, characterized in that the material of the barrier layer (3) has a permeation coefficient under standard conditions for oxygen of not more than 20 x 10'8 cm2 / (s bar), preferably of at most 15 x 10'8 cm2 / (s bar), in particular of at most 4 x 10'8 cm2 / (s bar), for example of not more than 0.15 x 10'8 cm2 / (s bar). 17. Dipping article according to one of claims 13 to 16, characterized in that the polymer chains of the carrier layer (2) are connected to one another via carbon-carbon bonds. 18. Dipping article according to one of claims 13 to 17, characterized in that the carrier layer (2) by a latex from a group comprising natural rubber, enzymatically deproteinated natural rubber, isoprene rubber, Polychloroprenkautschuk, polyurethane, nitrile rubber, isobutene-isoprene rubber, styrene-butadiene Rubber, copolymers of ethyl acrylate or other acrylates, such as Chloromethyl acrylate, further terpolymers of ethylene, propylene and with an unsaturated diene, such as. 5-ethylidene-2-norbornene, cyclopentadiene, ethylene / propylene copolymers, further polyester urethanes and mixtures thereof is formed. 19. Dipping article according to one of claims 13 to 18, characterized in that the barrier layer (3) is roughened. 20. Dipping article according to one of claims 13 to 19, characterized in that it comprises a glove, e.g. an examination glove, surgical glove or condom. 21. Dipping article according to one of claims 13 to 20, characterized in that the barrier layer (3) has a thickness selected from a range with a lower limit of 2 pm, in particular 5 pm, preferably 10 pm and an upper limit of 80 pm, in particular 65 pm, preferably 30 pm. 15/19 Austrian Patent Office AT500 557 B1 2011-08-15 22. Dipping article according to one of claims 13 to 21, characterized in that the barrier layer (3) has an elongation selected from a range with a lower limit of 20%, in particular 40%, preferably 55%, and an upper limit of 500%. , in particular 350%, preferably 200%. 23. Dipping article according to one of claims 13 to 22, characterized in that the barrier layer (3) has a surface roughness selected from a range of 1 pm to 40 pm. 3 sheets of drawings 16/19