Aqueous impregnation bath compound for treating reinforcing insert and use thereof, and method for producing viscous reinforcing insert

Abstract

The present invention relates to a dipping bath compound for treating a reinforcing insert and its use for producing a reinforced rubber product. The invention also relates to a method for producing a viscosity-enhancing insert.

Description

Technical Field

[0001] The present invention relates to a dipping bath compound for treating a reinforcement insert and its use for producing a reinforced rubber product. The present invention also relates to a method for producing an adhesive reinforcement insert. Background Art

[0002] It has been shown that it is advantageous in the production of reinforced rubber products if an adhesion promoter is used between the reinforcement insert and the rubber to increase the adhesion strength. Such an adhesion promoter is important, especially in the field of belts used as reinforcement inserts and other high-load composite materials containing reinforcing fibers. Solvent-containing dipping baths are used, especially in the field of belts for rigid applications, to achieve the necessary loading of the cord and the corresponding filament bonding and to result in the stiffness of the belt.

[0003] Adhesion promoters for producing adhesive reinforcement inserts are known in the prior art. Water-based dipping baths are used for soft cords, and solvent-based dipping baths are used for rigid cords. In terms of the method, a one-step method or a two-step method can be employed.

[0004] In the one-step method, the reinforcing element is impregnated with resorcinol formaldehyde latex (RFL) or preferably a mixture free of resorcinol formaldehyde (RF-free) and an adhesion promoter.

[0005] In the two-step method, the reinforcing element is first impregnated with an adhesion promoter, and then RFL (or preferably RF-free) is applied in the second step.

[0006] A significant problem with solvent-containing dipping bath compounds in the prior art is that special equipment including secondary combustion of the solvent must be operated, and therefore, explosion protection must be appropriately considered. In solvent-containing methods (such as in toluene), methylene diphenyl diisocyanate (MDI) is hazardous to human health in the form of free isocyanate and is carcinogenic.

[0007] A significant problem with solvent-free dipping bath compounds in the prior art is that the filament bonding is insufficient for use as a rigid cord. Summary of the Invention

[0008] Starting from this, the object of the present invention is to provide an aqueous solid-containing dipping bath compound for producing reinforcing inserts for rubber products, said reinforcing inserts having very good adhesion properties, in particular very good adhesion in the peel adhesion test (referred to as the H-test), and having good surface coverage after the H-test, without experiencing the above-mentioned problems due to the use of solvents.

[0009] This object is achieved by means of an aqueous solid-containing dipping bath compound according to the invention for treating reinforcing inserts according to claim 1, a method for producing sticky reinforcing inserts according to claim 14, a sticky reinforcing insert according to claim 16 and the use of a sticky reinforcing insert according to claim 17. Further dependent claims provide advantageous refinements.

[0010] According to the invention, there is provided at least one aqueous solid-containing dipping bath compound for treating reinforcing inserts, which contains the following components or is made of or consists of these components:

[0011] (A) at least one fully blocked or partially blocked isocyanate;

[0012] (B) at least one epoxy resin;

[0013] (C) At least one surfactant for enhancing wetting properties, and at least one surfactant (C) is selected from anionic surfactants, cationic surfactants, non-ionic surfactants, amphoteric surfactants, silicone-containing surfactants, perfluorinated surfactants, hydrophilically modified polyolefins, and mixtures thereof, and is particularly preferably selected from soaps, alkylbenzene sulfonates, linear alkylbenzene sulfonates, alkane sulfonates, ester sulfonates, methyl ester sulfonates, sulfosuccinate derivatives, α-olefin sulfonates, alkyl sulfates, fatty alcohol sulfates, fatty alcohol ether sulfates, fatty alcohol polyglycol ether sulfates, fatty alcohol polyglycol ethers, sodium diisooctyl sulfosuccinate, alkylphenol polyglycol ethers, sorbitan fatty acid esters, ethoxylated sorbitan fatty acid esters, alkyl polyglucosides, fatty acid glucamides, fatty acid ethoxylates, fatty amine ethoxylates, ethoxylated triglycerides, bilaterally alkylated polyethylene glycol ethers, alcohol ethoxylates, nonylphenol ethoxylates, polyglycerol fatty acid esters, fatty acid alkanolamides, amine oxides, alkyl dimethylamine oxides, alkyl polyglucosides, sucrose esters, sorbitan esters, fatty acid glucamides, fatty acid N-methylglucamides, ampholytes, betaines, sulfobetaines, N-(amidoalkyl)betaines, N-alkyl-β-aminopropionates, N-alkyl-β-iminopropionates, long-chain primary amine salts, quaternary ammonium salts, quaternary salts, tertiary salts, pyridinium salts, imidazolinium salts, oxazolines salts, esterquats, polyalkylene glycols, alkoxylated polyalkylene glycols, polysulfones, poly(2-hydroxyalkyl acrylates), poly(2-hydroxyalkyl methacrylates), ethylene oxide-propylene oxide block copolymers, polyethylene glycols, polypropylene glycols, polyethylene oxide resins, polypropylene oxides, salts of oligophosphates, salts of polyphosphates, and mixtures thereof;

[0014] (D) At least one latex selected from styrene-butadiene-vinylpyridine copolymer, styrene-butadiene-vinylpyridine copolymer modified with carboxylic acid, styrene-butadiene copolymer, styrene-butadiene copolymer modified with carboxylic acid, nitrile-butadiene copolymer, natural latex, chloroprene latex, and mixtures thereof; and

[0015] (E) Optionally, at least one additive selected from

[0016] · An antifoaming agent, preferably a long-chain alcohol, a high-polymeric glycol, a trialkylmethylamine, a silicone, or a mixture thereof, particularly preferably a silicone in the form of a silicone emulsion;

[0017] · An organic polymer, preferably polylignin, lignin sulfonic acid, kraft lignin;

[0018] · A filler, preferably a silicate;

[0019] · A dye, preferably carbon black;

[0020] · A preservative;

[0021] · A catalyst;

[0022] · A thickening agent;

[0023] · An acid;

[0024] · An alkali solution;

[0025] · A polyol; and

[0026] · Mixtures thereof.

[0027] Term Definition

[0028] The dipping bath compound according to the invention is aqueous, i.e., water is used as the liquid phase. Water is not listed below as a component of the dipping bath compound. The dipping bath compound preferably contains substantially no organic solvents, i.e., no organic liquids that do not participate in the reaction. Substantially free of should be understood to mean that, based on the total weight of the dipping bath compound, less than 5% by weight of organic solvents are present, preferably less than 2% by weight. The dipping bath compound preferably contains no organic solvents at all.

[0029] Furthermore, the dipping bath compound according to the invention preferably contains substantially no resorcinol and formaldehyde and their reaction products, i.e., based on the total weight of the dipping bath compound, their total content present is less than 1.0% by weight, preferably less than 0.5% by weight, particularly preferably less than 0.16% by weight. Particularly preferably, the dipping bath compound is completely free of resorcinol and formaldehyde and their reaction products.

[0030] The sizing bath compound according to the present invention can exist in the form of a single bath or multiple baths, particularly a two-bath form.

[0031] The terms "comprising" and "containing" in this claims and specification should be understood as not excluding other components. Within the scope of the present invention, the term "consisting of or composed of" should be understood as a preferred embodiment of the term "comprising" or "containing". When defining a group "comprising" or "containing" at least a certain number of components, this should also be understood as meaning that a group "consisting of or composed of" these components is also disclosed.

[0032] Sizing bath compound

[0033] Preferred embodiments of the sizing bath compound according to the present invention are described below.

[0034] According to a preferred embodiment of the present invention, based on the total weight of the sizing bath compound including water, the solid content of the sizing bath compound is 2% to 40% by weight, preferably 3% to 30% by weight, particularly preferably 4% to 22% by weight, and even more preferably 5% to 16% by weight.

[0035] According to another preferred embodiment, based on the solid content respectively, the water-containing solid-containing sizing bath compound has the following composition, where the parts by weight in each case are based on the total weight of 200 parts by weight of the sizing bath compound including water:

[0036] (A) 0.1 to 18.0 parts by weight, preferably 0.2 to 16.0 parts by weight, particularly preferably 1.0 to 14 parts by weight, and even more preferably 3.0 to 13 parts by weight;

[0037] (B) 0.4 to 8.0 parts by weight, preferably 0.7 to 6.0 parts by weight, particularly preferably 1.0 to 4.0 parts by weight, and even more preferably 1.2 to 3.0 parts by weight;

[0038] (C) 0.01 to 5.0 parts by weight, preferably 0.02 to 2 parts by weight, particularly preferably 0.05 to 0.50 parts by weight, and even more preferably 0.10 to 0.30 parts by weight;

[0039] (D) 5 to 40 parts by weight, preferably 8 to 30 parts by weight, and particularly preferably 12 to 25 parts by weight, and even more preferably 15 to 20 parts by weight; and

[0040] (E) 0 to 20 parts by weight, preferably 0.1 to 10 parts by weight, and particularly preferably 0.1 to 5 parts by weight, and even more preferably 0.1 to 3 parts by weight.

[0041] According to another preferred embodiment, the aqueous solid-containing dipping bath compound is divided into multiple baths, particularly two baths. In the case of two baths, the two baths have the following compositions:

[0042] Bath 1:

[0043] (A) At least one fully blocked or partially blocked isocyanate;

[0044] (B) At least one epoxy resin;

[0045] (C) At least one surfactant for enhancing wetting properties, and optionally

[0046] (E) At least one additive.

[0047] Bath 2:

[0048] (D) At least one latex;

[0049] and optionally

[0050] (A) At least one fully blocked or partially blocked isocyanate;

[0051] and optionally

[0052] (E) At least one additive.

[0053] According to the present invention, in particular with respect to isocyanates, it has been shown that lactam-blocked isocyanates are advantageous blocking agents. Examples are ε-caprolactam and δ-valerolactam. However, the present invention of course also includes other known blocking agents. The blocking agents are preferably selected from

[0054] · Monohydric phenols, particularly phenol, resorcinol, cresol, trimethylphenol, and tert-butylphenol;

[0055] · Lactams, particularly ε-caprolactam, δ-valerolactam, and dodecanolactam;

[0056] · Primary alcohols, secondary alcohols, and tertiary alcohols, glycol ethers;

[0057] · Oximes, particularly methyl ethyl ketoxime, methyl amyl ketoxime, and cyclohexanone oxime;

[0058] · Enol-forming compounds, particularly ethyl acetoacetate, acetylacetone;

[0059] · Aromatic secondary amines;

[0060] · Imide;

[0061] · Mercaptan;

[0062] · Triazole, and

[0063] · Their mixtures.

[0064] The capping agent is preferably selected from monohydric phenols, especially phenol, cresol, trimethylphenol and tert-butylphenol; lactams, especially ε-caprolactam, δ-valerolactam and laurolactam; and their mixtures, and the capping agent is particularly preferably selected from phenol, ε-caprolactam, and their mixtures. It is most preferred when the MDI mixture (A) is capped with ε-caprolactam.

[0065] In addition, it has been shown that it is advantageous for the adhesion promoter formulation when the isocyanate used is methylene diphenyl diisocyanate (MDI) and / or toluene diisocyanate (TDI) and / or 1,5-naphthalene diisocyanate (NDI). However, the present invention of course also includes all other known isocyanates that can be used in such adhesion promoter formulations. In this regard, reference is made by way of example to US2002 / 0122938A1 and the diisocyanates described therein.

[0066] According to another preferred embodiment of the present invention, the blocked MDI mixture (A) comprises MDI derivatives (i.e., modified MDI), which are preferably selected from MDI uretdione, adducts of MDI and / or MDI oligomers with other compounds.

[0067] According to another preferred embodiment of the present invention, the MDI is selected from 4,4'-MDI, 2,4'-MDI, 2,2'-MDI and their mixtures. In each case, based on the MDI mixture, the content of 2,4'-MDI and 2,2'-MDI is preferably less than 10% by weight, preferably less than 8% by weight, and particularly preferably 0.1% to 6% by weight.

[0068] According to a preferred embodiment, the mixture contains one or more MDI oligomers, where n in formula (I) is an integer from 1 to 8, and preferably an integer from 1 to 6:

[0069]

[0070] According to another preferred embodiment of the present invention, the MDI mixture has the following composition:

[0071] (i) MDI monomer, which is 25% to 60% by weight, preferably 25% to 49.9% by weight;

[0072] (ii) MDI oligomers, which are 40% to 75% by weight, preferably 50% to 74.9% by weight; and

[0073] (iii) Modified MDI, which is 0% to 9% by weight, preferably 0.1% to 6% by weight,

[0074] The total content of components (i) to (iii) is 100% by weight.

[0075] The MDI mixture is made from MDI oligomers of formula (I), MDI monomers and optionally MDI derivatives, and is commercially available under the name "polymeric MDI" (PMDI), such as Voronate (DowDuPont), Suprosec (Huntsman), Elastoflex (BASF), Lupronat (BASF) or Autofroth (BASF).

[0076] According to another preferred embodiment of the present invention, at least one epoxy resin (B) is soluble in the dispersion and / or has a molecular weight of 50 g / mol to 2000 g / mol. Epoxy resins with a molecular weight of 100 to 1000 are particularly preferred, especially water-soluble polyglycidyl ethers, epoxy novolac resins, polyfunctional alkylene epoxy resins, diglycidyl ethers and bisphenol A type resins. However, the present invention also includes all epoxy resins cited in EP 1 221 456 A1. Particularly preferably, at least one epoxy resin (B) in the present invention is selected from water-soluble polyglycidyl ethers, polyfunctional alkylene epoxy resins, diglycidyl ethers, and mixtures thereof.

[0077] According to another embodiment of the present invention, at least one surfactant (C) is selected from anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, silicone surfactants, perfluorinated surfactants, hydrophilically modified polyolefins, and mixtures thereof. The surfactant is preferably selected from soaps, alkylbenzene sulfonates, linear alkylbenzene sulfonates, alkane sulfonates, ester sulfonates, methyl ester sulfonates, sulfosuccinate derivatives, α-olefin sulfonates, alkyl sulfates, fatty alcohol sulfates, fatty alcohol ether sulfates, fatty alcohol polyglycol ether sulfates, fatty alcohol polyglycol ethers, sodium diisooctyl sulfosuccinate, alkylphenol polyglycol ethers, sorbitan fatty acid esters, ethoxylated sorbitan fatty acid esters, alkyl polyglucosides, fatty acid glucamides, fatty acid ethoxylates, fatty amine ethoxylates, ethoxylated triglycerides, alkylated polyethylene glycol ethers on both sides, alcohol ethoxylates, nonylphenol ethoxylates, polyglycerol fatty acid esters, fatty acid alkanolamides, amine oxides, alkyl dimethylamine oxides, alkyl polyglucosides, sucrose esters, sorbitan esters, fatty acid glucamides, fatty acid N-methyl glucamides, ampholytes, betaines, sulfobetaines, N-(amidoalkyl) betaines, N-alkyl-β-aminopropionates, N-alkyl-β-iminopropionates, long-chain primary amine salts, quaternary ammonium salts, quaternary salts, tertiary salts, pyridine salts, imidazoline salts, oxazoline salts, ester quaternary ammonium salts, polyalkylene glycols, alkoxylated polyalkylene glycols, polysulfones, poly(2-hydroxyalkyl acrylates), poly(2-hydroxyalkyl methacrylates), ethylene oxide-propylene oxide block copolymers, polyethylene glycols, polypropylene glycols, polyethylene oxide resins, polypropylene oxides, oligophosphates, polyphosphates, and mixtures thereof. At least one surfactant (C) used according to the present invention allows for enhanced wetting of the reinforcing insert to be treated. In particular, the surfactant (C) can wet the inner surface of the fiber bundle serving as the reinforcing insert, thereby enabling an increase in stiffness.

[0078] According to another preferred embodiment of the present invention, at least one surfactant (C) is a nonionic surfactant and / or an anionic surfactant.

[0079] According to another preferred embodiment of the present invention, at least one surfactant (C) is selected from sulfosuccinate derivatives, fatty alcohol sulfates, fatty acid ethoxylates, alkylated polyethylene glycol ethers on both sides, and ethylene oxide-propylene oxide block copolymers.

[0080] According to the most preferred embodiment of the present invention, at least one surfactant (C) is a fatty acid ethoxylate and / or sodium diisooctyl sulfosuccinate.

[0081] According to another preferred embodiment, at least one surfactant (C) does not contain any poly(2-hydroxyalkyl acrylate).

[0082] According to another embodiment of the present invention, at least one latex (D) is selected from styrene-butadiene-vinylpyridine copolymers, styrene-butadiene-vinylpyridine copolymers modified with carboxylic acids, styrene-butadiene copolymers, styrene-butadiene copolymers modified with carboxylic acids, nitrile-butadiene copolymers, natural latex, chloroprene latex, and mixtures thereof.

[0083] According to another embodiment of the present invention, at least one additive (E) is selected from

[0084] · Defoamers, preferably long-chain alcohols, highly polymerized diols, trialkylmethylamines, silicones or mixtures thereof, particularly preferably silicones in the form of silicone emulsions;

[0085] · Organic polymers, preferably polysaccharides, lignosulfonic acids, sulfated lignins;

[0086] · Fillers, preferably silicates;

[0087] · Dyes, preferably carbon black;

[0088] · Preservatives;

[0089] · Catalysts;

[0090] · Thickening agents;

[0091] · Acids;

[0092] · Alkaline solutions;

[0093] · Polyols; and

[0094] · Mixtures thereof.

[0095] By adding a catalyst in the form of a metal compound as an additive, the reaction rate of the adhesion promoter formulation according to the present invention can be further increased. Suitable catalysts are metal compounds of sodium, potassium, cesium, strontium, silver, cadmium, barium, cerium, uranium, titanium, chromium, tin, antimony, manganese, iron, cobalt, nickel, copper, zinc, lead, calcium and / or zirconium. Among the metal compounds, those of zinc are preferred. Suitable compounds are zinc acetate, zinc sulfate, zinc carbonate, zinc oxide, zinc acetylacetonate and / or zinc chloride. Zinc acetate is most particularly preferred. The catalyst is preferably present in the dispersion in a dissolved form, wherein the catalyst is preferably present at a concentration of 0.0001 mol / 1000 g to 0.1 mol / 1000 g of the dipping bath compound.

[0096] According to another preferred embodiment of the present invention, the average particle size d of the blocked MDI mixture 50 is from 0.1 μm to 2 μm, preferably from 0.6 μm to 1.5 μm.

[0097] According to another preferred embodiment of the present invention, the particle size d of the blocked MDI mixture 100 is from 0.1 μm to not more than 6 μm, preferably from 0.6 μm to 5 μm.

[0098] According to another preferred embodiment of the present invention, the number average molecular weight Mn of the blocked MDI mixture is from 550 g / mol to 1200 g / mol, and preferably from 700 g / mol to 1100 g / mol.

[0099] According to another preferred embodiment, the surfactant (C) satisfies the wetting test, and the wetting test comprises the following steps:

[0100] · Dissolve 2% by weight of the surfactant (C) in 50 mL of water at 20 °C so that the liquid level of the solution of the surfactant (C) in the beaker is at least 3 cm high;

[0101] · Provide 0.15 g of a blocked MDI mixture (CL-MDI) capped with ε-caprolactam, the number average molecular weight M n of which is 740 g / mol, particle size: d 50 = 1.2 μm, d 100 = 3.6 μm, and the solids content is 100%;

[0102] · Using a spoon, add 0.15 g of CL-MDI to the still, unstirred surface of the solution of the surfactant (C) without the spoon contacting the solution, such that the CL-MDI floats on the solution of (C),

[0103] · When no floating CL-MDI (less than 20% by weight) is seen on the solution of (C) after 10 minutes, the surfactant (C) is considered to be wetting, and

[0104] · When more than 50% by weight of the CL-MDI floats on the solution of the surfactant (C) after 10 minutes, the surfactant (C) is considered to be non-wetting.

[0105] Furthermore, it is preferred that the dipping bath compound does not contain tragacanth gum.

[0106] To prepare the dipping bath, first keep deionized water available in a container at room temperature, preferably in a stirred container, and then stir components (A), (B), (C), (D) and optionally component (E) into it.

[0107] Method for generating a tackiness-enhanced insert

[0108] The present invention also relates to a method for generating a tackiness-enhanced insert, which at least comprises the following steps:

[0109] a) Providing at least one reinforcing insert;

[0110] b) Immersing the provided reinforcing insert in at least one sizing bath compound as defined above;

[0111] c) Drying the reinforcing insert from step b) at 80 °C to 240 °C;

[0112] d) Sintering the coating of the reinforcing insert from step c) at 150 °C to 250 °C.

[0113] Hereinafter, a preferred embodiment of the method according to the invention for generating a tackiness-enhanced insert will be described.

[0114] According to a preferred embodiment of the present invention, step c) is carried out at a temperature of 110 °C to 210 °C, and preferably at a temperature of 140 °C to 180 °C.

[0115] According to another embodiment of the present invention, step d) is carried out at a temperature of 220 °C to 240 °C.

[0116] According to another preferred embodiment of the present invention, the reinforcing insert is selected from polyamide 6, polyamide 66, polyethylene terephthalate, polyethylene naphthalate, rayon, aramid, cotton, basalt fiber, sisal, hemp, flax, coconut fiber and mixtures thereof.

[0117] According to another preferred embodiment of the present invention, before step b), the reinforcing insert is immersed in an aqueous sizing bath compound containing solids, the sizing compound contains at least one blocked isocyanate, and the sizing compound preferably does not contain any other components. The blocked isocyanate (A) comprises an MDI oligomer of formula (I), n is an integer from 1 to 8, and contains MDI monomers.

[0118]

[0119] After the dipping step, preferably before carrying out step b) of the method according to the invention, the layer is dried and sintered under the above conditions. The drying is preferably carried out at a temperature of 110 °C to 210 °C, and particularly preferably at a temperature of 140 °C to 180 °C. In addition, the drying is preferably carried out for a period of 30 seconds to 120 seconds. Furthermore, the sintering is carried out at a temperature of 220 °C to 240 °C. In addition, the sintering is preferably continued for a period of 20 seconds to 120 seconds.

[0120] According to another preferred embodiment of the invention, before carrying out step b) of the method according to the invention and before introducing at least one latex (D) into the dipping bath compound, the pH value of the dipping bath compound is adjusted to 8 to 12, preferably 9 to 11, i.e., before setting the pH value, the dipping bath compound contains only components (A) and (C). An ammonia solution is preferably used as the base. Before carrying out step b), at least one latex (D) is introduced into the dipping bath compound.

[0121] The tire cord or other reinforcing inserts can be coated in a conventional coating machine, wherein the excess of the dipping bath is removed by mechanical means and / or by vacuum extraction at 1 mbar to 5 mbar. The coating is first dried in a furnace at 100 °C to 240 °C for 20 seconds to 120 seconds, and then sintered in another furnace at 200 °C to 250 °C for 20 seconds to 120 seconds.

[0122] Method for producing a reinforced rubber product

[0123] The invention also relates to a method for producing a reinforced rubber product, which comprises the following steps:

[0124] (i) providing at least one layer of a sticky reinforcing insert produced by the method according to the invention as described above;

[0125] (ii) embedding at least one layer of the sticky reinforcing insert from step (i) into a rubber mass in a mold;

[0126] (iii) pressing the layer from step (ii);

[0127] (iv) vulcanizing the reinforced rubber product from step (iii) at 140 °C to 210 °C and 5 bar to 110 bar for 5 minutes to 45 minutes; and

[0128] (v) removing the reinforced rubber product from step (iv) from the mold.

[0129] According to a preferred embodiment of the present invention, the reinforced rubber product is a tire for passenger cars, motorcycles, commercial vehicles and aircraft, as well as industrial rubber products, in particular conveyor belts, air springs, hoses (such as bellows for trains or buses) and drive belts, such as V-belts, multi-wedge V-belts, round belts, flat belts or toothed belts.

[0130] Adhesive reinforcement insert

[0131] The present invention also relates to an adhesive reinforcement insert that can be produced by the method according to the present invention. The adhesive reinforcement insert is preferably a drive belt.

[0132] The reinforcement insert is preferably made of or composed of a fiber bundle containing 200 to 500 filaments, wherein the fiber bundle preferably has a fineness of 400 to 1700 decitex, and wherein the reinforcement insert is particularly preferably formed by 3 to 30 of these fiber bundles.

[0133] In addition, the reinforcement insert preferably has a fineness of 4000 to 40000 decitex.

[0134] Use

[0135] The present invention also relates to the use of the adhesive reinforcement insert according to the present invention for producing a reinforced rubber product.

[0136] The present invention also relates to the use of the dipping bath compound according to the present invention for coating the reinforcement insert of a rubber product.

[0137] The reinforced rubber product is preferably a tire for passenger cars, motorcycles, bicycles, commercial vehicles and aircraft, as well as industrial rubber products, in particular conveyor belts, air springs, hoses and drive belts, such as V-belts, multi-wedge V-belts, round belts, flat belts or toothed belts.

[0138] The subject matter according to the present invention will be described in more detail based on the following examples, and the subject matter is not limited to the specific embodiments shown herein. Detailed description of the specific implementation

[0139] Measurement method

[0140] The following measurement methods are used within the scope of this application.

[0141] Particle size (d 50 value or d 100 value)

[0142] The particle size is determined by laser diffraction using a powder or aqueous dispersion at 23 °C according to ISO 13320. The laser measurement is carried out in a Cilas 1064 particle size analyzer manufactured by Quantachrome GmbH (Germany).

[0143] H-Test

[0144] The adhesion according to the H-test was determined on a polyester cord (1100×3×3 dtex, S100, z50) at a vulcanization temperature of 160 °C and a vulcanization time of 15 minutes in accordance with ASTM D4776.

[0145] Stiffness

[0146] The stiffness was determined on a polyester cord (1100×3×3 dtex, S100, z50) in accordance with ASTM D885.

[0147] Maximum Tension

[0148] The maximum tension was determined on a polyester cord (1100×3×3 dtex, S100, z50) in accordance with ASTM D885.

[0149] Dip Pickup (DPU)

[0150] The DPU was determined on a polyester cord (1100×3×3 dtex, S100, z50) in accordance with ASTM D2970.

[0151] Surface Coverage

[0152] The surface coverage according to the H-test was determined by visual inspection by comparing the corresponding tire material with an internal sample with a coverage of 0% to 100%. A coverage of 0% means that after the H-test, the adhesion-enhancing insert is completely peeled off from the rubber, i.e., the fracture occurs in the boundary layer between the tire cord and the rubber. Conversely, a coverage of 100% means that the adhesion-enhancing insert is not peeled off from the rubber, i.e., the fracture occurs in the rubber.

[0153] Solid Content

[0154] The solid content was determined by evaporation in a halogen dryer (Mettler HR 73 halogen dryer). For this purpose, approximately 3 g of the dipping bath compound was evenly distributed in an aluminum tray (diameter: 95 mm) at the bottom of the tray. The test duration was 25 minutes at 80 °C. The display type selected was the drying type "Dry content (100 - 0)". The average value of three determinations is shown.

[0155] Number-average molecular weight (M n )

[0156] The number average molecular weight (M n ) was determined by gel permeation chromatography (GPC) with UV detection.

[0157] For measurement, the sample was dissolved in THF (about 5 mg in 10 mL) and filtered through a disposable syringe filter before loading into the vial.

[0158] Equipment: Waters 2690 Alliance

[0159] Software: Waters Millennium 32 GPC module

[0160] Column: PLgel Particle size 3 μm

[0161] Length 30.0 cm

[0162] Inner diameter 7.5 mm

[0163] UV detector wavelength: 254 nm

[0164] Eluent: THF

[0165] Flow rate: 1.0 mL / min

[0166] The number-average molecular weight (M n ) was determined by conventional calibration. Polystyrene standards (with masses of 700, 1100, and 2000) and laurolactam (with a mass of 197) were used for calibration. Three determinations were made. The arithmetic mean of the molecular weights is expressed in g / mol. The THF solvent was a HPLC-quality solvent purchased from EGT Chemie, Switzerland. The disposable filter can be purchased from Macherey-Nagel GmbH & Co. KG, Germany, under the name Chromafil A-45 / 25 (pore size 0.45 μm, filter diameter 25 mm). The disposable syringe can be purchased from VWR International GmbH, Germany.

[0167] Wettability Evaluation

[0168] To evaluate wettability, 2 wt% surfactant was dissolved in 50 mL of water at 20 °C such that the liquid level in the beaker was at least 3 cm high. Additionally, 0.15 g of an MDI mixture capped with ε-caprolactam was prepared, with a number-average molecular weight M n of 740 g / mol and a particle size: d 50 = 1.2 μm, d 100= 3.6 μm, and the solids content is 100%. Using a spoon, 0.15 grams of CL-MDI was added to a solution of surfactant that was stationary and not stirred, with the spoon not touching the solution. When no floating CL-MDI (less than 20% by weight) was visible on the solution after 10 minutes, the surfactant was considered wetted. When more than half of the added CL-MDI floated on top without wetting, the surfactant was considered non-wetted.

[0169] Raw materials

[0170] The materials used in the examples and comparative examples are summarized in Table 1. Table 2 lists the evaluation results of wettability. If evaluated without a surfactant, more than half of the CL-capped MDI would also float on water without wetting after 10 minutes. Similarly, in the case of lignosulfonate or gum tragacanth, far more than half of the CL-capped MDI still floated on top after 10 minutes. It has even been shown that in the case of lignosulfonate or gum tragacanth, after 10 minutes, more than 90% by weight of the CL-capped MDI floated on top, and even after 24 hours, far more than 50% by weight of the CL-capped MDI floated on top without wetting. Even though gum tragacanth had no effect on wetting, it had to be considered negative because due to gum tragacanth, the liquid became viscous and the wettability of the solution decreased.

[0171] Table 1:

[0172]

[0173] a) The capped MDI mixture (A1) was prepared by capping the product "Voronate M600" available from DowDuPont

[0174] b) ε-Caprolactam.

[0175] Table 2:

[0176]

[0177] Polyester cord (1100×3×3 dtex, S100, z50) was used as the reinforcing insert.

[0178] This polyester cord was made of or consisted of polyethylene terephthalate with a total adhesion of 9900 dtex. More specifically, three fiber bundles were twisted at 100 turns per meter in the S direction, and each fiber bundle contained 200 to 350 filaments (1100 dtex). Subsequently, three of these three bundles were successively twisted at 50 turns per meter in the Z direction (opposite direction).

[0179] The coating machine used is a test system from Mehler Engineering & Service GmbH, Fulda, Germany.

[0180] Examples and Comparative Examples

[0181] Table 3 summarizes the results of the examples and comparative examples according to the present invention.

[0182] Table 3

[0183]

[0184] In Table 3, compared with Comparative Example 1 and Comparative Example 2, the increase in the stiffness of the fiber bundles treated in the dipping bath according to the present invention in Examples 3 to 6 is obvious.

[0185] In Examples 3 to 6, this can be attributed to the wetting surfactant (C) used, which also ensures a high amount of adhered rubber even within the fiber bundles.

[0186] When comparing Comparative Example 2 with Examples 4 and 6, it is obvious that the wetting surfactant rather than the lignosulfonate brings about good stiffness. The lignosulfonate is not a wetting surfactant and shows no effect on the CL-terminated MDI in water in the wettability evaluation. When comparing Comparative Example 1 and Comparative Example 2, it is also obvious that the lignosulfonate has no effect on the stiffness.

[0187] Divided according to the latex systems used, the increase in the amount of adhered rubber caused by the wetting surfactant is also obvious. The amount of adhered rubber in Examples 3 and 5 is much higher than that in Comparative Example 1, and the amount of adhered rubber in Examples 4 and 6 is higher than that in Comparative Example 2. The resulting enhancement of stiffness is important for use as a reinforcing insert (rigid cord). This is especially important for side-opening belts to ensure that the fibers of the fiber bundles do not wear during the cutting process.

[0188] Furthermore, it can be clearly seen from the comparison within the latex systems in Table 2 that there are no significant changes in the adhesion force and the maximum tension according to the H-test.

Claims

1. An aqueous, solids-containing dipping bath composition for treating reinforcing inserts for rubber products, comprising, made of or consisting of the following components: (A) at least one fully blocked or partially blocked isocyanate; (B) at least one epoxy resin; (C) at least one surfactant for enhancing the wetting properties, at least one surfactant (C) is selected from anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, silicon-containing surfactants, perfluorinated surfactants, hydrophilically modified polyolefins and mixtures thereof, and is particularly preferably selected from soaps, alkylbenzene sulfonates, linear alkylbenzene sulfonates, alkane sulfonates, ester sulfonates, methyl ester sulfonates, sulfosuccinic acid derivatives, α-olefin sulfonates, alkyl sulfates, fatty alcohol sulfates, fatty alcohol ether sulfates, fatty alcohol polyglycol ether sulfates, fatty alcohol polyglycol ethers, sodium dioctyl sulfosuccinate, alkylphenol polyglycol ethers, sorbitan fatty Acid esters, ethoxylated sorbitan fatty acid esters, alkyl polyglucosides, fatty acid glucose amides, fatty acid ethoxylates, fatty amine ethoxylates, ethoxylated triglycerides, polyglycol ethers alkylated on both sides, alcohol ethoxylates, nonylphenol ethoxylates, polyglycerol fatty acid esters, fatty acid alkanolamides, amine oxides, alkyl dimethylamine oxides, alkyl polyglucosides, sucrose esters, sorbitan esters, fatty acid glucose amides, fatty acid N-methylglucosamides, ampholytes, betaines, sulfobetaines, N-(amidoalkyl) betaines, N-alkyl-β-aminopropionates, N-alkyl-β-iminopropionates, long-chain primary amine salts, quaternary ammonium salts, quaternary Salt, Uncle Salt, pyridine Salt, imidazoline Salt, Oxazoline salts, ester quaternary ammonium salts, polyalkylene glycols, alkoxylated polyalkylene glycols, polysulfones, poly(2-hydroxyalkyl acrylates), poly(2-hydroxyalkyl methacrylates), ethylene oxide-propylene oxide block copolymers, polyethylene glycols, polypropylene glycols, polyethylene oxide resins, polypropylene oxides, oligophosphates, polyphosphates and mixtures thereof; (D) at least one latex selected from the group consisting of styrene-butadiene-vinylpyridine copolymers, styrene-butadiene-vinylpyridine copolymers modified with carboxylic acid, styrene-butadiene copolymers, styrene-butadiene copolymers modified with carboxylic acid, nitrile-butadiene copolymers, natural latex, chloroprene latex, and mixtures thereof; (E) optionally, at least one additive selected from Defoamers, preferably long-chain alcohols, high polymer diols, trialkylmethylamines, silicones or mixtures thereof, particularly preferably silicones in the form of silicone emulsions; Organic polymers, preferably polylignin, lignin sulfonic acid, kraft lignin; Fillers, preferably silicates; Dye, preferably carbon black; ·preservative; ·catalyst; Thickener; ·acid; Lye; Polyols; and mixtures thereof.

2. The aqueous, solid-containing dipping bath composition according to claim 1, characterized in that The solids content of the dipping bath composition is 2% to 40% by weight, preferably 3% to 30% by weight, and particularly preferably 5% to 27% by weight, based on the total weight of the dipping bath composition.

3. The aqueous, solid-containing dipping bath composition according to claim 1 or 2, characterized in that The dipping bath composition has the following composition, the parts by weight in each case being based on the solids content of the dipping bath composition: (A) 0.1 parts by weight to 18 parts by weight, preferably 0.2 parts by weight to 16 parts by weight, particularly preferably 1.0 parts by weight to 14 parts by weight, and still more preferably 3.0 parts by weight to 13 parts by weight; (B) 0.4 to 8.0 parts by weight, preferably 0.7 to 6.0 parts by weight, particularly preferably 1.0 to 4.0 parts by weight, and still more preferably 1.2 to 3.0 parts by weight; (C) 0.01 to 5.0 parts by weight, preferably 0.02 to 2 parts by weight, particularly preferably 0.05 to 0.50 parts by weight, and still more preferably 0.10 to 0.30 parts by weight; (D) 5 to 40 parts by weight, preferably 8 to 30 parts by weight, and particularly preferably 12 to 25 parts by weight, and still more preferably 15 to 20 parts by weight; and (E) 0 parts by weight to 20 parts by weight, preferably 0.1 parts by weight to 10 parts by weight, and particularly preferably 0.1 parts by weight to 5 parts by weight, and still more preferably 0.1 parts by weight to 3 parts by weight.

4. The aqueous, solid-containing dipping bath composition according to any one of claims 1 to 3, characterized in that The at least one isocyanate (A) is preferably blocked with a blocking agent selected from Monohydric phenols, in particular phenol, resorcinol, cresol, trimethylphenol and tert-butylphenol; Lactams, in particular ε-caprolactam, δ-valerolactam and laurolactam; Primary, secondary and tertiary alcohols, glycol ethers; oximes, in particular methyl ethyl ketone oxime, methyl amyl ketone oxime and cyclohexanone oxime; Enol-forming compounds, in particular ethyl acetoacetate and acetylacetone; ·Aromatic secondary amines; Imides; Mercaptans; Triazole, and mixtures thereof, and The at least one isocyanate (A) is particularly preferably blocked with a lactam as blocking agent, in particular with ε-caprolactam, δ-valerolactam and laurolactam as blocking agent.

5. The aqueous, solid-containing dipping bath composition according to any one of claims 1 to 4, characterized in that The at least one isocyanate (A) is selected from methylene diphenyl diisocyanate (MDI), toluene diisocyanate (TDI), 1,5-naphthalene diisocyanate (NDI), and mixtures thereof, and / or The at least one isocyanate (A) contains an MDI derivative, which is preferably selected from MDI uretdione, adducts of MDI with other compounds, adducts of MDI oligomers with other compounds, and mixtures thereof, the other compounds being in particular polyethylene glycol.

6. The aqueous, solid-containing dipping bath composition according to claim 5, wherein the MDI is selected from 4,4'-MDI, 2,4'-MDI, 2,2'-MDI and mixtures thereof, wherein the content of 2,4'-MDI and 2,2'-MDI is less than 10% by weight, preferably less than 8% by weight, and particularly preferably the content of 2,4'-MDI and 2,2'-MDI is 0.1% by weight to 6% by weight, based on the MDI mixture, and particularly preferably the mixture contains one or more than one MDI oligomer, and n in formula (I) is an integer from 1 to 8, and preferably an integer from 1 to 6: Formula (I).

7. The aqueous, solid-containing dipping bath composition according to any one of claims 1 to 6, characterized in that The MDI mixture has the following composition: (i) MDI monomer, which is 25% to 60% by weight, preferably 25% to 49.9% by weight; (ii) MDI oligomers at 40 to 75 wt%, preferably 50 to 74.9 wt%; and (iii) MDI derivatives, which are 0% to 9% by weight, preferably 0.1% to 6% by weight, The contents of components (i) to (iii) total 100% by weight.

8. The aqueous, solid-containing dipping bath composition according to any one of claims 1 to 7, characterized in that The molecular weight of the at least one epoxy resin (B) is 50 g / mol to 2000 g / mol, preferably 100 g / mol to 1000 g / mol, and the at least one epoxy resin (B) is preferably selected from water-soluble polyglycidyl ethers, epoxy novolac resins, multifunctional alkylene epoxy resins, diglycidyl ethers and bisphenol A type resins, and mixtures thereof.

9. The aqueous, solids-containing dipping bath composition according to any one of the preceding claims, characterized in that Average particle size of the capped MDI mixture 50 The particle size d of the blocked MDI mixture is 0.1 mm to 2 mm, preferably 0.6 mm to 1.5 mm. 100 is 0.1 mm to 6 mm, preferably 0.6 mm to 5 mm, and / or the number average relative molar mass M n It is 550 g / mol to 1200 g / mol, and preferably 700 g / mol to 1100 g / mol.

10. The aqueous, solids-containing dipping bath composition according to any one of the preceding claims, characterized in that The surfactant (C) satisfies the wetting test, which comprises the following steps: Dissolve 2 wt% of surfactant (C) in 50 mL of water at 20°C so that the liquid level of the surfactant (C) solution in the beaker is at least 3 cm high; · Providing 0.15 g of ε-caprolactam-terminated MDI mixture (CL-MDI), the number average molecular weight of the ε-caprolactam-terminated MDI mixture is n 740 g / mol, particle size: d 50 =1.2µm, d 100 =3.6µm, and the solid content is 100%; · Add 0.15 g of CL-MDI to the still, unstirred surface of the solution of dissolved surfactant (C) using a spoon, without the spoon coming into contact with the solution, so that the CL-MDI floats on the solution of (C); The surfactant (C) was considered wetted when no more floating CL-MDI (less than 20 wt%) was seen on the solution of (C) after 10 minutes; and • A surfactant (C) is considered non-wetting when more than 50% by weight of the CL-MDI floats on the solution of (C) after 10 minutes.

11. The aqueous, solids-containing dipping bath composition according to any one of the preceding claims, characterized in that The dipping bath composition does not contain tragacanth gum.

12. A method for producing a viscosity enhancing insert comprising at least the following steps: (a) providing at least one reinforcing insert; (b) dipping the provided reinforcement insert in at least one dipping bath compound according to any one of claims 1 to 9; (c) drying the reinforcement insert from step b) at 80° C. to 240° C.; and (d) sintering the coating of the reinforcement insert from step c) at 150°C to 250°C.

13. The method according to claim 12, characterized in that The reinforcing insert is a compound selected from the group consisting of polyamide 6, polyamide 66, polyethylene terephthalate, polyethylene naphthalate, rayon, aramid, cotton, basalt fiber, sisal, hemp, flax, coconut fiber, and mixtures thereof.

14. An adhesion enhancing insert producible by a method according to claim 12 or 13.

15. The adhesion enhancing insert according to claim 14, characterized in that The reinforcing insert is preferably made of or consists of fiber bundles containing 200 to 500 filaments, the fiber bundles preferably having a titer of 400 to 1700 dtex, the reinforcing insert is particularly preferably formed from 3 to 30 of these fiber bundles, and the reinforcing insert particularly preferably has a titer of 4000 to 40000 dtex.

16. Use of a viscous reinforcing insert according to claim 14 or 15 for producing a reinforced rubber product.

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