Polyurethane-polyurea aqueous dispersion and preparation method, use and slurry thereof, polyurethane glove preparation method and polyurethane glove

Abstract

The present invention relates to a polyurethane-polyurea aqueous dispersion, which comprises a polyurethane-polyurea having terminal polycarboxylic acid and / or carboxylate groups dispersed in water. The present invention also relates to a preparation method and use of the polyurethane-polyurea aqueous dispersion, a slurry comprising the polyurethane-polyurea aqueous dispersion, and a polyurethane glove and a preparation method thereof.

Description

Technical Field

[0001] The present invention belongs to the field of gloves, and specifically relates to a polyurethane-polyurea aqueous dispersion, a preparation method and use of the polyurethane-polyurea aqueous dispersion, a slurry containing the polyurethane-polyurea aqueous dispersion, and a polyurethane glove and a preparation method thereof. Background Art

[0002] Waterborne polyurethane gloves are non-toxic, odorless, and have simple production processes, and are a hot topic in the research of disposable gloves today. Because the preparation method of waterborne polyurethane is different from that of nitrile and latex, the preparation process of waterborne polyurethane gloves is quite different from that of nitrile and latex, especially the stability of the rubber containing polyurethane water dispersion used in the preparation of gloves.

[0003] The flocculation method of water-based polyurethane gloves usually involves dipping the glove model in a coagulant solution and then dipping it in a rubber compound containing a polyurethane aqueous dispersion. The coagulant solution used in the flocculation method contains high-valent electrolyte salts, such as salts containing calcium ions, magnesium ions, and aluminum ions. During use, it is inevitable that metal ions will migrate into the rubber compound, causing the stability of the rubber compound to change. In severe cases, the rubber compound becomes jelly-like and cannot be used. Therefore, how to increase the operating time (service life) of the rubber compound determines whether polyurethane gloves can achieve large-scale continuous production.

[0004] Therefore, there is still a need in the art to provide a method that can effectively reduce the migration of metal ions from a coagulant solution into a rubber compound containing a polyurethane aqueous dispersion used to prepare gloves, so that the rubber compound has a longer life, thereby enabling gloves to be produced continuously on a large scale, and the prepared gloves have excellent mechanical properties. Summary of the invention

[0005] The present invention is made in view of the above-mentioned problems in the prior art.

[0006] The first aspect of the present invention is to provide a polyurethane-polyurea aqueous dispersion, wherein the dispersion comprises a polyurethane-polyurea having terminal polycarboxylic acid and / or carboxylate groups dispersed in water.

[0007] The second aspect of the present invention is to provide a method for preparing the polyurethane-polyurea aqueous dispersion of the first aspect of the present invention, wherein the method prepares the polyurethane-polyurea by reacting a prepolymer containing a terminal isocyanate group, preferably at least two terminal isocyanate groups, with a polyamine containing at least two amine groups selected from primary and / or secondary amine groups, and a compound reactive with isocyanate containing a single amine group selected from primary or secondary amine groups or a hydroxyl group and containing multiple carboxyl groups.

[0008] The third aspect of the present invention is to provide the use of the polyurethane-polyurea aqueous dispersion of the first aspect of the present invention, or the polyurethane-polyurea aqueous dispersion prepared by the method of the second aspect of the present invention, for preparing a slurry for flocculation-process water-based polyurethane gloves, or polyurethane gloves.

[0009] The fourth aspect of the present invention is to provide a slurry comprising the polyurethane-polyurea aqueous dispersion according to the first aspect of the present invention or prepared by the method according to the second aspect of the present invention.

[0010] The fifth aspect of the present invention relates to a method for preparing polyurethane gloves using the slurry according to the fourth aspect of the present invention.

[0011] The sixth aspect of the present invention relates to polyurethane gloves, which comprise a polyurethane layer prepared using the slurry of the fourth aspect of the present invention as a raw material, preferably obtained by the method described in the fifth aspect of the present invention.

[0012] The applicant has found that when the polyurethane-polyurea polymer in the polyurethane-polyurea aqueous dispersion contains a terminal polycarboxyl group and / or a carboxylate group structure, the destructive effect of metal ions such as calcium ions from the coagulant solution on the rubber containing the polyurethane-polyurea aqueous dispersion used to prepare gloves can be effectively reduced, thereby extending the service life of the rubber, and at the same time, the produced gloves have excellent mechanical properties, such as improved elongation and excellent tensile strength. DETAILED DESCRIPTION

[0013] In order to make the invention purpose, technical scheme and beneficial technical effect of the present invention clearer, the present invention will be described in detail below. It should be noted that the various aspects, features, embodiments and advantages described in the present invention may be compatible and / or may be combined together. In addition, the following description is merely exemplary and is not intended to limit the present invention in any way.

[0014] Unless otherwise specified, the meanings of the technical terms in this specification are the same as those generally understood by those skilled in the art.

[0015] Relational terms such as “first” and “second” are used merely to distinguish one element, component or method step from another with the same name, but do not necessarily require or imply any such actual relationship or order between these elements, components or method steps.

[0016] In the present application, when the expressions “above”, “below” are used when describing numerical values, for example, “above (below)…”, the terms “above”, “below” are meant to include the stated numerical value itself.

[0017] In the present application, the terms "polyurethane-polyurea", "polyurethane-polyurea copolymer" and "polyurethane-polyurea polymer" have the same meaning, which all refer to copolymers containing urethane structural units and urea structural units and are used interchangeably, and are sometimes also simply referred to as "polyurethane".

[0018] In the present application, the term "rubber" means a rubber containing a polyurethane-polyurea aqueous dispersion used for preparing gloves.

[0019] The invention relates to a polyurethane-polyurea aqueous dispersion, a preparation method and use of the polyurethane-polyurea aqueous dispersion, a slurry containing the polyurethane-polyurea aqueous dispersion, and a polyurethane glove and a preparation method thereof.

[0020] The present invention will be described in detail below.

[0021] Polyurethane-polyurea aqueous dispersion

[0022] In a first aspect, the present invention provides an aqueous polyurethane-polyurea dispersion comprising a polyurethane-polyurea having terminal polycarboxylic acid and / or carboxylate groups dispersed in water.

[0023] In a preferred embodiment, the content of the terminal polycarboxylic acid and / or carboxylate groups is 7.0-30 mmol / 100 g, preferably 9 to 27 mmol / 100 g, based on the total weight of the polyurethane-polyurea, for example 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 mmol / 100 g.

[0024] In the present application, unless otherwise specified, the content of the terminal polycarboxylic acid and / or carboxylate groups stated is relative to the total weight of the polyurethane-polyurea.

[0025] In a preferred embodiment, the polyurethane-polyurea can be prepared by reacting raw materials comprising the following components:

[0026] Component a: one or more polyether or polyester polyols, wherein the number average molecular weight of the polyether or polyester polyol is greater than 500 g / mol;

[0027] Component b: one or more polyisocyanates;

[0028] Component c: one or more hydrophilic compounds, wherein the hydrophilic compound contains 2-3 groups reactive with NCO, and the hydrophilic group of the hydrophilic compound includes an ionic group and / or a potential ionic group;

[0029] Optional component d: one or more alcohol chain extenders different from component a, having a number average molecular weight of 300 g / mol or less;

[0030] Component e: one or more compounds that ionize the potential ion groups in component c, having the structural formula R1R2R3N, wherein R1-R3 are the same or different from each other and are independently selected from H, or C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, or C5-C6 cycloalkyl which is unsubstituted or substituted with OH;

[0031] Component f: one or more polyamines containing at least two amino groups selected from primary and / or secondary amino groups, and having a number average molecular weight of 500 g / mol or less;

[0032] Component g: one or more compounds reactive with isocyanate containing a single amine group selected from primary or secondary amine groups or a hydroxyl group and containing multiple carboxyl groups;

[0033] The terminal polycarboxylic acid and / or carboxylate groups in the polyurethane-polyurea are introduced by component g.

[0034] Component a

[0035] In an embodiment of the present invention, component a is one or more polyether or polyester polyols.

[0036] The hydroxyl functionality of component a can be selected as required. In a preferred embodiment, component a is one or more of a diol, a triol and a tetraol. In a further preferred embodiment, component a is a diol.

[0037] The number average molecular weight of component a can be selected as needed. In a preferred embodiment, the number average molecular weight of component a can be 500 g / mol or more, for example, 500 to 6000 g / mol, for example, 500 to 5000 g / mol, for example, the number average molecular weight of component a can be 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 5400, 5500, 5600, 5700, 5800, 5900, 6000 g / mol, or a range limited by any two of them.

[0038] The number average molecular weight can be measured by conventional means in the art, such as gel permeation chromatography (GPC) method, hydroxyl value (mg KOH / g) titration method. In the following, unless otherwise specified, the number average molecular weight refers to the number average molecular weight measured by titration method.

[0039] As non-limiting examples of polyether polyols that can be used in the present invention, polyether polyols formed from one or more of ethylene oxide, propylene oxide, and butylene oxide can be mentioned. When it is desired to use a polyether polyol that is a triol or a tetraol, it can be obtained by initiating the ring-opening polymerization of one or more of ethylene oxide, propylene oxide, and butylene oxide using a triol (e.g., glycerol) or a tetraol (e.g., pentaerythritol) as an initiator.

[0040] As non-limiting examples of polyester polyols that can be used in the present invention, there can be mentioned polyester polyols formed by the polymerization of one or more dibasic acids and one or more diols, and polyester polyols formed by the polymerization of one or more dibasic acids and one or more diols and optionally one or more tribasic or higher acids and optionally one or more trihydric or higher alcohols.

[0041] Non-limiting examples of diols include: 1,2-ethanediol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, tetrahydrofuran, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,3-hexanediol, 1,4-hexanediol, 1,5-hexanediol, 1,6-hexanediol, 1,2-heptanediol, 1,3-heptanediol, 1,4-heptanediol, 1,5-heptanediol, 1,6-heptanediol, 1,7-heptanediol, octanediol, nonanediol, decanediol, cyclopentanediol, cyclohexanediol, and the like.

[0042] Non-limiting examples of trihydric or higher alcohols include, for example, glycerol, pentaerythritol, and the like.

[0043] Non-limiting examples of dibasic acids include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, terephthalic acid, phthalic acid, isophthalic acid, cyclohexanedicarboxylic acid, and the like.

[0044] Non-limiting examples of trivalent or higher acids include, for example, trimesic acid, pyromellitic acid, and the like.

[0045] Component b

[0046] In a preferred embodiment of the present invention, the component b is one or more of aromatic, aliphatic and alicyclic polyisocyanates having at least two, preferably two isocyanate groups.

[0047] The functionality of the isocyanate groups of component b can be selected as desired. For example, the functionality of the isocyanate groups of component b can be 2, 3, 4 or higher.

[0048] As non-limiting examples of aromatic polyisocyanates, there may be mentioned diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), naphthalene diisocyanate, p-phenylene diisocyanate, xylylene diisocyanate, 1,3-bis(1-isocyanato-1-methylethyl)benzene, dimethylbiphenyl diisocyanate, polymethylene polyphenyl isocyanate, and the like.

[0049] As non-limiting examples of cycloaliphatic polyisocyanates, mention may be made of 4,4′-dicyclohexylmethane diisocyanate (HMDI), 1,4-cyclohexane diisocyanate, cyclohexane dimethylene diisocyanate, trimethyl-1,6-hexamethylene diisocyanate (e.g. 2,2,4-trimethyl-1,6-hexamethylene diisocyanate, 2,4,4-trimethyl-1,6-hexamethylene diisocyanate, and mixtures thereof), norbornane diisocyanates (e.g. 2,5-bis(isocyanatemethyl)bicyclo[2.2.1]heptane, 2,6-bis(isocyanatemethyl)bicyclo[2.2.1]heptane, or mixtures thereof), methylcyclohexyl diisocyanate and isophorone diisocyanate (IPDI).

[0050] As non-limiting example of aliphatic polyisocyanates, mention may be made of hexamethylene diisocyanate HDI.

[0051] Component c

[0052] In an embodiment of the present invention, component c is a hydrophilic compound, the hydrophilic compound contains 2-3 groups reactive with NCO, and the hydrophilic group of the hydrophilic compound includes an ionic group and / or a potential ionic group.

[0053] In the context of the present invention, an ionic group refers to a group that carries an electric charge itself. A non-limiting example of an ionic group is a carboxylate group.

[0054] In the context of the present invention, a potential ionic group refers to a group that can be converted into an ionic group by a chemical reaction. The chemical reaction may be an acid-base neutralization reaction or a protonation reaction. A non-limiting example of a potential ionic group is a carboxylic acid group.

[0055] In a preferred embodiment, component c may be one or more of dimethylolpropionic acid, dimethylolbutanoic acid, and aminosulfonate, more preferably dimethylolpropionic acid.

[0056] Component d

[0057] Component d is an alcohol chain extender different from component a, and its Mn is 300 or less. For example, the Mn of component d can be any of the following values ​​or within the range defined by any two of the following: 300, 290, 280, 270, 260, 250, 240, 230, 220, 210, 200, 190, 180, 170, 160, 150, 140, 130, 120, 110, 100, 90, 80, 70, or 60.

[0058] As non-limiting examples of component d, mention may be made of one or more of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,4-dihydroxycyclohexane, 1,4-dimethylolcyclohexane, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, neopentyl glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol and 2-ethyl-1,3-hexanediol; preferably 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,3-butanediol, neopentyl glycol and 1,4-cyclohexanedimethanol, and any combination thereof.

[0059] Component e

[0060] In the present invention, component e is a compound that ionizes the potential ion group in component c, and has a structural formula of R1R2R3N, wherein R1-R3 are the same or different from each other and are independently selected from H, or C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, or C5-C6 cycloalkyl which is unsubstituted or substituted with OH.

[0061] As non-limiting examples, component e may be an organic tertiary amine, such as triethylamine, dimethylethanolamine, triisopropylamine, or component e may be ammonia, more preferably component e may be volatile triethylamine.

[0062] Component f

[0063] In the present invention, component f is a polyamine containing at least two amine groups selected from primary and / or secondary amine groups, and its Mn is 500 g / mol or less, for example, 60 to 500 g / mol. 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500 g / mole, or a range defined by any two of them.

[0064] The polyamine has at least two amine groups selected from primary and / or secondary amine groups, for example, the amine groups may all be primary amine groups, all be secondary amine groups, or at least one of them may be primary and at least one may be secondary.

[0065] As non-limiting examples of component f, mention may be made of: ethylenediamine, 1,2-diaminopropane, 1,4-diaminobutane, 1,6-hexanediamine, 2-methyl-1,5-diamine, isophoronediamine, 4,4-diaminodicyclohexylmethane, piperazine and diethylenetriamine or any combination thereof. More preferably, component f may be ethylenediamine and / or isophoronediamine.

[0066] Component g

[0067] In the present invention, component g is one or more compounds reactive with isocyanate, containing a single amine group selected from a primary amine group or a secondary amine group or a hydroxyl group and containing a plurality of carboxyl groups.

[0068] In one embodiment of the present invention, the number of carboxyl groups in the component g is 2 or more, for example, 3 or more.

[0069] As a non-limiting example of component g, mention may be made of ethylenediaminetriacetic acid.

[0070] In an embodiment of the present invention, based on the total weight of component ag being 100 weight %, the weight proportion of component ag is as follows:

[0071] The content of component a may be 72-85% by weight, for example, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85% by weight, or a range defined by any two thereof;

[0072] The content of component b may be 10-23% by weight, for example, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23% by weight, or a range defined by any two thereof;

[0073] The content of component c may be 1.5-4% by weight, for example, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0% by weight, or a range defined by any two thereof;

[0074] The content of component d may be 0-3% by weight, for example, 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8-, 2.9, 3.0% by weight, or a range defined by any two thereof;

[0075] The content of component e can be 0.1-3% by weight, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0% by weight, or the range defined by any two thereof;

[0076] The content of component f can be 0 to 3 weight %, for example, 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0 weight %, or a range defined by any two thereof;

[0077] The content of component g can be 0.4-2.5% by weight, for example 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5% by weight, or a range limited by any two thereof.

[0078] In one embodiment of the present invention, based on the total weight of the polyurethane-polyurea aqueous dispersion, the content of polyurethane-polyurea in the aqueous dispersion is 35 wt % or more, for example, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90 wt %, or a range limited by any two thereof.

[0079] The particle size of the polyurethane-polyurea dispersed in the polyurethane-polyurea aqueous dispersion is not particularly limited, for example, it can be: less than 2 μm, for example, 10 nm, 20 nm, 40 nm, 60 nm, 80 nm, 100 nm, 120 nm, 140 nm, 160 nm, 180 nm, 200 nm, 220 nm, 240 nm, 260 nm, 280 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, 1200 nm, 1400 nm, 1600 nm, 1800 nm, 2000 nm average particle size.

[0080] The particle size can be measured by methods well known to those skilled in the art. For example, the particle size can be measured by a laser particle size analyzer (for example, commercially available from Malvern).

[0081] In the context of the present invention, if not specifically stated, the terms "particle diameter", "particle size", "particle size" and "particle size" are used interchangeably.

[0082] In the context of the present invention, unless otherwise specified, the term particle size refers to the volume average particle size D v 50, that is, in the volume cumulative distribution curve, 50% of the volume of the particles have a particle size higher than this particle size value, and 50% of the volume of the particles have a particle size lower than this particle size value.

[0083] The applicant has found that when the polyurethane-polyurea polymer in the polyurethane-polyurea aqueous dispersion contains terminal polycarboxyl groups and / or carboxylate structures, the terminal polycarboxyl groups and / or carboxylate structures can effectively reduce the concentration of metal ions such as calcium ions from the coagulant solution accumulated in the rubber containing the polyurethane-polyurea aqueous dispersion for preparing gloves, thereby effectively reducing the destructive effect of metal ions such as calcium ions on the rubber, extending the service life of the rubber, and at the same time improving the mechanical properties of the produced gloves, for example, improving the elongation and simultaneously having excellent tensile strength.

[0084] The polyurethane-polyurea copolymer also forms an aspect of the present invention. All the above descriptions of the polyurethane-polyurea copolymer in the polyurethane-polyurea aqueous dispersion are applicable to the polyurethane-polyurea copolymer. No further description will be given here.

[0085] Preparation method of polyurethane-polyurea aqueous dispersion

[0086] In a second aspect, the present invention provides a method for preparing the polyurethane-polyurea aqueous dispersion of the first aspect of the present invention, the preparation method comprising preparing the polyurethane-polyurea by:

[0087] A polyurethane prepolymer containing terminal isocyanate groups, preferably at least two terminal isocyanate groups, is reacted with a polyamine containing at least two amine groups selected from primary and / or secondary amine groups and a compound reactive with isocyanate containing a single amine group selected from primary or secondary amine groups or a hydroxyl group and containing multiple carboxyl groups.

[0088] The amine groups contained in the polyamine containing at least two amine groups selected from primary and / or secondary amine groups may all be primary amine groups, or all be secondary amine groups, or at least one of them may be a primary amine group and at least one may be a secondary amine group.

[0089] In a preferred embodiment, the preparation method comprises the following steps:

[0090] - reacting component a, component b, component c, and optionally component d in a first inert solvent to obtain a prepolymer containing terminal isocyanate groups, preferably at least two terminal isocyanate groups;

[0091] - optionally diluting with the addition of a second inert solvent;

[0092] - Add component e to neutralize, then add water to evenly disperse, to obtain a dispersion containing an inert solvent;

[0093] - Add components f and g to the dispersion containing an inert solvent to continue the reaction;

[0094] - removing the inert solvent to obtain a polyurethane-polyurea aqueous dispersion free of inert solvent;

[0095] - optionally, converting the terminal carboxyl groups in the polyurethane-polyurea into carboxylate groups,

[0096] The second inert solvent is the same as or different from the first inert solvent.

[0097] The above descriptions about components ag in the polyurethane-polyurea aqueous dispersion of the first aspect of the present invention are applicable here.

[0098] In this application, "inert solvent" refers to a solvent that does not react with the components used to prepare the polyurethane-polyurea.

[0099] The first inert solvent and the second inert solvent are not particularly limited. The first inert solvent and the second inert solvent may be the same or different. For example, the first inert solvent and the second inert solvent may be independently an ester solvent or a ketone solvent. Non-limiting examples of the ester solvent include esters formed by C1-C20 monocarboxylic acids and C1-C20 monohydric alcohols, such as ethyl acetate, methyl propionate, ethyl propionate, etc. Non-limiting examples of the ketone solvent include acetone, butanone (methyl ethyl ketone), pentanone, cyclopentanone, hexanone, cyclohexanone, and the like.

[0100] The method of removing the solvent may be any method known to those skilled in the art. As a non-limiting example, the solvent may be removed by distillation under normal or reduced pressure.

[0101] In the present invention, the terminal carboxyl groups in the polyurethane-polyurea can be converted into carboxylate groups by using a basic compound. Preferably, the basic compound is an alkali metal compound.

[0102] As non-limiting examples of alkali metal compounds that can be used in the present invention, alkali metal hydroxides, alkali metal carbonates, alkali metal carboxylates, alkali metal nitrates, alkali metal sulfates, alkali metal halides, alkali metal pseudohalides, etc. can be mentioned. In a preferred embodiment of the present invention, the alkali metal compound is an alkali metal hydroxide and / or an alkali metal carbonate. In a more preferred embodiment, the alkali metal compound is sodium hydroxide and / or sodium carbonate.

[0103] The alkali metal compound can be added directly to the polyurethane-polyurea aqueous dispersion without an inert solvent in solid form. Alternatively, the alkali metal compound can be added to the polyurethane-polyurea aqueous dispersion without an inert solvent in solution form.

[0104] The applicant has found that by reacting a polyurethane prepolymer containing a terminal isocyanate group with a polyamine and a compound containing a single amine group selected from a primary amine group or a secondary amine group or a hydroxyl group and containing multiple carboxyl groups, which is reactive with isocyanate, a polyurethane-polyurea polymer having multiple carboxyl functional groups or carboxyl salts thereof (such as sodium carboxylate) at the ends of its chain segments is obtained, thereby preventing the metal ions from the coagulant solution from damaging the stability of the rubber compound containing the polyurethane-polyurea polymer used for preparing the gloves during the preparation of the gloves, and at the same time improving the mechanical properties of the prepared gloves, for example, improving the elongation and simultaneously having excellent tensile strength.

[0105] Application of polyurethane-polyurea aqueous dispersion

[0106] In a third aspect, the present invention provides use of the polyurethane-polyurea aqueous dispersion of the first aspect of the present invention or the polyurethane-polyurea aqueous dispersion prepared by the method of the second aspect of the present invention for preparing a slurry for flocculation-processed aqueous polyurethane gloves or polyurethane gloves.

[0107] In the present application, "polyurethane gloves", "polyurethane-polyurea gloves", "polyurethane-polyurea polymer gloves", and "polyurethane-polyurea copolymer gloves" have the same meaning, which all refer to gloves containing the polyurethane-polyurea copolymer described in relation to the first aspect of the present invention as a constituent component (e.g., a constituent layer), and are used interchangeably herein.

[0108] Polyurethane slurry

[0109] In a fourth aspect, the present invention provides a polyurethane slurry comprising the polyurethane-polyurea aqueous dispersion of the first aspect of the present invention or the polyurethane-polyurea aqueous dispersion prepared by the method of the second aspect of the present invention, a crosslinking agent, an optional ion chelating agent and optionally additional water.

[0110] The additional water means water other than the water contained in the polyurethane-polyurea aqueous dispersion.

[0111] The crosslinking agent that can be used in the present invention is not particularly limited. In a preferred embodiment of the present invention, the crosslinking agent comprises one or more of polyfunctional aziridine, carbodiimide, amino resin, and sorbitol polyglycidyl ether.

[0112] The cross-linking agent that can be used in the present invention is not particularly limited. In one embodiment of the present invention, the ion chelating agent comprises one or more of sodium gluconate, sodium tartrate, disodium ethylenediaminetetraacetate, sodium diethylenetriaminepentaacetate.

[0113] In a preferred embodiment of the present invention, the weight ratio of the polyurethane-polyurea aqueous dispersion, the crosslinking agent, the ion chelating agent and the additional water is 100:0.3-1.2:0.01-0.5:100-200.

[0114] For example, based on 100 parts by weight of the polyurethane-polyurea aqueous dispersion, the content of the crosslinking agent may be 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2 parts by weight, or a range defined by any two of them.

[0115] For example, based on 100 parts by weight of the polyurethane-polyurea aqueous dispersion, the content of the ion chelating agent may be 0.01, 0.02, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50 parts by weight, or a range defined by any two of them.

[0116] For example, based on 100 parts by weight of the polyurethane-polyurea aqueous dispersion, the additional water content may be 100, 110, 120, 130, 140, 150 parts by weight, or 160 parts by weight, or 170 parts by weight, or 180 parts by weight, or 190 parts by weight, or 200 parts by weight.

[0117] Method for preparing polyurethane gloves

[0118] In a fifth aspect, the present invention provides a method for preparing a polyurethane glove, the method comprising the step of preparing a polyurethane layer using the slurry of the fourth aspect of the present invention.

[0119] In the present application, "polyurethane layer", "polyurethane-polyurea layer", "polyurethane-polyurea polymer layer" and "polyurethane-polyurea copolymer layer" have the same meaning and all refer to the layer formed by the polyurethane-polyurea (copolymer) described with respect to the polyurethane-polyurea aqueous dispersion of the first aspect of the present invention.

[0120] In a non-limiting embodiment, the method of the fifth aspect of the present invention comprises the following steps:

[0121] S1: dipping the optionally cleaned hand mold in a coagulant solution, and optionally drying it thereafter, to obtain a first treated hand mold;

[0122] S2: dipping the hand mold subjected to the first treatment in the slurry of the fourth aspect of the present invention, and optionally drying it afterwards; optionally repeating the dipping and drying process one or more times to obtain a hand mold subjected to the second treatment;

[0123] S3: Optionally, cleaning the second treated hand mold with water, and optionally drying it afterwards, to obtain a third treated hand mold;

[0124] S4: Optionally, immersing the hand mold after the second treatment or the hand mold after the third treatment in a slippery coating liquid;

[0125] S5: curling, plasticizing and demoulding to obtain polyurethane gloves.

[0126] In one embodiment, the hand model is cleaned before being immersed in the coagulant solution. The cleaning can be performed by known means in the art and is not particularly limited. For example, the cleaning can be performed by immersing in an acid (e.g., nitric acid) solution, then immersing in an alkali (e.g., sodium hydroxide) aqueous solution, then washing with water, and then drying.

[0127] The coagulant that can be used in the present invention is not particularly limited. For example, the coagulant solution contains a soluble salt, a release agent and water.

[0128] The soluble salt has a divalent or higher valent cation, such as but not limited to: Mg 2+ , Ca 2+ 、Al 3+ In a preferred embodiment, the soluble salt may be chloride, nitrate, etc. In a more preferred embodiment, the soluble salt may be selected from one or more of calcium nitrate, calcium chloride, magnesium nitrate, magnesium chloride, zinc nitrate and zinc chloride.

[0129] The mold release agent that can be used in the present invention can be any mold release agent known to those skilled in the art, such as calcium stearate, zinc stearate, magnesium stearate, starch, etc. The mold release agent can be commercially available, for example, under the brand names ZK-40 and LU-101.

[0130] In one embodiment of the present invention, the weight ratio of the soluble salt, the release agent and water can be 15-30 (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, or a range defined by any two of them): 8-20 (8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or a range defined by any two of them): 150-250 (150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, or a range defined by any two of them).

[0131] In one embodiment, the hand mold is dried after being dipped in the coagulant solution.

[0132] In one embodiment, the process of dipping the first treated hand model in the slurry of the fourth aspect of the present invention in step S2, and optionally drying thereafter, is performed once. Alternatively, the process may be performed multiple times (e.g., 2, 3 or more times) depending on the desired thickness of the polyurethane layer. In one embodiment, drying is performed after dipping the first treated hand model in the slurry of the fourth aspect of the present invention.

[0133] In one implementation, step S3 may not be performed.

[0134] In one embodiment, step S3 is performed, that is, the second treated hand mold is cleaned with water, and optionally dried to obtain a third treated hand mold. In one embodiment, the second treated hand mold is dried after being cleaned with water.

[0135] The method may optionally include a step of dipping in a slippery coating liquid (to form a slippery coating). When step S3 is not performed, the hand model treated by the second treatment is directly dipped in the slippery coating liquid. When step S3 is performed, the hand model treated by the third treatment is dipped in the slippery coating liquid. In one embodiment of the present invention, the slippery coating liquid comprises one or more of PU coating, acrylic coating, corn starch coating, and talcum powder coating. In a preferred embodiment, the slippery coating liquid is PU coating.

[0136] In step S5, curling, plasticization and demoulding are performed to obtain polyurethane gloves.

[0137] The curling, plasticizing and demoulding can be performed by any suitable method known in the art without any particular limitation.

[0138] The drying in steps S1 to S3 may each be independently performed by any known method and is not particularly limited.

[0139] In one embodiment, in step S2, the hand mold may be dried after being taken out of the dipping process. The drying may be performed, for example, by oven drying.

[0140] Drying can be carried out in any equipment known to those skilled in the art, such as but not limited to a forced air oven, a vacuum oven.

[0141] In a preferred embodiment of the present invention, when the dipping and drying process is repeated multiple times in S2, drying is performed after each dipping step.

[0142] The drying conditions can be selected according to the impregnation. Preferably, the drying can be performed at a temperature of 80-150° C. For example, the drying can be performed at a temperature of 80, 90, 100, 110, 120, 130, 140, 150° C., or a temperature in the range defined by any two thereof.

[0143] The plasticization in step S5 can be performed by means known to those skilled in the art, such as but not limited to baking. In some embodiments of the present invention, the plasticization can be performed at a temperature of 110 to 140° C., such as at a temperature of 115° C., 120° C., 125° C., 130° C., 135° C., 140° C. The duration of plasticization can be adjusted according to the raw materials used. In some embodiments, the plasticization can last for 20-40 minutes, such as 20, 25, 30, 35, 40 minutes.

[0144] Polyurethane gloves

[0145] In a sixth aspect, the present invention provides a polyurethane glove, comprising a polyurethane layer prepared using the slurry of the fourth aspect as a raw material.

[0146] Preferably, the polyurethane gloves are prepared by the method of the fifth aspect of the present invention.

[0147] The gloves may only include a polyurethane layer prepared using the slurry of the fourth aspect as a raw material. The gloves may also further include other layers, such as a slippery coating, as required.

[0148] By introducing a polycarboxyl structure at the end of the polyurethane-polyurea polymer molecular chain, the stability of the polyurethane-polyurea aqueous dispersion under high electrolyte conditions is improved. By using the polyurethane-polyurea aqueous dispersion of the present invention, even if no additional metal chelating agent is added to the glove slurry formula, the destructive effect of metal ions such as calcium ions from the coagulant solution on the rubber containing the polyurethane-polyurea aqueous dispersion used to prepare the gloves can be effectively reduced, the service life of the rubber can be extended, and at the same time, the mechanical properties of the prepared gloves can be improved, for example, the gloves have improved elongation and excellent tensile strength at the same time.

[0149] The applicant of the present invention has further found that, unexpectedly, if a chelating agent is further included in the polyurethane-polyurea aqueous dispersion, the chelating agent can produce a synergistic effect with the polyurethane-polyurea molecules, further significantly extending the service life of the rubber compound and improving the mechanical properties of the prepared gloves, for example, improving the elongation and simultaneously having excellent tensile strength.

[0150] Example

[0151] The following embodiments further illustrate the technical solutions provided by the present invention, but the present invention is not limited to the embodiments listed.

[0152] Main raw materials

[0153] Poly(neopentyl adipate) glycol, OH value = 56 mg KOH / g, brand WHP205, Wanhua Chemical;

[0154] Poly(hexanediol-neopentyl glycol-adipic acid ester diol), OH value = 56 mg KOH / g, brand WHP2056, Wanhua Chemical;

[0155] Poly(methyl propanediol adipate), OH value = 56 mg KOH / g, brand WHP208, Wanhua Chemical;

[0156] Poly(ethylene glycol adipate), OH value = 56 mg KOH / g, WHP207, Wanhua Chemical;

[0157] Polytetramethylene glycol, PTMEG 2000, OH value = 56 mgKOH / g, Mitsubishi Chemical, Japan;

[0158] 4,4'-Dicyclohexylmethane diisocyanate (HMDI), from Wanhua Chemical;

[0159] Isophorone diisocyanate (IPDI), from Wanhua Chemical;

[0160] Neopentyl glycol (NPG), from Wanhua Chemical;

[0161] Butanediol, from Sinopharm Chemical Reagent Company;

[0162] triethylamine, from Sinopharm Chemical Reagent Company;

[0163] Ethylenediamine, from Sinopharm Chemical Reagent Company;

[0164] diethanolamine, from Sinopharm Chemical Reagent Company;

[0165] Ethylenediaminetriacetic acid was from Sinopharm Chemical Reagent Company;

[0166] Dihydroxypropionic acid (DMPA), Sinopharm Chemical Reagent Company

[0167] Sodium gluconate, Sinopharm Chemical Reagent Company

[0168] Etherified amino resin crosslinker, CYMEL 385 from Allnex

[0169] PU coating, Stahl WF-78-923

[0170] Release agent, Zhukun ZK-40

[0171] Characterization methods

[0172] Average particle size Dv50: The polyurethane dispersion was diluted with water to a concentration of 0.5 wt %, and measured using Malvern Nano-ZS90;

[0173] pH value: measured using a Metrohm 6173 pH meter;

[0174] -NCO determination: The -NCO content in the polyurethane synthesis process is determined according to the chemical industry standard "HG / T2409-92 Determination of isocyanate content in polyurethane prepolymers".

[0175] Terminal carboxyl content: obtained by theoretical calculation based on raw materials.

[0176] Tensile strength: measured using a universal testing machine (model: GT-7005-A2LT, from High Speed ​​Rail Testing Instruments (Dongguan) Co., Ltd.) at a temperature of 24-26°C and a humidity of 40-50%;

[0177] Elongation: measured using a universal testing machine (model: GT-7005-A2LT, from High Speed ​​Rail Testing Instruments (Dongguan) Co., Ltd.) at a temperature of 24-26°C and a humidity of 40-50%;

[0178] Calcium ion content: tested by inductively coupled plasma optical emission spectrometer (purchased from Thermo Fisher Scientific, USA).

[0179] Example 1

[0180] 400g WHP205, 78g IPDI, 8g DMPA (dimethylol propionic acid) and 60g acetone were added to a 1L four-necked round-bottom flask equipped with a nitrogen inlet and outlet, and the mixture was stirred at 80°C until the NCO reached 1.40% by weight. The mixture was cooled to 40°C and 330g acetone was added for dilution, 6.0g triethylamine was added for neutralization for 5min, 900g deionized water was added for dispersion for 10min under high-speed stirring, and 3g ethylenediamine and 6.0g ethylenediaminetriacetic acid were added for post-chain extension for 15min. After acetone was separated by distillation, a solvent-free polyurethane-polyurea aqueous dispersion was obtained, which had a solid content of 35% by weight, an average particle size of 200nm, and a pH value of 8.3. The terminal carboxyl content in the obtained polyurethane-polyurea was 15.35mmol / 100g (the terminal carboxyl content was calculated relative to the total weight of the polyurethane-polyurea, the same below).

[0181] Gloves were prepared using the polyurethane-polyurea aqueous dispersion prepared in the above example (weight of the polyurethane-polyurea aqueous dispersion: 1000 g):

[0182] 100 parts by weight of polyurethane-polyurea aqueous dispersion, 1.2 parts by weight of etherified amino resin crosslinking agent, 0.1 parts by weight of sodium gluconate, and 100 parts by weight of deionized water were mixed and stirred for 2 hours to obtain a slurry.

[0183] The glove former was pretreated by first cleaning the glove former in a nitric acid solution with a pH value of 3, then cleaning it in an aqueous solution of sodium hydroxide with a pH value of 12, then rinsing it and drying it in an oven at 75°C.

[0184] Prepare a coagulant solution: add 18 parts by weight of calcium nitrate, 10 parts by weight of a release agent and 170 parts by weight of deionized water into a mixing barrel, stir evenly, and obtain a coagulant solution.

[0185] Prepare coating solution: add 5 parts by weight of PU coating and 95 parts by weight of deionized water into a mixing barrel, stir evenly, and obtain a coating aqueous solution.

[0186] The pretreated glove model was immersed in a coagulant solution at 75°C for 20 seconds, dried at 100°C, then immersed in the slurry at 25°C for 10 seconds, dried at 110°C, immersed in the slurry at 25°C for 10 seconds again, dried at 100°C, leached, immersed in a coating solution, curled, placed in an oven at 125°C, heated for 25 minutes, and demolded to obtain a polyurethane glove.

[0187] Example 2

[0188] 450g WHP207, 125g HMDI, 16g DMPA, 2g NPG and 70g acetone were added to a 1L four-necked round-bottom flask equipped with a nitrogen inlet and outlet, and the mixture was stirred at 85°C until the NCO reached 1.43% by weight. The mixture was cooled to 40°C and 477g acetone was added for dilution, and then 12.0g triethylamine was added for neutralization for about 5min, and then 1210g deionized water was added for dispersion for about 10min under high-speed stirring, and then 2g ethylenediamine and 13g ethylenediaminetriacetic acid were added for post-chain extension for about 15min. A solvent-free polyurethane-polyurea aqueous dispersion was obtained after acetone was separated by distillation. The obtained polyurethane-polyurea aqueous dispersion had a solid content of 35% by weight, an average particle size of 78nm, and a pH value of 8.7. The terminal carboxyl content in the obtained polyurethane-polyurea was 26.82mmol / 100g.

[0189] Gloves were prepared using the polyurethane-polyurea aqueous dispersion prepared in the above example (weight of the polyurethane-polyurea aqueous dispersion: 1000 g):

[0190] 100 parts by weight of polyurethane-polyurea aqueous dispersion, 1.0 parts by weight of amino resin crosslinking agent, 0.3 parts by weight of sodium gluconate, and 120 parts by weight of deionized water were mixed and stirred for 2 hours to obtain slurry.

[0191] The glove former was pretreated by first cleaning the glove former in a nitric acid solution with a pH value of 3, then cleaning it in an aqueous solution of sodium hydroxide with a pH value of 12, then rinsing it and drying it in an oven at 75°C.

[0192] Prepare a coagulant solution: add 20 parts by weight of calcium nitrate, 15 parts by weight of a release agent and 200 parts by weight of deionized water into a mixing barrel, stir evenly, and obtain a coagulant solution.

[0193] Prepare coating solution: add 5 parts by weight of PU coating and 95 parts by weight of deionized water into a mixing barrel, stir evenly, and obtain a coating aqueous solution.

[0194] The pretreated glove model was immersed in a coagulant solution at 75°C for 20 seconds, dried at 100°C, then immersed in the slurry at 25°C for 10 seconds, dried at 100°C, immersed in the slurry at 25°C for 10 seconds again, dried at 100°C, leached, immersed in a coating solution, curled, placed in an oven at 135°C, heated for 30 minutes, and demolded to obtain a polyurethane glove.

[0195] Example 3

[0196] 428g WHP2056, 69g IPDI, 45g HMDI, 10g DMPA, 3.5g butanediol and 80g acetone were added to a 1L four-necked round-bottom flask equipped with a nitrogen inlet and outlet, and the mixture was stirred at 80°C until the NCO reached 2.04% by weight. The mixture was cooled to 40°C and 449g acetone was added for dilution, and then 7.55g triethylamine was added for neutralization for about 5 minutes, and then 1141g deionized water was added for dispersion for about 10 minutes under high-speed stirring, and then 6g ethylenediamine and 1.2g ethylenediaminetriacetic acid were added for post-chain extension for about 15 minutes. A solvent-free polyurethane-polyurea aqueous dispersion was obtained after acetone was separated by distillation. The obtained polyurethane-polyurea aqueous dispersion had a solid content of 35% by weight, an average particle size of 169nm, and a pH value of 8.3. The terminal carboxyl content in the obtained polyurethane-polyurea was 13.46mmol / 100g.

[0197] Gloves were prepared using the polyurethane-polyurea aqueous dispersion prepared in the above example (weight of the polyurethane-polyurea aqueous dispersion: 1000 g):

[0198] 100 parts by weight of polyurethane-polyurea aqueous dispersion, 0.8 parts by weight of etherified amino resin crosslinking agent, 0.3 parts by weight of sodium gluconate, and 130 parts by weight of deionized water were mixed and stirred for 2 hours to obtain slurry.

[0199] The glove former was pretreated by first cleaning the glove former in a nitric acid solution with a pH value of 3, then cleaning it in an aqueous solution of sodium hydroxide with a pH value of 12, then rinsing it and drying it in an oven at 75°C.

[0200] Prepare a coagulant solution: add 22 parts by weight of calcium nitrate, 11 parts by weight of a release agent and 200 parts by weight of deionized water into a mixing barrel, stir evenly, and obtain a coagulant solution.

[0201] Prepare the coating solution: add 5 parts by weight of talcum powder and 95 parts by weight of deionized water into a mixing barrel, stir evenly, and obtain a coating aqueous solution.

[0202] The pretreated glove model was immersed in a coagulant solution at 75°C for 20 seconds, dried at 100°C, then immersed in the slurry at 25°C for 10 seconds, dried at 120°C, immersed in the slurry at 25°C for 10 seconds again, dried at 120°C, leached, immersed in a coating solution, curled, placed in an oven at 130°C, heated for 35 minutes, and demolded to obtain a polyurethane glove.

[0203] Example 4

[0204] 500g PTMEG2000, 107g IPDI, 13g DMPA and 78g acetone were added to a 1L four-necked round-bottom flask equipped with a nitrogen inlet and outlet, and the mixture was stirred at 80°C until the NCO reached 1.61% by weight. The mixture was cooled to 40°C and diluted with 548g acetone, then neutralized with 8.8g triethylamine for about 5min, then dispersed with 1270g deionized water under high-speed stirring for about 10min, then added with 6g ethylenediamine and 4.5g ethylenediaminetriacetic acid for post-chain extension for about 15min. A solvent-free polyurethane-polyurea aqueous dispersion was obtained after acetone was separated by distillation. The obtained polyurethane-polyurea aqueous dispersion had a solid content of 35% by weight, an average particle size of 109nm, and a pH value of 8.5. The terminal carboxyl content in the obtained polyurethane-polyurea was 9.10mmol / 100g.

[0205] Gloves were prepared using the polyurethane-polyurea aqueous dispersion prepared in the above example (weight of the polyurethane-polyurea aqueous dispersion: 1000 g):

[0206] 100 parts by weight of polyurethane-polyurea aqueous dispersion, 0.9 parts by weight of amino resin crosslinking agent, 0.2 parts by weight of sodium gluconate, and 100 parts by weight of deionized water were mixed and stirred for 2 hours to obtain slurry.

[0207] The glove former was pretreated by first cleaning the glove former in a nitric acid solution with a pH value of 3, then cleaning it in an aqueous solution of sodium hydroxide with a pH value of 12, then rinsing it and drying it in an oven at 75°C.

[0208] Prepare a coagulant solution: add 21 parts by weight of calcium nitrate, 15 parts by weight of a release agent and 223 parts by weight of deionized water into a mixing barrel, stir evenly, and obtain a coagulant solution.

[0209] Prepare coating solution: add 5 parts by weight of PU coating and 95 parts by weight of deionized water into a mixing barrel, stir evenly, and obtain a coating aqueous solution.

[0210] The pretreated glove model was immersed in a coagulant solution at 75°C for 20 seconds, dried at 100°C, then immersed in the slurry at 25°C for 10 seconds, dried at 100°C, immersed in the slurry at 25°C for 10 seconds again, dried at 100°C, leached, immersed in a coating solution, curled, placed in an oven at 125°C, heated for 25 minutes, and demolded to obtain a polyurethane glove.

[0211] Example 5

[0212] The chelating agent sodium gluconate is not added to the gloves of this embodiment.

[0213] 500g PTMEG2000, 107g IPDI, 13g DMPA and 78g acetone were added to a 1L four-necked round-bottom flask equipped with a nitrogen inlet and outlet, and the mixture was stirred at 80°C until the NCO reached 1.61% by weight. The mixture was cooled to 40°C and diluted with 548g acetone, then neutralized with 8.8g triethylamine for about 5min, then dispersed with 1270g deionized water under high-speed stirring for about 10min, then added with 6g ethylenediamine and 4.5g ethylenediaminetriacetic acid for post-chain extension for about 15min. A solvent-free polyurethane-polyurea aqueous dispersion was obtained after acetone was separated by distillation. The obtained polyurethane-polyurea aqueous dispersion had a solid content of 35% by weight, an average particle size of 109nm, and a pH value of 8.5. The terminal carboxyl content in the obtained polyurethane-polyurea was 9.10mmol / 100g.

[0214] Gloves were prepared using the polyurethane-polyurea aqueous dispersion prepared in the above example (weight of the polyurethane-polyurea aqueous dispersion: 1000 g):

[0215] 100 parts by weight of polyurethane-polyurea aqueous dispersion, 0.9 parts by weight of amino resin crosslinking agent, and 100 parts by weight of deionized water were mixed and stirred for 2 hours to obtain slurry.

[0216] The glove former was pretreated by first cleaning the glove former in a nitric acid solution with a pH value of 3, then cleaning it in an aqueous solution of sodium hydroxide with a pH value of 12, then rinsing it and drying it in an oven at 75°C.

[0217] Prepare a coagulant solution: add 21 parts by weight of calcium nitrate, 15 parts by weight of a release agent and 223 parts by weight of deionized water into a mixing barrel, stir evenly, and obtain a coagulant solution.

[0218] Prepare coating solution: add 5 parts by weight of PU coating and 95 parts by weight of deionized water into a mixing barrel, stir evenly, and obtain a coating aqueous solution.

[0219] The pretreated glove model was immersed in a coagulant solution at 75°C for 20 seconds, dried at 100°C, then immersed in the slurry at 25°C for 10 seconds, dried at 100°C, immersed in the slurry at 25°C for 10 seconds again, dried at 100°C, leached, immersed in a coating solution, curled, placed in an oven at 125°C, heated for 25 minutes, and demolded to obtain a polyurethane glove.

[0220] Comparative Example 1

[0221] The ethylenediaminetriacetic acid in Example 1 was replaced with an equal mole of diethanolamine, and the rest remained unchanged. The obtained polyurethane-polyurea aqueous dispersion had a solid content of 35 wt%, an average particle size of 207 nm, a pH value of 8.3, and a terminal carboxyl group content of 0 mmol / 100 g in the obtained polyurethane-polyurea.

[0222] Gloves were prepared using the polyurethane-polyurea aqueous dispersion prepared in the above example (weight of the polyurethane-polyurea aqueous dispersion: 1000 g):

[0223] 100 parts by weight of polyurethane-polyurea aqueous dispersion, 3 parts by weight of amino resin crosslinking agent, and 100 parts by weight of deionized water were mixed and stirred for 2 hours to obtain slurry.

[0224] The glove former was pretreated by first cleaning the glove former in a nitric acid solution with a pH value of 3, then cleaning it in an aqueous solution of sodium hydroxide with a pH value of 12, then rinsing it and drying it in an oven at 75°C.

[0225] Prepare a coagulant solution: add 12 parts by weight of calcium nitrate, 10 parts by weight of a release agent and 170 parts by weight of deionized water into a mixing barrel, stir evenly, and obtain a coagulant solution.

[0226] Prepare coating solution: add 5 parts by weight of PU coating and 95 parts by weight of deionized water into a mixing barrel, stir evenly, and obtain a coating aqueous solution.

[0227] The pretreated glove model was immersed in a coagulant solution at 75°C for 20 seconds, dried at 100°C, then immersed in the slurry at 25°C for 10 seconds, dried at 100°C, immersed in the slurry at 25°C for 10 seconds again, dried at 100°C, leached, immersed in a coating solution, curled, placed in an oven at 125°C, heated for 25 minutes, and demolded to obtain a polyurethane glove.

[0228] Comparative Example 2

[0229] The half mole of ethylenediaminetriacetic acid in Example 4 was replaced by an equal mole of diethanolamine.

[0230] 500g PTMEG2000, 107g IPDI, 13g DMPA and 78g acetone were added to a 1L four-necked round-bottom flask equipped with a nitrogen inlet and outlet, and the mixture was stirred at 80°C until the NCO reached 1.61% by weight. The mixture was cooled to 40°C and 548g acetone was added for dilution, and then 8.8g triethylamine was added for neutralization for about 5 minutes, and then 1270g deionized water was added for dispersion for about 10 minutes under high-speed stirring, and then 6g ethylenediamine, 2.25g ethylenediaminetriacetic acid and 1.0g diethanolamine were added for post-chain extension for about 15 minutes. A solvent-free polyurethane-polyurea aqueous dispersion was obtained after acetone was separated by distillation. The obtained polyurethane-polyurea aqueous dispersion had a solid content of 35% by weight, an average particle size of 109nm, a pH value of 8.5, and a terminal carboxyl content of 4.55mmol / 100g in the obtained polyurethane-polyurea.

[0231] Gloves were prepared using the polyurethane-polyurea aqueous dispersion prepared in the above example (weight of the polyurethane-polyurea aqueous dispersion: 1000 g):

[0232] 100 parts by weight of polyurethane-polyurea aqueous dispersion, 3 parts by weight of amino resin crosslinking agent, 0.05 parts by weight of sodium gluconate, and 100 parts by weight of deionized water were mixed and stirred for 2 hours to obtain slurry.

[0233] The glove former was pretreated by first cleaning the glove former in a nitric acid solution with a pH value of 3, then cleaning it in an aqueous solution of sodium hydroxide with a pH value of 12, then rinsing it and drying it in an oven at 75°C.

[0234] Prepare a coagulant solution: add 21 parts by weight of calcium nitrate, 15 parts by weight of a release agent and 223 parts by weight of deionized water into a mixing barrel, stir evenly, and obtain a coagulant solution.

[0235] Prepare coating solution: add 5 parts by weight of PU coating and 95 parts by weight of deionized water into a mixing barrel, stir evenly, and obtain a coating aqueous solution.

[0236] The pretreated glove model was immersed in a coagulant solution at 75°C for 20 seconds, dried at 100°C, then immersed in the slurry at 25°C for 10 seconds, dried at 100°C, immersed in the slurry at 25°C for 10 seconds again, dried at 100°C, leached, immersed in a coating solution, curled, placed in an oven at 125°C, heated for 25 minutes, and demolded to obtain a polyurethane glove.

[0237] Comparative Example 3

[0238] Repeat Example 4, the difference Only in Ethylenediaminetriacetic acid was replaced with an equal molar amount of diethanolamine.

[0239] Comparative Example 4

[0240] Repeat Example 5, the difference Only in Replace EDTA with an equal mole of diethanolamine. Glove performance test:

[0241] The palm part of the prepared polyurethane gloves was cut according to ASTM D412 standard, and the tensile strength and elongation of the sliced ​​samples were tested. At the same time, the calcium ion content in the prepared latex was tested when the gloves were continuously dipped for 200 times. The test results are shown in Table 1.

[0242] Table 1. Performance test results

[0243] Tensile strength / MPa Elongation / % Calcium ion content / ppm Example 1 50 580 40 Example 2 49 555 21 Example 3 52 550 62 Example 4 50 590 80 Example 5 51 587 92 Comparative Example 1 40 700 489 Comparative Example 2 42 710 232 Comparative Example 3 51 540 440 Comparative Example 4 50 580 330

[0244] As can be seen from Table 1 above, the presence of terminal polycarboxyl structures in the polyurethane-polyurea aqueous dispersion and the introduction of metal ion chelating agents in the glove formula can effectively reduce the enrichment of calcium ions in the rubber compound, improve the stability of the latex during continuous operation of the production line, and at the same time improve the strength of the gloves.

[0245] In addition, by comparing Examples 4-5 and Comparative Example 3 with Comparative Example 4, it can be found that:

[0246] - In terms of composition, the difference between Example 4 and Comparative Example 4 is equivalent to the sum of (the difference between Example 5 and Comparative Example 4) and (the difference between Comparative Example 3 and Comparative Example 4).

[0247] - The difference between Example 5 and Comparative Example 4 is that the polyurethane-polyurea polymer of Example 5 contains terminal carboxyl groups, but no additional metal ion chelating agent is added to the polyurethane-polyurea aqueous dispersion. The results in Table 3 show that compared with Comparative Example 4, Example 5 has the same tensile strength, an increase in elongation of 7%, and a reduction in the amount of calcium ions in the rubber compound of 238 ppm.

[0248] -Comparative Example 3 is different from Comparative Example 4 in that the polyurethane-polyurea polymer of Comparative Example 3 does not contain a terminal carboxyl group, but the polyurethane-polyurea aqueous dispersion has an additional metal ion chelating agent. The results in Table 3 show that compared with Comparative Example 4, the tensile strength of Example 4 is basically unchanged, the elongation increment is -40%, and the amount of calcium ions in the rubber compound is reduced by -110 ppm.

[0249] - The difference between Example 4 and Comparative Example 4 is that the polyurethane-polyurea polymer of Example 4 contains terminal carboxyl groups, and the polyurethane-polyurea aqueous dispersion has an additional metal ion chelating agent. The results in Table 3 show that compared with Comparative Example 4, the tensile strength of Example 4 is basically unchanged, the elongation increment is 10%, and the amount of calcium ions in the rubber compound is reduced by 250ppm, both of which are higher than the sum of the change values ​​of Example 5 relative to Comparative Example 4 and the change values ​​of Comparative Example 3 relative to Comparative Example 4.

[0250] It can be seen that when the polyurethane-polyurea containing terminal carboxyl groups is used in combination with another metal chelator, the effect of the combination of the terminal carboxyl groups and the metal chelator in increasing the elongation of the product and reducing the calcium ion in the rubber compound is greater than the sum of the technical effects produced by the terminal carboxyl groups and the metal chelator alone.

[0251] Therefore, in the polyurethane-polyurea aqueous dispersion of the present application, the carboxyl or carboxylate group at the end of the polyurethane-polyurea polymer and the additionally added metal chelating agent achieve a synergistic effect in improving the elongation of the product and reducing the calcium ion content in the latex, and the tensile strength of the product is not affected while achieving the synergistic effect. Therefore, the present application avoids the damage of metal ions to the stability of the rubber material, and at the same time improves the mechanical properties of the prepared gloves, for example, the gloves have improved elongation and excellent tensile strength at the same time.

Claims

1. A polyurethane-polyurea aqueous dispersion, characterized in that: The polyurethane-polyurea aqueous dispersion comprises a polyurethane-polyurea having terminal polycarboxylic acid and / or carboxylate groups dispersed in water; The polyurethane-polyurea is prepared by reacting raw materials comprising the following components: Component a: one or more polyether or polyester polyols, wherein the number average molecular weight of the polyether or polyester polyol is greater than 500 g / mol; Component b: one or more polyisocyanates; Component c: one or more hydrophilic compounds, wherein the hydrophilic compound contains 2-3 groups reactive with NCO, and the hydrophilic group of the hydrophilic compound includes an ionic group and / or a potential ionic group; Optional component d: one or more alcohol chain extenders different from component a, having a number average molecular weight of 300 g / mol or less; Component e: one or more compounds that ionize the potential ion groups in component c, having the structural formula R1R2R3N, wherein R1-R3 are the same or different from each other and are independently selected from H, or C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, or C5-C6 cycloalkyl which is unsubstituted or substituted with OH; Component f: one or more polyamines containing at least two amine groups selected from primary and / or secondary amine groups, and having a number average molecular weight of 500 g / mol or less; Component g: one or more compounds reactive with isocyanate containing a single amine group selected from primary or secondary amine groups or a hydroxyl group and containing multiple carboxyl groups; The terminal polycarboxylic acid and / or carboxylate groups in the polyurethane-polyurea are introduced by component g.

2. The polyurethane-polyurea aqueous dispersion according to claim 1, characterized in that Relative to the total weight of the polyurethane-polyurea, the content of the terminal polycarboxylic acid and / or carboxylate groups is 7-30 mmol / 100 g.

3. The polyurethane-polyurea aqueous dispersion according to claim 1, characterized in that The content of the terminal polycarboxylic acid and / or carboxylate groups is 9 to 27 mmol / 100 g, relative to the total weight of the polyurethane-polyurea.

4. The polyurethane-polyurea aqueous dispersion according to claim 1, characterized in that - Component a is one or more of diols, triols and tetraols; and / or - Component b is one or more of aromatic, aliphatic and alicyclic polyisocyanates having at least two isocyanate groups; and / or - Component c is one or more selected from dimethylolpropionic acid, dimethylolbutanoic acid, and aminosulfonate; and / or - the component d is selected from one or more of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,4-dihydroxycyclohexane, 1,4-dimethylolcyclohexane, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol and 2-ethyl-1,3-hexanediol; and / or - The component e is an organic tertiary amine or ammonia; and / or - the component f is a polyamine having a number average molecular weight of 60 to 500 g / mol; and / or - The number of carboxyl groups in the component g is 2 or more.

5. The polyurethane-polyurea aqueous dispersion according to claim 4, characterized in that The component a is a diol.

6. The polyurethane-polyurea aqueous dispersion according to claim 4, characterized in that The number average molecular weight of the component a is 500 to 6000 g / mol.

7. The polyurethane-polyurea aqueous dispersion according to claim 4, characterized in that The number average molecular weight of the component a is 500 to 5000 g / mol.

8. The polyurethane-polyurea aqueous dispersion according to claim 4, characterized in that The component b is one or more of aromatic, aliphatic and alicyclic polyisocyanates having two isocyanate groups.

9. The polyurethane-polyurea aqueous dispersion according to claim 4, characterized in that: The component c is dimethylolpropionic acid.

10. The polyurethane-polyurea aqueous dispersion according to claim 4, characterized in that: The component d is selected from one or more of 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, neopentyl glycol and 1,4-cyclohexanedimethanol.

11. The polyurethane-polyurea aqueous dispersion according to claim 4, characterized in that: The organic tertiary amine is selected from triethylamine, dimethylethanolamine and triisopropylamine.

12. The polyurethane-polyurea aqueous dispersion according to claim 4, characterized in that: The component e is triethylamine.

13. The polyurethane-polyurea aqueous dispersion according to claim 4, characterized in that The component f is selected from one or more of ethylenediamine, 1,2-diaminopropane, 1,4-diaminobutane, 1,6-hexanediamine, 2-methyl-1,5-diamine, isophoronediamine, 4,4-diaminodicyclohexylmethane, piperazine and diethylenetriamine.

14. The polyurethane-polyurea aqueous dispersion according to claim 4, characterized in that The component f is ethylenediamine and / or isophoronediamine.

15. The polyurethane-polyurea aqueous dispersion according to claim 4, characterized in that: The number of carboxyl groups in the component g is 3 or more.

16. The polyurethane-polyurea aqueous dispersion according to claim 4, characterized in that: The component g is ethylenediaminetriacetic acid.

17. The polyurethane-polyurea aqueous dispersion according to any one of claims 1 to 16, characterized in that Based on the total weight of component ag being 100%, the weight proportion of component ag is as follows: Component a: 72-85% by weight; Component b: 10-23% by weight; Component c: 1.5-4% by weight; Component d: 0-3% by weight; Component e: 0.1-3% by weight; Component f: greater than 0 wt% and less than or equal to 3 wt%; Component g: 0.4-2.5% by weight.

18. The polyurethane-polyurea aqueous dispersion according to any one of claims 1 to 16, characterized in that The polyurethane-polyurea content in the polyurethane-polyurea aqueous dispersion is 35 wt % or more, based on the total weight of the polyurethane-polyurea aqueous dispersion.

19. A method for preparing the polyurethane-polyurea aqueous dispersion according to any one of claims 1 to 18, characterized in that: The preparation method comprises preparing the polyurethane-polyurea by: - reacting component a, component b, component c, and optionally component d in a first inert solvent to obtain a prepolymer containing terminal isocyanate groups; - optionally diluting with a second inert solvent; - Add component e to neutralize, then add water to evenly disperse to obtain a dispersion containing an inert solvent; - Adding components f and g to the dispersion containing the inert solvent to continue the reaction; - removing the inert solvent to obtain a polyurethane-polyurea aqueous dispersion free of inert solvent; - optionally, converting the terminal carboxyl groups in the polyurethane-polyurea into carboxylate groups, The second inert solvent is the same as or different from the first inert solvent.

20. The preparation method according to claim 19, characterized in that: The prepolymer contains at least two terminal isocyanate groups.

21. The preparation method according to claim 19, characterized in that: The step of converting the terminal carboxyl groups in the polyurethane-polyurea into carboxylate groups is performed by adding a basic compound to the polyurethane-polyurea aqueous dispersion containing no inert solvent.

22. The preparation method according to claim 21, characterized in that: The basic compound is an alkali metal compound.

23. The preparation method according to claim 21, characterized in that: The alkaline compound is sodium hydroxide and / or sodium carbonate.

24. Use of the polyurethane-polyurea aqueous dispersion according to any one of claims 1 to 18, or the polyurethane-polyurea aqueous dispersion prepared by the method according to any one of claims 19 to 23, for preparing a slurry for flocculation-process water-based polyurethane gloves, or polyurethane gloves.

25. A slurry comprising the polyurethane-polyurea aqueous dispersion according to any one of claims 1 to 18 or prepared by the preparation method according to any one of claims 19 to 23, a crosslinking agent, an optional ion chelating agent and optionally additional water.

26. The slurry according to claim 25, characterized in that The cross-linking agent comprises one or more of multifunctional aziridine, carbodiimide, amino resin, and sorbitol polyglycidyl ether; and / or The ion chelating agent comprises one or more of sodium gluconate, sodium tartrate, disodium ethylenediaminetetraacetate, and sodium diethylenetriaminepentaacetate.

27. The slurry according to claim 25, characterized in that The weight ratio of the polyurethane-polyurea aqueous dispersion, the crosslinking agent, the ion chelating agent and the additional water is 100: 0.3~1.2: 0.01~0.5: 100~200.

28. A method for preparing a polyurethane glove, the polyurethane glove comprising a polyurethane layer, characterized in that: The method comprises the step of preparing a polyurethane layer using the slurry according to any one of claims 25 to 27.

29. The method of claim 28, wherein the method comprises the steps of: S1: dipping the optionally cleaned hand mold in a coagulant solution, and optionally drying it thereafter, to obtain a first treated hand mold; S2: dipping the first treated hand mold in the slurry according to any one of claims 25 to 27, and optionally drying it afterwards; optionally repeating the dipping and drying process one or more times to obtain a second treated hand mold; S3: Optionally, cleaning the second treated hand mold with water, and optionally drying it afterwards, to obtain a third treated hand mold; S4: Optionally, immersing the hand mold after the second treatment or the hand mold after the third treatment in a slippery coating liquid; S5: curling, plasticizing and demoulding to obtain polyurethane gloves.

30. The method according to claim 29, characterized in that The coagulant solution comprises a soluble salt, a release agent and water; and / or The slippery coating liquid comprises one or more of PU coating, acrylic coating, corn starch coating, and talcum powder coating; and / or The dipping and drying process in step S2 is performed at least twice, and the drying in step S2 is oven drying; and / or The plasticization in step S5 is performed by baking at a temperature of 110 to 140° C. for 20 to 40 minutes.

31. The method according to claim 30, characterized in that The soluble salt is selected from one or more of calcium nitrate, calcium chloride, magnesium nitrate, magnesium chloride, zinc nitrate and zinc chloride.

32. The method according to claim 30, characterized in that In the coagulant solution, the weight ratio of the soluble salt, the release agent and water is 15-30: 8-20: 150-250.

33. The method according to claim 30, characterized in that The drying temperature in step S2 is 80-150°C.

34. The method according to claim 30, characterized in that The drying temperature in step S2 is 90-140°C.

35. A polyurethane glove comprising a polyurethane layer prepared using the slurry according to any one of claims 25 to 27 as a raw material.

36. The polyurethane glove according to claim 35, characterized in that The gloves are obtained by the method according to any one of claims 29-34.