Binder compositions, methods of making and using the same

Abstract

The present application relates to a binder composition, preparation and application of the composition, and an article bonded using the composition. The binder composition comprises: a. an anionic aqueous polyurethane dispersion, wherein the polyurethane contained therein has a melting enthalpy of at least 3 J / g, measured by DSC according to DIN 65467 on the first heating curve at 20-100 DEG C; the hydroxyl content of the aqueous polyurethane dispersion is 0.001 wt% to 0.085 wt% relative to the total weight of the aqueous polyurethane dispersion; and b. an aqueous polyacrylate primary dispersion, the hydroxyl content of which is 0.5 wt% to 1.8 wt% relative to the total weight of the aqueous polyacrylate primary dispersion; the amount of the aqueous polyurethane dispersion is 30 wt% to 91 wt%, and the amount of the aqueous polyacrylate primary dispersion is 9 wt% to 70 wt%, the above weight percentages being relative to the total weight of the binder composition. The binder composition of the present application has good high-temperature resistance.

Description

Technical Field

[0001] This invention relates to an adhesive composition, the preparation and application of the composition, and articles obtained by bonding using the composition. Background Technology

[0002] Polyurethane adhesives have excellent bonding strength, mainly due to the physical bonding force generated by the close contact between the adhesive and the substrate, and the further enhancement of bonding force by the formation of hydrogen bonds on the substrate by polyurethane.

[0003] After the adhesive containing a polyester-based waterborne polyurethane dispersion is applied to a substrate, dried, and cooled, the adhesive forms a non-adhesive film on the substrate. This film is then thermally activated to impart adhesive strength. Thermal activation involves melting and activating the waterborne polyurethane dispersion at a specific temperature (such as in a hot drying tunnel or with the aid of infrared radiation) and then immediately cooling it. This causes the polyester chains of the waterborne polyurethane dispersion to recrystallize, rapidly increasing the adhesive strength to a high level.

[0004] Adhesives containing waterborne polyurethane dispersions have been widely used in industrial fields, such as the furniture, automotive, footwear, and textile industries that manufacture composite fibers. Particularly in the furniture industry, decorative films are laminated onto medium-density fiberboard (MDF) to produce three-dimensional furniture panels. In this process, an adhesive is applied to the MDF component and dried, then the decorative film is bonded to the MDF and molded into the shape of the furniture part using a thermoforming process.

[0005] US 2007 / 0054117 discloses heat-sealable adhesive paper coated with a thermally activated dispersion polymer, particularly suitable for "linerless label" applications. To avoid clumping, the polymer is required to have a melt temperature greater than 104.4°C and a glass transition temperature greater than 10°C. The adhesive paper in this system needs to be sealed under high temperature and high pressure.

[0006] US 5,354,588 discloses an adhesive layer for promoting adhesion of pressure-sensitive adhesives to a substrate, and for preventing the pressure-sensitive adhesive from transferring to an adhesive-free surface during label material unfolding. These pressure-sensitive adhesive materials are based on acrylate polymers.

[0007] CN103097482 discloses a water-based adhesive comprising at least one acrylate polymer with a glass transition temperature greater than 50°C and at least one amorphous polyurethane or polyurethane-polyurea polymer with a glass transition temperature less than 10°C. This adhesive is used to prepare a heat-activated adhesive layer that can be activated at temperatures below 90°C. When used as an adhesive layer on a roll, it eliminates the need for release paper and does not clump even under high winding tension and at temperatures up to 50°C.

[0008] One-component adhesives are simpler to use than two-component adhesives and are therefore widely welcomed in the industry. However, existing one-component polyurethane adhesives have poor high-temperature resistance, resulting in poor high-temperature performance of the bonded products. Especially when the temperature approaches the adhesive's activation temperature, delamination easily occurs at the bond joint, affecting the product's lifespan and quality. Therefore, there is a need to develop an adhesive with excellent high-temperature resistance. Summary of the Invention

[0009] The purpose of this invention is to provide an adhesive composition, particularly an adhesive composition with good high-temperature resistance, the preparation and application of the composition, and articles obtained by bonding using the composition.

[0010] The adhesive composition according to the present invention comprises:

[0011] a. An anionic aqueous polyurethane dispersion, wherein the polyurethane contained herein has a melting enthalpy of at least 3 J / g, the melting enthalpy being measured by DSC according to DIN 65467 on the first heating curve at 20℃-100℃; the hydroxyl content of the aqueous polyurethane dispersion is 0.001 wt%-0.085 wt%, relative to the total weight of the aqueous polyurethane dispersion.

[0012] b. An aqueous polyacrylate primary dispersion having a hydroxyl content of 0.5% to 1.8% by weight, relative to the total weight of the aqueous polyacrylate primary dispersion; and

[0013] c. Optional additives;

[0014] The amount of the aqueous polyurethane dispersion is 30%-91% by weight, and the amount of the aqueous polyacrylate primary dispersion is 9%-70% by weight, all of which are relative to the total weight of the adhesive composition.

[0015] According to one aspect of the present invention, a method for preparing the adhesive composition provided by the present invention is provided, comprising the steps of: mixing the anionic aqueous polyurethane dispersion, the aqueous polyacrylate primary dispersion and optional additives in any manner; wherein the amount of the aqueous polyurethane dispersion is 30%-91% by weight and the amount of the aqueous polyacrylate primary dispersion is 9%-70% by weight, all of the above weight percentages being relative to the total weight of the adhesive composition.

[0016] According to another aspect of the invention, the use of the adhesive composition provided according to the invention in the preparation of articles is provided.

[0017] According to another aspect of the invention, an article is provided comprising a substrate and a coating formed by applying an adhesive composition provided according to the invention onto said substrate.

[0018] According to another aspect of the present invention, a method for manufacturing an adhesive article is provided, comprising the following steps:

[0019] i. Applying the adhesive composition provided according to the present invention to at least one surface of a substrate;

[0020] ii. Thermally activate the surface of the substrate treated in step i; and

[0021] iii. By bringing the surface of the substrate treated in step ii into contact with the surface of the substrate itself or another substrate, the bonded article is obtained.

[0022] The adhesive composition of the present invention is an aqueous composition with good adhesion and good high-temperature resistance. The products obtained by bonding according to the present invention are not easy to delaminate at high temperatures and have good aging resistance. Attached Figure Description

[0023] In the following description, the invention will be illustrated with reference to the accompanying drawings, wherein:

[0024] Figure 1 This is a schematic diagram of the equipment used to test the peeling distance of test strips;

[0025] Figure 2 This refers to the failure mode of test specimen debonding when the test specimen is subjected to adhesion testing. Detailed Implementation

[0026] This invention provides an adhesive composition comprising: a. an anionic aqueous polyurethane dispersion, wherein the polyurethane contained herein has a melting enthalpy of at least 3 J / g, the melting enthalpy being measured by DSC according to DIN 65467 on the first heating curve at 20°C-100°C; the hydroxyl content of the aqueous polyurethane dispersion is 0.001 wt%-0.085 wt%, relative to the total weight of the aqueous polyurethane dispersion; b. an aqueous polyacrylate primary dispersion, the hydroxyl content of which is 0.5 wt%-1.8 wt%, relative to the total weight of the aqueous polyacrylate primary dispersion; and c. optional additives; the amount of the aqueous polyurethane dispersion is 30 wt%-91 wt%, and the amount of the aqueous polyacrylate primary dispersion is 9 wt%-70 wt%, all weight percentages relative to the total weight of the adhesive composition. This invention also provides a method for preparing the adhesive composition and its application, as well as articles bonded using the adhesive composition.

[0027] As used herein, the term "adhesive" refers to a chemical substance that can be applied to the surface of an object using various application techniques to form a coating on the object itself or on the surface of one object to another, and to bond the object itself or on the surface of one object to another. It is also used as a synonym for adhesive and / or sealant and / or binder.

[0028] As used in this document, the term "polyurethane" refers to polyurethane urea and / or polyurethane polyurea and / or polyurea and / or polysulfurethane.

[0029] As used herein, the term "aqueous polyurethane dispersion" refers to aqueous polyurethane urea dispersion and / or aqueous polyurethane polyurea dispersion and / or aqueous polyurea dispersion and / or aqueous polysulfuric ester dispersion.

[0030] Adhesive composition

[0031] The adhesive composition is an aqueous system and has low VOC content.

[0032] The amount of organic solvent in the adhesive composition is preferably no more than 5% by weight, and most preferably no more than 0.5% by weight, relative to the total weight of the adhesive composition.

[0033] The adhesive composition is preferably a one-component adhesive.

[0034] Anionic waterborne polyurethane dispersion

[0035] The hydroxyl content of the anionic aqueous polyurethane dispersion is preferably 0.01% to 0.03% by weight, relative to the total weight of the anionic aqueous polyurethane dispersion.

[0036] The enthalpy of fusion of the polyurethane contained in the anionic aqueous polyurethane dispersion is preferably 3 J / g-100 J / g, and the enthalpy of fusion is measured by DSC according to DIN65467 on the first heating curve at 20℃-100℃.

[0037] The average particle size of the aqueous polyurethane dispersion is preferably 30 nm-400 nm, more preferably 100 nm-300 nm, and most preferably 150 nm-280 nm. The particle size is determined by laser spectroscopy (using a Zatasizer 1000 laser particle size analyzer from Malvern Instruments) at 23°C after dilution with deionized water, and the average value is given.

[0038] The weight-average molecular weight of the aqueous polyurethane dispersion is preferably 190,000 g / mol to 300,000 g / mol, more preferably 220,000 g / mol to 280,000 g / mol, and most preferably 240,000 g / mol to 270,000 g / mol. The weight-average molecular weight of the aqueous polyurethane dispersion was determined by gel permeation chromatography (GPC).

[0039] Instrument: Hewlett Packard 1100 Series II with refractive index detector

[0040] Column heating device: VDS-Optilab Jetstream 2Plus

[0041] Column: 1. PSS HEMA 40; 50 × 7.8 mm; Polymer Standard Services

[0042] 2. Suprema 1000; 300 × 7.8 mm; Polymer Standard Services

[0043] 3. PSS HEMA 300; 300 × 7.8 mm; Polymer Standard Services

[0044] 4. PSS HEMA 40; 300×7.8 mm; Polymer Standard Services

[0045] 5. PSS HEMA 40; 300×7.8 mm; Polymer Standard Services

[0046] Mobile phase: Dimethylacetamide (DMAC)

[0047] Conditions: Flow rate 0.6 mL / min; pressure 110 bar; temperature 30 °C

[0048] Standard: PSS Polymer-Standard-Services GmbH, Mainz; Germany.

[0049] The solid content of the aqueous polyurethane dispersion is preferably 30%-70% by weight, relative to the total weight of the aqueous polyurethane dispersion.

[0050] The viscosity of the aqueous polyurethane dispersion is preferably 50 mPa·s-1000 mPa·s.

[0051] The pH value of the aqueous polyurethane dispersion is preferably 6-8.

[0052] The amount of residual organic solvent in the aqueous polyurethane dispersion is preferably less than 1.0% by weight, relative to the total weight of the solids content of the aqueous polyurethane dispersion.

[0053] The aqueous polyurethane dispersion can be added directly to the adhesive composition in the form of a dispersion, or it can be added to the adhesive composition in the form of polyurethane and water and mixed to form a dispersion.

[0054] The aqueous polyurethane dispersion comprises a polyurethane and water.

[0055] The aqueous polyurethane dispersion is preferably obtained by reacting a system comprising polyester polyol, polyisocyanate and hydroxyl-containing diamine.

[0056] The amount of the aqueous polyurethane dispersion is preferably 49%-89% by weight, relative to the total weight of the adhesive composition.

[0057] Polyisocyanates

[0058] The functionality of the polyisocyanate is preferably not less than 2, and most preferably 2-4.

[0059] The polyisocyanate is preferably one or more of the following: aliphatic polyisocyanates, alicyclic polyisocyanates, and their derivatives having iminooxadiazine dione, isocyanurate, urea dione, carbamate, urethane, biuret, urea, oxadiazine trione, oxazolidinone, acylurea, and / or carbodiimide groups.

[0060] The aliphatic polyisocyanate is preferably one or more of the following: 1,6-hexanediisocyanate, 2,2-dimethylpentanediisocyanate, 2,2,4-trimethylhexanediisocyanate, butene diisocyanate, 1,3-butadiene-1,4-diisocyanate, 2,4,4-trimethyl-1,6-hexanediisocyanate, 1,6,11-undecane triisocyanate, 1,3,6-hexamethylene triisocyanate, and 1,8-diisocyanate. 4-methyl isocyanate octane, bis(ethyl isocyanate) carbonate, bis(ethyl isocyanate) ether, lysine methyl ester diisocyanate, lysine triisocyanate, bis(methyl isocyanate) sulfide, bis(ethyl isocyanate) sulfide, bis(propyl isocyanate) sulfide, bis(hexyl isocyanate) sulfide, bis(methyl isocyanate) sulfone, bis(methyl isocyanate) disulfide, bis(ethyl isocyanate) disulfide, bis(propyl isocyanate) Disulfide, bis(isocyanate-methylthio)methane, bis(isocyanate-ethylthio)methane, bis(isocyanate-methylthio)ethane, bis(isocyanate-ethylthio)ethane, 1,5-diisocyanate-2-methylisocyanate-3-thiapentane, 1,2,3-tris(isocyanate-methylthio)propane, 1,2,3-tris(isocyanate-ethylthio)propane, 3,5-dithia-1,2,6,7-heptanetetraisocyanate The preferred diisocyanates are methyl 2,6-diisocyanate-3,5-dithia-1,7-heptane diisocyanate, 2,5-diisocyanate-methylthiophene, isocyanate-ethylthio-2,6-dithia-1,8-octane diisocyanate, thiobis(3-isothiocyanate-propane), thiobis(2-isothiocyanate-ethane), dithiobis(2-isothiocyanate-ethane), and hexamethylene diisocyanate, with hexamethylene diisocyanate being the most preferred.

[0061] The alicyclic polyisocyanate is preferably one or more of the following: 2,5-bis(methyl isocyanate)-bicyclo[2.2.1]heptane, 2,6-bis(methyl isocyanate)-bicyclo[2.2.1]heptane, bis(methyl isocyanate)cyclohexane, isophorone diisocyanate, 2,5-diisocyanate-tetrahydrothiophene, 2,5-diisocyanate-tetrahydrothiophene, 3,4-diisocyanate-tetrahydrothiophene, 2,5-diisocyanate-1,4-dithiane, 2,5-diisocyanate-1,4-dithiane, 4,5-diisocyanate-1,3 -Dithiocyclopentane, 4,5-bis(methyl isocyanate)-1,3-dithiocyclopentane, 4,5-diisocyanate-2-methyl-1,3-dithiocyclopentane, norbornene diisocyanate (NBDI), phenylenediamine diisocyanate (XDI), hydrogenated phenylenediamine diisocyanate (H6XDI), 1,4-cyclohexyl diisocyanate (H6PPDI), 1,5-pentane diisocyanate (PDI), m-tetramethylphenylenediamine diisocyanate (m-TMXDI) and cyclohexane diisothiocyanate, with isophorone diisocyanate being the most preferred.

[0062] The polyisocyanate may also have an isocyanate group and an isothiocyanate group, such as 1-isocyanate-6-isothiocyanate hexane, 1-isocyanate-4-isothiocyanate cyclohexane, 1-isocyanate-4-isothiocyanate benzene, 4-methyl-3-isocyanate-1-isothiocyanate benzene, 2-isocyanate-4,6-diisothiocyanate-1,3,5-triazine, 4-phenylisocyanate-4-phenylisothiocyanate sulfide, and 2-ethylisocyanate-2-ethylisothiocyanate disulfide.

[0063] The polyisocyanate may also be a halogenated derivative of the above polyisocyanate, such as a chlorinated derivative, a bromine derivative, an alkyl derivative, an alkoxy derivative, a nitro derivative, or a silane derivative such as propyltriethoxysilane or propyltrimethoxysilane.

[0064] The preferred polyisocyanate is one or more of the following: hexamethylene diisocyanate and isophorone diisocyanate.

[0065] The amount of the polyisocyanate is preferably 5%-20% by weight, most preferably 5%-15% by weight, relative to the total weight of the system.

[0066] Polyester polyols

[0067] The amount of the polyester polyol is preferably 70%-94% by weight, most preferably 75%-90% by weight, relative to the total weight of the system.

[0068] The preferred hydroxyl value of the polyester polyol is 20-80.

[0069] The melting enthalpy of the polyester polyol is preferably at least 3 J / g, most preferably 3 J / g-100 J / g, and is measured by DSC according to DIN 65467 at 20℃-100℃ for the first heating curve.

[0070] The number-average molecular weight of the polyester polyol is preferably 1500 g / mol to 2500 g / mol.

[0071] The polyester polyol is preferably one or more of the following: linear polyester polyol, slightly branched polyester polyol, and homopolymer or blended polymer of lactone.

[0072] The linear polyester polyol or slightly branched polyester polyol is prepared by comprising the following components: aliphatic, alicyclic, or aromatic di- or polycarboxylic acids, such as succinic acid, methylsuccinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, azelaic acid, decanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, cyclohexanedicarboxylic acid, maleic acid, fumaric acid, malonic acid, or trimellitic acid; acid anhydrides, such as phthalic anhydride, trimellitic anhydride, or succinic anhydride, or mixtures thereof; and low molecular weight polyols, and optionally higher functional polyols, such as trimethylolpropane, glycerol, or pentaerythritol, alicyclic and / or aromatic di- and poly-hydroxy compounds.

[0073] The homopolymers or blends of the lactones are preferably obtained by adding lactones or mixtures of lactones, such as butyrolactone, ε-caprolactone, and / or methyl-ε-caprolactone, to suitable di- and / or higher functional initiator molecules. The ε-caprolactone is preferably a polymer of ε-caprolactone.

[0074] The polyester polyol is preferably one or more of the following: polyester diols of 1,6-hexanediol, neopentyl glycol and adipic acid, and 1,4-butanediol polyadipate diol.

[0075] hydroxyl-containing diamines

[0076] The amount of the hydroxyl-containing diamine is preferably 0.01% to 0.5% by weight, most preferably 0.1% to 0.5% by weight, relative to the total weight of the system.

[0077] The hydroxyl-containing diamine is preferably one or more of the following: aminoethylethanolamine, aminoethylpropanolamine, aminopropylethanolamine, and aminoethylbutanolamine, with aminoethylethanolamine (HEEDA) being the most preferred.

[0078] emulsifier

[0079] The system may further include an emulsifier, preferably in an amount of 0.1% to 20% by weight relative to the total weight of the system.

[0080] The emulsifier preferably contains at least one isocyanate reactive group and at least one emulsifying group or potential emulsifying group.

[0081] The isocyanate reactive group is preferably one or more of the following: hydroxyl, thiol, and amino.

[0082] The emulsifying group or potential emulsifying group is preferably one or more of the following: sulfonic acid group, carboxylic acid group, tertiary amino group and hydrophilic polyether.

[0083] The emulsifier containing sulfonic acid groups and / or carboxylic acid groups is preferably one or more of the following: a diamino compound containing sulfonic acid groups and / or carboxylic acid groups and a dihydroxy compound containing sulfonic acid groups and / or carboxylic acid groups, more preferably one or more of the following: sodium, potassium, lithium, or tertiary amine salts of N-(2-aminoethyl)-2-aminoethanesulfonic acid, N-(3-aminopropyl)-2-aminoethanesulfonic acid, N-(3-aminopropyl)-3-aminopropanesulfonic acid, N-(2-aminoethyl)-3-aminopropanesulfonic acid, similar carboxylic acids, dimethylolpropionic acid, or dimethylolbutyric acid, most preferably one or more of the following: N-(2-aminoethyl)-2-aminoethanesulfonate and dimethylolpropionic acid.

[0084] The sulfonic acid group or carboxylic acid group can be used directly in the form of their salts, such as sulfonates or carboxylates.

[0085] The sulfonic acid group or carboxylic acid group can also be obtained by partially or completely adding a neutralizing agent to form a salt during or after the preparation of the polyurethane polymer.

[0086] organic solvents

[0087] The system may further include an organic solvent that is miscible with water but inert to isocyanate groups.

[0088] The amount of the organic solvent is preferably 0.001% to 20% by weight, based on the total weight of the system.

[0089] The organic solvent is preferably one or more of the following: acetone, 2-butanone, tetrahydrofuran, xylene, toluene, cyclohexane, butyl acetate, dioxane acetate, methoxypropyl acetate, N-methylpyrrolidone, N-ethylpyrrolidone, acetonitrile, dipropylene glycol dimethyl ether, and solvents containing ether or ester units, with one or more of the following being most preferred: acetone and 2-butanone.

[0090] The organic solvent may be added only at the beginning of the preparation, or a portion may be added during the preparation process as needed.

[0091] Reaction diluent

[0092] The system may further include a reaction diluent.

[0093] The amount of the reaction diluent is preferably 0.001% to 20% by weight, based on the total weight of the system.

[0094] The reactive diluent is preferably one or more of the following: acrylic acid and acrylate.

[0095] Preparation of waterborne polyurethane dispersions

[0096] The aqueous polyurethane dispersion is preferably obtained by a reaction comprising the following steps:

[0097] A. To react some or all of a polyisocyanate, a polyester polyol, and a hydroxyl-containing diamine to obtain a prepolymer, wherein the reaction is carried out in the presence of an optional water-miscible but isocyanate-inert organic solvent or the prepolymer is dissolved in an optional water-miscible but isocyanate-inert organic solvent after the reaction.

[0098] B. React the prepolymer, optionally an emulsifier, optionally a reaction diluent, a polyisocyanate not added in step A, a polyester polyol not added in step A, and a hydroxyl-containing diamine not added in step A to obtain the polyurethane; and

[0099] C. Water and an optional emulsifier are introduced before, during, or after step B to obtain the aqueous polyurethane dispersion.

[0100] All known processes in the prior art can be used to prepare the aqueous polyurethane dispersions of the present invention, such as the emulsifier / shear force method, the acetone method, the prepolymer mixing method, the melt emulsification method, the ketimine method, and the solid spontaneous dispersion method or methods derived therefrom, with the melt emulsification method or the acetone method being preferred, and the acetone method being the most preferred. These methods are summarized in Method der Organischen Chemie (Houben-Weyl, ErWeitenmgs-und zur4.Auflage, Volume E20, H.Bartl and J.Falbe, Stuttgart, New York, Thiem 1987, pp. 1671-1682).

[0101] The mixing order of the components in the system for preparing the aqueous polyurethane dispersion can be followed in a conventional manner.

[0102] The polyisocyanate, polyester polyol, and hydroxyl-containing diamine can be added all at once or in multiple additions, and can be the same or different components as those previously added.

[0103] Organic solvents present in the aqueous polyurethane dispersion can be removed by distillation. These organic solvents can be removed during or after the polyurethane formation process.

[0104] Aqueous polyacrylate primary dispersion

[0105] The aqueous polyacrylate primary dispersion is preferably self-crosslinked.

[0106] The hydroxyl content of the aqueous polyacrylate primary dispersion is preferably 0.8%-1.8% by weight, most preferably 0.8%-1.5% by weight, relative to the total weight of the aqueous polyacrylate primary dispersion.

[0107] The glass transition temperature of the aqueous polyacrylate primary dispersion is preferably 50℃-80℃, most preferably 55℃-70℃, and is determined by DSC (differential scanning calorimetry) according to DIN 65467.

[0108] The solids content of the aqueous polyacrylate primary dispersion is preferably 35%-45% by weight, relative to the total weight of the aqueous polyacrylate primary dispersion.

[0109] The average particle size of the aqueous polyacrylate primary dispersion is preferably 40 nm-200 nm, more preferably 60 nm-160 nm, and most preferably 60 nm-100 nm. The particle size is determined by laser spectroscopy (using a Zatasizer 1000 laser particle size analyzer from Malvern Instruments) at 23 °C after dilution with deionized water, and the average value is given.

[0110] The pH value of the aqueous polyacrylate primary dispersion is preferably 6-7.

[0111] The amount of the aqueous polyacrylate primary dispersion is preferably 9% to 49% by weight, relative to the total weight of the binder composition.

[0112] The preferred aqueous polyacrylate primary dispersion is a self-crosslinking aqueous polyacrylate primary dispersion containing hydroxyl groups.

[0113] additive

[0114] The additives are preferably one or more of the following: EVA resin, pigments and fillers, organic light stabilizers, free radical blockers, dispersants, leveling agents, wetting agents, thickeners, defoamers, additives for assisting construction, solvents, adhesion promoters, bactericides, stabilizers, inhibitors, and catalysts.

[0115] The amount of the additive can be any amount known to those skilled in the art, most preferably 0.5% to 10% by weight, relative to the total weight of the adhesive composition.

[0116] The stabilizer helps reduce hydrolysis of the composition and prolongs its pot life.

[0117] The stabilizer is preferably one or more of the following: carbodiimide compounds, epoxy group compounds, oxazoline compounds, and aziridine compounds.

[0118] The stabilizer content is preferably 0-10% by weight, more preferably 0.5%-10% by weight, and most preferably 0.5%-2% by weight, relative to the amount of solid components in the adhesive composition, which is 100% by weight.

[0119] The wetting agent is preferably a polyether-modified siloxane. The amount of the wetting agent is preferably 0.05% to 0.15% by weight, relative to the total weight of the adhesive composition.

[0120] The thickener is preferably Borchigel L75N. The amount of the thickener is preferably 1% to 5% by weight, and most preferably 1% to 2.5% by weight, relative to the total weight of the binder composition.

[0121] Products

[0122] The products are selected from automotive interiors, food packaging, and furniture.

[0123] The substrate is preferably one or more of the following: wood, plastic, metal, glass, textile, alloy, fabric, artificial leather, paper, cardboard, EVA, rubber, genuine leather, glass fiber, ethylene-vinyl acetate copolymer, polyolefin, thermoplastic polyurethane, polyurethane foam, polymer fiber and graphite fiber, and most preferably one or more of the following: EVA, rubber, genuine leather, artificial leather, ethylene-vinyl acetate copolymer, polyolefin, thermoplastic polyurethane and polyurethane foam.

[0124] The application may be to apply the composition to the entire surface of the substrate or to one or more portions of the surface of the substrate.

[0125] The application can be by brushing, dipping, spraying, roller coating, doctor blade coating, flow coating, pouring, printing or transfer, preferably by brushing, dipping or spraying.

[0126] In the method of manufacturing the bonded article, a further step iv may be included between step i and step ii: heating and drying the surface of the substrate to which the adhesive composition is applied. When the method of manufacturing the bonded article further includes step iv, step ii is to thermally activate the substrate surface treated in step iv.

[0127] Step iv, heating and drying the substrate surface to which the adhesive composition is applied, may refer to heating and drying only the substrate surface, or heating and drying part or all of the substrate, including the substrate surface to which the adhesive composition is applied.

[0128] The heating and drying process removes volatile components. These volatile components may be water.

[0129] The higher the heating temperature, the better, but it should not exceed the temperature limit at which the substrate deforms uncontrollably or suffers other damage.

[0130] The thermal activation can be carried out by heating in an oven, drying tunnel, or infrared radiation.

[0131] The preferred temperature for thermal activation in step ii is room temperature to 110°C, more preferably 40°C to 100°C, and most preferably 50°C to 80°C.

[0132] The contact is preferably performed before the temperature of the substrate surface drops below the adhesive composition's bonding temperature.

[0133] The additional substrate can be any substrate that needs to be bonded.

[0134] The additional substrate may be the same as or different from the base material.

[0135] The additional substrate is preferably coated and heat-treated in the same way as the substrate.

[0136] Example

[0137] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the event of any discrepancy between the definitions of terms in this specification and their commonly understood meaning by one of ordinary skill in the art to which this invention pertains, the definitions set forth herein shall prevail.

[0138] Unless otherwise stated, all numerical values ​​for the amounts of expressed components, reaction conditions, etc., used in the specification and claims are to be understood as being modified by the term "about". Therefore, unless otherwise indicated, the numerical parameters set forth herein are approximate values ​​that can be varied to obtain the desired performance.

[0139] The word “and / or” as used in this article refers to one or all of the elements mentioned.

[0140] The terms "include" and "contain" as used in this article cover both cases where only the mentioned elements exist and cases where other unmentioned elements exist in addition to the mentioned elements.

[0141] All percentages in this invention are weight percentages, unless otherwise stated.

[0142] All analytical measurements in this invention are performed at 23°C, unless otherwise stated.

[0143] Unless otherwise stated, the terms “a,” “an,” “an,” and “the” as used in this specification are intended to include “at least one” or “one or more.” For example, “a component” refers to one or more components, and therefore more than one component may be considered and may be employed or used in the implementation of the described embodiments.

[0144] The solids content of the dispersion was determined using a Mettler Toledo HS153 moisture analyzer according to DIN-EN ISO3251.

[0145] pH values ​​were measured at 23°C using a PB-10 pH meter from Sartorius, Germany.

[0146] The viscosity of the dispersion was determined using a Fa·Haake VT-500 rotational viscometer according to DIN 53019.

[0147] Raw materials and reagents

[0148] Polyester polyol I: 1,4-Butanediol polyadipate diol, OH value 50, melting temperature 49℃, melting enthalpy 91.0 J / g, number average molecular weight 2323 g / mol, available from Covestro AG, Germany.

[0149] Polyester Polyol II: A polyester diol composed of 1,6-hexanediol, neopentyl glycol and adipic acid, with an OH value of 66 and a number-average molecular weight of 1691 g / mol, available from Covestro GmbH, Germany.

[0150] Polyester polyol III: a polyester diol of 1,6-hexanediol and polyphthalic acid, OH value 56, available from Covestro GmbH, Germany.

[0151] H: 1,6-Hexamethylene diisocyanate, purchased from Covestro AG.

[0152] I: Isophorone diisocyanate, purchased from Covestro GmbH, Germany.

[0153] AAS: Sodium salt of N-(2-aminoethyl)-2-aminoethanesulfonic acid NH2-CH2CH2-NH-CH2CH2-SO3Na, in water at a concentration of 45%, purchased from Covestro AG, Germany.

[0154] Emulgatorfed 400: Fatty alcohol poly(ethylene glycol / propylene glycol) ether, emulsifier, available from Lanxess, Germany.

[0155] Lucramul 1820: Emulsifier.

[0156] Diethanolamine: purity ≥99.0%, purchased from Sinopharm Chemical Reagents.

[0157] 1,4-Butanediol: Purity ≥99.0%, available from ACROS Organics, Germany.

[0158] Ethylenediamine: 69% concentration, available from Aldrich GmbH, Germany.

[0159] Aminoethylethanolamine: purity ≥99.0%, available from ABCR GmbH, Germany.

[0160] PRIMAL TM ECONEXT TM 1101 Emulsion: Low formaldehyde modified acrylic resin, primary dispersion, solids content 45% by weight, pH value 7, viscosity 500 mPa·s, glass transition temperature 58℃, available from Dow.

[0161] DESMOPHEN 1380BT: Polyether polyol, available from Covestro GmbH, Germany.

[0162] Acrylic acid: purity ≥99.0%, available from Aldrich GmbH, Germany.

[0163] Methyl methacrylate: purity ≥99.0%, available from ACROS Organics, Germany.

[0164] Styrene: purity ≥ 99.0%, available from Aldrich GmbH, Germany.

[0165] Hydroxypropyl methacrylate: purity ≥99.0%, available from Aldrich GmbH, Germany.

[0166] Hydroxyethyl methacrylate: purity ≥99.0%, available from Aldrich GmbH, Germany.

[0167] Diacetone acrylamide: purity ≥99.0%, available from ACROS Organics, Germany.

[0168] Ethyl ethyl acrylate: purity ≥ 99.0%, available from Aldrich GmbH, Germany.

[0169] Adipic acid dihydrazide: purity ≥99.0%, available from ACROS Organics, Germany.

[0170] n-Butyl acrylate: purity ≥99.0%, available from Aldrich GmbH, Germany.

[0171] Ammonium persulfate: purity ≥ 99.0%, available from Aldrich GmbH, Germany.

[0172] 951: Emulsifier, available from Tanatex GmbH, Germany.

[0173] N-Dodecyl mercaptan: Purity ≥99.0%, available from Aldrich GmbH, Germany.

[0174] BYK349: Polyether-modified siloxane, wetting and dispersing agent, available from BYK AG, Germany.

[0175] Borchigel L75N: 25% by weight solids, thickener, purchased from OMG.

[0176] Table 1 lists the raw material components and contents for preparing waterborne polyurethane dispersions 1-4, as well as the solid content, pH value, viscosity, average particle size, weight-average molecular weight, melting enthalpy of the polyurethane contained in the waterborne polyurethane dispersion, and hydroxyl content of the waterborne polyurethane dispersion. Table 2 lists the raw material components and contents for preparing waterborne polyacrylate primary dispersions 1-3, as well as the solid content, pH value, viscosity, hydroxyl content, glass transition temperature, and average particle size of the waterborne polyacrylate dispersion. Table 3 shows the composition of the adhesive compositions of Examples 1-3 and Comparative Examples 1-9, the aging resistance test results of the test specimens, and the adhesion test results.

[0177] Table 1 Aqueous polyurethane dispersions 1-4

[0178]

[0179]

[0180] Table 2 Aqueous Polyacrylate Primary Dispersions 1-3

[0181]

[0182]

[0183] Preparation of waterborne polyurethane dispersions 1-4

[0184] According to the raw material composition and content shown in Table 1, the polyester polyol was dehydrated at 100°C and 15 mbar for 1 hour, and isocyanate was added at 60°C to obtain a mixture. The mixture was stirred at 90°C until the isocyanate content reached 1.80%. The reaction mixture was dissolved in acetone and cooled to 50°C. AAS, optional Emulgatorfd400, optional Lucramul1 820, water, optional diethanolamine, optional 1,4-butanediol, optional ethylenediamine, and optional aminoethylethanolamine were added under vigorous stirring. After stirring for 30 minutes, water was added and dispersed at 50°C over 20 minutes. The solvent was removed by distillation to obtain aqueous polyurethane dispersions 1-4.

[0185] Preparation of waterborne polyacrylate primary dispersions 1-3

[0186] Based on the raw material composition and content shown in Table 2, the corresponding amount of emulsifier was added to a 3-liter glass reactor equipped with controlled heating and cooling and a stirring motor under a nitrogen atmosphere. Mix 951 with water and heat to 80°C. Add pre-mixed mixture 1 and pre-mixed mixture 2 using a metering pump. Immediately thereafter, add pre-mixed mixture 3 and pre-mixed mixture 4, followed immediately by pre-mixed mixture 5. Continue stirring for 60 minutes, then cool. Set the pH to 7, and slowly add the appropriate amount of pre-mixed mixture 6. Finally, drain the aqueous polyacrylate primary dispersion 1-3 through a 125 mm filter.

[0187] Preparation of waterborne polyacrylate primary dispersion 4

[0188] In a 3-liter glass reactor equipped with controlled heating and cooling and a stirring motor, 11.1 g of a 21.5% concentration of [unspecified ingredient] was added under a nitrogen atmosphere. 951 and 500g of water were mixed and heated to 80°C. A pre-mixed mixture (14.1g methyl methacrylate, 2.5g ethylhexyl acrylate, 14g styrene, 2g acrylic acid, 3g hydroxyethyl methacrylate) and a mixture (0.5g ammonium persulfate, 70g deionized water) were added over 30 minutes using a metering pump and stirred for 30 minutes. Subsequently, a mixture (85.9g methyl methacrylate, 8.8g ethylhexyl acrylate, 132.6g styrene, 12.1g acrylic acid, 32g hydroxyethyl methacrylate, 6.2g diacetone acrylamide) and a mixture (0.77g ammonium persulfate, 3.7g 21.5% concentration) were added. Add 951g of deionized water and 185g of methyl methacrylate (171.6g, ethylhexyl acrylate (177.3g), styrene (169.4g), acrylic acid (14.1g), hydroxyethyl methacrylate (72g), and diacetone acrylamide (12.4g) immediately, and add the mixture (ammonium persulfate (1.54g) with a concentration of 21.5%). 9517.4g of ammonium persulfate and 372g of deionized water were added, followed immediately by the addition of a mixture (0.5g of ammonium persulfate and 70g of deionized water). After stirring for 60 minutes and cooling, a mixture (6.1g of 33% ammonia and 40g of deionized water) and a mixture (9.57g of adipic acid dihydrazide and 147g of deionized water) were slowly added dropwise. Finally, the mixture was discharged through a 125mm filter as a self-crosslinking aqueous polyacrylate primary dispersion PAC4, which meets the following characteristics: solid content 40% by weight, hydroxyl content 1.5% by weight (all weight percentages are relative to the total weight of the aqueous polyacrylate primary dispersion 4), glass transition temperature 64°C, pH value 6.5, viscosity 50-100mPa·s, and average particle size 80nm.

[0189] Preparation of adhesive compositions in the examples and comparative examples

[0190] According to the components and contents shown in Table 3, the aqueous polyurethane dispersion and the aqueous polyacrylate dispersion were added to a container and placed under a disperser. The container was dispersed at a speed of 1000 rpm - 1500 rpm (2.1-3.2 m / s) for 10-15 minutes. Then, BYK-349 and Borchigel L75N (pre-mixed with deionized water at a ratio of 1:1) were added and dispersed at a speed of 1000-1500 rpm (2.1-3.2 m / s) for 10-15 minutes. The above components were thoroughly stirred to obtain the adhesive composition.

[0191] Preparation of test specimens and aging resistance and adhesion tests on the test specimens.

[0192] The adhesive composition was applied to MDF (medium-density fiberboard) using a 100μm wire brush, with a brush application rate of 50g / m². 2(Dry adhesive weight); Dry in a 50℃ oven for 10-15 minutes; Activate in an 85℃ oven for 2 minutes, then immediately remove and laminate with PVC, laminating for 100mm; Place the PVC-laminated MDF into a molding machine for pressing, setting the molding machine parameters to a temperature of 103℃, a pressure of 4 bar, and a pressing time of 10 seconds; Finally, leave at room temperature for 3 days to obtain test samples.

[0193] 1. Aging Resistance Test: Place the prepared test strips into an aging chamber (initial test temperature of the aging chamber is 80℃), and hang a 2.5kg weight on the PVC end of the strip. Test the distance the PVC is peeled off within 5 minutes and 30 minutes, recording this as the peel distance. (Refer to...) Figure 1 If the sample does not fully separate from the adhesive within 5 or 30 minutes, record the time it takes for the sample to fully separate. The peel distance is the length of separation between the bonded parts of the sample, measured with a ruler. Full separation means that all bonded parts of the sample have completely separated.

[0194] Rating Criteria Explanation:

[0195] A peeling distance of less than 2mm within 5 minutes is considered acceptable; the smaller the value (the shorter the distance), the better the result.

[0196] Within 30 minutes, a peeling distance of less than 40mm is considered acceptable; the smaller the value (the shorter the distance), the better the result.

[0197] 2. Adhesion Test: The prepared test strips were subjected to a 180-degree peel test at room temperature using a Zwick material teser instrument. The adhesion strength was measured and the failure mode of the test strips was observed. The peel speed was 100 mm / min, and the strip width was 30 mm.

[0198] Rating Criteria Explanation: An adhesion strength value greater than 2.0 aver. N / mm is considered acceptable. Failure Mode: PVC with wood chips shown in [image / description]. Figure 2 .

[0199] Table 3. Composition and test results of the adhesive compositions of the examples and comparative examples.

[0200]

[0201] The strips obtained by bonding with the adhesive compositions of the present invention in Examples 1-3 have good adhesion and short peel distance at 80°C, indicating that the strips have good aging resistance at high temperatures, which shows that the adhesive composition has good high temperature resistance.

[0202] The hydroxyl content of the aqueous polyacrylate primary dispersion in the adhesive compositions of Comparative Examples 1-3 was 2.0 wt%, 4.0 wt%, and 4.8 wt%, respectively. The strips bonded by the adhesive compositions had a long peel distance at 80°C, indicating poor aging resistance at high temperatures and poor high-temperature resistance of the adhesive compositions.

[0203] The adhesive composition of Comparative Example 4 contains PRIMAL TM ECONEXT TM The 1101 emulsion does not contain hydroxyl groups. The strips obtained by bonding with the binder combination have a long peel distance at 80°C, which means that the strips have poor aging resistance at high temperatures, indicating that the binder composition has poor high temperature resistance.

[0204] The aqueous polyurethane dispersion contained in the adhesive composition of Comparative Example 5 is non-crystalline, with a melting enthalpy of less than 3 J / g and no hydroxyl groups. The strips bonded by the adhesive composition have a long peel distance at 80°C, indicating poor aging resistance of the strips at high temperatures, which shows that the adhesive composition has poor high-temperature resistance.

[0205] Compared with the adhesive compositions of Examples 6 and 7, the aqueous polyurethane dispersion contained in the adhesive compositions did not contain hydroxyl groups. The strips obtained by bonding the adhesive compositions had a long peel distance at 80°C, which means that the strips had poor aging resistance at high temperature, indicating that the adhesive compositions had poor high temperature resistance.

[0206] Compared to Example 8, the adhesive composition did not contain an aqueous polyacrylate dispersion, and the resulting bonded sample had a long peel distance at 80°C, indicating poor aging resistance at high temperatures. This suggests that the adhesive composition has poor high-temperature resistance.

[0207] The binder composition of Comparative Example 9 contained 24.5% by weight of aqueous polyurethane dispersion and 73.5% by weight of aqueous polyacrylate dispersion, relative to the total weight of the binder composition. The adhesive composition resulted in poor adhesion of the resulting samples, and the samples exhibited a long peel distance at 80°C, indicating poor aging resistance at high temperatures and thus poor high-temperature resistance of the binder composition.

[0208] It will be readily apparent to those skilled in the art that this invention is not limited to the specific details described above, and that it may be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments described should be considered illustrative rather than restrictive in any way, and the scope of the invention is determined by the claims rather than the foregoing description; and thus any modifications that fall within the meaning and scope of the equivalents of the claims should be considered part of this invention.

Claims

1. An adhesive composition comprising: a. An anionic aqueous polyurethane dispersion, wherein the polyurethane contained herein has a melting enthalpy of at least 3 J / g, the melting enthalpy being measured by DSC according to DIN 65467 on the first heating curve at 20℃-100℃; the hydroxyl content of the aqueous polyurethane dispersion is 0.001 wt%-0.085 wt%, relative to the total weight of the aqueous polyurethane dispersion. b. An aqueous polyacrylate primary dispersion having a hydroxyl content of 0.5% to 1.8% by weight, relative to the total weight of the aqueous polyacrylate primary dispersion; and c. Optional additives; The amount of the aqueous polyurethane dispersion is 30%-91% by weight, and the amount of the aqueous polyacrylate primary dispersion is 9%-70% by weight, all of which are relative to the total weight of the adhesive composition.

2. The adhesive composition according to claim 1, characterized in that, The average particle size of the aqueous polyurethane dispersion is 30nm-400nm.

3. The adhesive composition according to claim 1, characterized in that, The average particle size of the aqueous polyurethane dispersion is 100nm-300nm.

4. The adhesive composition according to claim 1, characterized in that, The average particle size of the aqueous polyurethane dispersion is 150nm-280nm.

5. The adhesive composition according to claim 1, characterized in that, The weight-average molecular weight of the aqueous polyurethane dispersion is 190,000 g / mol to 300,000 g / mol, and the weight-average molecular weight is determined by gel permeation chromatography (GPC).

6. The adhesive composition according to claim 1, characterized in that, The weight-average molecular weight of the aqueous polyurethane dispersion is 220,000 g / mol to 280,000 g / mol, and the weight-average molecular weight is determined by gel permeation chromatography (GPC).

7. The adhesive composition according to claim 1, characterized in that, The weight-average molecular weight of the aqueous polyurethane dispersion is 240,000 g / mol to 270,000 g / mol, and the weight-average molecular weight is determined by gel permeation chromatography (GPC).

8. The adhesive composition according to claim 1, characterized in that, The aqueous polyurethane dispersion is obtained by reacting a system comprising polyester polyol, polyisocyanate and hydroxyl-containing diamine.

9. The adhesive composition according to claim 8, characterized in that, The amount of the polyester polyol is 70%-94% by weight, relative to the total weight of the system.

10. The adhesive composition according to claim 8, characterized in that, The amount of the polyester polyol is 75%-90% by weight, relative to the total weight of the system.

11. The adhesive composition according to claim 8, characterized in that, The amount of the hydroxyl-containing diamine is 0.01% to 0.5% by weight, relative to the total weight of the system.

12. The adhesive composition according to claim 8, characterized in that, The amount of the hydroxyl-containing diamine is 0.1% to 0.5% by weight, relative to the total weight of the system.

13. The adhesive composition according to claim 1, characterized in that, The aqueous polyacrylate primary dispersion is self-crosslinked.

14. The adhesive composition according to claim 1, characterized in that, The hydroxyl content of the aqueous polyacrylate primary dispersion is 0.8%-1.8% by weight, relative to the total weight of the aqueous polyacrylate primary dispersion.

15. The adhesive composition according to claim 1, characterized in that, The hydroxyl content of the aqueous polyacrylate primary dispersion is 0.8%-1.5% by weight, relative to the total weight of the aqueous polyacrylate primary dispersion.

16. The adhesive composition of claim 1, characterized in that, The glass transition temperature of the aqueous polyacrylate primary dispersion is 50℃-80℃, and the glass transition temperature is determined by DSC (differential scanning calorimetry) according to DIN65467.

17. The adhesive composition of claim 1, characterized in that, The glass transition temperature of the aqueous polyacrylate primary dispersion is 55℃-70℃, and the glass transition temperature is determined by DSC (differential scanning calorimetry) according to DIN65467.

18. The adhesive composition according to claim 1, characterized in that, The average particle size of the aqueous polyacrylate primary dispersion is 40nm-200nm.

19. The adhesive composition according to claim 1, characterized in that, The average particle size of the aqueous polyacrylate primary dispersion is 60nm-160nm.

20. A method for preparing an adhesive composition according to any one of claims 1-19, comprising the steps of: mixing the anionic aqueous polyurethane dispersion, the aqueous polyacrylate primary dispersion and optional additives in any manner; wherein the amount of the aqueous polyurethane dispersion is 30%-91% by weight and the amount of the aqueous polyacrylate primary dispersion is 9%-70% by weight, all of the above weight percentages being relative to the total weight of the adhesive composition.

21. Use of the adhesive composition according to any one of claims 1-19 in the preparation of articles.

22. The use as described in claim 21, characterized in that, The products are selected from automotive interiors, food packaging, and furniture.

23. An article comprising a substrate and a coating formed by applying an adhesive composition according to any one of claims 1-19 onto the substrate.

24. A method for manufacturing an adhesive article, comprising the following steps: i. Applying the adhesive composition according to any one of claims 1-19 to at least one surface of a substrate; ii. Thermally activate the surface of the substrate treated in step i; and iii. Bring the surface of the substrate treated in step ii into contact with the surface of the substrate itself or another substrate to obtain the bonded article.

25. The method as described in claim 24, characterized in that, The temperature for thermal activation is room temperature - 110°C.

26. The method as described in claim 24, characterized in that, The temperature for thermal activation is 40℃-100℃.

27. The method as described in claim 24, characterized in that, The temperature for thermal activation is 50℃-80℃.

Images