Technical Field

The present invention relates to a composition, the preparation and the use of the composition, a two- component system containing the composition and the use thereof, and an article obtained by coating or bonding with the composition or the two-component system.

Background technology

With the growth in the people's living standard and the popularization of vehicles in family, people pay more and more attention to the quality of air in vehicles. The evaluation of the quality of air in vehicles is mainly in two aspects: the content of volatile organic compounds (VOC for short) in vehicles and the degree of odor in vehicles. According to the statistical data, by referring to indoor air quality standards, the problem that the VOC content exceeds the standard exists in nearly 90% of vehicles. The excessive content of VOC can cause the maladjustment of the immunization level of human body, affect the function of nervous system, cause symptoms such as dizziness, headache, sleepiness, weakness and the like, affect the digestive system, cause anorexia, nausea and the like, may damage the liver and hematopoietic system if serious, and threaten the health of human body. In the PP100 (the number of problems experienced per 100 vehicles) list of the Initial Quality Study (IQS), "unpleasant smells/odors" remains at the top in recent years, and although these odors do not necessarily threaten the human health, consumers often do not want odors to be present in vehicles. Sources of VOC and odor in vehicles are diverse, for example, seat foam, fabric coating, plastic interiors, binder, and the like.

The aqueous dispersion system has a very low VOC content, and can effectively solve the problem of excessive VOC content in the vehicle. And the aqueous dispersion system per se has lower odor, and can solve the problem of unpleasant odor in vehicles.

CN 104151540A discloses a process for preparing a poly ether polyol with low V OC content and high resilience for polyurethane foam, which is characterized in that the reaction is carried out under a pressure of 0-0.6MPa at a temperature of 60-140°C with a polyol compound as starter and an alkali metal hydroxide as catalyst in a step-wise polymerization with an epoxy compound, followed by a special post-treatment to obtain the poly ether polyol; wherein the polyol compound comprises 10- 19.5 wt.% of the total feedstock, the epoxy compound comprises 80-89.5 wt.% of the total feedstock, and the alkali metal hydroxide comprises 0.2-0.5 wt.% of the total feedstock. CN104592878B discloses an environment-friendly water-based paint and a preparation process thereof, which paint comprises a water-based resin dispersion, water, a composite anion powder, an anion additive, a film forming aid, a defoamer, a thickener, a dispersant and a pH regulator. Said composite anion powder consists of crystal salt, nano-silica, nano-phosphoric acid-titanium dioxide and nano-zinc dioxide. Nano-silica, nano-phosphoric acid titanium dioxide and nano-zinc dioxide as photocatalyst materials can effectively degrade harmful gases such as formaldehyde and the like in the air under illumination to produce superoxide anion free radicals and associated negative oxygen ions.

CN103980814A discloses a polyurethane odorless matt wear-resistant finish varnish and a preparation method thereof, which is formulated by a main agent, a curing agent and a diluent in the weight ratio of 1-1.4:0.5-0.7:0.7-1.2; wherein the specific ratio of the main agent to the curing agent is 1-1.4:0.5-0.7, so that the hydroxyl group in the main agent and the isocyanate group in the curing agent are fully and completely reacted, where the optimal molar ratio of the hydroxyl group to the isocyanate group is 2:1, thereby it is as much as possible in the construction process to achieve the optimal ratio of the hydroxyl group to the isocyanate group so as to accomplish the complete reaction and form the stable polyurethane bonds, and thereby achieve the odorless effect and eliminate the pungent odor brought by the raw materials per se.

CN 106009271 A discloses a modified polypropylene composition, which contains the following blended components: polypropylene, ethylene propylene grafted maleic anhydride copolymer, reinforcing filler, deodorant, antioxidant, and processing aid. Among others, the deodorant is an organic salt and/or a silicate salt with micropores, and the silicate salt with micropores is at least one of a sodium silicate salt, an aluminum silicate salt, a magnesium silicate salt and a calcium silicate salt; the specific surface area of the silicate salt with micropores is 200-600 m ² /g, preferably 300-500 m ² /g; the micropores of the silicate salt with micropores have an average pore diameter of 0.2-2 nm, preferably 0.1-1 nm.

CN101379157A discloses a use of nanoparticles, especially finely dispersed barium sulfate, which may be used with an optional chemical modification, for preparing binding agents such as aqueous dispersion poly acrylates, polyurethanes and epoxy resins and the like. By the introduction of nanoparticles, the properties of such binding agents such as cohesion and heat resistance are improved while maintaining the comparable adhesion.

CN103608361B discloses a process of concentrating an aqueous dispersion containing organic polymer particles and silica particles and the aqueous dispersion obtained by this process and its use as a binding agent and the use of such a dispersion as a binding agent; the preparation step of the aqueous dispersion contains: a) providing an aqueous dispersion comprising organic polymer particles and silica particles, the dispersion having an initial content of organic polymers and an initial content of silica, b) contacting the dispersion of step a) with a creaming agent to produce an aqueous clear liquid phase and an aqueous concentration phase, and c) separating the aqueous clear liquid phase from the concentration phase.

However, the consumer's demand on the low odor in vehicle is becoming more and more stringent, and it is difficult for the existing aqueous dispersion systems to meet the requirement.

It is desirable to develop a new composition with low VOC and low odor to further lower the odor based on the existing products to meet the stringent odor requirements in the application fields, such as automotive interior coatings or automotive interior binders.

Summary of the Invention

The object of the present invention is to provide a composition, in particular a composition not containing a chelating agent, the preparation and the use of the composition, a two-component system containing the composition and the use thereof, and an article obtained by coating or bonding with the composition or the two-component system.

The composition according to the invention contains:

A) 70 wt.%-99.6 wt.% of an aqueous polyurethane dispersion; and

B) 0.4 wt.%-2 wt.% of a hydroxyl-containing aqueous nanosilica dispersion; the above weight percentages are relative to the total weight of the composition; said aqueous polyurethane dispersion is prepared by a reaction containing a polyester polyol; said hydroxyl-containing aqueous nanosilica dispersion has a particle size of 5 nm-18 nm; the weight ratio of said hydroxyl-containing aqueous nanosilica dispersion to the aqueous polyurethane dispersion is 1:249-1:49.

According to one aspect of the present invention, there is provided a process for preparing the composition provided by the present invention, containing a step of mixing said aqueous polyurethane dispersion and the hydroxyl-containing aqueous nanosilica dispersion in any manner.

According to another aspect of the present invention, there is provided the use of the composition provided according to the present invention for producing an article. According to a further aspect of the present invention, there is provided an article containing a substrate and a coating formed by applying the composition provided according to the present invention to the substrate.

According to yet another aspect of the present invention, there is provided a method of producing a coated article, containing a step of applying the composition provided according to the present invention to a substrate surface followed by curing the composition.

According to yet another aspect of the present invention, there is provided a method of producing a bonded article, containing steps of: i. Applying the composition provided according to the present invention to at least one surface of a substrate; and ii. Contacting the surface of the substrate treated in step i with the substrate itself or with a surface of another base to obtain said bonded article.

According to yet another aspect of the present invention, there is provided a two-component system containing Component A which is the composition provided according to the present invention and Component B which is a cross-linking agent.

According to yet another aspect of the present invention, there is provided the use of the two- component system provided according to the present invention for producing an article.

According to yet another aspect of the present invention, there is provided an article containing a substrate and a coating formed by applying the two-component system provided according to the present invention to the substrate.

The composition of the present invention is an aqueous composition. It is suitable for industrial application, and has the characteristic of low VOC. The composition of the present invention also has the advantage of low odor, and can meet the strict requirements on VOC and odor in the application fields, for example automotive interiors, indoor furnishings and the like.

Detailed Description

The present invention provides a composition containing: A) 70 wt.%-99.6 wt.% of an aqueous polyurethane dispersion; and B) 0.4 wt.%-2 wt.% of a hydroxyl-containing aqueous nanosilica dispersion; the above weight percents are relative to the total weight of the composition; said aqueous polyurethane dispersion is prepared by a reaction containing a polyester polyol; said hydroxyl- containing aqueous nanosilica dispersion has a particle size of 5 nm-18 nm; the weight ratio of said hydroxyl-containing aqueous nanosilica dispersion to the aqueous polyurethane dispersion is 1:249- 1:49. The present invention also provides a process for preparing the composition and the use of the composition, in particular in coating and binders, a two-component system containing the composition and the use thereof, and an article obtained by coating or binding with the composition or the two-component system.

The term "curing" as used herein refers to a process in which a composition or a two-component system containing the composition converts from liquid state to solid state.

The term "coating" as used herein refers to a chemical substance that can be applied with a variety of application techniques to a surface of an object to form a strongly bonded, continuous solid coating having a certain strength.

The term "binder" as used herein refers to a chemical substance that can be applied with a variety of application techniques to a surface of an object, so as to form a coating on the object itself or between the surface of the object and a surface of another object, and to adhere the object itself or adhere the surface of the object and the surface of another object together. This term is also used as a synonym for adhesive and/or sealant and/or binding agent.

The term "polyurethane polymer" as used herein refers to polyurethane urea polymer and/or polyurethane polyurea polymer and/or polyurea polymer and/or polythiourethane polymer.

The term "aqueous polyurethane dispersion" as used herein refers to aqueous polyurethane urea dispersion and/or aqueous polyurethane polyurea dispersion and/or aqueous polyurea dispersion and/or aqueous polythiourethane dispersion.

The term "emulsifier" as used herein refers to a compound containing emulsifying group(s) or latent emulsifying group(s).

The term "isocyanate -reactive group" as used herein refers to a group containing Zerevitinov-active hydrogen, which is defined with reference to Rompp's Chemical Dictionary (Rommp Chemie Lexikon), 10th ed., Georg Thieme Verlag Stuttgart, 1996. In general, the group containing Zerevitinov-active hydrogen is understood in the art to refer to hydroxyl groups (OH), amino groups (NH _x ) and thiol groups (SH).

The term "chelating agent" as used herein refers to a compound capable of forming a stable complex with metal ions, in particular heavy metal ions or transition metal ions. The term "not containing a chelating agent" as used herein means that the amount of the chelating agent in the composition is less than 0.05 wt .%.

Composition

The composition preferably does not contain a chelating agent, and most preferably the amount of the chelating agent in the composition is 0.

The amount of the organic solvent in the composition preferably does not exceed 5 wt.%, most preferably does not exceed 0.5 wt.%, relative to the total weight of the composition.

The weight ratio of said hydroxyl-containing aqueous nanosilica dispersion to the aqueous polyurethane dispersion is preferably 1:200-1:50.

The composition is an aqueous system and has the characteristic of low VOC.

The composition is preferably a coating or a binder, most preferably an interior coating or an interior binder.

Aqueous polyurethane dispersion

The amount of said aqueous polyurethane dispersion is preferably 90 wt.%-99 wt.%, most preferably 98 wt.%-99.6 wt.%, relative to the total weight of the composition.

The solid content of said aqueous polyurethane dispersion is preferably 40 wt.%-60 wt.%, relative to the total weight of the aqueous polyurethane dispersion.

The amount of the residual organic solvent in said aqueous polyurethane dispersion is preferably less than 1.0 wt.%, relative to the total weight of the solid components of the aqueous polyurethane dispersion.

Said aqueous polyurethane dispersion may be directly added to the composition as a dispersion or may be added to the composition as a polyurethane polymer and water and then mixed to form a dispersion.

Said aqueous polyurethane dispersion contains a polyurethane polymer and water, wherein said polyurethane polymer is preferably obtained by the reaction of a system containing a polyisocyanate, a polyester polyol and an emulsifier. Polyisocyanate

The functionality of said polyisocyanate is preferably not less than 2, and further preferably 2-4.

The amount of said polyisocyanate is preferably 5 wt.%-70 wt.%, further preferably 5 wt.%-40 wt.%, still further preferably 5 wt.%-35 wt.%, most preferably 10 wt.%-30 wt.%, relative to the total weight of the system for preparing said polyurethane polymer.

The polyisocyanate is preferably one or more of the following: aliphatic polyisocyanates, cycloaliphatic polyisocyanates, aromatic polyisocyanates, and derivatives thereof having iminooxadiazinedione, isocyanurate, uretdione, urethane, allophanate, biuret, urea, oxadiazinetrione, oxazolidinone, acylurea and/or carbodiimide groups.

Said aliphatic polyisocyanate is preferably one or more of the following: 1,6-hexamethylene diisocyanate, 2,2-dimethylpentamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, butylene diisocyanate, 1,3-butadiene-1,4-diisocyanate, 2,4,4-trimethyl-1,6- hexamethylene diisocyanate, 1,6,11 -undecane triisocyanate, 1,3,6-hexamethylene triisocyanate, 1,8- diisocyanato-4-isocyanatomethyl octane, bis(isocyanatoethyl) carbonate, bis(isocyanatoethyl) ether, lysine methyl ester diisocyanate, lysine triisocyanate, bis(isocyanatomethyl)thioether, bis(isocyanatoethyl)thioether, bis(isocyanatopropyl)thioether, bis(isocyanatohexyl)thioether, bis(isocyanatomethyl)sulfone, bis(isocyanatomethyl)dithioether, bis(isocyanatoethyl)dithioether, bis(isocyanatopropyl)dithioether, bis(isocyanatomethylthio)methane, bis(isocyanatoethylthio)methane, bis(isocyanatomethylthio)ethane, bis(isocyanatoethylthio)ethane,

1.5 -diisocyanato-2-isocyanatomethyl-3-thia-pentane, 1,2,3 -tris(isocyanatomethylthio)propane,

1,2,3-tris(isocyanatoethylthio)propane, 3,5-dithia-1,2,6,7-heptane tetraisocyanate, 2,6- diisocyanatomethyl-3,5-dithia-1,7-heptane diisocyanate, 2,5-diisocyanatomethylthiophene, isocyanatoethylthio-2,6-dithia-1,8-octane diisocyanate, thiobis(3-isothiocyanatopropane), thiobis(2- isothiocyanatoethane), dithiobis(2-isothiocyanatoethane), hexamethylene diisocyanate and isophorone diisocyanate, most preferably one or more of the following: 1,6-hexamethylene diisocyanate and hexamethylene diisocyanate.

Said cycloaliphatic polyisocyanate is preferably one or more of the following: 2,5- bis(isocyanatomethyl)-bicyclo[2.2.1]heptane, 2,6-bis(isocyanatomethyl)-bicyclo[2.2.1]heptane, bis(isocyanatomethyl)cyclohexane, isophorone diisocyanate, 2,5-diisocyanatotetrahydrothiophene,

2.5-diisocy anatome thy ltetrahydrothiophene , 3 ,4-diisocy anatomethyltetr ahydrothiophene , 2,5- diisocyanato-1,4-dithiane, 2,5-diisocyanatomethyl-1,4-dithiane, 4,5-diisocyanato-1,3- dithiacyclopentane, 4,5-bis(isocyanatomethyl)-1,3-dithiacyclopentane, 4,5-diisocyanatomethyl-2- methyl-1,3-dithiacyclopentane, norbornane diisocyanate (NBDI), xylidene diisocyanate (XDI), hydrogenated xylidene diisocyanate (H ₆ XDI), 1,4-cyclohexyl diisocyanate (H ₆ PPDI), 1,5- pentamethylene diisocyanate (PDI), meta-tetramethyl xylidene diisocyanate (m-TMXDI) and cyclohexane diisothiocyanate, most preferably one or more of the following: isophorone diisocyanate and dicyclohexyl diisocyanate.

Said aromatic polyisocyanate is preferably one or more of the following: 1,2-diisocyanatobenzene, 1,3-diisocyanatobenzene, 1,4-diisocyanatobenzene, 2,4-diisocyanatotoluene, ethylbenzene diisocyanate, isopropylbenzene diisocyanate, toluene diisocyanate, diethylbenzene diisocyanate, diisopropylbenzene diisocyanate, trimethylbenzene triisocyanate, benzene triisocyanate, biphenyl diisocyanate, toluidine diisocyanate, 4,4'-methylene bis(phenylisocyanate), 4,4'-methylene bis(2- methylphenylisocyanate), bibenzyl-4,4'-diisocyanate, bis(isocyanatophenyl)ethylene, bis(isocyanatomethyl)benzene, bis(isocyanatoethyl)benzene, bis(isocyanatopropyl)benzene, α,α,α',α'-tetramethylxylidene diisocyanate, bis(isocyanatobutyl)benzene, bis(isocyanatomethyl)naphthalene, bis(isocyanatomethyl phenyl)ether, bis(isocyanatoethyl)phthalate, 2,6-di(isocyanatomethyl)furan, 2-isocyanatophenyl-4- isocyanatophenyl sulfide, bis(4-isocyanatophenyl)sulfide, bis(4-isocyanatomethyl phenyl)sulfide, bis(4-isocyanatophenyl)disulfide, bis(2-methyl-5-isocyanatophenyl)disulfide, bis(3-methyl-5- isocyanatophenyl)disulfide, bis(3-methyl-6-isocyanatophenyl)disulfide, bis(4-methyl-5- isocyanatophenyl)disulfide, bis(4-methoxy-3-isocyanatophenyl)disulfide, 1,2-diisothiocyanato benzene, 1,3-diisothiocyanato benzene, 1,4-diisothiocyanato benzene, 2,4-diisothiocyanato toluene, 2,5-diisothiocyanato-meta-xylene, 4,4'-methylene bis(phenylisothiocyanate), 4,4'-methylene bis(2- methylphenylisothiocyanate), 4,4'-methylene bis(3-methylphenylisothiocyanate), 4,4'- diisothiocyanatobenzophenone, 4,4'-diisothiocyanato-3,3'-dimethylbenzophenone, bis(4- isothiocyanatophenyl)ether, l-isothiocyanato-4-[(2-isothiocyanato)sulfonyl]benzene, thiobis(4- isothiocyanatobenzene), sulfonyl(4-isothiocyanatobenzene), hydrogenated toluene diisocyanate (H ₆ TDI), diphenylmethane diisocyanate and dithiobis(4-isothiocyanatobenzene), most preferably one or more of the following: 1,2-diisocyanatobenzene, 1,3-diisocyanatobenzene, 1,4- diisocyanatobenzene, diphenylmethane diisocyanate and 2,4-diisocyanatotoluene.

Said polyisocyanate may also have an isocyanate group and an isothiocyanate group, for example 1- isocyanato-6-isothiocyanatohexane, 1-isocyanato-4-isothiocyanatocyclohexane, 1-isocyanato-4- isothiocyanatobenzene, 4-methyl-3-isocyanato-1-isothiocyanatobenzene, 2-isocyanato-4,6- diisothiocyanato-1,3,5-triazine, 4-isocyanatophenyl-4-isothiocyanatophenylsulfide and 2- isocyanatoethyl-2-isothiocyanatoethyldisulfide.

Said polyisocyanate may also be a halogen substitute such as a chlorine substitute, a bromine substitute, an alkyl substitute, an alkoxy substitute, a nitro substitute or a silane substitute of the above polyisocyanates, for example, isocyanatopropyltriethoxy silane or isocyanatopropyltrimethoxysilane.

Polyester polyol

The amount of said polyester polyol is preferably 5 wt.%-95 wt.%, preferably 10 wt.%-90 wt.%, relative to the total weight of the system for preparing said polyurethane polymer.

The hydroxyl value of said polyester polyol is preferably 20-80.

The polyester polyol is preferably a linear polyester polyol.

Said linear polyester polyol or lightly branched polyester polyol is prepared by containing the following components: aliphatic, alicyclic or aromatic di- or poly-carboxylic acids, for example succinic acid, methyl succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, nonane dicarboxylic acid, decane dicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, cyclohexane dicarboxylic acid, maleic acid, fumaric acid, malonic acid or trimellitic acid; anhydrides, for example phthalic anhydride, trimellitic anhydride or succinic anhydride or a mixture thereof; and low molecular weight polyols, and optionally higher functional polyols, for example trimethylolpropane, glycerol or pentaerythritol, alicyclic and/or aromatic di- and poly-hydroxyl compounds.

Emulsifier

The amount of the emulsifier is preferably 0.1 wt.%-20 wt.%, relative to the total weight of the system for preparing said polyurethane polymer.

Said emulsifier preferably contains at least one isocyanate -reactive group and at least one emulsifying group or latent emulsifying group.

Said isocyanate-reactive group is preferably one or more of the following: hydroxyl, thiol and amino groups.

Said emulsifying group or latent emulsifying group is preferably one or more of the following: a sulfonic acid group, a carboxylic acid group, a tertiary amino group, and a hydrophilic polyether.

The emulsifier containing a sulfonic acid group and/or a carboxylic acid group is preferably one or more of the following: a diamino compound containing a sulfonic acid group and/or a carboxylic acid group and a dihydroxy compound containing a sulfonic acid group and/or a carboxylic acid group, further preferably one or more of the following: sodium, potassium, lithium, 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, dime thy lolpropionic acid or dimethylolbutyric acid, most preferably one or more of the following: N-(2-aminoethyl)-2-aminoethanesulfonic acid salt and dihydroxymethylpropionic acid.

The sulfonic acid group or the carboxylic acid group can be directly used in their salt forms, such as a sulfonic acid salt or a carboxylic acid salt.

The sulfonic acid group or the carboxylic acid group can also be obtained by partial or complete addition of a neutralizing agent to form a salt during or after the preparation of the polyurethane polymer.

The neutralizing agent used for forming a salt is preferably one or more of the following: triethylamine, dimethyl cyclohexylamine, ethyldiisopropylamine, ammonia, diethanolamine, triethanolamine, dime thy lethanolamine, sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, methyldiethanolamine and aminomethylpropanol, most preferably one or more of the following: triethylamine, dimethylcyclohexylamine and ethyldiisopropylamine.

Organic solvent

The system for preparing the polyurethane polymer may further comprise an organic solvent that is miscible with water but inert to isocyanate groups.

The amount of said organic solvent is preferably 0.001 wt.%-20 wt.%, relative to the total weight of the system for preparing said polyurethane polymer.

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

Said organic solvent may be added only at the beginning of the preparation, or may be added in part during the preparation as needed.

Reaction diluent

The system for preparing the polyurethane polymer may further comprise a reaction diluent. The amount of said reaction diluent is preferably 0.001 wt.%-90 wt.%, relative to the total weight of the system for preparing said polyurethane polymer.

Said reaction diluent is preferably one or more of: acrylic acids and acrylic acid esters.

Said aqueous polyurethane dispersion is preferably an anionic aqueous polyurethane dispersion, most preferably one or more of the following: Dispercoll U56 and Dispercoll U54.

Hydroxyl-containing aqueous nanosilica dispersion

The amount of said hydroxyl-containing aqueous nanosilica dispersion is preferably 0.4 wt.%-1.8 wt.%, most preferably 0.7 wt.%-1.8 wt.%, relative to the total weight of the composition.

The particle size of said hydroxyl-containing aqueous nanosilica dispersion is preferably 8 nm-15 nm, most preferably 9 nm-15 nm.

The pH value of said hydroxyl-containing aqueous nanosilica dispersion is preferably greater than or equal to 7, most preferably 8-10.

The specific surface area of said hydroxyl-containing aqueous nanosilica dispersion is preferably 100 m ² /g-400 m ² /g, further preferably 120 m ² /g -350 m ² /g, most preferably 200 m ² /g -300 m ² /g.

The density of said hydroxyl-containing aqueous nanosilica dispersion is preferably 1.1 g/cm ³ -1.3 g/cm ³ .

When said composition contains two or more hydroxyl-containing aqueous nanosilica dispersions, the particle size refers to the average of the particle sizes of all hydroxyl-containing aqueous nanosilica dispersions, preferably the particle size of each hydroxyl-containing aqueous nanosilica dispersion in the composition is in the range of 5 nm-18 nm.

The solid content of said hydroxyl-containing aqueous nanosilica dispersion is preferably 15 to 60 wt.%

Stabilizer

The composition may further contain a stabilizer which is beneficial to reduce hydrolysis of the composition and prolong the storage life of the composition.

Said stabilizer is preferably one or more of the following: carbodiimide compounds, epoxy compounds, oxazoline compounds, and aziridine compounds. The content of the stabilizer is preferably 0-10 wt.%, more preferably 0.5 wt.%-10 wt.%, most preferably 0.5-2 wt.%, relative to the total weight of the solid components of said composition.

Additive

Said composition may further contain an additive.

Said additive is preferably one or more of the following: co-binding agent, thickener, bonding promoter, lubricant, wetting additive, dye, light stabilizer, aging inhibitor, pigment, flow control agent, antistatic agent, UV absorbent, film formation aid, defoamer and plasticizer.

The amount of said additive may be an amount well known to those skilled in the art.

Aqueous dispersion

Said composition may further comprise an aqueous dispersion different from said aqueous polyurethane dispersion, preferably one or more of the following: aqueous polyester dispersion, aqueous polyurethane -polyacrylate dispersion, aqueous polyacrylate dispersion, aqueous polyester- polyacrylate dispersion, alkyd resin, aqueous polyamide/imide dispersion and aqueous polyepoxide dispersion.

The weight ratio of said aqueous dispersion different from said aqueous polyurethane dispersion to said aqueous polyurethane dispersion is preferably 0-0.42:1.

Process for preparing the composition

Said aqueous polyurethane dispersion is preferably obtained from a reaction containing the following steps: a. Reacting some or all of the polyisocyanate and the polyester polyol to obtain a prepolymer, the reaction is carried out in the presence of an optional organic solvent which is miscible with water but inert to isocyanate groups, or the optional organic solvent which is miscible with water but inert to isocyanate groups is added after the reaction to dissolve the prepolymer; b. Reacting the prepolymer, an emulsifier, an optional reaction diluent, the polyisocyanate that is not added in step a and the polyester polyol that is not added in step a to obtain said polyurethane polymer; and c. Introducing water and an optional emulsifier before, during or after step b to obtain said aqueous polyurethane dispersion. The aqueous polyurethane polymer is preferably prepared by using a prepolymer mixing process, an acetone process or a melt dispersion process, most preferably using the acetone process.

The order of mixing the components of the system for preparing said aqueous polyurethane dispersion can be in the conventional manner.

Said polyisocyanate and polyester polyol may be added in one portion or in multiple portions, either of the same or different composition as previously added.

The organic solvent present in the aqueous polyurethane dispersion can be removed by distillation. The organic solvent may be removed during or after the formation of the polyurethane polymer.

When the composition further contains a stabilizer, an additive or an aqueous dispersion different from said aqueous polyurethane dispersion, the process for preparing the composition of the present invention preferably contains a step of mixing said aqueous polyurethane dispersion, the hydroxyl- containing aqueous nanosilica dispersion, the optional stabilizer, the optional additive and the optional aqueous dispersion different from said aqueous polyurethane dispersion in any manner.

The article is preferably selected from automotive interiors and indoor furnishings.

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

The application may be of applying the composition to the entire surface of the substrate or to only one or more parts of the surface of the substrate.

The application can be brush coating, dipping, spraying, roll coating, blade coating, flow coating, casting, printing or transfer-printing, preferably brush coating, dipping or spraying.

In the method for producing the bonded article, a step iii: heating and drying the surface of the substrate to which the composition is applied, may be further contained between step i and step ii. In case that the method for producing the bonded article further comprises step iii, step ii is to contact the surface of the substrate treated in step iii with the substrate itself or the surface of the additional base to obtain said bonded article. The step iii of heating and drying the surface of the substrate to which the binder is applied may mean heating and drying only the surface of the substrate, or heating and drying a part of or the whole of the substrate including the surface of the substrate to which the binder is applied.

The heating and drying may remove the volatile components. The volatile component may be water.

The heating and drying is preferably one or more of: infrared thermal radiation, near infrared thermal radiation, microwaves and using a convection oven or a spray dryer under an elevated temperature condition.

The higher the temperature of the heating is, the better it is, but should not be above the temperature limit at which the substrate deforms in an uncontrolled manner or suffers other damage.

The contact is preferably performed before the temperature of the substrate surface is reduced below the temperature at which the binder can bond.

The additional base may be any base that needs to be bonded.

Said additional base and said substrate can be identical to or different from each other.

Said additional base is preferably coated and heat treated as said substrate.

Two-component system

The amount of the organic solvent in said two-component system preferably does not exceed 5 wt.%, most preferably does not exceed 0.5 wt.%, relative to the total weight of said two-component system.

Said two-component system preferably does not contain a chelating agent.

Said two-component system is aqueous, and the VOC content of the two-component system is low.

Said Component A and Component B are preferably stored separately and mixed prior to use.

The weight ratio of said Component A to said Component B is preferably 1:1-100:1, most preferably 15:1-25:1.

Said cross-linking agent is preferably an isocyanate group-containing compound.

Said two-component system is preferably a coating or a binder, most preferably an interior coating or an interior binder.

The article is preferably selected from automotive interiors and indoor furnishings. The substrate is preferably one or more of the following: wood, plastic, metal, glass, textile, alloy, fabric, artificial leather, paper, cardboard, EVA, rubber, leather, glass fiber, ethylene vinyl acetate copolymer, polyolefin, thermoplastic polyurethane, polyurethane foam, polymer fiber, and graphite fiber, most preferably one or more of the following: EVA, rubber, leather, artificial leather, ethylene vinyl acetate copolymer, polyolefin, thermoplastic polyurethane, and polyurethane foam.

The application may be of applying the composition to the entire surface of the substrate or to only one or more parts of the surface of the substrate.

The application can be brush coating, dipping, spraying, roll coating, blade coating, flow coating, casting, printing or transfer-printing, preferably brush coating, dipping or spraying.

Examples

Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which this invention belongs. To the extent that the definitions of terms used in this specification conflict with meanings commonly understood by those skilled in the art to which this invention belongs, the definitions set forth herein prevail.

Unless otherwise indicated, all numbers expressing quantities of ingredients, reaction conditions, and the like used in the specification and claims are to be understood as being modified by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth herein are approximations that can vary depending upon the desired properties to be obtained.

The expression "and/or" as used herein means one or all of the mentioned elements.

The use of "comprise" and "contain" herein encompasses the presence of the mentioned elements alone and the presence of other elements not mentioned in addition to the mentioned elements.

All percentages in the present invention are by weight unless otherwise stated.

The analytical measurements of the invention are carried out at 23 °C, unless otherwise stated.

As used in this specification, unless otherwise indicated, "a", "an", and "the/said" are intended to comprise "at least one" or "one or more". For example, "a component" refers to one or more components, and thus more than one component may be considered and may be employed or used in the practice of the described embodiments.

The solid content of the aqueous polyurethane dispersion is determined by using a HS153 moisture meter from Mettler Toledo according to DIN-EN ISO 3251. The isocyanate group (NCO) content is volumetrically measured in accordance with DIN-EN ISO 11909, and the measured data comprise the free and potentially free NCO content.

The pH value is measured at 20°C by using a PB-10pH meter from Sartorius Corporation, Germany.

The specific surface area (BET) is determined in accordance with DIN ISO 9277 standard test method.

Raw materials and reagents

Dispercoll U56: anionic aqueous polyurethane dispersions having a solid content of 50 +/- 1%, commercially available from Covestro AG, Germany.

Dispercoll U54: anionic aqueous polyurethane dispersions having a solid content of 50 +/- 1%, commercially available from Covestro AG, Germany.

Dispercoll U53: anionic aqueous polyurethane dispersions having a solid content of 50 +/- 1%, commercially available from Covestro AG, Germany.

Dispercoll S 4020: hydrophilic gas-phase nanosilica dispersion, having a solid content of 40 wt.%, a particle size of 15 nm, a BET of 200 m ² /g, a density of 1.29 g/cm ³ , a pH of 9, commercially available from Covestro AG, Germany.

Dispercoll S 5005: hydrophilic gas-phase nanosilica dispersion, having a solid content of 50 wt.%, a particle size of 55 nm, a BET of 50 m ² /g, a density of 1.39 g/cm ³ , a pH of 9, commercially available from Covestro AG, Germany.

Dispercoll S 4510: hydrophilic gas-phase nanosilica dispersion, having a solid content of 45 wt.%, a particle size of 30 nm, a BET of 100 m ² /g, a density of 1.34 g/cm ³ , a pH of 9, commercially available from Covestro AG, Germany.

Dispercoll S 3030: hydrophilic gas-phase nanosilica dispersion, having a solid content of 30 wt.%, a particle size of 9 nm, a BET of 300 m ² /g, a density of 1.21 g/cm ³ , a pH of 9, commercially available from Covestro AG, Germany.

Dispercoll S 2020 XP: hydrophilic gas-phase nanosilica dispersion, having a solid content of 20 wt.%, a particle size of 15 nm, a BET of 200 m ² /g, a density of 1.13 g/cm ³ , a pH of 9, commercially available from Covestro AG, Germany. Borchigel L75N: thickener, having a solid content of 25 wt.%, commercially available from OMG Corporation.

Table 1 shows the evaluation criteria and the rating of the odor test. Table 2 shows the constitution of the compositions of Examples and Comparative Examples, and the test results for the odor test of the compositions and the viscosity of the compositions after being thickened.

Method for preparing the compositions of Examples 1-9 and Comparative Examples 1-9

According to the amounts indicated in Table 2, the aqueous polyurethane dispersion was weighed and added into a vessel and stirred at a speed of 800 rpm. A small amount of the aqueous nanosilica dispersion was added. The mixture was stirred at a speed of 800 rpm to disperse the aqueous nanosilica dispersion in the aqueous polyurethane dispersion. The remaining aqueous nanosilica dispersion was added, and the mixture was continuously stirred at a speed of 900 rpm -1000 rpm for about 30 minutes until a uniformly dispersed composition was obtained. Among others, the compositions of Comparative Examples 1-3 comprised only the aqueous polyurethane dispersions.

Odor test

1. The composition sample was uniformly coated on a matt surface of an aluminum foil paper, and stood alone at room temperature until the coating was completely dried;

2. The aluminum foil paper coated with the sample to be tested was made into mass having a volume of 50+/-5 cm ³ by cutting, stacking and the like, and stood alone for 7 days at room temperature;

3. The aluminum foil paper obtained in step 2 was put into a clear-glass bottle with the capacity of about 1L and no special odor per se, and sealed;

4. The glass bottle was put into an oven, heated for 2 hours at 80°C, and then cooled to 60°C, and the temperature was maintained for more than half an hour;

5. The glass bottle was taken out from the oven and opened, and then five persons each smelled the odor and gave an odor rating according to the standard of Table 1. If the difference in the results given by 5 persons was larger than 1, the results were invalid and the test was required to be performed again. If the difference in the results was less than or equal to 1, an average value of 5 results was taken as the final result, which could have an accuracy of 0.1. The results are listed in Table 2. Table 1: odor test standards and ratings

Thickening of the composition

The composition sample was mechanically stirred at the rotation speed of 700-800 rpm by using an IKA machine for 10 minutes. The stirring was discontinued, and Borchigel L75N (0.8 parts of Borchigel L75N per 100 parts of the composition) was added, and the mixture was stirred at the rotation speed of 300-400 rpm until Borchigel L75N was mixed with the composition. Finally, the mixture was stirred at the rotation speed of 700-800 rpm for 30 minutes to obtain the thickened composition. The thickened compositions were tested for the initial viscosity and for the viscosity after being aged for 2 weeks at 50°C and the results were shown in Table 2. In the practical industrial applications, it is often necessary to thicken the composition before use. When the viscosity of the thickened composition is less than 1000 mPa·s, it cannot meet the industrial requirements. Viscosity test method: the samples were tested by means of a Brook Field viscometer at the rotation speed set to 30RPM with a rotor of No. S62 if the sample viscosity was less than 900 mPa·s and with a rotor of No. S63 if the sample viscosity was greater than 900 mPa·s.

Test results

The compositions of Comparative Examples 1-3 contained only the aqueous polyurethane dispersion and did not contain the hydroxyl-containing aqueous nanosilica dispersion, and the compositions of the Comparative Examples had the odor test reading values significantly higher than those of Examples 1-9. The particle size of the hydroxyl-containing aqueous nanosilica dispersions contained in the compositions of Comparative Examples 4, 6 and 9 were 55 nm and 30 nm respectively, the compositions of Comparative Examples 4 and 6 had the odor test reading values significantly higher than those of Examples 1-4, and the composition of Comparative Example 9 had the odor test reading value significantly higher than those of Examples 5-8.

The particle size of the hydroxyl-containing aqueous nanosilica dispersion contained in the composition of Comparative Example 5 was 30 nm and the hydroxyl-containing aqueous nanosilica dispersion comprised 2.4% of the composition, after the composition of Comparative Example 5 was thickened and aged for 2 weeks, its viscosity decreased very rapidly and was much less than 1000 mPa*s, i.e. the thickened composition already could not meet the industrial use requirement.

The hydroxyl-containing aqueous nanosilica dispersion contained in the composition of Comparative Example 7 comprised 0.3% of the composition, the composition of Comparative Example 7 had the odor test reading value significantly higher than those of Examples 1-9.

The hydroxyl-containing aqueous nanosilica dispersion contained in the composition of Comparative Example 8 comprised 2.2% of the composition, after the composition of Comparative Example 8 was thickened and aged at 50°C for 2 weeks, its viscosity decreased very rapidly and was much less than 1000 mPa·s, i.e. the thickened composition already could not meet the industrial use requirement.

TABLE 2: the constitution of the compositions of Examples and Comparative Examples, and the test result of odor and viscosity

K

O

The present invention also provides a binding agent, which is composed of 79.20 g of Dispercoll C84 (aqueous neoprene latex), 1.74 g of TSR-1068, 1.45 g of Dnano-233W-30WS, 8.71 g of Revacryl X 9045 (tackifying resin emulsion), 8.89 g of PRIMAL AS-2010 (tackifying resin emulsion), 2.00 g of Eastman TXIB and 2.50 g of glycine. The components of the above binding agent were mixed homogeneously, the viscosity (using a Brookfield/LV/Sp3/60 rpm/23°C) was 263.0 mPa·s and the pH value was 8.00. The binding agent was uniformly sprayed on the surface of a sponge substrate to be tested, and then the manual bonding was carried out. The minimum time period in which the sponge can be completely bonded was recorded as the initial bonding time, and the maximum time period in which the sponge can be completely bonded and finally the sponge material can be broken was recorded as the opening time. The initial bonding time of the binding agent, measured at 23 °C and 60% RH, was 10 seconds to 20 seconds, and the opening time was 20 minutes - 25 minutes.

It will be evident to those skilled in the art that the invention is not limited to the details set forth, and that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not limiting, and thereby the scope of the present invention is indicated by the appended claims rather than by the foregoing description; and moreover any changes, as long as it falls within the meaning and range of the equivalence to the claims, should be considered as a part of the present invention.