Mildew-proof polyurethane composition as well as preparation method and application thereof

Abstract

The invention discloses a mildew-proof polyurethane composition as well as a preparation method and application thereof. The composition comprises at least one polyether-based polyurethane prepolymer, at least one plasticizer, at least one mildew inhibitor selected from organic mildew inhibitors free of active H, and at least one inorganic filler, wherein the polyether-based polyurethane prepolymer is a reaction product or a mixture of reaction products of at least one polyether polyol and at least one aromatic polyisocyanate, wherein the at least one polyether polyol comprises at least one polyether glycol and at least one polyether triol and the weight ratio of the at least one polyether triol to the at least one polyether glycol is in the range of from 4: 1 to 13: 1. The composition can be used in particular for the anti-mold adhesion or sealing of structures in the construction field, or for the anti-mold adhesion or sealing of product surfaces.

Description

Technical Field

[0001] The invention relates to the field of polyurethane compositions, in particular to a mildew-proof polyurethane composition, in particular an adhesive and sealant composition, and a preparation method and use thereof. Background Art

[0002] Adhesives and sealants are usually based on polyurethane, silicone, epoxy resin or water-based systems. Since in the application fields of adhesives and sealants, such as house decoration and renovation, sealants and adhesives often come into contact with water, which causes mold, resulting in mold spots on the products using the sealants or adhesives, poor appearance, or even poor product performance and premature damage. Such mold contamination can also cause harm to human health. Therefore, it is necessary to prepare mildew-resistant adhesives and sealants.

[0003] At present, some research has been conducted on the anti-mold technology of adhesives and sealants, but the research is mainly aimed at silicone and epoxy resin based systems. The anti-mold sealants available on the market are basically silicone based sealants. Such silicone anti-mold sealants often have unsatisfactory anti-mold effects.

[0004] The mildew-proof (also known as anti-mildew, mildew-resistant) properties of a product are usually achieved by adding a mildewcide during the preparation of the sealant or adhesive.

[0005] Mold inhibitors are commonly used additives in a class of polymer materials that can inhibit the growth of mold and kill mold. They can protect polymer materials from fungal erosion and maintain good appearance and physical and mechanical properties. Inorganic mold inhibitors are mainly used in existing mold-proof sealants and adhesives. Inorganic mold inhibitors are usually based on metal ions such as silver, copper, and zinc ions and metal oxides (such as titanium dioxide, zinc oxide, etc.), such as silver-loaded zeolite, silver-loaded molecular sieve, silver-loaded activated carbon, nano titanium dioxide, nano zinc oxide, etc.

[0006] For example, CN115299460A discloses a mildew-proof silicone sealant, which contains a composite mildew-proof agent, wherein the composite mildew-proof agent includes: zinc oxide whiskers; a polyphenol amine layer disposed on the zinc oxide whiskers; and silver particles disposed on the polyphenol amine layer.

[0007] In addition, it has also been proposed to use organic antifungal agents alone or in combination for antifungal purposes.

[0008] EP881265A2 discloses an anti-mildew organopolysiloxane composition, comprising (A) an organopolysiloxane having a silanol group or an alkoxy group, (B) a hydrolyzable silane, and (C) a compound containing a triazole group. The composition further comprises (D) bis(2-pyridylthiol-1-oxy) zinc salt. Component (C) and component (D) are used synergistically for anti-mildew of an organosilicon sealant.

[0009] CN112877016A discloses a flexible epoxy resin adhesive, in which dehydroacetic acid is used as a mildew preventer.

[0010] The molds that corrode sealants and adhesives belong to fungi. Therefore, antifungal agents are usually used as antifungal agents in adhesives and sealants. However, traditional antifungal agents generally use solvents or alcohols as carriers, which is not in line with the concept of environmental protection. In addition, alcohols will also react with polyurethane systems. Therefore, existing antifungal agents are incompatible with polyurethane systems. In the prior art, modified polyurethanes are usually used or antifungal agents are introduced into the skeleton structure of polyurethane.

[0011] CN108531124A discloses a method for preparing a polyurethane adhesive for electrical equipment, wherein a diamine compound material A containing a guanidine group is obtained by a nucleophilic addition reaction, and the material A is used together with diethanolamine for a chain extension reaction of a polyurethane prepolymer, thereby fixing the material A on the molecular chain of the polyurethane. Since the guanidine group contained in the material A has a very strong positive charge, it can react with functional proteins, DNA, RNA, etc. inside the negatively charged surface area of ​​bacteria, thereby showing a very strong antibacterial property. The guanidine compound used in the method participates in the chain extension reaction of the polyurethane prepolymer and is finally combined into the polyurethane skeleton structure.

[0012] CN110655898A discloses a mildew-proof silane-modified polyurethane sealant, in which a mildew-proof silane-modified polyurethane prepolymer is used, and an active mildew-proof agent is added during the preparation of the prepolymer, wherein active hydrogen reacts with isocyanate functional groups so that the active mildew-proof agent is directly grafted onto the main chain of the prepolymer.

[0013] CN101434825A discloses a two-component thiol-terminated polyurethane mildew-proof sealant, wherein component A comprises thiol-terminated polyurethane liquid rubber, filler, plasticizer, tackifier, mildew-proof agent, vulcanization regulator, antioxidant, and can be used in the fields of electronics, machinery, etc. The mildew-proof agent used is any one of halides, heterocyclic compounds, isothiazolins and quaternary ammonium salts, or any two or any three. The sealant is a two-component system, and the matrix resin is thiol-terminated polyurethane liquid rubber.

[0014] CN105482763A discloses a one-component mildew-proof and root-blocking polyurethane building sealant, comprising: a polyurethane prepolymer, a mildew-proof agent (1%-5%), a chemical root-blocking agent (1%-7%), a filler, a silane adhesion promoter, a catalyst and a moisture scavenger. The polyurethane prepolymer comprises: polyoxypropylene diol, polyoxypropylene triol, polyisocyanate and a plasticizer. The mildew-proof agent used is a substance that does not contain active H, specifically a mixture of one or more of silver-loaded zeolite, silver-loaded molecular sieve, silver-loaded activated carbon, nano-titanium dioxide, nano-zinc oxide, isothiazolinone compounds, pyrazole compounds, thiophene compounds and aziridine compounds. The sealant disclosed here uses a combination of mildew-proof agents and chemical root-blocking agents to achieve the dual functions of mildew-proof and root-blocking. The plasticizer used is not used as a carrier of the mildew-proof agent, but as a component of the polyurethane prepolymer. In addition, the proportion of polyoxypropylene diol in the polyurethane prepolymer is greater than the proportion of polyoxypropylene triol. In the examples, an inorganic mildew preventer or a combination of an inorganic mildew preventer and an organic mildew preventer is mainly used, and a relatively large amount of the mildew preventer is used.

[0015] With the development of the housing decoration and renovation market, there is an urgent need for sealants and adhesives with good anti-mildew effects in the market, especially in the field of polyurethane sealants, which need to provide anti-mildew properties.

[0016] Therefore, it is necessary to provide a new solution to make the mildew-proof agent compatible with the polyurethane system, obtain a polyurethane sealant and adhesive that can effectively prevent mildew, and ensure that other properties of the obtained polyurethane sealant and adhesive are not adversely affected; in addition, the preparation method is simple and environmentally friendly. Summary of the invention SUMMARY OF THE INVENTION

[0018] In view of the above problems existing in the prior art, an object of the present invention is to provide a mildew-proof polyurethane composition, in particular a mildew-proof polyurethane adhesive or sealant composition, especially a one-component moisture-curable mildew-proof polyurethane adhesive or sealant composition, in which the mildewcide is compatible with the polyurethane system and can be well dispersed in the polyurethane system, thereby ensuring a good mildew-proof effect, or even a durable mildew-proof effect, while other properties of the polyurethane composition will not be adversely affected.

[0019] Another object of the present invention is to provide a method for preparing the mildew-proof polyurethane composition of the present invention, which method is simple and environmentally friendly.

[0020] Another object of the present invention is to provide a bonding or sealing method using the mildew-proof polyurethane composition of the present invention, which method is simple and environmentally friendly.

[0021] Another object of the present invention is to provide a use of the mildew-proof polyurethane composition according to the present invention as an adhesive or sealant, especially for mildew-proof bonding or sealing of structures in the construction field or mildew-proof bonding or sealing of product surfaces.

[0022] Surprisingly, the inventors of the present invention have discovered for the first time that by using a plasticizer as a carrier or dispersant for an organic mildew inhibitor and adding or dispersing the organic mildew inhibitor into a specific polyether-based polyurethane prepolymer system containing an inorganic filler and a plasticizer as additives, the effects of traditional mildew inhibitors on the performance of polyurethane sealant and adhesive systems can be minimized, thereby obtaining polyurethane sealants and adhesives having good mildew inhibitory effects, even durable mildew inhibitory effects, while having no adverse effects on other properties (such as reactivity, mechanical properties, adhesion properties and / or application properties), and the system is environmentally friendly and has a low preparation cost.

[0023] Therefore, in a first aspect, the present invention provides a mildew-proof polyurethane composition, especially a one-component moisture-curable mildew-proof polyurethane composition, comprising:

[0024] - at least one polyether-based polyurethane prepolymer, wherein the polyether-based polyurethane prepolymer is a reaction product or a mixture of reaction products of at least one polyether polyol and at least one aromatic polyisocyanate, wherein the at least one polyether polyol comprises at least one polyether diol and at least one polyether triol and the weight ratio of the at least one polyether triol to the at least one polyether diol is in the range of 4:1 to 13:1;

[0025] - at least one plasticizer;

[0026] - at least one mildewcide selected from organic mildewcides that do not contain active H; and

[0027] - at least one inorganic filler.

[0028] In another aspect, the present invention provides a method for preparing a mildew-proof polyurethane sealant or adhesive composition according to the present invention, comprising mixing all components of the composition, or first mixing a portion of the plasticizer with the mildew-proof agent to prepare a premix containing the mildew-proof agent, and then mixing the premix containing the mildew-proof agent with a polyurethane prepolymer, the remaining plasticizer, at least one inorganic filler and possibly other components.

[0029] In another aspect, the present invention provides a cured composition obtained after curing the mildew-proof polyurethane composition according to the present invention.

[0030] In another aspect, the present invention provides a method for bonding or sealing a substrate using the mildew resistant polyurethane adhesive or sealant composition of the present invention, comprising:

[0031] a) applying the anti-mildew polyurethane composition on a first substrate;

[0032] b) providing a second substrate, on which the mildew-resistant polyurethane composition is optionally applied;

[0033] c) contacting the first and second substrates with each other;

[0034] The first substrate and the second substrate are made of the same or different materials.

[0035] In another aspect, the present invention provides an article obtained by the method of bonding or sealing substrates.

[0036] In another aspect, the present invention provides the use of the mildew-proof polyurethane composition as an adhesive or sealant, for example, for bonding or sealing structures in the construction field, especially for decoration or repair of houses, especially for bonding or sealing of locations or components in contact with water; or for bonding or sealing the surface of products made or coated with PVC, silicone, polyolefin, polyurethane or acrylic resin, such as shower curtains, ski clothes, raincoats, tents, wallpapers, floors, conveyor belts, soles, uppers, roofing waterproof membranes, sheathing materials for wires and conduits, automotive accessories, foam materials, household appliance gaskets, tarpaulins or awnings. DETAILED DESCRIPTION OF THE INVENTION

[0038] The mildew-proof polyurethane composition of the present invention comprises at least one specific polyether-based polyurethane prepolymer, at least one plasticizer, at least one inorganic filler and at least one mildew-proof agent selected from organic mildew-proof agents containing no active H.

[0039] In the present invention, a plasticizer is used as a carrier of an organic mildew preventer, or as a dispersant of an organic mildew preventer, thereby avoiding the introduction of organic solvents such as alcohols reactive with the polyurethane system into the polyurethane system, and achieving good compatibility of the organic mildew preventer with the polyurethane system and good dispersion in the polyurethane system.

[0040] The plasticizer can be added as an additive to replace the organic solvent, so the entire composition may not contain an organic solvent. The organic solvent refers to an organic solvent commonly used in polyurethane compositions, especially ketones, aromatic hydrocarbons, dimethylformamide, tetrahydrofuran, and the like.

[0041] The organic mildew-proof agent without active H is added to the composition of the present invention as a mildew-proof additive, and is not incorporated into the polyurethane skeleton structure.

[0042] The mildew-proof polyurethane composition of the present invention comprises:

[0043] - at least one polyether-based polyurethane prepolymer, wherein the polyether-based polyurethane prepolymer is a reaction product or a mixture of reaction products of at least one polyether polyol and at least one aromatic polyisocyanate, wherein the at least one polyether polyol comprises at least one polyether diol and at least one polyether triol and the weight ratio of the polyether triol to the at least one polyether diol is in the range of 4:1 to 13:1;

[0044] - at least one plasticizer;

[0045] - at least one mildewcide selected from organic mildewcides that do not contain active H; and

[0046] - at least one inorganic filler.

[0047] In a preferred embodiment, the mildew-proof polyurethane composition of the present invention comprises:

[0048] - 15-50% by weight, preferably 20-40% by weight, of at least one polyether-based polyurethane prepolymer, wherein the polyether-based polyurethane prepolymer is a reaction product or a mixture of reaction products of at least one polyether polyol and at least one aromatic polyisocyanate, wherein the at least one polyether polyol comprises at least one polyether diol and at least one polyether triol and the weight ratio of the at least one polyether triol to the at least one polyether diol is in the range of 4:1 to 13:1;

[0049] - 10-30% by weight, preferably 15-25% by weight, of at least one plasticizer;

[0050] - 0.1-1% by weight, preferably 0.1-0.9% by weight, more preferably 0.2-0.6% by weight of at least one mildewcide, wherein the mildewcide is selected from organic mildewcides that do not contain active H;

[0051] - 25% to 40% by weight, preferably 30% to 35% by weight, of at least one inorganic filler;

[0052] Each is based on the total weight of the composition.

[0053] The mildew-proof polyurethane composition of the present invention is particularly a one-component moisture-curable mildew-proof polyurethane composition.

[0054] Some terms and definitions

[0055] Substance names beginning with "poly", such as polyol or polyisocyanate, refer herein to substances which formally contain two or more of the functional groups occurring in their name per molecule.

[0056] The term "polymer" in this context includes, on the one hand, a collection of macromolecules that are chemically identical but differ in degree of polymerization, molecular weight and chain length, obtained by polymerization (polyaddition, addition polymerization, polycondensation). The term also includes, on the other hand, derivatives of the collection of macromolecules from polymerization, i.e. chemically identical or chemically non-identical compounds obtained by reaction (e.g. addition or substitution) of functional groups on predetermined macromolecules.

[0057] The term "prepolymer" herein generally refers to an oligomer or polymer used as an intermediate in producing a polymer having a higher molecular weight.

[0058] The term "polyether-based polyurethane prepolymer" refers to a prepolymer having an ether group as a repeating unit and additionally containing a urethane group.

[0059] "Molecular weight" is understood herein as the molar mass of a molecule (in grams / mole).

[0060] "Average molecular weight" refers to the number average molecular weight (Mn) of a mixture of molecules in oligomeric or polymeric form, typically determined by gel permeation chromatography (GPC) relative to polystyrene standards.

[0061] "Room temperature" or "ambient temperature" herein means a temperature of 23°C.

[0062] A composition which is referred to as a "one-component" is one in which all of the ingredients are present in the same container and which is inherently storage-stable.

[0063] Polyurethane prepolymer

[0064] The composition of the present invention comprises a polyether-based polyurethane prepolymer. The polyurethane prepolymer is a reaction product or a mixture of reaction products obtained by reacting at least one polyether polyol with at least one aromatic polyisocyanate. The at least one polyether polyol comprises at least one polyether diol and at least one polyether triol and the proportion of the at least one polyether triol is greater than the proportion of the at least one polyether diol. The weight ratio of the at least one polyether triol to the at least one polyether diol may be in the range of 4:1 to 13:1, preferably in the range of 5:1 to 12:1.

[0065] The polyurethane prepolymer obtained by reacting the at least one polyether polyol with the at least one aromatic polyisocyanate has good compatibility with the organic mildew preventer and can also achieve good mechanical properties, heat resistance, UV crack resistance, suitable toughness and excellent weather resistance of the polyurethane composition.

[0066] The at least one polyether polyol preferably consists of at least one polyether diol and at least one polyether triol.

[0067] Suitable polyurethane prepolymers can be prepared by methods commonly used in the art. Such polyurethane prepolymers are, for example, polyurethane prepolymers used in sealants and adhesives under the trademark Sikaflex produced by Swiss Sika Company.

[0068] The polyurethane prepolymer PU suitable for use in the composition of the present invention may be a polymer or a polymer mixture, preferably a polymer mixture.

[0069] Such prepolymers are obtainable by reacting the at least one polyether polyol with at least one aromatic polyisocyanate, preferably a diisocyanate, by reacting the polyol and the polyisocyanate by conventional methods, for example at temperatures of 50° C. to 100° C., optionally with the use of a suitable catalyst, the polyisocyanate being metered in such a way that its isocyanate groups are present in a stoichiometric excess relative to the hydroxyl groups of the polyol.

[0070] In particular, the excess of aromatic polyisocyanate is selected such that, based on the entire polymer, after reaction of all hydroxyl groups of the polyether polyol, an amount of free isocyanate groups remains in the polyurethane polymer obtained.

[0071] As an alternative, the polyurethane prepolymer PU can also be prepared with the co-use of a plasticizer, wherein the plasticizer used does not contain groups reactive toward isocyanate.

[0072] Preferred are polyurethane prepolymers with the stated content of free isocyanate groups which are obtained by reaction of all diisocyanates with all polyether polyols in an NCO:OH ratio of 1.3:1 to 4:1, in particular 1.5:1 to 3:1 and particularly preferably 1.7:1 to 2.5:1. Advantageously, the residual free NCO content of the polyurethane prepolymer PU is 1.0 to 2.5% by weight.

[0073] Particularly suitable polyether polyols (also known as polyoxyalkylene polyols or oligoether alcohols) are the polymerization products of ethylene oxide, 1,2-propylene oxide, 1,2- or 2,3-butylene oxide, oxetanes, tetrahydrofuran or mixtures thereof, optionally with the aid of starter molecules having two or more active hydrogen atoms, for example water, ammonia or compounds having a plurality of OH- or NH-groups, for example 1,2-ethylene oxide, 1,2- or 2,3-butylene oxide, oxetanes, tetrahydrofuran or mixtures thereof. diols, 1,2- and 1,3-propylene glycol, neopentyl glycol, diethylene glycol, triethylene glycol, isomeric dipropylene glycol and tripropylene glycol, isomeric butanediols, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, undecanediol, 1,3- and 1,4-cyclohexanedimethanol, bisphenol A, hydrogenated bisphenol A, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, glycerol, aniline, and mixtures thereof. It is possible to use polyoxyalkylene polyols having a low degree of unsaturation (measured in accordance with ASTM D-2849-69 and expressed in milliequivalents of unsaturation per gram of polyol (mEq / g)), prepared, for example, with the aid of so-called double metal cyanide complex catalysts (DMC catalysts), but also polyoxyalkylene polyols having a higher degree of unsaturation, prepared, for example, with the aid of anionic catalysts such as NaOH, KOH, CsOH or alkali metal alcoholates.

[0074] Likewise suitable are ethylene oxide-terminated ("EO-endcapped") polyoxypropylene polyols. The latter are in particular polyoxypropylene polyoxyethylene polyols, which are obtained, for example, by further alkoxylating pure polyoxypropylene polyols, in particular polyoxypropylene diols and triols, with ethylene oxide after the polypropoxylation reaction has ended, and thus providing them with primary hydroxyl groups. Preferred in this case are polyoxypropylene polyoxyethylene diols and polyoxypropylene polyoxyethylene triols. Suitable polyether diols are preferably selected from polyoxyethylene diols, polyoxypropylene diols and polyoxypropylene polyoxyethylene diols, more preferably EO-endcapped polyether diols and / or PO-endcapped polyether diols.

[0075] Suitable polyether triols are preferably selected from polyoxyethylene triols, polyoxypropylene triols and polyoxypropylene polyoxyethylene triols, more preferably EO-terminated polyether triols and / or PO-terminated polyether triols.

[0076] The polyol may have an average molecular weight of 250 to 30,000 g / mol, in particular 1,000 to 20,000 g / mol. The number average molecular weight Mn of the polyether diol is preferably in the range of 2,000 to 5,000 g / mol. The number average molecular weight Mn of the polyether triol is preferably in the range of 3,000 to 6,000 g / mol.

[0077] The polyols can have an average OH functionality in the range from 1.6 to 3.

[0078] In the preparation of the polyurethane prepolymers PU having terminal isocyanate groups, in addition to these polyols, small amounts of low molecular weight diols or polyols such as 1,2-ethanediol, 1,2- and 1,3-propylene glycol, neopentyl glycol, diethylene glycol, triethylene glycol, isomeric dipropylene glycols and tripropylene glycols, isomeric butanediols, pentanediols, hexanediols, heptanediols, octanediol, nonanediol, decanediol, undecanediol, 1,3- and 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, dimerized fatty alcohols, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, glycerol, pentaerythritol, sugar alcohols such as xylitol, sorbitol or mannitol, sugars such as sucrose, other higher alcohols, low molecular weight alkoxylation products of the diols and polyols, and mixtures of the above alcohols can be used concomitantly.

[0079] In the preparation of the polyurethane prepolymer PU according to the present invention, at least one aromatic polyisocyanate must be used, preferably at least two aromatic polyisocyanates. For example, a mixture of prepolymers or reaction products obtained by reacting two or more different aromatic polyisocyanates with corresponding polyether polyols can be used, or a reaction product obtained by reacting two or more different aromatic polyisocyanates with corresponding polyether polyols at the same time can be used. Compared with aromatic polyisocyanates, aliphatic polyisocyanates or their prepolymers usually react too slowly, cannot form crosslinks in time, and are prone to cracking during the later aging process. In addition, aliphatic polyisocyanates or their prepolymers may also cause the TVOC content of the product to increase. In addition, from the perspective of product weather resistance, using two or more aromatic polyisocyanates in the polyurethane prepolymer PU of the present invention may bring products with better weather resistance than using a single aromatic polyisocyanate.

[0080] Suitable aromatic polyisocyanates are preferably diisocyanates, preferably selected from the group consisting of meta- and para-xylylene diisocyanate (meta- and para-XDI), meta- and para-tetramethyl-1,3-xylylene diisocyanate, meta- and para-tetramethyl-1,4-xylylene diisocyanate, bis-(1-isocyanato-1-methylethyl)-naphthalene, 2,4- and 2,6-toluene diisocyanate (TDI), 4,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanate (MDDI). I), 1,3- and 1,4-phenylene diisocyanate, 2,3,5,6-tetramethyl-1,4-diisocyanatobenzene, naphthalene-1,5-diisocyanate (NDI), 3,3'-dimethyl-4,4'-diisocyanatobiphenyl (TODI) and mixtures and oligomers thereof; particularly preferably, the aromatic polyisocyanate is selected from 4,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanate (MDI) and 2,4- and 2,6-toluene diisocyanate (TDI) and combinations thereof.

[0081] In principle, the polyurethane prepolymer PU of the present invention can be obtained by any form of reaction product. For example, the polyurethane prepolymer PU can be a reaction product obtained by reacting at least one polyether triol, at least one polyether diol and two aromatic polyisocyanates such as MDI and TDI. It can also be obtained by first reacting at least one polyether triol and / or diol with one of the two aromatic polyisocyanates separately and then mixing the resulting reaction products.

[0082] In a particularly preferred embodiment, the polyurethane prepolymer PU is a mixture of a reaction product of at least one polyether triol and MDI as described above and a reaction product of at least one polyether triol and at least one polyether diol and TDI.

[0083] In the polyurethane composition of the present invention, the polyurethane prepolymer PU may be present in an amount of 15-50 wt %, preferably 20-40 wt %, based on the total weight of the composition. Such a polyurethane prepolymer content is conducive to achieving good storage stability and good weather resistance of the product in the later stage.

[0084] Antifungal agent

[0085] The antifungal agent that can be used in the present invention can be any suitable organic antifungal agent commonly used in polymer materials and compositions, especially an antifungal agent, but the organic antifungal agent must not contain active H to avoid reaction with the polyurethane system.

[0086] Organic mildew inhibitors can be mainly divided into phenolic compounds, elemental organic compounds (nitrogen-containing organic matter, halogen-containing organic matter, sulfur-containing organic matter), etc., especially one or a mixture of two or more selected from isothiazolinone compounds, pyridinethione compounds, hydroxypyridone compounds, triazole compounds, pyrazole compounds, thiophene compounds and aziridine compounds, more preferably isothiazolinone compounds and combinations thereof with the above-mentioned other organic mildew inhibitors, more preferably isothiazolinone compounds and mixtures thereof with one or more selected from pyridinethione compounds and hydroxypyridone compounds. Particularly preferred isothiazolinone compounds are benzisothiazolinone compounds.

[0087] The pyrithione compound is preferably selected from zinc pyrithione (ZPT), copper pyrithione and bispyrithione.

[0088] The isothiazolinone compound is preferably selected from 2-methyl-1-isothiazolin-3-one (MIT), 5-chloro-2-methyl-1-isothiazolin-3-one (CMIT), 2-n-octyl-4-isothiazolin-3-one (OIT), 4,5-dichloro-2-n-octyl-3-isothiazolin-3-one (DCOIT), 1,2-benzisothiazolin-3-one (BIT), 4-methyl-1,2-benzisothiazolin-3-one (MBIT) and N-n-butyl-1,2-benzisothiazolin-3-one (BBIT).

[0089] The hydroxypyridone compound is preferably piroctone ethanolamine (PO / OCT).

[0090] Particularly preferred is a benzisothiazolinone compound and a mixture thereof with one or more compounds selected from pyridinethione compounds and hydroxypyridone compounds, in particular N-n-butyl-1,2-benzisothiazolin-3-one (BBIT), or a combination of N-n-butyl-1,2-benzisothiazolin-3-one and zinc pyridinethione or piroctone olamine (PO / OCT). Preferably, the ratio of the benzisothiazolinone compound to the pyridinethione compound or the hydroxypyridone compound is 10:1 to 2:1.

[0091]

[0092] BBIT has the advantages of high efficacy and low dosage. It also contains no arsenic, no tin, no volatile organic compounds (VOCs), no special smell, and no bioaccumulation, so it will not cause continuous pollution to the environment or cause irritation to the skin.

[0093] In order to achieve good dispersibility of the organic mildew preventer in the polyurethane composition, a plasticizer can be used as a carrier of the mildew preventer. The mildew preventer can be mixed with a portion of the plasticizer in advance, for example, dissolved in the plasticizer, to form a premix loaded in the plasticizer, and then mixed with other components of the polyurethane composition. However, some organic mildew preventers themselves can also be well dispersed in the polyurethane system of the present invention, so they can be directly added to the system without the help of a plasticizer as a carrier. In this case, the plasticizer added to the composition can act as a dispersant for the mildew preventer. For example, BBIT can be used as a carrier with the help of a plasticizer; it can also be directly added to the composition and then dispersed with the help of a plasticizer. The mildew preventer can be added to the polyurethane composition of the present invention according to the usual amount or the recommended dosage of the supplier. However, it is preferred that the mildew preventer is added to the polyurethane composition in an amount of 0.1-1% by weight, preferably 0.1-0.9% by weight, and more preferably 0.2-0.6% by weight.

[0094] Plasticizers

[0095] The polyurethane composition of the present invention is added with at least one plasticizer, which can replace the organic solvent, so that the entire composition does not contain an organic solvent.

[0096] Suitable plasticizers are esters selected in particular from organic carboxylic acids, in particular phthalic acid esters, for example dioctyl phthalate, dinonyl phthalate, for example diisononyl phthalate (DINP), diisodecyl phthalate (DIDP) or di(2-propylheptyl) phthalate (DPHP); hydrogenated phthalates, for example diisononyl phthalate or diisononyl cyclohexane-1,2-dicarboxylate (DINCH); terephthalic acid esters, in particular di(2-propylheptyl) phthalate. esters of organic phosphoric and sulfonic acids; hydrocarbons, such as polybutene or polyisobutene; and plasticizers derived from natural fats or oils, especially epoxidized soybean oil or linseed oil.

[0097] Preferred plasticizers are selected from phthalates, hydrogenated phthalates and adipates. Most preferred are diisononyl phthalate, diisodecyl phthalate, dioctyl adipate (DOA) and / or diisononyl cyclohexane-1,2-dicarboxylate.

[0098] The plasticizer may be added in an amount ranging from 10 to 30% by weight, preferably from 15 to 25% by weight, based on the weight of the entire composition.

[0099] The mildew preventer can be loaded into a plasticizer and added to the polyurethane system in this loaded form, or the plasticizer in the system can be used as a dispersant, thereby achieving convenient addition and good dispersion of the mildew preventer and good compatibility with the polyurethane system, thereby the mildew preventer is well dispersed and distributed in the system, thereby helping to achieve a good mildew preventer effect.

[0100] filler

[0101] The polyurethane composition of the present invention further comprises at least one inorganic filler. The inorganic filler preferably comprises or is selected from calcium carbonate. The content of the inorganic filler can be 25% to 40% by weight, preferably 30% to 35% by weight, based on the total weight of the composition.

[0102] Calcium carbonate can be ground calcium carbonate (i.e. heavy calcium carbonate) or precipitated calcium carbonate (i.e. light calcium carbonate), which can be surface treated by coating with fatty acid (especially stearic acid) or its salt or ester. It is preferred to use ground calcium carbonate (i.e. heavy calcium carbonate) without surface treatment.

[0103] The combination of inorganic fillers with plasticizers and mildew inhibitors ensures good mildew resistance while maintaining good application properties and mechanical properties.

[0104] The polyurethane composition of the present invention may also contain one or more other inorganic fillers or organic fillers selected from the following: barite (BaSO4), silicon dioxide (e.g., quartz powder, quartz sand, high-dispersed silicon dioxide obtained from pyrogenic process), dolomite, wollastonite, titanium dioxide, clay, layered silicate (e.g., talc, mica powder), zeolite, aluminum oxide, aluminum hydroxide, magnesium hydroxide, zinc oxide, glass spheres, kaolin (e.g., calcined kaolin), microsilica, cement, gypsum, fly ash, polyamide, PVC powder or paste or hollow spheres, one or a mixture of two or more thereof. Nanofillers such as graphene or carbon nanotubes may also be used.

[0105] The total amount of fillers used may be 15% to 70% by weight, preferably 20% to 50% by weight, based on the total weight of the composition.

[0106] Other additives

[0107] The composition of the present invention may further contain other additives commonly used in polyurethane compositions, especially sealants or adhesives.

[0108] For example, the polyurethane composition may contain at least one additive selected from the following: tackifiers, catalysts, curing agents, rheology modifiers, desiccants, light stabilizers (especially UV-resistant light stabilizers), antioxidants, pigments, dyes, flame retardants, surfactants, other biocides, fibers and latent curing agents, as well as other common admixtures or process aids.

[0109] Suitable adhesion promoters, in particular silane adhesion promoters, are organoalkoxysilanes with a reactive group on the organic radical, in particular epoxysilanes, mercaptosilanes, vinylsilanes, (meth)acryloylsilanes, isocyanatosilanes, anhydridesilanes, carbamatesilanes, S-(alkylcarbonyl)-mercaptosilanes, iminosilanes, aldiminesilanes or oligomeric forms of these silanes, or adducts of aminosilanes or mercaptosilanes with polyisocyanates; or titanates. Preferred are 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane or 3-methacryloyloxypropyltrimethoxysilane. Most preferred is 3-glycidyloxypropyltrimethoxysilane. One or more adhesion promoters may be used.

[0110] The amount of the tackifier used may be in the range of 0.1-2 wt%, preferably 0.1-1 wt%, based on the total weight of the composition.

[0111] The composition of the present invention may also include at least one catalyst, preferably an amine catalyst. Suitable amine catalysts are tertiary amines, particularly those with low pKa values, preferably pKa values ​​between 12 and 7. Suitable amine catalysts are, for example, N-ethyl-diisopropylamine, N,N,N',N'-tetramethyl-alkylenediamine, 1,4-diazabicyclo[2.2.2]octane, and preferably 2,2'-dimorpholinodiethyl ether (DMDEE) and derivatives thereof having substituents on the morpholine ring. Particularly preferred is DMDEE.

[0112] The amount of amine catalyst added may range from 0 wt % to 1.0 wt %.

[0113] The composition may also preferably contain at least one metal catalyst. The metal catalyst may be added additionally or may already be present in the raw materials of the composition, for example from the synthesis of a polyurethane prepolymer having isocyanate groups. Preferred metal catalysts are organic tin (IV) compounds, organic titanates or organic zirconates. Complexes of tin (IV), bismuth (III) or zirconium (IV) may be used, in particular those having ligands selected from alcoholates, carboxylates, 1,3-diketonates, oxinatates, 1,3-ketoesters and 1,3-ketoamidates, or compounds containing tertiary amino groups, in particular 2,2'-dimorpholinyl diethyl ether (DMDEE).

[0114] Particularly preferred are organotin(IV) compounds. Suitable organotin(IV) compounds are in particular dialkyltin oxides, dialkyltin dichlorides, dialkyltin dicarboxylates and dialkyltin diacetylacetonates, for example dibutyltin oxide, dibutyltin dichloride, dibutyltin diacetate, dibutyltin dilaurate, dimethyltin dilaurate, dibutyltin diacetylacetonate, dioctyltin oxide, dioctyltin dichloride, dioctyltin diacetate, dioctyltin dilaurate or dioctyltin diacetylacetonate.

[0115] The metal catalyst may be included in an amount ranging from 0.001 wt % to 1.0 wt %, for example from 0.005 wt % to 0.1 wt %, based on the total weight of the composition.

[0116] The content of the organotin(IV) compound which may be used in the composition is preferably in the range of 0.001% to 0.2% by weight, in particular 0.005% to 0.1% by weight, based on the weight of the entire composition.

[0117] The total amount of the catalyst added may be controlled within the range of 0.001-0.5 wt %, preferably 0.001-0.3 wt %, based on the total weight of the composition.

[0118] One or more light stabilizers, preferably hindered amine light stabilizers, may be added to the composition of the present invention, including light stabilizers that resist ultraviolet rays, such as UV absorbers (which absorb light energy such as from sunlight and fluorescent lamps and convert them into harmless heat energy), and quenchers that extinguish active centers triggered by light energy. Most of these hindered amine light stabilizers are commercially available, including, for example, ADEKASTAB LA-52, LA-57, LA-62, LA-67, LA-63, LA-68, LA-77, LA-82 and LA-87 (produced by ASAHIDENKA KOGYO). KK production); di(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, di(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, 1-methyl-8-(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, 1-[2-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionyloxy]ethyl]-4-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy]-2,2,6,6-tetramethylpiperidinylsuccinate, dimethyl-1-(2-hydroxy

[0063] In some embodiments, the present invention relates to a condensate of bis(1,2,2,6,6-tetramethylbutyl)imino-1,3,5-triazine-2,4-diyl][2,2,6,6-tetramethyl-4-piperidinyl]imino]hexamethylene[(2,2,6,6-tetramethyl-4-piperidinyl)imino]], di(1,2,2,6,6-pentamethyl-4-piperidinyl)2-(3,5-di-tert-butyl-4-hydroxybenzyl)-2-n-butyl malonate, or a mixture thereof. Preferred is, for example, commercially available Tinuvin 292, which is a mixture of di(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate and 1-methyl-8-(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate. The composition may include a combination of an anti-ultraviolet light stabilizer and a photocurable material, in particular, a combination of a photocurable material selected from unsaturated acrylic compounds (preferably polyester acrylate) and a hindered amine light stabilizer.

[0119] Light stabilizers, especially anti-ultraviolet light stabilizers, may be used in an amount ranging from 0.1 to 0.5 wt %, based on the total weight of the composition.

[0120] The inventors have found that the use of one or more photocurable materials selected from unsaturated acrylic compounds together with a hindered amine light stabilizer in the composition according to the present invention is particularly advantageous for improving weather resistance.

[0121] Photocurable materials can easily undergo chemical changes in their molecular structure in a very short time when exposed to light, accompanied by physical changes such as curing. Unsaturated acrylic compounds are particularly suitable here, including acrylic and / or methacrylic monomers, oligomers thereof and mixtures thereof having one or more unsaturated groups, and polyester acrylate compounds are particularly preferred.

[0122] The photocurable material may be included in an amount of 0-2% by weight, preferably 0.1-2% by weight, based on the total weight of the composition.

[0123] The composition may also contain one or more rheology modifiers, such as thickeners or thixotropic agents, for example modified polyureas, polyamide waxes, polyethylene waxes, fibrous talc, castor oil derivatives, bentonites or fumed silica, for example HAT-paste available from SIKA, as thixotropic agents ("thixotropy-imparting agents") as described on pages 9 to 11 of WO 02 / 48228 A2.

[0124] Rheology modifiers, especially thixotropic agents, may be used in amounts of 2 to 15% by weight, based on the total weight of the composition.

[0125] The composition of the present invention may also contain conventional curing agents or crosslinking agents. The crosslinking agent may be, for example, an oligomer or derivative of a diisocyanate, such as MDI, TDI, HDI or IPDI, in particular isocyanurate, carbodiimide, uretonimide, biuret, allophanate and imino Diazinediones, or mixtures of MDI and MDI homologues (polymeric MDI or PMDI).

[0126] To reduce bubble formation, blocked amines, so-called "latent curing agents", can be added to the polyurethane composition, e.g. Oxazolidine, ketimine or aldimine.

[0127] The curing agent or crosslinking agent (including latent curing agent) may be used in an amount of 0 to 5 wt %, based on the total weight of the composition.

[0128] The composition of the present invention may also contain conventional antioxidants, such as antioxidants 1010, 1330 and 1076. The antioxidant may be used in an amount of 0-0.5 wt %, based on the total weight of the composition.

[0129] The composition may also contain a drying agent or dehydrating agent, for example p-toluene isocyanate such as p-toluenesulfonyl isocyanate and other reactive isocyanates, calcium oxide or molecular sieves. The drying agent or dehydrating agent may be present in an amount of 0.1-2 wt %, based on the total weight of the composition.

[0130] In addition to the above, the composition of the present invention may also contain other components common to polyurethane adhesives and sealants, such as the following components:

[0131] - flame retardant substances;

[0132] - surface-active substances, such as wetting agents, leveling agents, deaerators or defoamers;

[0133] - other biocides, such as algaecides;

[0134] - other substances commonly used in isocyanate-containing polyurethane prepolymer systems, for example fibers, for example polyethylene fibers;

[0135] - dyes, pigments or other admixtures known to those skilled in the art.

[0136] Advantageously, the composition is substantially free of organic solvents, i.e., the content of organic solvents is less than 1 wt%, preferably less than 0.5 wt%, more preferably less than 0.1 wt%, and most preferably free of organic solvents, based on the total weight of the composition. The organic solvents are organic solvents commonly used in polyurethane compositions, in particular ketones, aromatic hydrocarbons, dimethylformamide, tetrahydrofuran, and the like.

[0137] Preparation method

[0138] The compositions of the present invention can be prepared simply by directly mixing all components of the composition.

[0139] Alternatively, the mildewproofing agent may be first mixed with a portion of the plasticizer to prepare a premix containing the mildewproofing agent loaded in the plasticizer, and then the premix containing the mildewproofing agent may be mixed with the polyurethane prepolymer, the remaining plasticizer, at least one inorganic filler and possible other components.

[0140] For example, the mildew inhibitor and the plasticizer may be uniformly mixed in a ratio of 1:9 to 1:4. In particular, in order to improve compatibility and dispersibility, a portion (1 wt%-10 wt%) of the plasticizer in the premix may be replaced with fumed silica to prepare a paste premix, and the premix prepared in this way is stable in storage and is not easy to stratify or settle.

[0141] In one embodiment, the premix of the mildewproofing agent loaded in the plasticizer can be first mixed with the polyurethane prepolymer and other additives except the filler and the catalyst, and then the filler is added and stirred evenly under vacuum, and then the vacuum is released with dry nitrogen, and the catalyst is further added and vacuumed and stirred evenly, and then the material is discharged.

[0142] The obtained polyurethane composition is preferably filled in a sealed container.

[0143] For moisture-curing polyurethane compositions, they can be produced under dehumidification and stored at ambient temperature in moisture-proof containers. Suitable moisture-proof containers are made especially of optionally coated metal and / or plastic and are especially barrels, transport boxes, sealed hobbocks, pails, square drums, cans, bags, tubular bags, boxes or tubes.

[0144] The moisture-curing polyurethane composition can be in the form of a one-component composition or in the form of a multicomponent, in particular a two-component composition.

[0145] A composition which is referred to as a "one-component" is one in which all of the ingredients are present in the same container and which is inherently storage-stable.

[0146] Compositions referred to as "two-component" are compositions whose ingredients are present in two different components which are stored in separate containers and are not mixed with one another until shortly before or during application of the composition.

[0147] The moisture-curing polyurethane composition according to the invention is preferably a one-component composition.

[0148] The moisture-curing polyurethane composition can be formulated so that it has a pasty consistency with structural viscosity. Compositions of this type can be applied by means of suitable devices, for example from commercially customary boxes or drums or sealed sheet metal containers, for example in the form of strips, which can have a substantially circular or triangular cross section.

[0149] The moisture-curable polyurethane composition may also be formulated so that it is fluid and so-called "self-leveling" or only slightly thixotropic and can be poured for application.

[0150] Sealing or bonding method

[0151] Another aspect of the present invention relates to a method for bonding or sealing substrates, comprising the steps of:

[0152] a) applying the composition according to the invention as described above to a first substrate;

[0153] b) providing a second substrate, to which is optionally applied a composition according to the invention as described above;

[0154] c) contacting the first and second substrates with each other;

[0155] The first substrate and the second substrate are made of the same or different materials. Preferably, the first substrate and the second substrate are made of the same or different materials selected from glass, ceramics, concrete, mortar, metal profiles, wood or plastic. More preferably, the substrate is a part of a building (e.g., a house) or a component thereof.

[0156] The composition can be applied to the substrate by means of a glue gun or pump system, or by extrusion through a suitable glue nozzle.

[0157] The composition according to the invention preferably has a paste consistency with structural viscous properties to facilitate application and build-up of initial strength and adhesion.

[0158] When the moisture-curing polyurethane composition is applied, the curing process begins. A cured composition is thus produced. The moisture required for curing can originate from the air (air moisture), wherein the composition is cured by diffusion of moisture from the outside to the inside. However, it is also possible to add an aqueous component to the composition, for example in the form of an aqueous paste, which is mixed with the composition in a uniform or non-uniform manner, for example, by a static mixer. Moisture can also enter the composition additionally or completely from one or more substrates (to which the composition has been applied), and / or can come from an accelerator component that is mixed into the composition during application or that is contacted with it after application (for example by coating or spraying).

[0159] For a one-component moisture-curing composition, it is applied as it is, and after application, under the action of moisture, optionally accelerated by heating, the composition according to the invention cures rapidly, and the polyurethane prepolymer PU and the optionally contained curing agent and / or latent curing agent cure rapidly at the same time. In order to accelerate the curing, an accelerator component containing or releasing water and / or a catalyst and / or a curing agent can be mixed into the composition during application, or the composition can be contacted with such an accelerator component after its application.

[0160] During the curing process, the isocyanate groups react with one another under the influence of moisture. If the moisture-curing polyurethane composition contains blocked amines, the isocyanate groups additionally react with hydrolyzable blocked amino groups. These reactions of the isocyanate groups that lead to the curing of the composition are also collectively referred to as crosslinking.

[0161] The moisture-curing polyurethane composition is preferably applied at ambient temperature, in particular in the range of approximately -10 to 50°C, preferably in the range of -5 to 45°C, in particular in the range of 0 to 40°C.

[0162] The moisture-curing polyurethane composition is preferably likewise cured at ambient temperature.

[0163] The moisture-curable polyurethane composition has a long processing time (open time) and a fast cure (short tack-free time).

[0164] The open time is understood to mean the period of time during which the composition can be processed or reprocessed after application without any loss of its functional capacity. If the composition is used as an adhesive, the open time is also understood to mean the period of time during which bonding must take place after its application in order to establish sufficient adhesion.

[0165] Tack-free time refers to the time it takes for a sealant or adhesive to become sticky when touched with a finger, the back end of a dropper, or the tip of a pencil during the curing process when exposed to the atmosphere, and is specifically measured as described in the Examples.

[0166] The composition according to the invention has a long durability, i.e. is storage stable over a long period of time. "Storage stable" or "storable" means that the composition can be stored in a suitable container at room temperature for a long time, generally at least 3 months to 6 months and longer, without its application properties or use properties (especially viscosity, extrusion force required for application from the container and crosslinking speed) changing due to storage to an extent relevant to its use.

[0167] Thus, the present invention also relates to a cured anti-mold adhesive or sealant obtained from a composition as described above after curing with water, especially in the form of air moisture.

[0168] By applying and curing the moisture-curing polyurethane composition, or by a bonding or sealing process, an article bonded or sealed with the composition is obtained. Such an article may be a building structure or a part thereof, in particular a building structure in an above-ground or underground project, a bridge, a roof, a staircase or a facade, or it may be an industrial or consumer product, in particular a window, a pipe, a rotor blade for a wind turbine, a household appliance or a means of transport, in particular, for example, a car, a bus, a truck, a rail vehicle, a ship, an airplane or a helicopter or a mounting part thereof.

[0169] The invention therefore further provides an article obtained by the bonding or sealing process.

[0170] use

[0171] The present invention also provides the use of the above composition as an adhesive or sealant, in particular a moisture-curing adhesive or sealant.

[0172] The composition according to the invention is particularly suitable for application on concrete, mortar, bricks, tiles, plaster, natural stone such as granite or marble, glass, glass ceramics, screen-printed ceramics, metals or metal alloys, wood, plastics and painted materials, thereby achieving bonding or sealing of these substrates and effectively preventing mold.

[0173] The composition according to the present invention is particularly suitable for use as an adhesive or sealant in the construction field, and can be particularly used in the decoration or repair of buildings or houses, especially in parts or structures or rooms that are often in contact with water, such as sinks in kitchens and bathrooms and swimming pools.

[0174] For example, the polyurethane composition can be suitable for bonding and / or sealing building structures or parts thereof, in particular for balconies, terraces, roofs, in particular flat roofs or slightly sloping roof surfaces or roof gardens, or in building interiors under tiles or ceramic slabs in bathrooms or kitchens, or in collecting tanks, channels, shafts, silos, sinks or wastewater treatment systems. It can also be used for repair purposes as a sealant or adhesive for, for example, leaking roof membranes or floor coverings that are no longer suitable, or as a repair compound for highly reactive spray sealants.

[0175] The mildew-proof polyurethane composition of the present invention can also be used for mildew-proof bonding or sealing of product surfaces made or coated with PVC, silicone, polyolefin, polyurethane or acrylic resin, etc., such as shower curtains, ski clothes, raincoats, tents, wallpapers, floors, conveyor belts, soles, uppers, roofing waterproof membranes, sheathing materials for wires and conduits, automotive accessories (such as hoods, door seals, shock absorbers, steering wheels), foam materials (such as seat cushions, gaskets, insulating materials), household appliance gaskets, tarpaulins or awnings.

[0176] Effect

[0177] The polyurethane composition of the present invention has good mildew-proof effect, and even has a lasting mildew-proof effect.

[0178] In the anti-mildew test, the composition of the present invention maintains a grade of 0 or 1 in at least the first cycle (one cycle is 28 days), especially when N-n-butyl-1,2-benzisothiazolin-3-one (BBIT) and its combination with other mildew inhibitors are used, the composition can even maintain a grade of 0 in 4 cycles of testing.

[0179] The anti-mildew effect is measured according to the standard GBT 1741-2020.

[0180] In the present invention, by means of a plasticizer as a carrier added to a specific polyurethane system or by means of a plasticizer in the system as a dispersant, good compatibility of the organic mildew inhibitor with the polyurethane system and good dispersion and distribution in the polyurethane system can be achieved, so that after curing (especially wet curing), a bonding or sealing connection with excellent and even lasting mildew-proof effect can be obtained.

[0181] At the same time, due to the combined use of the specific polyether-based polyurethane prepolymer, plasticizer, and inorganic filler in the composition of the present invention, other properties of the obtained polyurethane composition, such as reactivity, mechanical properties, adhesion properties, and / or application properties, are not adversely affected.

[0182] After curing, the polyurethane composition preferably has a tensile strength of at least 1 MPa, in particular at least 1.5 MPa, measured in accordance with DIN EN ISO 527 at a tensile speed of 200 mm / min.

[0183] After curing, the polyurethane composition preferably also has an elongation at break determined in accordance with DIN EN ISO 527 at a tensile speed of 200 mm / min of at least 300%, in particular at least 350%.

[0184] The polyurethane composition additionally has good extrusion force, short open time (preferably less than 30 minutes) and good anti-sag rating.

[0185] Since organic solvents such as alcohol are not used as carriers of the mildew inhibitor, the influence on the polyurethane system is avoided and the product is also environmentally friendly.

[0186] The preparation method of the composition of the present invention is simple and environmentally friendly.

[0187] The method of bonding or sealing substrates using the mildew-proof polyurethane adhesive or sealant composition of the present invention is also simple to operate and environmentally friendly.

[0188] The mildew-proof polyurethane composition of the present invention can expand the application market of polyurethane sealants and adhesives, and at the same time provide consumers with more options in application scenarios requiring mildew resistance, making polyurethane sealants and adhesives more competitive. DETAILED DESCRIPTION

[0189] The present invention is further illustrated below in conjunction with examples, but the present invention is not limited to these examples.

[0190] 1) Ingredients list

[0191]

[0192]

[0193] Other chemicals not specified were obtained commercially.

[0194] Test Method

[0195] Mildew resistance test: Tested in accordance with standard GBT 1741-2020. The mildew resistance level was tested for one cycle (28 days) in accordance with this standard. In view of the good evaluation results within one cycle, the longer-term mildew resistance level was further evaluated, and the results of a total of 4 cycles (each cycle was 28 days) were evaluated.

[0196] According to this standard, the fungus resistance level is rated according to the table below.

[0197]

[0198] Note: After the incubation, take the test sample out of the constant temperature and humidity incubator and inspect it visually. When the moldy area is less than 10%, observe it with a microscope magnified 50 times, and evaluate the mold resistance grade according to the above table. The result is based on the consistency of the grade of at least two samples.

[0199] 2) Extrusion force: The composition is filled into an internally painted aluminum barrel (external diameter 46.9 mm, internal diameter 46.2 mm, length 215 mm, metric ISO thread M15×1.5 mm) and hermetically sealed with a polyethylene stopper (diameter 46.1 mm) from Novelis Deutschland GmbH. After a temperature treatment at 23° C. for 24 hours, the barrel is opened and extruded through an extrusion device. For this purpose, a nozzle with an internal diameter opening of 3 mm is screwed onto the barrel thread. The force required to extrude the composition at an extrusion speed of 60 mm / min is determined using an extrusion device (Zwick / Roell Z005). The values ​​given are the average values ​​of the forces measured after an extrusion distance of 22 mm, 24 mm, 26 mm and 28 mm. The measurement is stopped after an extrusion distance of 30 mm.

[0200] 3) Mechanical property values ​​such as tensile strength: The tensile strength and elongation at break were determined according to DIN EN ISO 527 (tensile speed: 200 mm / min) on films with a layer thickness of 2 mm cured for 7 days (d) at 23° C. (room temperature “RT”) and 50% relative air humidity.

[0201] 4) Surface Dry Time: At 23°C (room temperature "RT") and 50% relative air humidity, the surface characteristics of the material are checked by periodically touching the material with the back end of a dropper or the tip of a pencil. The time required for the material to be touched without leaving any material on the dropper / tip or forming strings when the dropper / tip is removed is recorded as the Surface Dry Time.

[0202] 5) Anti-sagging grade: Place a piece of cardboard in a completely upright position, use an 8mm x 10mm triangle nozzle to carefully and evenly apply the material into a specified triangle (15cm), and then judge its appearance according to the following conditions:

[0203] Rating describe 1-Excellent Tip not moving 2-Good The tip is between the center axis and the bottom axis 3- General Tip at bottom shaft 4-Poor Tip below bottom shaft 5-Bad No cutting edge

[0204] Preparation of polyurethane prepolymer PU-1

[0205] Place Desmodur 44C in a 70°C oven for 2 hours. Place a 1L glass reactor on an electric heating mantle. Add 300g of 330N and 88g of plasticizer DIDP under nitrogen protection, and heat to 50°C. Add 50g of Desmodur44C at a molar ratio of NCO to OH of 2.1:1. After stirring for 5 minutes, add 0.04g of Dabco33LV catalyst, continue to heat to 80°C, then start timing, measure the NCO content after 1 hour, and stop the reaction when the measured value is close to the set value of 2.4%. The resulting product can be used directly for subsequent use or stored under nitrogen protection without post-treatment.

[0206] Preparation of polyurethane prepolymer PU-2

[0207] Place a 1L glass reactor on an electric heating mantle. Add 39g of Desmodur T80, 325g of JH-240, and 130g of GY-4000 under nitrogen protection, and heat to 50°C. After stirring for 5 minutes, add 0.04g of Dabco33LV catalyst, continue to heat to 80°C, then start timing, and measure the NCO content after 1 hour. When the measured value is close to the set value of 1.5%, stop the reaction. The obtained product can be directly used for subsequent use or stored under nitrogen protection without post-treatment.

[0208] Preparation of sealant:

[0209] Into a 1 L planetary stirring reactor, at room temperature and under vacuum (gauge pressure less than -90 KPa), each polyurethane prepolymer was added in the amount and type shown in Table 1.

[0210] In another mixer, the mildewproofing agent listed in Table 1 is pre-mixed with a portion of the plasticizer at a ratio of mildewproofing agent to plasticizer of 1:9 to form a premix containing the mildewproofing agent.

[0211] Then, the premix containing the mildew inhibitor and other additives are directly added into the planetary stirring kettle containing the polyurethane prepolymer, stirred evenly, and then the vacuum is released with dry nitrogen and the material is discharged.

[0212] The obtained product is filled in a sealed container for later use.

[0213] However, the mildew-proofing agent ZPT used in Example 6 is a solid powder, which is not mixed with a plasticizer in advance to prepare a premix, but is directly added to a planetary stirring kettle containing a polyurethane prepolymer together with other additives.

[0214] The weight % composition of each composition is shown in Table 1 below.

[0215]

[0216] Performance Test Results

[0217] The prepared compositions were tested for various properties according to the test methods described above. The results are listed in Tables 2 and 3 below.

[0218] Table 2: Mildew resistance test results

[0219]

[0220] Note: x indicates that the experiment failed

[0221]

[0222] The results in Table 2 show that the polyurethane composition according to the present invention exhibits a good mildew resistance effect and even exhibits a durable mildew resistance.

[0223] In addition, it can be seen that the dosage of the mildew preventer below 0.6% is sufficient to make the system have a good or even lasting mildew preventive effect, thereby achieving a good mildew preventive effect at a relatively low cost.

[0224] In addition, BBIT or its combination with ZPT or PO showed the most excellent and durable anti-mildew effect in the one-component moisture-curing polyurethane system, and could maintain a grade 0 anti-mildew effect in the 4-cycle test.

[0225] It can be seen from Table 3 that the polyurethane composition according to the present invention has good anti-mildew effect, and still has good extrusion force, tensile strength and elongation at break, and also has a short surface drying time and good anti-sagging grade, that is, the reactivity, mechanical properties, adhesion properties and application performance of the polyurethane composition are not adversely affected.

[0226] From the comparison between Example 4 and Comparative Example 9, it can be seen that compared with the case where the polyurethane prepolymer is prepared using less polyether triol and more polyether diol, the polyurethane composition according to the present invention has a shorter surface drying time, higher tensile strength, and lower elongation at break. Therefore, for mildew prevention applications, it is more conducive to construction and daily use.

[0227] Although the present invention has been described in detail and illustrated by the embodiments above, other modifications and changes within the spirit and scope of the present invention will be apparent to those skilled in the art. In addition, it should be understood that the various aspects of the present invention, the various parts of the different specific embodiments, and the various features listed may be combined or interchanged in whole or in part. In addition, it will be understood by those skilled in the art that the foregoing description is by way of example only and is not intended to limit the present invention.

Claims

1. A mildew-proof polyurethane composition, especially a one-component moisture-curable mildew-proof polyurethane composition, comprising: - at least one polyether-based polyurethane prepolymer, wherein the polyether-based polyurethane prepolymer is a reaction product or a mixture of reaction products of at least one polyether polyol and at least one aromatic polyisocyanate, wherein the at least one polyether polyol comprises at least one polyether diol and at least one polyether triol and the weight ratio of the at least one polyether triol to the at least one polyether diol is in the range of 4:1 to 13:1, preferably in the range of 5:1 to 12:1; - at least one plasticizer; - at least one mildewcide selected from organic mildewcides that do not contain active H; and - at least one inorganic filler.

2. The composition according to claim 1, wherein The polyether diol is selected from polyoxyethylene diol, polyoxypropylene diol and polyoxypropylene polyoxyethylene diol, preferably EO-terminated polyether diol and / or PO-terminated polyether diol; and / or The number average molecular weight Mn of the polyether diol is in the range of 2000-5000 g / mol.

3. The composition according to claim 1 or 2, wherein The polyether triol is selected from polyoxyethylene triol, polyoxypropylene triol and polyoxypropylene polyoxyethylene triol, preferably EO-terminated polyether triol and / or PO-terminated polyether triol; and / or The number average molecular weight Mn of the polyether triol is in the range of 3000-6000 g / mol.

4. The composition according to any one of claims 1 to 3, wherein the polyether-based polyurethane prepolymer is a mixture of reaction products formed by the separate reactions of at least one polyether triol and / or at least one polyether diol with one of two aromatic polyisocyanates, preferably a mixture of the reaction product of at least one polyether triol with MDI and the reaction product of at least one polyether triol and at least one polyether diol with TDI.

5. The composition according to any one of claims 1 to 4, wherein the polyether-based polyurethane prepolymer has a free NCO group content of 1.0 to 2.5% by weight.

6. The composition according to any one of claims 1 to 5, wherein the composition comprises 15 to 50 wt%, preferably 20 to 40 wt%, of the at least one polyether-based polyurethane prepolymer, based on the total weight of the composition.

7. The composition according to any one of claims 1 to 6, wherein the organic mildew preventer is an organic antifungal agent, preferably selected from isothiazolinone compounds (such as 2-methyl-1-isothiazolin-3-one (MIT), 5-chloro-2-methyl-1-isothiazolin-3-one (CMIT), 2-n-octyl-4-isothiazolin-3-one (OIT), 4,5-dichloro-2-n-octyl-3-isothiazolin-3-one (DCOIT), 1,2-benzisothiazolin-3-one (BIT), 4-methyl-1,2-benzisothiazolin-3-one (MBIT), N-n-butyl-1,2-benzisothiazolin-3-one (BBIT)), pyridinethione compounds (such as zinc pyridinethione (ZPT), copper pyridinethione, bispyribacyl pyridone), hydroxypyridone compounds (such as piroctone ethanolamine), triazole compounds, pyrazoles. A mixture of one or more of a compound, a thiophene compound and an aziridine compound, more preferably a mixture of one or more of isothiazolinone compounds, pyridinethione compounds and hydroxypyridone compounds, more preferably an isothiazolinone compound and a mixture of one or more selected from pyridinethione compounds and hydroxypyridone compounds, more preferably a benzisothiazolinone compound and a mixture of one or more selected from pyridinethione compounds and hydroxypyridone compounds, especially preferably N-n-butyl-1,2-benzisothiazolin-3-one (BBIT) and a combination of pyridinethione zinc (ZPT) or piroctone ethanolamine; preferably, the composition comprises 0.1-1% by weight, preferably 0.1-0.9% by weight, more preferably 0.2-0.6% by weight of at least one mildew inhibitor, based on the total weight of the composition.

8. The composition according to any one of claims 1 to 7, wherein the plasticizer is selected from esters of organic carboxylic acids (preferably phthalates, such as dioctyl phthalate, dinonyl phthalate, diisodecyl phthalate (DIDP) or di(2-propylheptyl) phthalate (DPHP); hydrogenated phthalates, such as hydrogenated diisononyl phthalate or diisononyl cyclohexane-1,2-dicarboxylate (DINCH); terephthalates, especially bis(2-ethylhexyl) terephthalate or diisononyl terephthalate; hydrogenated terephthalates, especially hydrogenated bis(2-isopropylhexyl) terephthalate). -ethylhexyl) ester or diisononyl terephthalate; or bis(2-ethylhexyl) cyclohexane-1,4-dicarboxylate; trimellitates; adipates, such as dioctyl adipate (DOA); azelaic acid ester; and sebacate); esters of organic phosphoric and sulfonic acids; hydrocarbons (such as polybutene or polyisobutylene); and plasticizers derived from natural fats or oils (especially epoxidized soybean oil or linseed oil); more preferably selected from phthalates, hydrogenated phthalates and adipates; preferably, the composition comprises 10-30% by weight, preferably 15-25% by weight, of at least one plasticizer, based on the total weight of the composition.

9. The composition according to any one of claims 1 to 8, wherein the inorganic filler comprises or is selected from calcium carbonate, such as ground calcium carbonate or precipitated calcium carbonate, which is optionally coated with a fatty acid, especially stearic acid, or a salt or ester thereof, preferably ground calcium carbonate that has not been surface treated; preferably, the composition comprises 25 to 40% by weight, preferably 30 to 35% by weight, of at least one inorganic filler, based on the total weight of the composition.

10. The composition according to any one of claims 1 to 9, wherein the aromatic polyisocyanate is a diisocyanate, preferably selected from meta- and para-xylylene diisocyanate, meta- and para-tetramethyl-1,3-xylylene diisocyanate, meta- and para-tetramethyl-1,4-xylylene diisocyanate, bis-(1-isocyanato-1-methylethyl)-naphthalene, 2,4- and 2,6-toluene diisocyanate (TDI), 4,4'-, 2,4'- and 2,2'-toluene diisocyanate. - diphenylmethane diisocyanate (MDI), 1,3- and 1,4-phenylene diisocyanate, 2,3,5,6-tetramethyl-1,4-diisocyanatobenzene, naphthalene-1,5-diisocyanate, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl and mixtures and oligomers thereof; particularly preferably, the aromatic polyisocyanate is selected from 4,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanate, 2,4- and 2,6-toluene diisocyanate and mixtures and oligomers thereof.

11. The composition according to any one of claims 1 to 10, wherein the composition further comprises at least one other additive selected from the group consisting of other fillers, tackifiers, catalysts, curing agents, rheology modifiers, desiccants, light stabilizers (especially anti-ultraviolet light stabilizers, optionally in combination with photocurable materials; preferably a combination of hindered amine light stabilizers and photocurable materials selected from unsaturated acrylic compounds (preferably polyester acrylates)), antioxidants, pigments, dyes, flame retardants, surfactants, other biocides, fibers and latent curing agents.

12. The composition according to claim 11, wherein the composition comprises 0-5 wt% of a curing agent; 2-15 wt% of a thixotropic agent; 0.1-2 wt% of a tackifier; 0.1-0.5 wt % of an anti-ultraviolet light stabilizer, optionally in combination with 0-2 wt % of a photocurable material; 0-0.5 wt% antioxidant; 0.001-0.5 wt % of a catalyst; and 15-70% by weight of the total amount of fillers, Each is based on the total weight of the composition.

13. A method for preparing a mildew-proof polyurethane composition according to any one of claims 1 to 12, comprising: directly mixing all components of the composition; or First, the mildewproofing agent is mixed with a part of the plasticizer to prepare a premix containing the mildewproofing agent, and then the premix containing the mildewproofing agent is mixed with the polyurethane prepolymer, the remaining plasticizer, at least one inorganic filler and possible other components.

14. The method according to claim 13, wherein 1 wt% to 10 wt% of the plasticizer used to prepare the premix is ​​replaced with fumed silica, thereby preparing a paste-like premix.

15. A cured composition obtained by curing the mildew-proof polyurethane composition according to any one of claims 1 to 12.

16. A method of bonding or sealing substrates comprising the steps of: a) applying the mildew-proof polyurethane composition according to any one of claims 1 to 12 to a first substrate; b) providing a second substrate, to which the mildew-proof polyurethane composition according to any one of claims 1 to 12 is optionally applied; c) contacting the first and second substrates with each other; The first substrate and the second substrate are made of the same or different materials.

17. The method according to claim 16, wherein the first substrate and the second substrate are made of a material selected from the group consisting of glass, ceramics, concrete, mortar, metal profiles, wood and plastic, identically or differently.

18. Articles obtained by the process according to claim 16 or 17, such as building structures or parts thereof, in particular building structures in above-ground or underground works, bridges, roofs, stairs or facades, or industrial or consumer products, in particular windows, pipes, rotor blades for wind turbines, household appliances or vehicles, such as in particular cars, buses, trucks, rail vehicles, ships, aircraft or helicopters or mountings thereof.

19. Use of the mildew-proof polyurethane composition according to any one of claims 1 to 12 as an adhesive or sealant, for example, for bonding or sealing structures in the construction field, in particular for decoration or repair of houses, in particular for bonding or sealing locations or components in contact with water; or for bonding or sealing the surface of products made or coated with PVC, silicone, polyolefin, polyurethane or acrylic resin, such as shower curtains, ski clothes, raincoats, tents, wallpapers, floors, conveyor belts, soles, uppers, roofing waterproof membranes, sheathing materials for wires and conduits, automotive accessories, foam materials, household appliance gaskets, tarpaulins or awnings.

Images