CN111154057A - Coating composition - Google Patents

Abstract

The present invention relates to coating compositions, methods and applications for applying the compositions, and products coated with the coating compositions. The coating composition comprises: (a) a monoisocyanate reactive component, (b) a monoisocyanate component, comprising: (b1) at least one isocyanate prepolymer comprising at least one aliphatic isocyanate and The reaction product of the components of at least one polyether polyol having a weight average molecular weight of 400-6000, the polyether polyol having the structure: HO-R ¹ _n -R ² ; and (b2) and ( c) a catalyst; the molar ratio of the isocyanate group and the isocyanate-reactive group of the coating composition is 1.5:1-4:1.

Description

a coating composition

technical field

The present invention relates to a coating composition, a coating method and application of the coating composition, and products coated with the coating composition.

Background technique

Aspartate coatings are widely used because of their advantages of weather resistance, wear resistance, humidity and heat resistance, and salt spray resistance, as well as their ability to meet the requirements of high solids, low viscosity and environmental protection, especially for waterproofing, anticorrosion . However, the existing aspartate coatings generally have a short pot life, which is difficult to apply to construction methods such as roller coating and brush coating, which are widely used in the field of flooring, and can only be constructed by using special spraying equipment. , which increases the difficulty and cost of construction, and greatly affects the application of aspartate coatings in the fields of flooring and other fields.

At present, the main methods of extending the pot life of aspartate coatings are: 1) Add a large amount of reactive diluent or solvent to the coating to reduce the speed of the viscosity increase of the coating, thereby ensuring sufficient pot life, but many reactive diluents ( For example, vinylene carbonate) and solvents have certain toxicity, and the addition of a large amount of active diluents or solvents will cause additional environmental pollution, which does not meet the trend and requirements of environmental protection. 2) Select a low-activity isocyanate, such as an isocyanate prepolymer, to reduce the reactivity, thereby ensuring that the coating has a sufficient pot life, but generally the low-activity isocyanate prepolymer has a high viscosity, which increases the difficulty of construction, and the prepared The coating dries too slowly and has a lower hardness. Therefore, low-activity isocyanates are only suitable for applications in the field of polyurethane elastomers or waterproof coatings, but not for anti-corrosion coatings or floor coatings, such as US20040067315A. 3) Select low-activity amino compounds, such as aspartic acid esters synthesized based on 3,3'-dimethyl-4,4-diaminodicyclohexylmethane, although the pot life can be extended, it greatly prolongs the pot life. The drying time of the paint.

Therefore, it is desirable to develop a coating with a long pot life, and at the same time, the resulting coating has the advantages of fast drying and high hardness.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a coating composition, a coating method and application of the coating composition, and a product coated with the coating composition.

The coating composition according to the present invention comprises:

(a) an isocyanate-reactive component comprising:

(a1) at least one aspartate, and

(a2) optional monopolyether aspartate;

(b) an isocyanate component comprising:

(b1) at least one isocyanate prepolymer which is the reaction product of components comprising at least one aliphatic isocyanate and at least one polyether polyol having a weight average molecular weight of 400- 6000, the polyether polyol has the structure of formula I:

HO-R ¹ _n -R ²

I,

Wherein, R ¹ has one or more of the following structures:

R ² is one or more of the following: hydrogen and an isocyanate non-reactive organic group,

n is an integer from 6-100,

the amount of the -R ¹ _n - structure is at least 40% by weight based on the weight of the polyether polyol; and

(b2) at least one isocyanate oligomer containing not less than 2 isocyanate groups, the weight ratio of the isocyanate prepolymer (b1) and the isocyanate oligomer (b2) is greater than 1:4 and less than 4:1 ;

(c) a catalyst; and

(d) an optional additive;

The molar ratio of isocyanate groups to isocyanate-reactive groups of the coating composition is 1.5:1 to 4:1.

According to one aspect of the present invention, there is provided the use of the coating composition provided according to the present invention for protecting the surface of a substrate or a coating on the surface of a substrate.

According to yet another aspect of the present invention, a coating method is provided, comprising the steps of: applying the coating composition provided by the present invention to the surface of a substrate, followed by curing and drying.

According to yet another aspect of the present invention, there is provided a coated product comprising a substrate and applying the coating composition provided by the present invention to the substrate to cure and dry to form a coating.

The coating composition of the present invention has a long pot life, and the coating formed by the composition not only has the advantages of fast drying and high hardness, but also has a high bubble-free film thickness, which greatly reduces the risk of coating foaming.

Detailed ways

The present invention provides a coating composition, comprising:

(a) an isocyanate-reactive component comprising:

(a1) at least one aspartate, and

(a2) optional monopolyether aspartate;

(b) an isocyanate component comprising:

(b1) at least one isocyanate prepolymer which is the reaction product of components comprising at least one aliphatic isocyanate and at least one polyether polyol having a weight average molecular weight of 400- 6000, the polyether polyol has the structure of formula I:

HO-R ¹ _n -R ²

I,

Wherein, R ¹ has one or more of the following structures:

R ² is one or more of the following: hydrogen and an isocyanate non-reactive organic group,

n is an integer from 6-100,

the amount of the -R ¹ _n - structure is at least 40% by weight based on the weight of the polyether polyol; and

(b2) at least one isocyanate oligomer containing not less than 2 isocyanate groups,

The weight ratio of the isocyanate prepolymer (b1) and the isocyanate oligomer (b2) is greater than 1:4 and less than 4:1;

(c) a catalyst; and

(d) an optional additive;

The molar ratio of isocyanate groups to isocyanate-reactive groups of the coating composition is 1.5:1 to 4:1. The present invention also provides a coating method and application of the coating composition, and products coated with the coating composition.

coating composition

An organic group that does not react with an isocyanate group or an isocyanate-non-reactive organic group described herein refers to an organic group that does not contain Zerevitinov active hydrogen. The definition of Zerevitinov active hydrogen can be found in Rompp's Dictionary of Chemistry (Rompp's Encyclopedia of Chemistry), tenth edition, Georg Thieme Verlag Stuttgart, 1996. In general, groups containing Zerevitinov active hydrogens include, but are not limited to, hydroxy, amino, and thiol groups.

The coating compositions described herein are two-component coating compositions, and the term two-component refers to coating compositions comprising at least two components that must be stored in separate containers due to their mutual reactivity. When the two separate components are mixed and applied to a substrate, the mutually reactive compounds of the two components react to crosslink and form a cured coating.

As used herein, the term "curing, drying" refers to the process by which a liquid coating composition passes from a liquid state to a cured state.

The term "each independently" as used herein means that it may or may not be the same.

The molar ratio of isocyanate groups and isocyanate-reactive groups of the composition is preferably 1.5:1-3.5:1, more preferably 1.5:1-3:1, most preferably 1.5:1-2.5:1.

The isocyanate-reactive groups can be hydroxyl, mercapto, and amino groups, with secondary amino groups being most preferred.

The organic solvent content of the coating composition is preferably less than 60 g/L.

Isocyanate Reactive Component (a)

Polyaspartate (a1)

The term "polyamine" as used herein refers to compounds containing at least two free primary and/or secondary amino groups, and polyamines include polymers containing at least two pendant and/or terminal amino groups.

The polyaspartic acid esters are obtained by Michael addition reactions of systems comprising polyamines and esters.

The esters are preferably one or more of the following: maleate and fumarate.

The reaction to prepare the polyaspartic acid ester can be carried out in the absence of a solvent or in the presence of a suitable solvent.

The solvent is preferably one or more of the following: alcohols, ethers, acetates and ketones.

The alcohol is preferably one or more of the following: methanol, ethanol, butyl glycol and propanol.

The acetate is preferably n-butyl acetate.

The ketone is preferably methyl ethyl ketodioxane.

Said polyaspartate (a1) preferably comprises a polyaspartate according to formula XI:

in,

Z represents an aliphatic residue,

R ³ and R ⁴ are each independently an organic group that does not react with an isocyanate group at normal pressure and 100° C. or less,

m is an integer not less than 2.

Said ^R3 and ^R4 are each independently preferably an alkyl residue having 1-10 carbon atoms, most preferably one or more of the following: methyl, ethyl and butyl.

Said m is preferably an integer of 2-4, most preferably 2.

The aliphatic residue of the polyaspartate is preferably one or more of the following: linear alkyl residues, branched alkyl residues and cycloalkyl residues, most preferably cycloalkyl residues Residues.

The amount of the polyaspartate is preferably greater than 50% by weight, based on the amount of the isocyanate-reactive component (a) being 100% by weight.

The amount of the polyaspartate is most preferably 65 to 100% by weight, based on the amount of the isocyanate-reactive component (a) being 100% by weight.

The equivalent weight of the amino group of the polyaspartate is preferably 200-500.

The viscosity of the polyaspartate is preferably 50-4000 mPa.s (23°C).

When m of the polyaspartate ester is 2, it is obtained by the reaction of a polyamine comprising the formula and maleate and/or fumarate of the formula:

The polyamine is preferably one or more of the following: ethylenediamine, 1,2-diaminopropane, 1,4-diaminobutane, 1,3-diaminopentane, 1,6-diaminohexane Alkane, 2,5-diamino-2,5-dimethylhexane, 2,2,4-trimethyl-1,6-diaminohexane, 2,4,4-trimethyl-1, 6-Diaminohexane, 1,11-diaminoundecane, 1,12-diaminododecane, 1,3-cyclohexanediamine and 1,4-cyclohexanediamine, amino-3,3 , 5-trimethyl-5-aminomethylcyclohexane, 2,4-hexahydrotoluenediamine, 2,6-hexahydrotoluenediamine, 2,4'-diamino-dicyclohexylmethane, 4 , 4'-diamino-dicyclohexylmethane, 3,3'-dialkyl-4,4'-diaminodicyclohexylmethane, 2-methyl-1,5-pentanediamine, 1,3- Xylylenediamine and 1,4-xylenediamine, further preferably one or more of the following: 1,4-diaminobutane, 1,6-diaminohexane, 2,2,4- Trimethyl-1,6-diaminohexane, 2,4,4-trimethyl-1,6-diaminohexane, amino-3,3,5-trimethyl-5-aminomethyl ring Hexane, 4,4'-diamino-dicyclohexylmethane, 3,3'-dialkyl-4,4'-diaminodicyclohexylmethane and 2-methyl-1,5-pentanediamine, Further preferred is one or more of the following: 2-methyl-1,5-pentanediamine, amino-3,3,5-trimethyl-5-aminomethylcyclohexane, 2,4'-diamine Amino-dicyclohexylmethane and 4,4'-diamino-dicyclohexylmethane, most preferably one or more of the following: 2,4'-diamino-dicyclohexylmethane and 4,4'-diamino - Dicyclohexylmethane.

The maleate and/or fumarate is preferably one or more of the following: dimethyl maleate, diethyl maleate, dibutyl maleate, dimethyl fumarate, Diethyl fumarate and dibutyl fumarate.

The temperature of the reaction is preferably 0°C to 100°C.

The molar ratio of the maleate and/or fumarate to the polyamine is preferably 2:1.

The molar ratio of the olefinic double bond of the maleate and/or fumarate to the primary amino group of the polyamine is preferably 1:1.

The reaction components for preparing the polyaspartate may or may not contain a solvent, and most preferably contain a solvent.

The solvent is preferably one or more of the following: methanol, ethanol, propanol and dioxane.

The polyaspartate (a1) preferably comprises one or more of the following:

(i) polyaspartate esters having the structure of formula XII:

(ii) a polyaspartate having the structure of formula XIII, and

(iii) a polyaspartate having the structure of formula XIV,

wherein ^R3 and ^R4 are each independently one or more of the following: methyl, ethyl, and butyl.

^{The R3} and R4 are each independently most preferably ethyl.

The polyaspartate (a1) further preferably comprises a polyaspartate having the structure of formula XIII:

wherein ^R3 and ^R4 are each independently one or more of the following: methyl, ethyl, and butyl.

^{The R3} and R4 are each independently most preferably ethyl.

The polyaspartate is most preferably one or more of the following: isocyanate-reactive components, Desmophen NH1220, Desmophen NH1220, Desmophen NH1420, Desmophen NH1520 and Desmophen NH1521.

Polyether aspartate (a2)

The amount of the polyether aspartate is preferably less than 35% by weight, based on the amount of the isocyanate-reactive component being 100% by weight.

The amount of the polyether aspartate is most preferably less than 25% by weight, based on the amount of the isocyanate reactive component being 100% by weight.

The equivalent weight of the amino group of the polyether aspartate is preferably 200-2500, preferably 200-500.

The viscosity of the polyether aspartate is preferably 50-2000 mPa.s (23° C.).

The polyether aspartate (a2) preferably comprises a polyether aspartate according to formula XV:

where Q represents an aliphatic residue,

R ⁶ and R ⁷ are each independently an organic group that does not react with an isocyanate group at normal pressure and 100° C. or less,

R ⁵ represents a C ₁ -C ₆ alkyl residue,

m is an integer not less than 2,

f is an integer of 1-35, more preferably 1-8, most preferably 1-5.

Said R ⁶ and R ⁷ are each independently preferably an alkyl residue having 1-10 carbon atoms, most preferably one or more of the following: methyl, ethyl and butyl.

The aliphatic residue is preferably one or more of the following: straight-chain alkyl residues, branched-chain alkyl residues, and cycloalkyl residues.

The polyether aspartate is preferably obtained by the Michael addition reaction of a system comprising polyetheramine and dialkyl maleate.

The polyether aspartate is further preferably obtained by the reaction of a polyether polyamine comprising the formula and a maleate and/or fumarate of the formula:

R⁶OOC-CR¹¹＝CR¹²-COOR⁷，

R ⁶ OOC-CR ¹¹ =CR ¹² -COOR ⁷ ,

Wherein, k is an integer not less than 2, more preferably 2-35, still more preferably 2-8, most preferably 2.5-6.1, R ⁶ and R ⁷ are each independently at normal pressure, 100° C. or less and do not interact with isocyanate groups reacting organic groups,

R ⁹ and R ¹⁰ are each independently one or more of the following: a hydrogen atom and an alkyl residue having C ₁ -C ₄ , and R ¹¹ and R ¹² are each independently one or more of the following: hydrogen and isocyanate non-reactive organic groups.

Said R ⁶ and R ⁷ are each independently preferably an alkyl residue having 1-10 carbon atoms, most preferably one or more of the following: methyl, ethyl and butyl.

The R ⁹ and R ¹⁰ are each independently most preferably one or more of the following: a hydrogen atom and a methyl group.

Said R ¹¹ and R ¹² are each independently preferably hydrogen.

The number average molecular weight of the polyether polyamine is preferably 100g/mol-5000g/mol, more preferably 100g/mol-2000g/mol, most preferably 148g/mol-600g/mol.

The polyether polyamine is preferably an aliphatic polyether polyamine containing primary amino groups, such as Jeffamine polyether polyamines, available from Huntsman Corporation, The Woodlands, TX.

The maleate and/or fumarate preferably comprises one or more of the following groups: dimethyl, diethyl, dibutyl, dipentyl, di-2-ethyl Hexyl ester, substituted with methyl at the 2-position and substituted with methyl at the 3-position.

The dibutyl ester is preferably one or more of the following: di-n-butyl ester, di-sec-butyl ester and di-tert-butyl ester.

The maleate and/or fumarate is most preferably one or more of the following: dimethyl maleate, diethyl maleate, dibutyl maleate, dimethyl fumarate , diethyl fumarate and dibutyl fumarate.

The component for preparing the polyether aspartate (a2) preferably further comprises a polyether polyamine according to the formula:

wherein J is one or more of the following: straight-chain alkyl residues, branched-chain alkyl residues, and cycloalkyl residues,

g is an integer from 1-35,

R ⁸ is an alkyl residue with C ₁ -C ₆ .

The polyether aspartate (a2) preferably comprises a polyether aspartate according to formula XVI:

where h is an integer from 2 to 4,

g is an integer from 1-35,

s is 1 or 2,

J is an alkyl residue,

R ⁶ and R ⁷ are each independently an organic group that does not react with an isocyanate group at normal pressure and 100° C. or less,

R ⁸ is an alkyl residue with C ₁ -C ₆ .

The g is preferably an integer of 1-8, most preferably an integer of 1-5.

Said R ⁶ and R ⁷ are each independently preferably an alkyl residue having 1-10 carbon atoms, most preferably one or more of the following: methyl, ethyl and butyl.

Said J is preferably one or more of the following: straight-chain alkyl residues, branched alkyl residues and cycloalkyl residues, most preferably one or more of the following: ethyl, propyl, Butyl, hexyl, cyclohexyl, dicyclohexylmethyl, 3,3'-dimethyldicyclohexylmethyl, 2-methylpentyl, 1,1,1-tri(methyl)propyl and 2 , 2-bis(methyl)propyl.

Said R ⁸ is preferably one or more of the following: methyl, ethyl and butyl.

The polyether aspartate is most preferably Desmophen NH2850 XP, available from Covestro Germany, Leverkusen, Germany.

Isocyanate component (b)

The isocyanate groups of the compositions of the present invention include free and potentially free isocyanate groups.

Isocyanate Prepolymer (b1)

The isocyanate group functionality of the isocyanate prepolymer is preferably 1.9-4.5.

The isocyanate group content of the isocyanate prepolymer is preferably 1-40% by weight, more preferably 1-20% by weight, most preferably 3-10% by weight, based on the amount of the isocyanate prepolymer being 100% by weight.

The viscosity of the isocyanate prepolymer is preferably 1000-20000 mPa·s (23°C), most preferably 1000-8500 mPa·s (23°C).

The isocyanate group equivalent of the isocyanate prepolymer is preferably 400-1200.

The excess isocyanate monomer in the reaction for preparing the isocyanate prepolymer can be removed by distillation, thereby obtaining the prepolymer without the presence of the monomer.

Aliphatic isocyanate

The isocyanate functionality of the aliphatic isocyanate is preferably no greater than 2.

The aliphatic isocyanate used for synthesizing the isocyanate prepolymer is preferably one or more of the following: pentamethylene diisocyanate, hexamethylene diisocyanate (HDI), 2,2-dimethylpentamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, butene diisocyanate, 1,3-butadiene-1,4-diisocyanate, 2,4,4-trimethyl 1,6-hexamethylene diisocyanate, Bis(isocyanatoethyl)carbonate, bis(isocyanatoethyl)ether and lysine methyl ester diisocyanates, most preferably hexamethylene diisocyanate.

Polyether polyol

The weight average molecular weight of the polyether polyol is preferably 600-4000, most preferably 1000-4000.

The hydroxyl functionality of the polyether polyol is preferably 2.

The hydroxyl value of the polyether polyol is preferably 25-400 mg/g KOH, most preferably 25-115 mg/g KOH.

Said R ¹ preferably has one or more of the following structures: structure of formula III and structure of formula IV.

Said n is preferably an integer of 10-70, most preferably an integer of 14-52.

The polyether polyol is preferably one or more of the following:

(i) a polyether polyol having the structure of formula V:

(ii) a polyether polyol having the structure of formula VI:

(iii) a polyether polyol having the structure of formula VII:

(iv) a polyether polyol having the structure of formula VIII:

(v) a polyether polyol having the structure of formula IX:

(vi) a polyether polyol having the structure of formula X:

Here, p, q, r, s, t, and u are each independently an integer of not less than 1, the sum of p and q is n, the sum of r and s is n, and the sum of t and u is n.

The amount of the -R ¹ _n - structure is preferably at least 50% by weight of the polyether polyol, more preferably at least 70% by weight of the polyether polyol, and most preferably the polyether polyol 90%-100% by weight of the weight.

The polyether polyol is most preferably a polyoxypropylene diol or a mixture of polyoxypropylene diol and polyoxyethylene diol.

The polyether polyol can be a mixture of two or more polyether polyols having the structure of formula I.

The component for preparing the isocyanate prepolymer preferably further comprises at least one polyol different from the polyether polyol, in which case the amount of the -R ¹ _n - structure at least accounts for the polyether polyol and the different polyol. 50% by weight of the sum of the weight of the polyol in the polyether polyol.

The polyols other than the polyether polyols are preferably one or more of the following: polyether polyols, polyester polyols and polycarbonate polyols, most preferably polyether polyols and/or polyester polyols.

The molecular weight of the polyol different from the polyether polyol is preferably greater than 300 g/mol, more preferably not less than 500 g/mol, and most preferably 500-8000 g/mol.

The polyols other than the polyether polyols preferably contain 2-6 hydroxyl functional groups, most preferably 2-3 hydroxyl functional groups.

Isocyanate oligomer (b2)

The isocyanate oligomer is preferably obtained by oligomerization of a system comprising one or more of the following components: 1,4-diisocyanate butane, 1,5-diisocyanate-pentane, 1 , 6-diisocyanate-hexane (HDI), 1,5-diisocyanate-2,2-dimethylpentane, 2,2,4- or 2,4,4-trimethyl-1,6- Diisocyanate hexane, 1-isocyano-3,3,5-trimethyl-5-isocyanomethylcyclohexane (IPDI), 1-isocyano-1-methyl-4-(3 )-isocyanomethylcyclohexane, bis(4)-isocyanocyclohexylmethane, 2,4- or 4,4-diisocyanatecyclohexylmethane, 1,10-diisocyanate-decane, 1, 12-Diisocyanate dodecane, 1,3- or 1,4-cyclohexane diisocyanate, m-xylylene diisocyanate and its isomers, 4-isocyanomethyl-1,8-octandi Isocyanates (TIN), 2,4-diisocyanotoluene or, 2,6-diisocyanotoluene, 2,2'- or 2,4'- or 4'4'-diphenylmethane diisocyanate and Pentamethylene diisocyanate.

The oligomerization reaction may be carbodiimization, dimerization, trimerization, biuretization, ureidoation, urethanization, allophanization or cyclization to form oxadiazine groups, the above The reactions usually occur simultaneously or consecutively.

The isocyanate oligomer preferably contains one or more of the following groups: iminooxadiazinedione, isocyanurate, uretdione, urethane, allophanate, biuret, Urea, oxadiazinetrione, oxazolidinone, acylurea and carbodiimide groups, most preferably containing one or more of the following: allophanate group, biuret group, urea Diketone groups, isocyanurate groups and iminooxadiazinedione groups.

The isocyanate oligomer is preferably one or more of the following: aliphatic polyisocyanates, cycloaliphatic polyisocyanates, araliphatic polyisocyanates and aromatic polyisocyanates with iminooxadiazine diones, isocyanurates Derivatives of ester, uretdione, urethane, allophanate, biuret, urea, oxadiazinetrione, oxazolidinone, acylurea and/or carbodiimide groups.

The isocyanate oligomer is further preferably one or more of the following: aliphatic polyisocyanates and cycloaliphatic polyisocyanates with imino oxadiazine diones, isocyanurates, uretdiones, urethanes Derivatives of ester, allophanate, biuret, urea, oxadiazinetrione, oxazolidinone, acylurea and/or carbodiimide groups.

The isocyanate oligomer is further preferably one or more of the following: aliphatic triisocyanates, alicyclic triisocyanates, araliphatic triisocyanates and aromatic triisocyanates with imino oxadiazine diones, isocyanurates Derivatives of ester, uretdione, carbamate, allophanate, biuret, urea, oxadiazinetrione, oxazolidinone, acylurea and/or carbodiimide groups, Also preferred are aliphatic, cycloaliphatic, araliphatic and aromatic triisocyanates with allophanate, biuret, uretdione, isocyanurate and/or iminooxane Derivatives of diazinedione groups, also preferably aliphatic and cycloaliphatic triisocyanates with allophanate, biuret, uretdione, isocyanurate and/or iminooxadiene Derivatives of the oxazinedione group, most preferably one or more of the following: Desmodur N 3300, Desmodur N 3600 and Desmodur N 3900.

The isocyanate group content of the isocyanate oligomer is preferably 10-50% by weight, most preferably 20-25% by weight, based on the amount of the isocyanate oligomer being 100% by weight.

The isocyanate group functionality of the isocyanate oligomer is preferably 2-4.

The viscosity of the isocyanate oligomer is preferably 700-3000 mPa·s (23° C.).

The isocyanate group equivalent of the isocyanate oligomer is preferably 170-200.

The weight ratio of the isocyanate prepolymer and the isocyanate oligomer is preferably 1:2-2:1, more preferably 1:1.5-1.5:1, most preferably 1:1.5-1:1.

Isocyanate prepolymers (b3) other than the isocyanate prepolymers (b1)

The isocyanate component may further comprise an isocyanate prepolymer b3 different from the isocyanate prepolymer b1.

The amount of the isocyanate prepolymer b3 is preferably less than 70% by weight, most preferably not more than 50% by weight, based on the sum of the weights of the isocyanate prepolymer b1 and the isocyanate prepolymer b3 being 100% by weight.

The weight ratio of the isocyanate prepolymer b1 and the isocyanate prepolymer b3 to the weight ratio of the isocyanate oligomer is preferably greater than 1:4 and less than 4:1, more preferably 1:2-2:1, still more preferably 1:1.5 -1.5:1, most preferably 1:1.5-1:1.

The sum of the amounts of the isocyanate-reactive component (a) and the isocyanate component (b) is preferably from 93 to 100% by weight, based on the amount of the composition being 100% by weight.

catalyst (c)

The catalyst may be a catalyst capable of accelerating the reaction of isocyanate groups with moisture such as water.

The catalyst is preferably one or more of the following: tertiary amines and metal salts, most preferably tertiary amines.

The tertiary amine catalyst is preferably one or more of the following: triethylamine, dimorpholinyl diethyl ether, N,N-dimethylaminocyclohexane, tris-(dimethylaminomethyl)phenol, 1, 3,5-Tris(dimethylaminopropyl)hexahydrotriazine, bis(dimethylaminoethyl)ether and 2-[[2-[2-(dimethylamino)ethoxyethyl]methylamino] -Ethanol.

The metal salt is preferably one or more of the following: ferric chloride, zinc chloride, bismuth isooctanoate and bismuth carboxylate.

The amount of the catalyst is preferably 0.001-5% by weight, more preferably 0.01%-3% by weight, particularly preferably 0.1-1.5% by weight, most preferably 0.15%-0.35% by weight, based on the isocyanate component The amount is 100% by weight.

Additive (d)

The additives are preferably one or more of the following: wetting agents, dispersing agents, matting agents, antifoaming agents, film-forming agents, thickening agents, elastic agents, pigments and fillers, leveling agents and well-known to those skilled in the art Other additives that can be added to the coating composition.

The amount of the additive may be an amount known to those skilled in the art that can be added.

use

The coating composition is preferably used to protect floor surfaces, wall surfaces, reinforced concrete surfaces, metal container surfaces or other surfaces requiring protection.

The substrate may be artificial stone, wood, artificial wood, marble, terrazzo, ceramic, linoleum, metal, mineral material, plastic, rubber, concrete, composite board, paper, leather or glass.

The substrate may be pretreated, preferably sanding or coating.

coating method

The curing and drying temperature is preferably 23±2°C, and the humidity is preferably 50±5%.

The application may be by methods well known to those skilled in the art, such as knife coating, dip coating, brush coating, roller coating, spray coating or flow coating.

Coated Products

The coated product is preferably a floor, a wall, a fan blade or a metal object.

The thickness of the coating is preferably 60-250 μm.

The coating may be monolayer or multilayer.

Example

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

All numerical values used in the specification and claims to express amounts of ingredients, reaction conditions, etc. are understood to be modified by the term "about" unless otherwise indicated. Accordingly, unless indicated to the contrary, the numerical parameters set forth herein are approximations that can vary depending upon the desired properties sought to be obtained.

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

As used herein, "and/or" refers to one or all of the referred elements.

As used herein, "comprising" and "comprising" encompass only the recited element as well as instances where there are other unrecited elements in addition to the recited element.

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

The analytical measurements of the present invention are all carried out at 23±2° C., 50+5% humidity, unless otherwise stated.

The weight-average molecular weight was determined in tetrahydrofuran using polystyrene as a standard according to DIN 55672-1:2016-03.

The isocyanate group (NCO) content is determined according to DIN-EN ISO 11909, the measured data including the free and potentially free NCO content.

The isocyanate monomer content is determined according to DIN EN ISO 10283.

Viscosity was determined according to DIN EN ISO 3219, MV-DIN spindle was selected.

Amino group content was determined according to AFAM 2011-06054.

The hydroxyl group content is tested according to DIN EN ISO 4629-2.

Bubble-Free Film Thickness (BFFT): Coatings with different thicknesses were prepared on glass with a film thickness adjustable film scraper (set the film thickness to 100 μm, 200 μm and 400 μm) (test method for coating thickness: after curing The coating is peeled off from the glass and measured with a film thickness measuring instrument), and the application area is about 15cm*10cm. When the coating is cured for one day, there are no obvious bubbles (<10) on the surface of the coating. The thickness of the bubble film is greater than or equal to the thickness of the coating.

Surface drying time: Use a film scraper (set the film thickness to 200μm) to prepare the coating on the glass, measure according to GB/T13477.5-2002, touch the surface of the coating with your fingers, if you feel sticky, but no coating It is considered tack-dry when it gets on the finger, and the time it takes from the time the composition is applied to the glass surface until the coating becomes tack-dry is the tack-dry time.

Pendulum hardness: The coating was prepared on glass with a film scraper (set the film thickness to 200 μm), and the hardness of the coating was measured with a BYK pendulum hardness tester. Pendulum hardness (1d) refers to the pendulum hardness after the coating is stored for one day, and pendulum hardness (7d) refers to the pendulum hardness after the coating is stored for seven days.

Pot life: The time from when the components of the coating composition are mixed until the coating composition cannot be applied by hand with a roller without additional materials. The longer the pot life, the longer the working time of the coating composition.

Raw materials and reagents

Desmophen NH 1420: amino group equivalent weight of 279, viscosity of 1500 mPa.s (25°C), available from Covestro AG, Germany.

Desmophen NH 2850: amino group equivalent weight of 295, viscosity of 100 mPa.s (25°C), available from Covestro AG, Germany.

Desmodur N 3600: HDI-based aliphatic trimer, 100 wt% solids, NCO equivalent 183, NCO content 23.0 wt.%, HDI monomer content less than 0.25 wt.%, viscosity about 1200 mPa s (23°C) , available from Covestro AG.

Desmodur N 3900: HDI-based aliphatic trimer, 100 wt% solids, NCO equivalent 179, NCO content 23.5 wt.%, HDI monomer content less than 0.25 wt.%, viscosity about 730 mPa s (23°C) , NCO functionality 3, available from Covestro AG.

Desmodur N 3300: HDI-based aliphatic trimer, 100 wt% solids, NCO equivalent 194, NCO content 21.7 wt.%, HDI monomer content less than 0.25 wt.%, viscosity about 3000 mPa s (23°C) , NCO functionality 3, available from Covestro AG. (parameters need to be confirmed again)

Desmodur E2863 XP: reaction product of aliphatic polyester polyol and HDI, 100 wt% solids, NCO equivalent weight of 378, NCO content of 11.1 wt.%, HDI monomer content of less than 0.3 wt.%, viscosity of about 1350 mPa s ( 23°C), available from Covestro Co., Ltd.

Desmodur XP 2617: reaction product of aliphatic polyether polyol and HDI, 100 wt% solids, NCO equivalent of 336, NCO content of 12.5 wt.%, HDI monomer content of less than 0.5 wt.%, viscosity of about 4250 mPa s ( 23° C.), the weight-average molecular weight of the aliphatic polyether polyol is less than 400, which can be purchased from Covestro Co., Ltd.

Polyether L 800: Polyoxypropylene glycol, including the structure of formula III and IV, the hydroxyl value is 515mg/gKOH, the functionality is 2, the weight-average molecular weight Mw is 220, and the amount of -R ¹ _n - structure accounts for the polyether polyol More than 90% by weight of alcohol can be purchased from Covestro Co., Ltd.

Polyether LP 112: Polyoxypropylene glycol, including the structure of formula III and IV, the hydroxyl value is 112mg/gKOH, the functionality is 2, the weight average molecular weight Mw is 1000, and the amount of -R ¹ _n - structure accounts for the polyether polyol More than 90% by weight of alcohol can be purchased from Covestro Co., Ltd.

Acclaim 4200: Polyoxypropylene diol, including the structure of formula III and the structure of formula IV, the hydroxyl value is 28mg/g KOH, the functionality is 2, the weight average molecular weight Mw is 4000, and the amount of -R ¹ _n - structure accounts for the polyether polyol More than 90% by weight of alcohol can be purchased from Covestro Co., Ltd.

Polyether L 5050: a copolymer of polyoxypropylene diol and polyoxyethylene diol, comprising a structure of formula III and a structure of formula IV, having a structure of formula X, hydroxyl value of 57 mg/g KOH, polyoxypropylene diol: polyoxyethylene diol The alcohol is 1:1 (weight ratio), the functionality is 2, the weight average molecular weight Mw is 1968, and the amount of -R ¹ _n - structure accounts for about 50% of the weight of the polyether polyol, which can be purchased from Covestro Co., Ltd. .

PO ₃ GH 2400: Poly-1,3-propylene glycol, including the structure of formula II, the hydroxyl value is 47.5 mg/g KOH, the functionality is 2, the weight average molecular weight Mw is 2362, and the amount of -R ¹ _n - structure accounts for the polyether polyol More than 90% by weight of alcohol, available from ALLESSA.

Desmophen 3600 Z: Polyoxypropylene glycol, including the structure of formula III and IV, the hydroxyl value is 56mg/gKOH, the functionality is 2, the weight average molecular weight Mw is 2000, the amount of -R ¹ _n - structure accounts for the polyether polyol More than 90% by weight of alcohol can be purchased from Covestro Co., Ltd.

H：1，6-六亚甲基二异氰酸酯，异氰酸酯官能度为2，购自科思创股份有限公司。

H: 1,6-hexamethylene diisocyanate, isocyanate functionality 2, purchased from Covestro AG.

Isophthaloyl chloride: terminator, available from Sigma-Aldrich (Shanghai) Trading Co., Ltd.

DABCO NE310: tertiary amine catalyst, viscosity 12mPa·s (25℃), available from Air Chemistry.

DABCO BL-19: tertiary amine catalyst, viscosity 4mPa·s (25°C), available from Air Chemistry.

Zirconium 18HS: Zirconium metal catalyst, available from OMG Borchers GmbH. BYK 085: Silicone surface additive for solvent-free coatings, available from BYK Additives.

Irganox E 201: Antioxidant, available from BASF.

Kat 22：催化剂，可购自OMG Borchers GmbH。

Kat 22: Catalyst, commercially available from OMG Borchers GmbH.

BYK 333: Silicone surface additive for solvent-free, solvent-borne and waterborne coatings and printing inks, available from BYK Additives.

BYK 331: Silicone surface additive for solvent-free, solvent-borne and waterborne coatings and printing inks, available from BYK Additives.

分子筛，可购自格蕾斯贸易(上海)有限公司。Molecular sieve:

Molecular sieve, available from Grace Trading (Shanghai) Co., Ltd.

PGDA: Low odor solvent, available from The Dow Chemical.

DMM: Low odor solvent, available from Dow Chemical.

Method for preparing isocyanate prepolymer

Isocyanate Prepolymer 1

H中，加热至100℃，通过滴液漏斗逐滴加入69.46g Polyether L 800，当容器内的混合物NCO值达到43.54％时，将温度降低到95℃，然后逐滴加入0.7mL

Kat 22溶液(将

Kat22溶于2-乙基己醇得到浓度为5wt.％的溶液)，当容器内的混合物NCO值达到39.81％时，加入0.28g间苯二酰氯终止反应并停止加热。多余的

H单体通过蒸馏和薄膜蒸发装置除去，得到对比异氰酸酯预聚物1。In a 1 L reaction vessel, under nitrogen atmosphere and stirring, add 0.11 g of Irganox E 201 to 450 g

H, heated to 100°C, added 69.46g Polyether L 800 dropwise through a dropping funnel, when the NCO value of the mixture in the container reached 43.54%, lowered the temperature to 95°C, and then added 0.7mL dropwise

Kat 22 solution (will

Kat22 was dissolved in 2-ethylhexanol to obtain a solution with a concentration of 5 wt.%). When the NCO value of the mixture in the container reached 39.81%, 0.28 g of isophthaloyl chloride was added to terminate the reaction and the heating was stopped. extra

The H monomer was removed by distillation and a thin film evaporation apparatus to obtain Comparative Isocyanate Prepolymer 1.

Isocyanate Prepolymer 2

H中，加热至100℃，通过滴液漏斗逐滴加入237g Polyether LP 112，当容器内的混合物NCO值达到33.51％时，将温度降低到95℃，然后逐滴加入0.3mL

Kat22溶液(将

Kat22溶于Polyether LP 112得到浓度为10wt.％的溶液)，当容器内的混合物NCO值达到31.34％时，加入0.23g间苯二酰氯终止反应并停止加热。多余的

H单体通过蒸馏和薄膜蒸发装置除去，得到异氰酸酯预聚物2。In a 1 L reaction vessel, under nitrogen atmosphere and stirring, add 0.11 g of Irganox E 201 to 600 g

H, heated to 100°C, added 237g Polyether LP 112 dropwise through a dropping funnel, when the NCO value of the mixture in the container reached 33.51%, lowered the temperature to 95°C, and then added 0.3mL dropwise

Kat22 solution (will

Kat22 was dissolved in Polyether LP 112 to obtain a solution with a concentration of 10 wt.%). When the NCO value of the mixture in the container reached 31.34%, 0.23 g of isophthaloyl chloride was added to terminate the reaction and the heating was stopped. extra

The H monomer was removed by distillation and a thin film evaporation apparatus to obtain isocyanate prepolymer 2.

Isocyanate Prepolymer 3

H中，加热至100℃，通过滴液漏斗逐滴加入300g Acclaim 4200，当容器内的混合物NCO值达到31.78％时，将温度降低到95℃，然后逐滴加入0.9mL

Kat 22溶液(将

Kat 22溶于2-乙基己醇得到浓度为5wt.％的溶液)，当容器内的混合物NCO值达到39.81％时，加入0.33g间苯二酰氯终止反应并停止加热。多余的

H单体通过蒸馏和薄膜蒸发装置除去，得到异氰酸酯预聚物3。In a 1 L reaction vessel, under nitrogen atmosphere and stirring, add 0.12 g of Irganox E 201 to 550 g

H, heated to 100°C, added 300g Acclaim 4200 dropwise through a dropping funnel, when the NCO value of the mixture in the container reached 31.78%, lowered the temperature to 95°C, and then added 0.9mL dropwise

Kat 22 solution (will

Kat 22 was dissolved in 2-ethylhexanol to obtain a solution with a concentration of 5 wt.%). When the NCO value of the mixture in the container reached 39.81%, 0.33 g of isophthaloyl chloride was added to terminate the reaction and the heating was stopped. extra

The H monomer was removed by distillation and a thin film evaporation apparatus to obtain isocyanate prepolymer 3 .

Isocyanate Prepolymer 4

H中，加热至100℃，通过滴液漏斗逐滴加入355g Polyether L 5050，当容器内的混合物NCO值达到25.69％时，将温度降低到95℃，然后逐滴加入1.874mL

Kat 22溶液(将

Kat 22溶于2-乙基己醇得到浓度为5wt.％的溶液)，当容器内的混合物NCO值达到24.05％时，加入0.72g间苯二酰氯终止反应并停止加热。多余的

H单体通过蒸馏和薄膜蒸发装置除去，得到异氰酸酯预聚物4。In a 1 L reaction vessel, under nitrogen atmosphere and stirring, add 0.12 g of Irganox E 201 to 430 g

H, heated to 100°C, added 355g Polyether L 5050 dropwise through a dropping funnel, when the NCO value of the mixture in the container reached 25.69%, lowered the temperature to 95°C, and then added 1.874mL dropwise

Kat 22 solution (will

Kat 22 was dissolved in 2-ethylhexanol to obtain a solution with a concentration of 5 wt.%). When the NCO value of the mixture in the container reached 24.05%, 0.72 g of isophthaloyl chloride was added to terminate the reaction and the heating was stopped. extra

The H monomer was removed by distillation and a thin film evaporation apparatus to obtain isocyanate prepolymer 4.

Isocyanate Prepolymer 5

H中，加热至100℃，通过滴液漏斗逐滴加入350g PO₃G H 2400，当容器内的混合物NCO值达到24.05％时，将温度降低到95℃，然后逐滴加入0.5mL

Kat 22溶液(将

Kat 22溶于2-乙基己醇得到浓度为5wt.％的溶液)，当容器内的混合物NCO值达到22.46％时，加入0.18g间苯二酰氯终止反应并停止加热。多余的

H单体通过蒸馏和薄膜蒸发装置除去，得到异氰酸酯预聚物5。In a 1 L reaction vessel, under nitrogen atmosphere and stirring, add 0.11 g of Irganox E 201 to 375 g

H, heated to 100°C, 350g PO ₃ GH 2400 was added dropwise through a dropping funnel, when the NCO value of the mixture in the container reached 24.05%, the temperature was lowered to 95°C, and then 0.5mL was added dropwise

Kat 22 solution (will

Kat 22 was dissolved in 2-ethylhexanol to obtain a solution with a concentration of 5 wt.%). When the NCO value of the mixture in the container reached 22.46%, 0.18 g of isophthaloyl chloride was added to terminate the reaction and the heating was stopped. extra

The H monomer was removed by distillation and a thin film evaporation apparatus to obtain isocyanate prepolymer 5 .

Isocyanate Prepolymer 6

H中，加热至100℃，通过滴液漏斗逐滴加入350g Desmophen 3600 Z，当容器内的混合物NCO值达到26.07％时，停止加热。多余的

H单体通过蒸馏和薄膜蒸发装置除去，得到异氰酸酯预聚物6。In a 1 L reaction vessel, under nitrogen atmosphere and stirring, add 0.11 g of Irganox E 201 to 450 g

In H, heat to 100°C, add 350 g of Desmophen 3600 Z dropwise through a dropping funnel, and stop heating when the NCO value of the mixture in the container reaches 26.07%. extra

The H monomer was removed by distillation and a thin film evaporation apparatus to obtain isocyanate prepolymer 6.

Isocyanate Prepolymer 7

H，加热至100℃，通过滴液漏斗逐滴加入356.8g Desmophen 3600 Z，当容器内的混合物NCO值达到25.75％时，将温度降低到95℃，然后逐滴加入0.3mL

Kat 22溶液(将

Kat22溶于Desmophen 3600 Z得到浓度为10wt.％的溶液)，当容器内的混合物NCO值达到24.12％时，加入0.0244g间苯二酰氯终止反应并停止加热。多余的

H单体通过蒸馏和薄膜蒸发装置除去，得到异氰酸酯预聚物7。In a 1L reaction vessel, under nitrogen atmosphere and stirring, add 450g

H, heat to 100°C, add 356.8g Desmophen 3600 Z dropwise through a dropping funnel, when the NCO value of the mixture in the container reaches 25.75%, lower the temperature to 95°C, then add 0.3mL dropwise

Kat 22 solution (will

Kat22 was dissolved in Desmophen 3600 Z to obtain a solution with a concentration of 10 wt.%). When the NCO value of the mixture in the container reached 24.12%, 0.0244 g of isophthaloyl chloride was added to terminate the reaction and the heating was stopped. extra

The H monomer was removed by distillation and a thin film evaporation apparatus to obtain isocyanate prepolymer 7 .

The isocyanate equivalent weight, isocyanate content, solid content and viscosity of the isocyanate prepolymers 1-7 are listed in Table 1, and Table 1 is the physical property parameters of the isocyanate prepolymers 1-7.

Table 1 Physical parameters of isocyanate prepolymers 1-7

Isocyanate Prepolymer NCO equivalent NCO content/wt% Solid content/wt% Viscosity/mPa.s 1 248 17.0 100 2363 2 464 9.1 100 1647 3 1053 4.0 100 2597 4 691 6.1 100 1736 5 852 4.9 100 8231 6 1135 3.7 100 1374 7 700 6.0 100 2500

Reference values for bubble-free film thickness, pot life, tack-free time and coating properties of coating compositions

Table 2 is the reference value of the bubble-free film thickness, pot life, tack-free time and coating performance index of the coating composition.

Table 2 Bubble-free film thickness, pot life, surface dry time and coating performance index reference values of coating compositions

index Reference Bubble-Free Film Thickness (BFFT) ≥200μm Applicable period ≥30min Dry time ≤2.5h Pendulum hardness (1d) >10s Pendulum hardness (7d) >70s

The ideal coating composition has a bubble-free film thickness, pot life greater than or equal to the reference value, surface dry time less than or equal to the reference value, and the pendulum hardness (1d, 7d) of the coating formed by the coating composition is greater than the reference value.

Preparation method of coating composition

The amounts of the components are shown in Tables 3-7. Mix the isocyanate reactive components, BYK085, molecular sieve, optional NE310, optional BYK333, optional BYK331, optional DMM and optional PGDA, and stir at room temperature for 10-30min to obtain mixture A. Mix the isocyanate oligomer and the isocyanate prepolymer, and stir at room temperature for 5-10 min to obtain mixture B. Mix mixture A and mixture B, and stir at room temperature for 3-5 min to obtain a coating composition.

Method for preparing the coating

The coating composition is applied on the glass surface by a scraper with adjustable film thickness, the application area is 15cm*10cm, and the coating is obtained by curing and drying at 23° C. and 50% RH.

Examples 1-7 and Comparative Examples 1-5

Table 3 is the components of the compositions of Examples 1-7 and Comparative Examples 1-5, and the test results of the compositions and their coatings.

The coating compositions of Examples 1-7 have a long pot life, and the coatings formed by the coating compositions can combine short tack-free time, good bubble-free film thickness and good pendulum hardness.

It can be seen from Comparative Examples 1, 3 and 5 that when the weight-average molecular weight of polyether polyol, one of the reaction components of the isocyanate prepolymer in the coating composition, is less than 400, the polyether polyol containing the isocyanate prepolymer prepared therefrom is less than 400. The coating formed by the coating composition has a short surface dry time and good pendulum hardness, but the pot life of the coating composition is lower than the reference value, and the thickness of the coating formed by the coating composition is also lower than the reference value.

As can be seen from Comparative Examples 2 and 4, when one of the reaction components of the isocyanate prepolymer in the coating composition is polyester polyol, the coating composition comprising the isocyanate prepolymer prepared therefrom has a long pot life. , the formed coating has short surface drying time and good pendulum hardness, and the thickness of the coating without bubble film is lower than the reference value.

Examples 6, 8-9 and Comparative Examples 6-8

Table 4 is the components of the compositions of Examples 6, 8-9 and Comparative Examples 6-8, and the test results of the compositions and their coatings.

Table 4 Components and test results of the compositions of Examples 6, 8-9 and Comparative Examples 6-8

The coating compositions of Examples 6 and 8-9 have a long pot life, and the coatings formed by the coating compositions can have both short surface drying time, good bubble-free film thickness and good pendulum hardness.

It can be seen from Comparative Examples 6-8 that when the coating composition does not contain isocyanate prepolymer or the weight ratio of the isocyanate prepolymer and isocyanate oligomer of the composition is 1:4 or 4:1, the coating composition is prepared by The resulting coating composition of the isocyanate prepolymer does not provide a coating that has a good combination of bubble-free film thickness and pendulum hardness.

Examples 10-18

Table 5 is the components of the compositions of Examples 10-18, and the test results of the compositions and their coatings.

Table 5 Components and test results of the compositions of Examples 10-18

It can be seen from Examples 10-18 that when the NCO/NH molar ratio in the coating composition is adjusted, within the range of the NCO/NH molar ratio being 1.5:1-4:1, the coating composition has a long pot life, and the coating composition has a long pot life. The resulting coating combines short dry time, good bubble-free film thickness and good pendulum hardness. Especially when the molar ratio of NCO/NH is 1.5:1-3:1, the comprehensive properties of the coating composition and the coating formed therefrom are better, and the surface drying time required for the coating is shorter.

Examples 19-20

Table 6 is the components of the compositions of Examples 19-20, and the test results of the compositions and their coatings.

Table 6 Components and Test Results of the Compositions of Examples 19-20

Composition component/g Example 19 Example 20 NH 1420 30 45 NH 2850 15 BYK085 0.20 0.20 BYK 331 0.10 0.10 NE 310 0.23 0.19 Molecular sieve 1 1 PGDA 6.50 3.50 DMM 3.50 Desmodur N 3600 20 18 Desmodur N 3300 28 28 Isocyanate Prepolymer 7 46 50 NCO/NH(mol%) 2.0 2.0 VOC(g/L) 49.43 52.29 Applicable period/min >30 >30 Dry time/min 70 50 Pendulum hardness (1d)/s 15 28 Pendulum hardness (7d)/s 81 100 No bubble film thickness/μm ≥200 ≥200

As can be seen from Examples 19-20, when the isocyanate-reactive component in the coating composition is a mixture of aspartic acid esters, the coating composition has a long pot life, and the coating formed by the coating composition can have both short and Tack dry time, good bubble-free film thickness and good pendulum hardness.

Examples 21-23 and Comparative Example 9

Table 7 is the components of the compositions of Examples 21-23 and Comparative Example 9, and the test results of the compositions and their coatings.

Table 7 Components and test results of the compositions of Examples 21-23 and Comparative Example 9

As can be seen from Comparative Example 9, when the amount of the isocyanate prepolymer b1 of the isocyanate component accounts for 30% by weight of the sum of the amounts of the isocyanate prepolymer b1 and the isocyanate prepolymer b3 different from the isocyanate prepolymer b1 , the thickness of the bubble-free film of the coating formed by the coating composition is lower than the reference value.

It can be seen from Example 21 that when using the mixture of different isocyanate prepolymers b1, the coating composition has a long pot life, and the coating formed by the coating composition can have both short surface drying time, good bubble-free film thickness and Good sway bar stiffness.

It can be seen from Examples 22-23 that by changing the catalyst in the coating composition, the coating composition has a long pot life, and the coating formed by the coating composition can have both short surface drying time, good bubble-free film thickness and good Pendulum hardness.

It will be apparent to those skilled in the art that the present invention is not limited to the foregoing specific details, and that the present invention may be embodied in other specific forms without departing from the spirit or main characteristics of the present invention. The described embodiments are therefore to be regarded in all respects as illustrative and not restrictive, whereby the scope of the invention is to be indicated by the claims rather than the foregoing description; and therefore any changes, so long as they fall within the claims, etc. In the meaning and scope of the effect, it should be regarded as belonging to the present invention.

Claims (18)

1. A coating composition comprising:

(a) an isocyanate-reactive component comprising:

(a1) at least one polyaspartic acid ester, and

(a2) optionally a polyether aspartate;

(b) an isocyanate component comprising:

(b1) at least one isocyanate prepolymer, the isocyanate prepolymer being the reaction product of components comprising at least one aliphatic isocyanate and at least one polyether polyol, the polyether polyol having a weight average molecular weight of 400-6000, the polyether polyol having the structure of formula I:

HO-R¹ _n-R²

I，

wherein R is¹Having one or more of the following structures:

R²is one or more of the following: hydrogen and an isocyanate non-reactive organic group,

n is an integer of 6 to 100,

said-R¹ _n-the amount of structure is at least 40% by weight based on the weight of the polyether polyol; and

(b2) at least one isocyanate oligomer containing not less than 2 isocyanate groups, the weight ratio of the isocyanate prepolymer (b1) to the isocyanate oligomer (b2) being greater than 1: 4 and less than 4: 1;

(c) a catalyst; and

(d) optionally an additive;

the coating composition has a molar ratio of isocyanate groups to isocyanate-reactive groups of from 1.5: 1 to 4: 1.

2. The composition of claim 1 wherein the polyether polyol has a weight average molecular weight of 600-4000, most preferably 1000-4000.

3. The composition of claim 1, wherein R is¹Having one or more of the following structures: III and IV.

4. The composition of claim 1, wherein the polyether polyol is one or more of the following:

(i) a polyether polyol having the structure of formula V:

(ii) a polyether polyol having the structure of formula VI:

(iii) a polyether polyol having the structure of formula VII:

(iv) a polyether polyol having the structure of formula VIII:

(v) a polyether polyol having the structure of formula IX:

(vi) a polyether polyol having the structure of formula X:

wherein p, q, r, s, t, and u are each independently an integer of not less than 1, the sum of p and q is n, the sum of r and s is n, and the sum of t and u is n.

5. The composition of claim 1, wherein the components for preparing said isocyanate prepolymer further comprise at least one polyol different from said polyether polyol, said-R¹ _nThe amount of structure being at least in said polyether polyol and said different from50% by weight of the sum of the weights of the polyols of the polyether polyol.

6. The composition according to any one of claims 1-5, wherein the polyaspartic ester (a1) comprises a polyaspartic ester conforming to formula XI:

wherein,

z represents an aliphatic residue, and Z represents,

R³and R⁴Independently of one another, are organic radicals which do not react with isocyanate groups at atmospheric pressure at temperatures of up to 100 ℃,

m is an integer of not less than 2.

7. The composition of any of claims 1-5, wherein the amount of polyaspartic ester (a1) is greater than 50 wt%, based on 100 wt% of the isocyanate-reactive component (a).

8. The composition of any one of claims 1-5, wherein the polyaspartic ester (a1) comprises one or more of the following:

(i) a polyaspartic acid ester having the structure of formula XII:

(ii) polyaspartic acid esters having the structure of formula XIII, and

(iii) polyaspartic acid esters having the structure of formula XIV,

wherein R is³And R⁴Each independently is one or more of the following: methyl, ethyl and butyl.

9. The composition according to any one of claims 1-5, wherein the polyether aspartate (a2) comprises a polyether aspartate according to formula XV:

wherein Q represents an aliphatic residue,

R⁶and R⁷Independently of one another, are organic radicals which do not react with isocyanate groups at atmospheric pressure at temperatures of up to 100 ℃,

R⁵represents C₁-C₆The alkyl residue of (a) is,

m is an integer of not less than 2,

f is an integer from 1 to 35.

10. The composition of claims 1-5, wherein the polyether aspartate (a2) comprises a polyether aspartate according to formula XVI:

wherein h is an integer of 2 to 4,

g is an integer of 1 to 35,

s is an integer of 1 to 2,

j is a residue of an alkyl group,

R⁶and R⁷Independently of one another, are organic radicals which do not react with isocyanate groups at atmospheric pressure at temperatures of up to 100 ℃,

R⁸is provided with C₁-C₆An alkyl residue of (2).

11. The composition of any of claims 1-5, wherein the isocyanate oligomer (b2) comprises one or more of the following groups: allophanate groups, biuret groups, uretdione groups, isocyanurate groups and iminooxadiazinedione groups.

12. The composition of any of claims 1-5, wherein the isocyanate oligomer (b2) is one or more of the following: derivatives of aliphatic and cycloaliphatic triisocyanates having allophanate, biuret, uretdione, isocyanurate and/or iminooxadiazinedione groups.

13. The composition as claimed in any of claims 1 to 5, wherein the isocyanate group content of the isocyanate oligomer (b2) is preferably 10 to 50% by weight, based on 100% by weight of the isocyanate oligomer.

14. The composition of any of claims 1-5, wherein the weight ratio of isocyanate prepolymer (b1) to isocyanate oligomer (b2) is from 1: 2 to 2: 1.

15. Use of a coating composition according to any one of claims 1 to 14 for protecting a substrate surface or a coating of a substrate surface.

16. A coating method comprising the steps of: a coating composition according to any one of claims 1 to 14 applied to a substrate surface and subsequently cured and dried.

17. A coated product comprising a substrate and a coating layer formed by applying the coating composition according to any one of claims 1 to 14 to the substrate and curing and drying the coating layer.

18. The coated product of claim 17, wherein the coated product is a floor, wall, fan blade, or metal object.