CN118344559A - A kind of water-based blocked isocyanate composition and its preparation method and application - Google Patents

Abstract

The invention relates to a water-based closed isocyanate composition, and belongs to the technical field of water-based compositions. The aqueous blocked isocyanate composition of the present invention has an isocyanate group having a first hydrophilic group, and a blocked isocyanate group obtained by blocking the isocyanate group with a blocking agent; the isocyanate group with the first hydrophilic group is obtained by reacting an amine compound with the formula (1) with the isocyanate group; the amine compound is contained in an amount of 1 to 9.9mol% based on the total content of the blocked isocyanate groups. The aqueous blocked isocyanate composition can maintain excellent storage stability when only a very small amount of the amine compound having the specific structure of formula (1) is contained. The aqueous closed isocyanate composition has high solid content, high NCO value, excellent storage stability and good water repellency, and is particularly suitable for being matched with a waterproof finishing agent to be used in aqueous textile waterproof paint.

Description

A kind of water-based blocked isocyanate composition and its preparation method and application

Technical Field

The present invention relates to the technical field of aqueous compositions, and in particular to an aqueous blocked isocyanate composition and a preparation method and application thereof.

Background technique

In the field of waterproof textile fabric applications, water-based polymers, such as water-based acrylic resins or water-based polyurethane resins, are usually used in combination with water-based blocked isocyanate crosslinkers. The addition of blocked isocyanate crosslinkers can increase the crosslinking density of the polymer, thereby improving the waterproof and washing fastness. In particular, cationic water-based blocked isocyanate crosslinkers have a higher bonding fastness to the fabric and better waterproof and washing fastness, and therefore have received widespread attention.

CN1101493C discloses a blocked isocyanate emulsion, which uses a combination of cationic and nonionic external emulsifiers to emulsify hydrophobic blocked isocyanate by external emulsification to obtain an aqueous blocked isocyanate composition by external emulsification. However, the blocked isocyanate emulsion obtained by this method has relatively poor stability, and the emulsifier contained therein cannot participate in the chemical cross-linking reaction and will remain in the coating film, affecting the water resistance of the coating film.

CN104870508B discloses an aqueous composition, in which an amine compound containing a hydroxyl group (such as N,N-dimethylethanolamine, etc.) is used as a hydrophilic agent in a specific embodiment to obtain a cationic aqueous blocked isocyanate composition. However, a relatively high proportion of amine compounds (the ratio to the total content of blocked isocyanate groups is 10-400 mol%) must be used in the aqueous composition of CN104870508B to obtain a relatively stable aqueous dispersion, which also improves the hydrophilicity of the aqueous composition, while reducing the solid content and NCO value of the composition, resulting in poor water repellency and waterproof and washability of the aqueous composition.

CN117567724A discloses a water-based blocked isocyanate crosslinking agent, which is modified with a nonionic hydrophilic agent and a fluorinated diol and is used for waterproof fabric treatment and has excellent water repellency and water-proof and wash-resistant effects. However, the system contains environmentally unfriendly fluorine elements, which limits further application and promotion.

All of the above isocyanates have some defects, and a water-based blocked isocyanate composition with excellent water repellency and waterproof and washable properties is needed.

Summary of the invention

Based on this, the object of the present invention is to provide an aqueous blocked isocyanate composition and a preparation method and application thereof. The aqueous blocked isocyanate composition has excellent storage stability and good water repellency, and is particularly suitable for use in textile waterproof coatings.

To achieve the above object, the present invention adopts the following technical solutions:

A water-based blocked isocyanate composition, comprising an isocyanate group with a first hydrophilic group and a blocked isocyanate group obtained by blocking the isocyanate group with a blocking agent; the isocyanate group with the first hydrophilic group is obtained by reacting an amine compound of formula (1) with the isocyanate group; the content of the amine compound is 1-9.9 mol% of the total content of the blocked isocyanate group;

In formula (1), _R1 and _R2 are each independently a C1-C4 alkyl group, and _R3 and _R4 are each independently H or a C1-C4 alkyl group.

The aqueous blocked isocyanate composition of the present invention defines the content of the amine compound of formula (1) as 1-9.9 mol% of the total content of the blocked isocyanate group (those skilled in the art will appreciate that the content of the amine compound of formula (1) described herein may also refer to the content of the first hydrophilic group derived from the amine compound of formula (1) or the content of the isocyanate group with the first hydrophilic group), so that the aqueous blocked isocyanate composition has excellent storage stability and good water repellency, and is particularly suitable for use in aqueous textile waterproof coatings.

The present invention uses the hydroxyl group of the amine compound of the structure of formula (1) to undergo an amination reaction with the isocyanate group to obtain the isocyanate group with the first hydrophilic group, that is, the first hydrophilic group in the isocyanate group with the first hydrophilic group is derived from the amine compound of the structure of formula (1). The amine compound of the structure of formula (1) contains two tertiary amine structures and two hydroxyl groups, one of which is located in the side chain; the amine compound of the structure of formula (1) of the present invention is used in an aqueous blocked isocyanate composition, and is more likely to form a stable charge layer than other amine compounds (such as N,N-dimethylethanolamine), so that the stability of the aqueous blocked isocyanate composition is better. In the amine compound of the structure of formula (1), the structures of R ₁ , R ₂ , R ₃ , and R ₄ should not be too large. If the structure is too large, the amine compound may become more hydrophobic in structure, affecting the hydrophilicity of the amine compound as a hydrophilic agent, resulting in poor stability of the aqueous dispersion.

The present invention surprisingly found that, in the case of the aqueous blocked isocyanate composition containing only a very small amount of the specific amine compound of formula (1) structure (or the first hydrophilic group derived from the amine compound of formula (1) structure), that is, when the content of the amine compound is 1-9.9 mol% of the total content of the blocked isocyanate group, the storage stability of the aqueous blocked isocyanate composition can be maintained, and at the same time, the aqueous blocked isocyanate composition is ensured to have good water repellency after being used in the aqueous textile waterproof coating. If the ratio of the content of the amine compound to the total content of the blocked isocyanate group in the aqueous blocked isocyanate composition is less than 1 mol%, the aqueous blocked isocyanate composition has poor storage stability and cannot be used in the aqueous textile waterproof coating. If the ratio of the content of the amine compound to the total content of the blocked isocyanate group in the aqueous blocked isocyanate composition is greater than 9.9 mol%, although the aqueous blocked isocyanate composition has good storage stability, the aqueous blocked isocyanate composition is too hydrophilic, resulting in poor water repellency and waterproof and washability. The present invention adopts an amine compound of a specific structure of formula (1) as a hydrophilic agent of the aqueous blocked isocyanate composition, and only a small amount (the ratio to the total content of the blocked isocyanate is 1-9.9 mol%) is needed to make the aqueous blocked isocyanate composition have excellent storage stability and good water repellency. The aqueous blocked isocyanate composition of the present invention overcomes the prejudice that the aqueous composition of CN104870508B must use a higher proportion of amine compounds (the ratio to the total content of the blocked isocyanate group is 10-400 mol%) to obtain a low-solid content and low-NCO value aqueous dispersion with relatively stable storage; and solves the technical problem that the aqueous composition of CN104870508B has a higher proportion of amine compounds, which makes it hydrophilic, but its use in aqueous textile waterproof coatings leads to poor water repellency and waterproof washability.

As a preferred solution, the aqueous blocked isocyanate composition comprises a hydrophobic blocked isocyanate and a hydrophilic blocked isocyanate; the hydrophobic blocked isocyanate does not contain a hydrophilic group, and has a first blocked isocyanate group obtained by blocking the isocyanate group with a first blocking agent; the hydrophilic blocked isocyanate has the isocyanate group with the first hydrophilic group, and a second blocked isocyanate group obtained by blocking the isocyanate group with a second blocking agent; the blocked isocyanate group comprises the first blocked isocyanate group and the second blocked isocyanate group.

In the aqueous blocked isocyanate composition, since the content of the amine compound is relatively small, that is, 1-9.9 mol% of the total content of the blocked isocyanate group, the aqueous composition of the present invention contains the hydrophobic blocked isocyanate and the hydrophilic blocked isocyanate, and the content of the amine compound is adjusted to be within the range by matching two different types of isocyanates. The hydrophobic blocked isocyanate does not contain a hydrophilic group and has a first blocked isocyanate group whose isocyanate group is blocked by a first blocking agent; the hydrophilic blocked cyanate contains a first hydrophilic group, which is derived from the amine compound of the structure of formula (1), and the hydrophilic blocked cyanate has a second blocked isocyanate group whose isocyanate group is blocked by a second blocking agent. By combining the hydrophobic blocked isocyanate and the hydrophilic blocked isocyanate, it is easier to ensure that the content of the amine compound in the aqueous blocked isocyanate composition is 1-9.9 mol% of the total content of the blocked isocyanate group (or the total content of the first blocked isocyanate group and the second blocked isocyanate group), so that the aqueous blocked isocyanate composition has excellent storage stability and good water repellency, and is particularly suitable for aqueous textile waterproof coatings.

As an optional scheme, the aqueous blocked isocyanate composition further has an isocyanate group with a second hydrophilic group; the second hydrophilic group is a nonionic hydrophilic group and/or a cationic hydrophilic group; in the aqueous blocked isocyanate composition, the total content of the amine compound (or the first hydrophilic group, or the isocyanate group with the first hydrophilic group) and the second hydrophilic group (or the isocyanate group with the second hydrophilic group) is 1.1-9.9 mol% of the total content of the blocked isocyanate group.

The present application has found that in addition to the isocyanate group with a first hydrophilic group, an isocyanate group with a second hydrophilic group can also be introduced into the aqueous blocked isocyanate composition. In order to ensure that the aqueous blocked isocyanate composition has excellent stability and water repellency, the total content of the hydrophilic group in the aqueous blocked isocyanate composition (referring to the total content of the first hydrophilic group derived from the amine compound of the structure of formula (1) and the second hydrophilic group (including cationic hydrophilic group and non-ionic hydrophilic group)) is controlled to be 1.1-9.9 mol% of the total content of the blocked isocyanate group.

The cationic hydrophilic group is derived from other tertiary amine structure amine compounds other than the amine compound of formula (1). The other tertiary amine structure amine compounds contain active hydrogen that can react with isocyanate groups, for example, dimethylethanolamine, diethylethanolamine, diethanolamine, methyldiethanolamine, N,N-dimethylaminohexanol, N,N-dimethylaminoethoxyethanol, N,N-dimethylaminoethoxyethoxyethanol, N,N,N'-trimethylaminoethylethanolamine, N-methyl-N-(dimethylaminopropyl)aminoethanol, etc.

The nonionic hydrophilic group is derived from a polyether compound containing a polyoxyalkylene segment of formula (2);

In formula (2), R ₅ is H or a C1-C4 alkyl group.

The structure of R ₅ should not be too large. If the structure is too large, the amine compound may become more hydrophobic in structure, affecting the hydrophilicity of the amine compound as a hydrophilic agent, resulting in poor stability of the aqueous dispersion.

The polyether compound contains active hydrogen that can react with an isocyanate group, and examples thereof include trimethylolpropane polyethylene glycol monomethyl ether, polyethylene glycol monoalkyl ether, polyethylene glycol polypropylene glycol monoalkyl ether, polyethylene glycol polybutylene glycol monoalkyl ether, and the like.

Those skilled in the art should know that, in the aqueous blocked isocyanate composition, the isocyanate group with the first hydrophilic group and the isocyanate group with the second hydrophilic group may refer to the isocyanate group with the first hydrophilic group and the isocyanate group with the second hydrophilic group being present on the same isocyanate molecule at the same time; or two isocyanate molecules may respectively have the above two hydrophilic groups, one of which has the isocyanate group with the first hydrophilic group and the other has the isocyanate group with the second hydrophilic group; such isocyanate molecules having the isocyanate group with the first hydrophilic group and/or the isocyanate group with the second hydrophilic group all belong to the above-mentioned hydrophilic blocked isocyanate.

As a preferred solution, the aqueous blocked isocyanate composition (or the hydrophobic blocked isocyanate and the hydrophilic blocked isocyanate are each independently) is derived from an aliphatic isocyanate and/or an aromatic isocyanate. Preferably, the aqueous blocked isocyanate composition (or the hydrophobic blocked isocyanate and the hydrophilic blocked isocyanate are each independently) has an aliphatic diisocyanate monomer unit and/or an aromatic diisocyanate monomer unit.

As a preferred embodiment, the precursor isocyanate compound of the aqueous blocked isocyanate composition (the precursor isocyanate compound of the hydrophobic blocked isocyanate and the precursor isocyanate compound of the hydrophilic blocked isocyanate are each independently) is at least one of hexamethylene diisocyanate, pentamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, MDI oligomer, naphthalene-1,5-diisocyanate, xylyl diisocyanate, 4,4-dicyclohexylmethane diisocyanate, norbornane diisocyanate, isophorone diisocyanate, diisocyanate adducts, allophanate modifiers, biuret modifiers, isocyanurate modifiers, carbodiimide modifiers and polyurethane prepolymers.

As a preferred solution, the blocking agent (or the first blocking agent and the second blocking agent independently) is at least one of pyrazole compounds, imidazole compounds, ketoxime compounds, amide compounds, phenolic compounds, alcohol compounds, and dialkyl malonate. The blocking agents are all substances containing an active hydrogen that can react with an isocyanate group. The first blocking agent and the second blocking agent can be the same or different, so as to facilitate the blocking of the isocyanate group, that is, the first blocked isocyanate group and the second blocked isocyanate group can be the same or different.

As a preferred solution, the aqueous blocked isocyanate composition further comprises water; the solid content of the aqueous blocked isocyanate composition is 35-55wt%, and the theoretical blocked NCO value is 5-10%. The theoretical blocked NCO value refers to the NCO value after the blocked isocyanate groups of the aqueous blocked isocyanate composition are unblocked.

The present invention also provides a method for preparing any of the above-mentioned aqueous blocked isocyanate compositions, comprising the following steps:

(1) adding an organic solvent, a precursor isocyanate compound, the amine compound, and the blocking agent into a reaction container to react until the detected NCO value is 0;

Wherein: the amine compound reacts with the isocyanate group on the precursor isocyanate compound to generate the isocyanate group with the first hydrophilic group; the blocking agent reacts with the isocyanate group on the precursor isocyanate compound to obtain the blocked isocyanate group; the content of the amine compound is 1-9.9 mol% of the total content of the blocked isocyanate group;

(2) adding an acid neutralizing agent, adding water, stirring and dispersing, and removing the organic solvent to obtain the water-based blocked isocyanate composition.

The preparation method of the water-based blocked isocyanate of the present invention, in the added precursor isocyanate compound, the amine compound, and the blocking agent, the isocyanate group of the precursor isocyanate compound is greatly excessive relative to the amine compound, and after the amine compound reacts with part of the isocyanate groups on the precursor isocyanate compound to generate the isocyanate group with the first hydrophilic group, there will still be a large number of isocyanate groups of the precursor isocyanate compound that do not participate in the reaction, and these isocyanate groups that are not connected to the amine compound are blocked by the blocking agent to generate the blocked isocyanate compound. The present invention controls the content of the amine compound (or refers to the content of the first hydrophilic group, or refers to the content of the isocyanate group with the first hydrophilic group) to 1-9.9mol% of the total content of the blocked isocyanate group, so that the prepared water-based blocked isocyanate composition has excellent storage stability and good water repellency, and is particularly suitable for use in water-based textile waterproof coatings.

Before adding water for dispersion, the isocyanate group with the first hydrophilic group (derived from the amine compound of formula (1)) needs to be partially or completely neutralized by an acid neutralizing agent. The acid neutralizing agent is not particularly limited and can be an organic acid or an inorganic acid with a neutralization degree of 10-120%.

Furthermore, when an isocyanate group having a second hydrophilic group is also introduced into the aqueous blocked isocyanate composition, the cationic hydrophilic agent and/or anionic hydrophilic agent as defined above are added in step (1) for reaction, wherein the cationic hydrophilic agent and/or anionic hydrophilic agent reacts with the isocyanate group on the precursor isocyanate compound to generate the isocyanate group having the second hydrophilic group; in the aqueous blocked isocyanate composition, the total content of the amine compound (or the first hydrophilic group, or the isocyanate group having the first hydrophilic group) and the second hydrophilic group (or the isocyanate group having the second hydrophilic group) is 1.1-9.9 mol % of the total content of the blocked isocyanate group.

The present invention also provides a use of any of the above-mentioned water-based blocked isocyanate compositions in a water-based textile waterproof coating.

The water-based blocked isocyanate composition of the present invention has excellent water repellency and is used in a water-based textile waterproof coating in combination with a waterproof finishing agent. That is, a water-based textile waterproof coating comprises any of the above-mentioned water-based blocked isocyanate compositions and a waterproof finishing agent.

The water-based blocked isocyanate composition of the present invention is used in water-based textile water-based coatings, and the formed coating has excellent water repellency, so that the textile fabric has good waterproof and washable effects.

Furthermore, the waterproof finishing agent is at least one of TF-5548 (Transfer Waterproofing Agent), UNIDYNE XF series (such as XF-5003, XF-5005, XF-5007) of Daikin, Arkophob FFR liquid of Archroma, and PHOBOL RSH waterproofing agent of Huntsman.

Compared with the prior art, the present invention has the following beneficial effects:

The aqueous blocked isocyanate composition of the present invention adopts an amine compound of the structure of formula (1) as a hydrophilic agent, and limits the content of the amine compound of formula (1) to 1-9.9 mol% of the total content of the blocked isocyanate group, so that the aqueous blocked isocyanate composition has excellent storage stability and good water repellency, and is particularly suitable for use in aqueous textile waterproof coatings.

The present invention overcomes the prejudice that the aqueous composition of CN104870508B must use a higher proportion of amine compounds (the ratio to the total content of blocked isocyanate groups is 10-400 mol %) to obtain a low-solid content and low-NCO value aqueous dispersion with relatively stable storage; and solves the technical problem that the aqueous composition of CN104870508B has a higher proportion of amine compounds and has strong hydrophilicity, but its use in aqueous textile waterproof coatings leads to poor water repellency and waterproof and washable effects.

Detailed ways

The present invention is further described below in conjunction with examples. These examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods in the following examples that do not specify specific conditions are usually carried out according to conventional conditions in the art or according to the conditions recommended by the manufacturer; the raw materials, reagents, etc. used, unless otherwise specified, are all raw materials and reagents that can be obtained from commercial channels such as conventional markets. Any non-substantial changes and substitutions made by those skilled in the art on the basis of the present invention belong to the scope of protection claimed by the present invention.

Example 1

This embodiment provides an aqueous blocked isocyanate composition and a preparation method thereof.

The aqueous blocked isocyanate composition of this embodiment has an isocyanate group with a first hydrophilic group and a blocked isocyanate group obtained by blocking the isocyanate group with a blocking agent. The aqueous blocked isocyanate composition of this embodiment does not contain an isocyanate group with a second hydrophilic group (or does not contain a second hydrophilic group).

Wherein: the isocyanate group with the first hydrophilic group is obtained by reacting an amine compound A1 with an isocyanate group, and the amine compound A1 is N,N-dimethyl-N'N'-di(hydroxyethyl)-1,3-propylenediamine, having a structure shown in formula (1), wherein R ₁ =R ₂ =Me, R ₃ =R ₄ =H.

The preparation method of amine compound A1 is synthesized according to the method of Example 1 of patent CN113996332B, except that "diisopropanolamine" is replaced by "diethanolamine" in equal moles, and finally N,N-dimethyl-N'N'-di(hydroxyethyl)-1,3-propylenediamine is obtained, namely amine compound A1.

In the aqueous blocked isocyanate composition, the content of the amine compound A1 (or the first hydrophilic group or the isocyanate group with the first hydrophilic group) is 9.9 mol % of the total content of the blocked isocyanate group.

The preparation method of the aqueous blocked isocyanate composition of the present embodiment comprises the following steps:

(1) Add 40.0g acetone, 100.0g Wanhua Wannate HT-100 (HDI trimer, NCO value: 22.0%), and 8.2g N,N-dimethyl-N'N'-di(hydroxyethyl)-1,3-propylenediamine to a four-necked flask, raise the temperature to 60-65°C, and keep the temperature for 4 hours. Cool down to below 50°C, add 45.0g 3,5-dimethylpyrazole in batches, raise the temperature to 60-65°C, and keep the temperature until the NCO value is zero.

Wherein: Since HDI trimer is in excess relative to N,N-dimethyl-N'N'-di(hydroxyethyl)-1,3-propylenediamine (amine compound A1), therefore, during the reaction:

① A portion of the HDI trimer, part of its isocyanate groups react with N,N-dimethyl-N'N'-di(hydroxyethyl)-1,3-propylenediamine (amine compound A1) to make the portion of the HDI trimer have a first hydrophilic group, and then the remaining isocyanate groups on the portion of the HDI trimer are blocked with a portion of 3,5-dimethylpyrazole (blocking agent) to obtain a first blocked isocyanate group, thereby obtaining a hydrophilic blocked isocyanate;

② The isocyanate group of the remaining HDI trimer is blocked by the remaining blocking agent to obtain a second blocked isocyanate group, thereby obtaining a hydrophobic blocked isocyanate. The second blocked isocyanate group has the same structure as the first blocked isocyanate group.

(2) Add 2.6 g of glacial acetic acid and stir for 20 min. Cool to 50° C., add 184.7 g of water under rapid stirring, remove acetone in vacuo, and obtain a milky white aqueous blocked isocyanate composition. The aqueous blocked isocyanate composition of this embodiment has a solid content of 45.0 wt % and a theoretical blocked NCO value of 5.4%.

The aqueous blocked isocyanate composition (aqueous dispersion) of this example showed no obvious precipitation and stratification after heat storage in an oven at 50° C. for 2 weeks.

Example 2

This embodiment provides an aqueous blocked isocyanate composition and a preparation method thereof.

The aqueous blocked isocyanate composition of this embodiment has an isocyanate group with a first hydrophilic group and a blocked isocyanate group obtained by blocking the isocyanate group with a blocking agent. The aqueous blocked isocyanate composition of this embodiment does not contain an isocyanate group with a second hydrophilic group (or does not contain a second hydrophilic group).

Wherein: the isocyanate group with the first hydrophilic group is obtained by reacting the amine compound A1 in Example 1 with the isocyanate group.

In the aqueous blocked isocyanate composition, the content of the amine compound A1 (or the first hydrophilic group or the isocyanate group with the first hydrophilic group) is 4.3 mol % of the total content of the blocked isocyanate group.

The preparation method of the aqueous blocked isocyanate composition of the present embodiment comprises the following steps:

(1) Add 40.0g acetone, 100.0g Wanhua Wannate MDI-50 (a mixture of 2,4'-diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate), and 6.0g N,N-dimethyl-N'N'-di(hydroxyethyl)-1,3-propylenediamine to a four-necked flask, heat to 60-65°C, and keep warm for 4h. Cool to below 50°C, add 65.3g methyl ethyl ketone oxime in batches, heat to 60-65°C, and keep warm until the NCO value is zero.

Wherein: Since the mixture of 2,4'-diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate is in excess relative to N,N-dimethyl-N'N'-di(hydroxyethyl)-1,3-propylenediamine (amine compound A1), therefore, during the reaction:

① Part of the isocyanate groups of 2,4'-diphenylmethane diisocyanate and/or 4,4'-diphenylmethane diisocyanate react with the amine compound A1 to make the part of the 2,4'-diphenylmethane diisocyanate and/or 4,4'-diphenylmethane diisocyanate have a first hydrophilic group, and then the remaining isocyanate groups on the part of the 2,4'-diphenylmethane diisocyanate and/or 4,4'-diphenylmethane diisocyanate are blocked with a part of the blocking agent to obtain a first blocked isocyanate group, thereby obtaining a hydrophilic blocked isocyanate;

② The isocyanate groups of the remaining 2,4'-diphenylmethane diisocyanate and/or 4,4'-diphenylmethane diisocyanate are blocked by the remaining blocking agent to obtain a second blocked isocyanate group, thereby obtaining a hydrophobic blocked isocyanate. The second blocked isocyanate group has the same structure as the first blocked isocyanate group.

(2) Add 3.0 g of glacial acetic acid and stir for 20 min. Cool to 50° C., add 203.8 g of water under rapid stirring, remove acetone in vacuo, and obtain a milky white aqueous blocked isocyanate composition. The aqueous blocked isocyanate composition of this embodiment has a solid content of 45.4 wt % and a theoretical blocked NCO value of 8.9%.

The aqueous dispersion obtained in this example showed no obvious precipitation and stratification after heat storage in an oven at 50°C for 2 weeks.

Example 3

This embodiment provides an aqueous blocked isocyanate composition and a preparation method thereof.

The aqueous blocked isocyanate composition of this embodiment has an isocyanate group with a first hydrophilic group, an isocyanate group with a second hydrophilic group, and a blocked isocyanate group obtained by blocking the isocyanate group with a blocking agent.

Wherein: the isocyanate group with the first hydrophilic group is obtained by reacting the amine compound A1 of Example 1 with the isocyanate group. The isocyanate group with the second hydrophilic group is obtained by reacting a nonionic hydrophilic agent with the isocyanate group.

In the aqueous blocked isocyanate composition, the content of the amine compound A1 (or the first hydrophilic group or the isocyanate group with the first hydrophilic group) is 3.7 mol% of the total content of the blocked isocyanate group, and the total content of the amine compound A1 (or the first hydrophilic group or the isocyanate group with the first hydrophilic group) and the second hydrophilic group (or the isocyanate group with the second hydrophilic group) is 4.4 mol% of the total content of the blocked isocyanate group.

The nonionic hydrophilic agent has a polyether compound containing a polyoxyalkylene segment of formula (2), wherein R ₅ =H.

The preparation method of the aqueous blocked isocyanate composition of the present embodiment comprises the following steps:

(1) Add 3.0g of Ymer N 120 (purchased from Pasto, a non-ionic hydrophilic agent containing 2 hydroxyl groups, the chemical composition is trimethylolpropane polyethylene glycol monomethyl ether, molecular weight 1000) to a four-necked flask, heat to 110°C, and evacuate for 2h. Cool to below 70°C, add 40.0g of acetone, 100.0g of Wanhua Wannate HT-100 (HDI trimer, NCO value: 22.0%), and 3.4g of N,N-dimethyl-N'N'-di(hydroxyethyl)-1,3-propylenediamine, heat to 60-65°C, and keep warm for 4h. Cool to below 50°C, then add 50.2g of 3,5-dimethylpyrazole in batches, heat to 60-65°C, and keep warm until the NCO value is zero.

Wherein: Since HDI trimer is in excess relative to nonionic hydrophilic agent and N,N-dimethyl-N'N'-di(hydroxyethyl)-1,3-propylenediamine (amine compound A1), therefore, during the reaction:

① Part of the HDI trimer, part of its isocyanate groups react with the non-ionic hydrophilic agent and the amine compound A1 respectively, so that the part of the HDI trimer has the first hydrophilic group and/or the second hydrophilic group, and then the remaining isocyanate groups on the part of the HDI trimer are blocked by a part of the blocking agent to obtain the first blocked isocyanate group, thereby obtaining a hydrophilic blocked isocyanate;

② The isocyanate group of the remaining HDI trimer is blocked by the remaining blocking agent to obtain a second blocked isocyanate group, thereby obtaining a hydrophobic blocked isocyanate. The second blocked isocyanate group has the same structure as the first blocked isocyanate group.

(2) Add 2.0 g of glacial acetic acid and stir for 20 min. Cool to 50° C., add 154.6 g of water under rapid stirring, remove acetone in vacuo, and obtain a milky white aqueous blocked isocyanate composition. The aqueous blocked isocyanate composition of this embodiment has a solid content of 50.0 wt % and a theoretical blocked NCO value of 6.5%.

The aqueous blocked isocyanate composition (aqueous dispersion) of this example showed no obvious precipitation and stratification after heat storage in an oven at 50° C. for 2 weeks.

Example 4

This embodiment provides an aqueous blocked isocyanate composition and a preparation method thereof.

The aqueous blocked isocyanate composition of this embodiment has an isocyanate group with a first hydrophilic group, an isocyanate group with a second hydrophilic group, and a blocked isocyanate group obtained by blocking the isocyanate group with a blocking agent.

Wherein: the isocyanate group with the first hydrophilic group is obtained by reacting the amine compound A2 with the isocyanate group. The isocyanate group with the second hydrophilic group is obtained by reacting the nonionic hydrophilic agent of Example 3 with the isocyanate group.

The amine compound A2 is N,N-di-n-butyl-N'N'-di(2-hydroxypropyl)-1,3-propylenediamine, having a structure shown in formula (1), wherein R ₁ =R ₂ =nBu, R ₃ =R ₄ =Me.

The preparation method of amine compound A2 is synthesized according to the method of Example 1 of patent CN113996332B, except that "dimethylaminopropionitrile" is replaced by "dibutylaminopropionitrile" in equal moles, and finally N,N-di-n-butyl-N'N'-di(2-hydroxypropyl)-1,3-propylenediamine is obtained, namely amine compound A2.

In the aqueous blocked isocyanate composition, the content of the amine compound A2 (or the first hydrophilic group or the isocyanate group with the first hydrophilic group) is 3.7 mol% of the total content of the blocked isocyanate group, and the total content of the amine compound A1 (or the first hydrophilic group or the isocyanate group with the first hydrophilic group) and the second hydrophilic group (or the isocyanate group with the second hydrophilic group) is 4.4 mol% of the total content of the blocked isocyanate group.

The preparation method of the aqueous blocked isocyanate composition of the present embodiment comprises the following steps:

(1) Add 3.0g of Ymer N 120 (purchased from Pasto, a non-ionic hydrophilic agent containing 2 hydroxyl groups, the chemical composition is trimethylolpropane polyethylene glycol monomethyl ether, molecular weight 1000) to a four-necked flask, heat to 110°C, and evacuate for 2h. Cool to below 70°C, add 40.0g of acetone, 100.0g of Wanhua Wannate HT-100 (HDI trimer, NCO value: 22.0%), and 5.4g of N,N-di-n-butyl-N'N'-di(2-hydroxypropyl)-1,3-propylenediamine, heat to 60-65°C, and keep warm for 4h. Cool to below 50°C, then add 50.2g of 3,5-dimethylpyrazole in batches, heat to 60-65°C, and keep warm until the NCO value is zero.

Wherein: Since HDI trimer is in excess relative to nonionic hydrophilic agent, N,N-di-n-butyl-N'N'-di(2-hydroxypropyl)-1,3-propylenediamine (amine compound A2), therefore, during the reaction:

① Part of the HDI trimer, part of its isocyanate groups react with the non-ionic hydrophilic agent and the amine compound A2 respectively, so that the part of the HDI trimer has the first hydrophilic group and/or the second hydrophilic group, and then the remaining isocyanate groups on the part of the HDI trimer are blocked by a part of the blocking agent to obtain the first blocked isocyanate group, thereby obtaining a hydrophilic blocked isocyanate;

② The isocyanate group of the remaining HDI trimer is blocked by the remaining blocking agent to obtain a second blocked isocyanate group, thereby obtaining a hydrophobic blocked isocyanate. The second blocked isocyanate group has the same structure as the first blocked isocyanate group.

(2) Add 2.0 g of glacial acetic acid and stir for 20 min. Cool to 50° C., add 156.6 g of water under rapid stirring, remove acetone in vacuo, and obtain a milky white aqueous blocked isocyanate composition. The aqueous blocked isocyanate composition of this embodiment has a solid content of 50.0 wt % and a theoretical blocked NCO value of 6.4%.

The aqueous blocked isocyanate composition (aqueous dispersion) of this example showed no obvious precipitation and stratification after heat storage in an oven at 50° C. for 2 weeks.

Example 5

This embodiment provides an aqueous blocked isocyanate composition and a preparation method thereof.

The aqueous blocked isocyanate composition of this embodiment has an isocyanate group with a first hydrophilic group, an isocyanate group with a second hydrophilic group, and a blocked isocyanate group obtained by blocking the isocyanate group with a blocking agent.

Wherein: the isocyanate group with the first hydrophilic group is obtained by reacting the amine compound A3 with the isocyanate group. The isocyanate group with the second hydrophilic group is obtained by reacting the nonionic hydrophilic agent of Example 3 with the isocyanate group.

The amine compound A3 is N,N-dimethyl-N'N'-di(2-hydroxypropyl)-1,3-propylenediamine, having a structure shown in formula (1), wherein R ₁ ＝R ₂ ＝Me, R ₃ ＝R ₄ ＝Me.

The preparation method of amine compound A3 is synthesized according to the method of Example 1 of patent CN113996332B.

In the aqueous blocked isocyanate composition, the content of the amine compound A3 (or the first hydrophilic group or the isocyanate group with the first hydrophilic group) is 3.7 mol% of the total content of the blocked isocyanate group, and the total content of the amine compound A1 (or the first hydrophilic group or the isocyanate group with the first hydrophilic group) and the second hydrophilic group (or the isocyanate group with the second hydrophilic group) is 4.4 mol% of the total content of the blocked isocyanate group.

The preparation method of the aqueous blocked isocyanate composition of the present embodiment comprises the following steps:

(1) Add 3.0g of Ymer N 120 (purchased from Pasto, a nonionic hydrophilic agent containing 2 hydroxyl groups, the chemical composition is trimethylolpropane polyethylene glycol monomethyl ether, molecular weight 1000) to a four-necked flask, heat to 110°C, and evacuate for 2h. Cool to below 70°C, add 40.0g of acetone, 100.0g of Wanhua Wannate HT-100 (HDI trimer, NCO value: 22.0%), and 3.9g of N,N-dimethyl-N'N'-di(2-hydroxypropyl)-1,3-propylenediamine, heat to 60-65°C, and keep warm for 4h. Cool to below 50°C, then add 50.2g of 3,5-dimethylpyrazole in batches, heat to 60-65°C, and keep warm until the NCO value is zero.

Wherein: Since HDI trimer is in excess relative to nonionic hydrophilic agent, N,N-di-n-butyl-N'N'-di(2-hydroxypropyl)-1,3-propylenediamine (amine compound A3), therefore, during the reaction:

① Part of the HDI trimer, part of its isocyanate groups react with the non-ionic hydrophilic agent and the amine compound A3 respectively, so that the part of the HDI trimer has the first hydrophilic group and/or the second hydrophilic group, and then the remaining isocyanate groups on the part of the HDI trimer are blocked by a part of the blocking agent to obtain the first blocked isocyanate group, thereby obtaining the hydrophilic blocked isocyanate;

② The isocyanate group of the remaining HDI trimer is blocked by the remaining blocking agent to obtain a second blocked isocyanate group, thereby obtaining a hydrophobic blocked isocyanate. The second blocked isocyanate group has the same structure as the first blocked isocyanate group.

(2) Add 1.95 g of glacial acetic acid and stir for 20 min. Cool to 50° C., add 155.1 g of water under rapid stirring, remove acetone in vacuo, and obtain a milky white aqueous blocked isocyanate composition. The aqueous blocked isocyanate composition of this embodiment has a solid content of 50.0 wt % and a theoretical blocked NCO value of 6.4%.

The aqueous blocked isocyanate composition (aqueous dispersion) of this example showed no obvious precipitation and stratification after heat storage in an oven at 50° C. for 2 weeks.

Example 6

This embodiment provides an aqueous blocked isocyanate composition and a preparation method thereof.

The aqueous blocked isocyanate composition of this embodiment has an isocyanate group with a first hydrophilic group, an isocyanate group with a second hydrophilic group, and a blocked isocyanate group obtained by blocking the isocyanate group with a blocking agent.

Wherein: the isocyanate group with the first hydrophilic group is obtained by reacting the amine compound A1 of Example 1 with the isocyanate group. The isocyanate group with the second hydrophilic group is obtained by reacting the nonionic hydrophilic agent of Example 3 with the isocyanate group.

In the aqueous blocked isocyanate composition, the content of the amine compound A1 (or the first hydrophilic group or the isocyanate group with the first hydrophilic group) is 1.4 mol% of the total content of the blocked isocyanate group, and the total content of the amine compound A1 (or the first hydrophilic group or the isocyanate group with the first hydrophilic group) and the second hydrophilic group (or the isocyanate group with the second hydrophilic group) is 2.9 mol% of the total content of the blocked isocyanate group.

The preparation method of the aqueous blocked isocyanate composition of the present embodiment comprises the following steps:

(1) Add 7.4g of Ymer N 120 (purchased from Pasto, a nonionic hydrophilic agent containing 2 hydroxyl groups, the chemical composition is trimethylolpropane polyethylene glycol monomethyl ether, molecular weight 1000) to a four-necked flask, heat to 110°C, and evacuate for 2h. Cool to below 70°C, add 40.0g of acetone, 100.0g of Wanhua Wannate HT-100 (HDI trimer, NCO value: 22.0%), and 1.3g of N,N-dimethyl-N'N'-di(hydroxyethyl)-1,3-propylenediamine, heat to 60-65°C, and keep warm for 4h. Cool to below 50°C, then add 50.2g of 3,5-dimethylpyrazole in batches, heat to 60-65°C, and keep warm until the NCO value is zero.

Wherein: Since HDI trimer is in excess relative to nonionic hydrophilic agent, N,N-dimethyl-N'N'-di(hydroxyethyl)-1,3-propylenediamine (amine compound A1), therefore, during the reaction:

① Part of the HDI trimer, part of its isocyanate groups react with the non-ionic hydrophilic agent and the amine compound A1 respectively, so that the part of the HDI trimer has the first hydrophilic group and/or the second hydrophilic group, and then the remaining isocyanate groups on the part of the HDI trimer are blocked by a part of the blocking agent to obtain the first blocked isocyanate group, thereby obtaining the hydrophilic blocked isocyanate;

② The isocyanate group of the remaining HDI trimer is blocked by the remaining blocking agent to obtain a second blocked isocyanate group, thereby obtaining a hydrophobic blocked isocyanate. The second blocked isocyanate group has the same structure as the first blocked isocyanate group.

(2) Add 0.84 g of glacial acetic acid and stir for 20 min. Cool to 50° C., add 160.3 g of water under rapid stirring, remove acetone in vacuo, and obtain a milky white aqueous blocked isocyanate composition. The aqueous blocked isocyanate composition of this embodiment has a solid content of 50.0 wt % and a theoretical blocked NCO value of 6.5%.

The aqueous blocked isocyanate composition (aqueous dispersion) of this example showed no obvious precipitation and stratification after heat storage in an oven at 50° C. for 2 weeks.

Example 7

This embodiment provides an aqueous blocked isocyanate composition and a preparation method thereof.

The aqueous blocked isocyanate composition of this embodiment has an isocyanate group with a first hydrophilic group, an isocyanate group with a second hydrophilic group, and a blocked isocyanate group obtained by blocking the isocyanate group with a blocking agent.

Wherein: the isocyanate group with the first hydrophilic group is obtained by reacting the amine compound A1 of Example 1 with the isocyanate group. The isocyanate group with the second hydrophilic group is obtained by reacting the nonionic hydrophilic agent of Example 3 with the isocyanate group.

In the aqueous blocked isocyanate composition, the content of the amine compound A1 (or the first hydrophilic group or the isocyanate group with the first hydrophilic group) is 3.7 mol% of the total content of the blocked isocyanate group, and the total content of the amine compound A1 (or the first hydrophilic group or the isocyanate group with the first hydrophilic group) and the second hydrophilic group (or the isocyanate group with the second hydrophilic group) is 4.4 mol% of the total content of the blocked isocyanate group.

The preparation method of the aqueous blocked isocyanate composition of the present embodiment comprises the following steps:

(1) Add 3.0g of Ymer N 120 (purchased from Pasto, a nonionic hydrophilic agent containing 2 hydroxyl groups, the chemical composition is trimethylolpropane polyethylene glycol monomethyl ether, molecular weight 1000) to a four-necked flask, heat to 110°C, and evacuate for 2h. Cool down to below 70°C, add 40.0g of acetone, 100.0g of Covestro Desmodur CQ N 7300 (PDI trimer, NCO value: 21.9%), and 3.43g of N,N-dimethyl-N'N'-di(hydroxyethyl)-1,3-propylenediamine, heat to 60-65°C, and keep warm for 4h. Cool down to below 50°C, add 50.2g of 3,5-dimethylpyrazole in batches, heat to 60-65°C, and keep warm until the NCO value is zero.

Wherein: Since PDI trimer is in excess relative to nonionic hydrophilic agent, N,N-dimethyl-N'N'-di(hydroxyethyl)-1,3-propylenediamine (amine compound A1), and 3,5-dimethylpyrazole (blocking agent) is in excess relative to PDI trimer, therefore, during the reaction:

① Part of the PDI trimer, part of its isocyanate groups react with the nonionic hydrophilic agent and the amine compound A1 respectively, so that the part of the PDI trimer has the first hydrophilic group and/or the second hydrophilic group, and then the remaining isocyanate groups on the part of the PDI trimer are blocked by a part of the blocking agent to obtain the first blocked isocyanate group, thereby obtaining a hydrophilic blocked isocyanate;

② The isocyanate group of the remaining PDI trimer is blocked by the remaining blocking agent to obtain a second blocked isocyanate group, thereby obtaining a hydrophobic blocked isocyanate. The second blocked isocyanate group has the same structure as the first blocked isocyanate group.

(2) Add 2.0 g of glacial acetic acid and stir for 20 min. Cool to 50° C., add 154.6 g of water under rapid stirring, remove acetone in vacuo, and obtain a milky white aqueous blocked isocyanate composition. The aqueous blocked isocyanate composition of this embodiment has a solid content of 50.0 wt % and a theoretical blocked NCO value of 6.5%.

The aqueous blocked isocyanate composition (aqueous dispersion) of this example showed no obvious precipitation and stratification after heat storage in an oven at 50° C. for 2 weeks.

Example 8

This embodiment provides an aqueous blocked isocyanate composition and a preparation method thereof.

The aqueous blocked isocyanate composition of this embodiment has an isocyanate group with a first hydrophilic group, an isocyanate group with a second hydrophilic group, and a blocked isocyanate group obtained by blocking the isocyanate group with a blocking agent.

Wherein: the isocyanate group with the first hydrophilic group is obtained by reacting the amine compound A1 of Example 1 with the isocyanate group. The isocyanate group with the second hydrophilic group is obtained by reacting a cationic hydrophilic agent with the isocyanate group, and the cationic hydrophilic agent is a tertiary amine structure amine compound: N,N-dimethylethanolamine.

In the aqueous blocked isocyanate composition, the content of the amine compound A1 (or the first hydrophilic group or the isocyanate group with the first hydrophilic group) is 3.9 mol% of the total content of the blocked isocyanate group, and the total content of the amine compound A1 (or the first hydrophilic group or the isocyanate group with the first hydrophilic group) and the second hydrophilic group (or the isocyanate group with the second hydrophilic group) is 6.3 mol% of the total content of the blocked isocyanate group.

The preparation method of the aqueous blocked isocyanate composition of the present embodiment comprises the following steps:

(1) Add 40.0g acetone, 100.0g Wanhua Wannate HT-100 (HDI trimer, NCO value: 22.0%), 3.4g N,N-dimethyl-N'N'-di(hydroxyethyl)-1,3-propylenediamine, and 1.0g N,N-dimethylethanolamine to a four-necked flask, heat to 60-65°C, and keep warm for 4h. Cool to below 50°C, add 50.2g 3,5-dimethylpyrazole in batches, heat to 60-65°C, and keep warm until the NCO value is zero.

Wherein: Since HDI trimer is in excess relative to the cationic hydrophilic agent (N,N-dimethylethanolamine) and N,N-dimethyl-N'N'-di(hydroxyethyl)-1,3-propylenediamine (amine compound A1), therefore, during the reaction:

① Part of the HDI trimer, part of its isocyanate groups react with the cationic hydrophilic agent and the amine compound A1 respectively, so that the part of the HDI trimer has the first hydrophilic group and/or the second hydrophilic group, and then the remaining isocyanate groups on the part of the HDI trimer are blocked by a part of the blocking agent to obtain the first blocked isocyanate group, thereby obtaining a hydrophilic blocked isocyanate;

② The isocyanate group of the remaining HDI trimer is blocked by the remaining blocking agent to obtain a second blocked isocyanate group, thereby obtaining a hydrophobic blocked isocyanate. The second blocked isocyanate group has the same structure as the first blocked isocyanate group.

(2) Add 2.6 g of glacial acetic acid and stir for 20 min. Cool to 50° C., add 152.1 g of water under rapid stirring, remove acetone in vacuo, and obtain a milky white aqueous blocked isocyanate composition. The aqueous blocked isocyanate composition of this embodiment has a solid content of 50.0 wt % and a theoretical blocked NCO value of 6.3%.

The aqueous blocked isocyanate composition (aqueous dispersion) of this example showed no obvious precipitation and stratification after heat storage in an oven at 50° C. for 2 weeks.

Comparative Example 1

This comparative example provides an aqueous blocked isocyanate composition and a preparation method thereof.

The aqueous blocked isocyanate composition of this comparative example has an isocyanate group with a second hydrophilic group and a blocked isocyanate group obtained by blocking the isocyanate group with a blocking agent. The aqueous blocked isocyanate composition of this comparative example does not contain an isocyanate group with a first hydrophilic group (i.e., does not contain an amine compound with the structure of formula (1)).

The isocyanate group with the second hydrophilic group is obtained by reacting the nonionic hydrophilic agent of Example 3 with the isocyanate group.

The total content of the second hydrophilic group (or the isocyanate group having the second hydrophilic group) is 1.5 mol% of the total content of the blocked isocyanate group.

The preparation method of the aqueous blocked isocyanate composition of this comparative example comprises the following steps:

(1) Add 7.4g of Ymer N 120 (purchased from Pasto, a nonionic hydrophilic agent containing 2 hydroxyl groups, the chemical composition is trimethylolpropane polyethylene glycol monomethyl ether, molecular weight 1000) to a four-necked flask, heat to 110°C, and evacuate for 2h. Cool to below 70°C, add 40.0g of acetone and 100.0g of Wanhua Wannate HT-100 (HDI trimer, NCO value: 22.0%), heat to 60-65°C, and keep warm for 4h. Cool to below 50°C, add 50.2g of 3,5-dimethylpyrazole in batches, heat to 60-65°C, and keep warm until the NCO value is zero.

Among them: the isocyanate groups of the HDI trimer are all blocked by the blocking agent.

(2) Cooling to 50°C, adding 161.3 g of water under rapid stirring, and removing acetone in vacuo to obtain a milky white aqueous blocked isocyanate composition. The aqueous blocked isocyanate composition of this comparative example has a solid content of 50.0 wt % and a theoretical blocked NCO value of 6.6%.

The aqueous blocked isocyanate composition (aqueous dispersion) of this comparative example had a large amount of precipitation after heat storage in an oven at 50° C. for 1 day.

Comparative Example 2

This comparative example provides an aqueous blocked isocyanate composition and a preparation method thereof.

The aqueous blocked isocyanate composition of this comparative example has an isocyanate group having a first hydrophilic group, an isocyanate group having a second hydrophilic group, and a blocked isocyanate group obtained by blocking the isocyanate group with a blocking agent.

Wherein: the isocyanate group with the first hydrophilic group is obtained by reacting the amine compound A1 of Example 1 with the isocyanate group. The isocyanate group with the second hydrophilic group is obtained by reacting the nonionic hydrophilic agent of Example 3 with the isocyanate group.

In the aqueous blocked isocyanate composition, the content of the amine compound A1 (or the first hydrophilic group or the isocyanate group with the first hydrophilic group) is 0.70 mol% of the total content of the blocked isocyanate group, and the total content of the amine compound A1 (or the first hydrophilic group or the isocyanate group with the first hydrophilic group) and the second hydrophilic group (or the isocyanate group with the second hydrophilic group) is 2.2 mol% of the total content of the blocked isocyanate group.

The preparation method of the aqueous blocked isocyanate composition of this comparative example comprises the following steps:

(1) Add 7.4g of Ymer N 120 (purchased from Pasto, a nonionic hydrophilic agent containing 2 hydroxyl groups, the chemical composition is trimethylolpropane polyethylene glycol monomethyl ether, molecular weight 1000) to a four-necked flask, heat to 110°C, and evacuate for 2h. Cool to below 70°C, add 40.0g of acetone, 100.0g of Wanhua Wannate HT-100 (HDI trimer, NCO value: 22.0%), and 0.67g of N,N-dimethyl-N'N'-di(hydroxyethyl)-1,3-propylenediamine, heat to 60-65°C, and keep warm for 4h. Cool to below 50°C, then add 50.2g of 3,5-dimethylpyrazole in batches, heat to 60-65°C, and keep warm until the NCO value is zero.

(2) Add 0.84 g of glacial acetic acid and stir for 20 min. Cool to 50° C., add 160.8 g of water under rapid stirring, remove acetone in vacuo, and obtain a milky white aqueous blocked isocyanate composition. The aqueous blocked isocyanate composition of this comparative example has a solid content of 50.0 wt % and a theoretical blocked NCO value of 6.5%.

The aqueous blocked isocyanate composition (aqueous dispersion) of this comparative example had obvious precipitation after heat storage in an oven at 50° C. for 1 day.

Comparative Example 3

This comparative example provides an aqueous blocked isocyanate composition and a preparation method thereof.

The aqueous blocked isocyanate composition of this comparative example has an isocyanate group having a first hydrophilic group and a blocked isocyanate group obtained by blocking the isocyanate group with a blocking agent.

Wherein: the isocyanate group with the first hydrophilic group is obtained by reacting the amine compound A1 of Example 1 with the isocyanate group. The aqueous blocked isocyanate composition of this comparative example does not contain the isocyanate group with the second hydrophilic group (or does not contain the second hydrophilic group).

In the aqueous blocked isocyanate composition, the content of the amine compound A1 (or the first hydrophilic group or the isocyanate group with the first hydrophilic group) is 17.2 mol % of the total content of the blocked isocyanate group.

The preparation method of the aqueous blocked isocyanate composition of this comparative example comprises the following steps:

(1) Add 40.0g acetone, 100.0g Wanhua Wannate HT-100 (HDI trimer, NCO value: 22.0%), and 12.8g N,N-dimethyl-N'N'-di(hydroxyethyl)-1,3-propylenediamine to a four-necked flask, heat to 60-65°C, and keep warm for 4h. Cool to below 50°C, add 40.1g 3,5-dimethylpyrazole in batches, heat to 60-65°C, and keep warm until the NCO value is zero.

(2) Add 3.89 g of glacial acetic acid and stir for 20 min. Cool to 50° C., add 320.8 g of water under rapid stirring, remove acetone in vacuo, and obtain a translucent aqueous blocked isocyanate composition. The aqueous blocked isocyanate composition of this comparative example has a solid content of 32.0 wt %, and a theoretical blocked NCO value of 3.4%.

The aqueous blocked isocyanate composition (aqueous dispersion) of this comparative example had no obvious precipitation and stratification after heat storage in an oven at 50° C. for 2 weeks.

Comparative Example 4

This comparative example provides an aqueous blocked isocyanate composition and a preparation method thereof.

The aqueous blocked isocyanate composition of this comparative example has an isocyanate group with a second hydrophilic group and a blocked isocyanate group obtained by blocking the isocyanate group with a blocking agent. The aqueous blocked isocyanate composition of this comparative example does not contain an amine compound (or a first hydrophilic group or an isocyanate group with a first hydrophilic group) of the formula (1).

Wherein: the isocyanate group with the second hydrophilic group is obtained by reacting the nonionic hydrophilic agent of Example 3 and N,N-dimethylethanolamine (not having the structure of formula (1) and not an amine compound within the scope of the present invention) with the isocyanate group.

In the aqueous blocked isocyanate composition of this comparative example, the total content of the second hydrophilic group (or the isocyanate group with the second hydrophilic group) is 8.7 mol % of the total content of the blocked isocyanate group.

The preparation method of the aqueous blocked isocyanate composition of this comparative example comprises the following steps:

(1) Preparation of aqueous blocked isocyanate composition: Add 3.0g of Ymer N 120 (purchased from Pasto, a nonionic hydrophilic agent containing 2 hydroxyl groups, the chemical composition is trimethylolpropane polyethylene glycol monomethyl ether, molecular weight 1000) to a four-necked flask, heat to 110°C, and evacuate for 2h. Cool to below 70°C, add 40.0g of acetone, 100.0g of Wanhua Wannate HT-100 (HDI trimer, NCO value: 22.0%), and 3.2g of N,N-dimethylethanolamine, heat to 60-65°C, and keep warm for 4h. Cool to below 50°C, add 50.2g of 3,5-dimethylpyrazole in batches, heat to 60-65°C, and keep warm until the NCO value is zero.

(2) Add 2.2 g of glacial acetic acid and stir for 20 min. Cool to 50° C., add 232.3 g of water under rapid stirring, remove acetone in vacuo, and obtain a milky white aqueous blocked isocyanate composition. The aqueous blocked isocyanate composition of this comparative example has a solid content of 40.0 wt % and a theoretical blocked NCO value of 5.2%.

The aqueous blocked isocyanate composition (aqueous dispersion) of this comparative example had a large amount of precipitation after heat storage in an oven at 50° C. for 1 day.

Comparative Example 5

This comparative example provides an aqueous blocked isocyanate composition and a preparation method thereof.

The aqueous blocked isocyanate composition of this comparative example has an isocyanate group with a second hydrophilic group and a blocked isocyanate group obtained by blocking the isocyanate group with a blocking agent. The aqueous blocked isocyanate composition of this comparative example does not contain an amine compound (or a first hydrophilic group or an isocyanate group with a first hydrophilic group) of the formula (1).

Wherein: the isocyanate group with the second hydrophilic group is obtained by reacting the nonionic hydrophilic agent of Example 3 and N-methyldiethanolamine (not having the structure of formula (1) and not an amine compound within the scope of the present invention) with the isocyanate group.

In the aqueous blocked isocyanate composition of this comparative example, the total content of the second hydrophilic group (or the isocyanate group with the second hydrophilic group) is 8.7 mol % of the total content of the blocked isocyanate group.

The preparation method of the aqueous blocked isocyanate composition of this comparative example comprises the following steps:

(1) Add 3.0g of Ymer N 120 (purchased from Pasto, a nonionic hydrophilic agent containing 2 hydroxyl groups, the chemical composition is trimethylolpropane polyethylene glycol monomethyl ether, molecular weight 1000) to a four-necked flask, heat to 110°C, and evacuate for 2h. Cool to below 70°C, add 40.0g of acetone, 100.0g of Wanhua Wannate HT-100 (HDI trimer, NCO value: 22.0%), and 4.3g of N-methyldiethanolamine, heat to 60-65°C, and keep warm for 4h. Cool to below 50°C, add 46.5g of 3,5-dimethylpyrazole in batches, heat to 60-65°C, and keep warm until the NCO value is zero.

(2) Add 2.2 g of glacial acetic acid and stir for 20 min. Cool to 50° C., add 151.6 g of water under rapid stirring, remove acetone in vacuo, and obtain a milky white aqueous blocked isocyanate composition. The aqueous blocked isocyanate composition of this comparative example has a solid content of 50.0 wt %, and a theoretical blocked NCO value of 6.1%.

The aqueous blocked isocyanate composition (aqueous dispersion) of this comparative example had a large amount of precipitation after heat storage in an oven at 50° C. for 1 day.

Comparative Example 6

This comparative example provides an aqueous blocked isocyanate composition and a preparation method thereof.

The aqueous blocked isocyanate composition of this comparative example has an isocyanate group with a second hydrophilic group and a blocked isocyanate group obtained by blocking the isocyanate group with a blocking agent. The aqueous blocked isocyanate composition of this comparative example does not contain an amine compound (or a first hydrophilic group or an isocyanate group with a first hydrophilic group) of the formula (1).

Wherein: the isocyanate group with the second hydrophilic group is obtained by reacting the nonionic hydrophilic agent of Example 3 and N-methyldiethanolamine (not having the structure of formula (1) and not an amine compound within the scope of the present invention) with the isocyanate group.

In the aqueous blocked isocyanate composition of this comparative example, the total content of the second hydrophilic group (or the isocyanate group with the second hydrophilic group) is 32.4 mol % of the total content of the blocked isocyanate group.

The preparation method of the aqueous blocked isocyanate composition of this comparative example comprises the following steps:

(1) Add 3.0g of Ymer N 120 (purchased from Pasto, a nonionic hydrophilic agent containing 2 hydroxyl groups, the chemical composition is trimethylolpropane polyethylene glycol monomethyl ether, molecular weight 1000) to a four-necked flask, heat to 110°C, and evacuate for 2h. Cool to below 70°C, add 40.0g of acetone, 100.0g of Wanhua Wannate HT-100 (HDI trimer, NCO value: 22.0%), and 8.9g of N,N-dimethylethanolamine, heat to 60-65°C, and keep warm for 4h. Cool to below 50°C, then add 43.6g of 3,5-dimethylpyrazole in batches, heat to 60-65°C, and keep warm until the NCO value is zero.

(2) Add 6.0 g of glacial acetic acid and stir for 20 min. Cool to 50° C., add 356.7 g of water under rapid stirring, remove acetone in vacuo, and obtain a translucent aqueous blocked isocyanate composition. The aqueous blocked isocyanate composition of this comparative example has a solid content of 30.0 wt % and a theoretical NCO value of 3.4%.

The aqueous blocked isocyanate composition (aqueous dispersion) of this comparative example turned white in appearance and had a small amount of precipitation after being heat-stored in an oven at 50° C. for 7 days.

Comparative Example 7

This comparative example provides an aqueous blocked isocyanate composition and a preparation method thereof.

The aqueous blocked isocyanate composition of this comparative example has an isocyanate group with a second hydrophilic group and a blocked isocyanate group obtained by blocking the isocyanate group with a blocking agent. The aqueous blocked isocyanate composition of this comparative example does not contain an amine compound (or a first hydrophilic group or an isocyanate group with a first hydrophilic group) of the formula (1).

Wherein: the isocyanate group with the second hydrophilic group is obtained by reacting the non-ionic hydrophilic agent of Example 3 with the isocyanate group.

In the aqueous blocked isocyanate composition of this comparative example, the total content of the second hydrophilic group (or the isocyanate group with the second hydrophilic group) is 10.4 mol % of the total content of the blocked isocyanate group.

The preparation method of the aqueous blocked isocyanate composition of this comparative example comprises the following steps:

(1) Add 45.0g of Ymer N 120 (purchased from Pasto, a nonionic hydrophilic agent containing 2 hydroxyl groups, the chemical composition is trimethylolpropane polyethylene glycol monomethyl ether, molecular weight 1000) to a four-necked flask, heat to 110°C, and evacuate for 2h. Cool to below 70°C, add 40.0g of acetone and 100.0g of Wanhua Wannate HT-100 (HDI trimer, NCO value: 22.0%), heat to 60-65°C, and keep warm for 4h. Cool to below 50°C, add 44.6g of 3,5-dimethylpyrazole in batches, heat to 60-65°C, and keep warm until the NCO value is zero.

(2) Cooling to 50°C, adding 403.0 g of water with rapid stirring, and removing acetone in vacuo to obtain a translucent aqueous blocked isocyanate composition. The aqueous blocked isocyanate composition of this comparative example has a solid content of 32.0 wt % and a theoretical NCO value of 3.1%.

The aqueous blocked isocyanate composition (aqueous dispersion) of this comparative example had no obvious precipitation and stratification after heat storage in an oven at 50° C. for 2 weeks.

Example 8

This embodiment provides an application of a water-based blocked isocyanate composition in a water-based textile waterproof coating. The water-based blocked isocyanate compositions of embodiments 1 to 7 are respectively combined with a waterproof finishing agent and used in a water-based textile waterproof coating.

Performance Testing

The performance of the water-based blocked isocyanate compositions provided in Examples 1-8 and Comparative Examples 3, 6-7 was tested. The process is as follows:

(1) The water repellency of the aqueous blocked isocyanate compositions provided in Examples 1-8 and Comparative Examples 3, 6-7, and the commercial nonionic isocyanate composition BL-8128W (Guangzhou Guanzhi New Materials, solid content: 40wt%, theoretical blocked NCO value: 4.8%) was tested on textile fabrics separately. Test method: The wetting condition was directly tested on white cotton twill fabric using the dripping method. The shorter the wetting time of the fabric surface, the worse the water repellency of the composition. If it cannot be wetted, the water repellency is optimal. The test results are shown in Table 1:

Table 1 Water repellency of isocyanate composition tested alone

(2) The aqueous blocked isocyanate compositions provided in Examples 1-8 and Comparative Examples 3 and 6-7, as well as the commercial nonionic isocyanate composition BL-8128W (Guangzhou Guanzhi New Materials) and the commercially available waterproof finishing agent TF-5548 (Chuanhua) were respectively formulated into textile waterproof coatings, and the relevant properties of the coatings were tested.

Water-based textile waterproof coatings are shown in Table 2:

Table 2 Water-based textile waterproof coating formula (parts)

Among them, the aqueous blocked isocyanate compositions of Examples 1-8 were respectively formulated into aqueous textile waterproof coatings 1-8, the aqueous blocked isocyanate composition of Comparative Example 3 was formulated into aqueous textile waterproof coating 9, the aqueous blocked isocyanate compositions of Comparative Examples 6-7 were respectively formulated into aqueous textile waterproof coatings 10-11, and the commercial nonionic isocyanate composition BL-8128W was formulated into aqueous textile waterproof coating 12.

The relevant properties of the coatings formed by coatings 1-12 on textile fabrics were tested respectively:

Process: padding → drying at 110℃ → shaping at 170℃×120s → testing the waterproof effect before and after washing.

Textile: White cotton twill.

Waterproof effect test standard: GB/T 4745-2012.

Washing test standard: GB/T 8629-2017 4N program, wash 3 times, tumble dry.

The performance test results of water-based textile waterproof coatings 1-12 are shown in Table 3:

Table 3 Performance test results of water-based textile waterproof coatings

According to the above results, we can know that:

In the aqueous blocked isocyanate compositions of Examples 1 to 8 of the present invention, when only a very small amount of the specific amine compound of the structure of formula (1) (or a hydrophilic group derived from the amine compound of the structure of formula (1)) is contained, that is, when the content of the amine compound of the structure of formula (1) is 1-9.9 mol% of the total content of the blocked isocyanate group (or the first blocked isocyanate group and the second blocked isocyanate group), the storage stability of the aqueous blocked isocyanate composition can be maintained, and the aqueous blocked isocyanate composition can be ensured to have good water repellency, and is particularly suitable for use in aqueous textile waterproof coatings in combination with a waterproof finishing agent.

It should be emphasized that the core of the present invention is that the water-based blocked isocyanate composition can maintain the storage stability of the water-based blocked isocyanate composition even when it contains only a very small amount of the specific amine compound of formula (1) (or the hydrophilic group derived from the amine compound of formula (1)). Those skilled in the art can choose to introduce or introduce different second hydrophilic groups according to actual conditions or needs, but the total amount of the first hydrophilic group (derived from the amine compound of formula (1)) and the second hydrophilic group must meet the defined conditions.

The aqueous blocked isocyanate composition within the scope of the present invention has a high solid content (35-55wt%), a high theoretical blocked NCO value (5-10%), and is stable for storage. The aqueous blocked isocyanate compositions of Examples 1-8 of the present invention were tested separately on textile fabrics and had good water repellency, did not wet the textile fabrics, and had good waterproof and washable effects.

In the aqueous blocked isocyanate compositions of Comparative Examples 1-2 and 4-5, an amine compound of the structure of formula (1) with too low a proportion is used or an amine compound within the scope of the present invention is not used as a hydrophilic agent, and the obtained aqueous blocked isocyanate compositions (aqueous dispersions) cannot be stably stored, so no further performance tests are performed. Among them, the aqueous blocked isocyanate composition of Comparative Example 1 does not contain the amine compound of formula (1) of the present invention, nor does it use other amine compounds as hydrophilic agents, and cannot be stably stored; the aqueous blocked isocyanate composition of Comparative Example 2 contains the amine compound of formula (1) of the present invention, but its content is too low and cannot be stably stored. The aqueous blocked isocyanate compositions of Comparative Examples 4 and 5 do not use the amine compound of the structure of formula (1) of the present invention, and cannot be stably stored when the content is low (1-9.9 mol%).

The aqueous blocked isocyanate composition of Comparative Example 3 contains the amine compound of formula (1) of the present invention, but its content is too high. Although it can be stably stored, the hydrophilicity of the aqueous blocked isocyanate composition is too strong, which affects the water repellency and waterproof and washable properties. In addition, the solid content and NCO value of the obtained aqueous blocked isocyanate composition are both low.

The aqueous blocked isocyanate composition of Comparative Example 6 does not use the amine compound of the structure of formula (1) of the present invention as a hydrophilic agent, but uses the common amine compound N,N-dimethylethanolamine as a hydrophilic agent, and the content of N,N-dimethylethanolamine accounts for 32.4 mol% of the total content of blocked isocyanate groups; although the aqueous blocked isocyanate composition has good storage stability, due to the excessively high content of hydrophilic groups derived from N,N-dimethylethanolamine, the aqueous blocked isocyanate composition has excessive hydrophilicity, poor water repellency, and is easy to wet textile fabrics, and has poor waterproof and washable effects, and cannot achieve the same water repellency and waterproof and washable effects as the present invention. Moreover, due to the excessive number of hydrophilic groups, the solid content of the aqueous blocked isocyanate composition cannot be increased, and the theoretical blocked NCO value is also low.

The aqueous blocked isocyanate composition of Comparative Example 7 and the commercial nonionic isocyanate composition BL-8128W only use nonionic hydrophilic agents. In order to obtain better storage stability, a larger amount of nonionic hydrophilic agents needs to be added, which also leads to a low theoretical blocked NCO value of the blocked isocyanate composition itself, and causes the blocked isocyanate composition to be highly hydrophilic, with poor water repellency and waterproof and washable effects.

The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, and the present invention is also intended to include these modifications and modifications.

Claims (10)

1. An aqueous blocked isocyanate composition characterized by: an isocyanate group having a first hydrophilic group, and a blocked isocyanate group obtained by blocking the isocyanate group with a blocking agent; the isocyanate group with the first hydrophilic group is obtained by reacting an amine compound with the formula (1) with the isocyanate group; the content of the amine compound is 1 to 9.9mol% of the total content of the blocked isocyanate groups;

In formula (1), R ₁ and R ₂ are each independently C1-C4 alkyl, and R ₃ and R ₄ are each independently H or C1-C4 alkyl.

2. The aqueous blocked isocyanate composition of claim 1, wherein: comprising a hydrophobic blocked isocyanate and a hydrophilic blocked isocyanate; the hydrophobic blocked isocyanate does not contain a hydrophilic group, and has a first blocked isocyanate group obtained by blocking an isocyanate group with a first blocking agent; the hydrophilic blocked isocyanate has the isocyanate group having the first hydrophilic group, and a second blocked isocyanate group obtained by blocking the isocyanate group with a second blocking agent; the blocked isocyanate groups include the first blocked isocyanate group and the second blocked isocyanate group.

3. The aqueous blocked isocyanate composition according to claim 1 or 2, characterized in that: the aqueous blocked isocyanate composition further has an isocyanate group having a second hydrophilic group; the second hydrophilic group is a nonionic hydrophilic group and/or a cationic hydrophilic group; the total content of the amine compound and the second hydrophilic group in the aqueous blocked isocyanate composition is 1.1 to 9.9mol% of the total content of blocked isocyanate groups;

the cationic hydrophilic group is derived from other tertiary amine structure amine compounds except the amine compound of the formula (1);

the nonionic hydrophilic group is derived from a polyether compound containing a polyoxyalkylene segment of formula (2);

in formula (2), R ₅ is H or C1-C4 alkyl.

4. The aqueous blocked isocyanate composition according to claim 1 or 2, characterized in that: having aliphatic diisocyanate monomer units and/or aromatic diisocyanate monomer units.

5. The aqueous blocked isocyanate composition of claim 4, wherein: the precursor isocyanate compound of the aqueous blocked isocyanate composition is at least one of hexamethylene diisocyanate, pentamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, MDI oligomer, naphthalene-1, 5-diisocyanate, xylylene diisocyanate, 4-dicyclohexylmethane diisocyanate, norbornane diisocyanate, isophorone diisocyanate, adducts of diisocyanates, allophanate modifications, biuret modifications, isocyanurate modifications, carbodiimide modifications, and polyurethane prepolymers.

6. The aqueous blocked isocyanate composition according to claim 1 or 2, characterized in that: the blocking agent is a substance containing active hydrogen capable of reacting with isocyanate and comprises at least one of pyrazole compounds, imidazole compounds, ketoxime compounds, amide compounds, phenol compounds, alcohol compounds and dialkyl malonates.

7. The aqueous blocked isocyanate composition according to claim 1 or 2, characterized in that: comprising water; the solid content of the aqueous blocked isocyanate composition is 35-55wt% and the theoretical blocked NCO value is 5-10%.

8. A process for the preparation of the aqueous blocked isocyanate composition according to any one of claims 1 to 7, characterized in that: the method comprises the following steps:

(1) Adding an organic solvent, a precursor isocyanate compound, the amine compound and the blocking agent into a reaction container for reaction until the NCO value is 0;

Wherein: reacting the amine compound with an isocyanate group on the precursor isocyanate compound to generate the isocyanate group with a first hydrophilic group; reacting the blocking agent with an isocyanate group on the precursor isocyanate compound to obtain the blocked isocyanate group; the content of the amine compound is 1 to 9.9mol% of the total content of the blocked isocyanate groups;

(2) Adding an acid neutralizer, adding water, stirring and dispersing, and removing the organic solvent to obtain the water-based closed isocyanate composition.

9. The process for preparing an aqueous blocked isocyanate composition according to claim 8, wherein: the acid neutralizer is organic acid or inorganic acid.

10. Use of an aqueous blocked isocyanate composition according to any one of claims 1 to 8 in an aqueous textile waterproof coating.