Water-based hardener, water-based matte coating composition containing the same and related applications thereof

Abstract

The present invention provides a water-based hardener, which is an adduct of a polyisocyanate compound and an aminosulfonic acid compound having an ether group of formula (I), wherein R1, R2 and R3 are as defined herein. The present invention also provides a water-based matte coating composition comprising the water-based hardener, and related applications thereof.

Description

Technical Field

[0001] The invention relates to a water-based hardener, a water-based matte coating composition containing the water-based hardener, and related applications thereof. Background Art

[0002] Matting paint can reduce the glossiness of the surface of an object to achieve the purpose of matting. According to the principle of matting, it can be roughly divided into physical matting and chemical matting.

[0003] Physical matting is to add a matting agent to the coating. When the coating dries and the solvent evaporates, the matting agent particles will form a microscopically uneven rough surface on the coating surface, which changes the reflection direction of the incident light and causes scattering, thereby producing a low-gloss appearance. Common matting agents can be roughly divided into two categories: organic and inorganic. Inorganic matting agents include silica, kaolin, diatomaceous earth, etc., while organic matting agents include wax, metal stearate, etc. The surface of silica can also be treated with wax to prepare a composite matting agent. However, the disadvantage of physical matting is that physical matting coatings must have surface defects, which reduces physical properties. In addition, physical matting coatings may also have the problem of uneven dispersion of matting agents.

[0004] Chemical matting is usually a resin coating, for example, it can take advantage of the physical and chemical property differences between two or more resins, such as different curing temperatures or different surface tensions, to cause uneven shrinkage of the coating surface and form a rough surface. However, chemical matting has the disadvantage of complex resin synthesis technology and high difficulty.

[0005] Although the structural design of resins varies greatly and the synthesis technology is complex, the industry hopes to develop a coating that can achieve a matte effect using a single resin without adding a matte agent. It also hopes that the matte coating developed will have excellent physical properties compared to traditional matte coatings with matte agents added. Summary of the invention

[0006] The present invention provides a water-based hardener, which is an adduct of a polyisocyanate compound and an aminosulfonic acid compound having an ether group of formula (I).

[0007]

[0008] wherein R1 is a straight or branched alkyl group having 2 to 6 carbon atoms,

[0009] wherein R2 and R3 are each a straight or branched alkyl group having at least 1 carbon atom, and the sum of the carbon atoms of R2 plus R3 is 2 to 15; and

[0010] The amount of the aminosulfonic acid used is 0.3 to 25 weight % based on the total weight of the polyisocyanate and the aminosulfonic acid.

[0011] The present invention also provides a method for preparing the aforementioned aqueous hardener, which comprises reacting the polyisocyanate with the aminosulfonic acid in the presence of a tertiary amine.

[0012] The present invention also provides a polyurethane resin, which is obtained by polymerization reaction of the above-mentioned water-based hardener and polyol.

[0013] The present invention also provides a water-based matte coating composition comprising the water-based hardener.

[0014] In order to make the above-mentioned objectives, technical features and advantages of the present invention more obvious and easy to understand, some specific embodiments are described in detail below. DETAILED DESCRIPTION

[0015] To facilitate understanding of the disclosure set forth herein, several terms are defined below.

[0016] The term "alkyl" means a saturated straight or branched hydrocarbon group, preferably having 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms; examples include (but are not limited to): methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and t-butyl, etc.

[0017] The term "about" means an acceptable error for the particular value as determined by one of ordinary skill in the art, which depends in part on how the value is measured or determined.

[0018] Each aspect and each embodiment of the present invention disclosed in this specification can be individually combined with all other aspects and embodiments of the present invention, covering all possible combinations.

[0019] The present invention provides a water-based hardener, which is a modified polyisocyanate. The modified polyisocyanate is prepared by using a tertiary amine as a catalyst and an aminosulfonic acid compound having an ether group of formula (I) to modify the polyisocyanate compound.

[0020]

[0021] wherein R1 is a straight or branched alkyl group having 2 to 6 carbon atoms,

[0022] wherein R2 and R3 are each a straight or branched alkyl group having at least 1 carbon atom, and the sum of the carbon atoms of R2 plus R3 is 2 to 15; and

[0023] The amount of the aminosulfonic acid having an ether group is 0.3 to 25 wt % based on the total weight of the polyisocyanate and the aminosulfonic acid.

[0024] According to some embodiments of the present invention, R1 is a straight-chain alkyl group having 2, 3, 4, 5 or 6 carbon atoms, or R1 is a branched-chain alkyl group having 2, 3, 4, 5 or 6 carbon atoms.

[0025] According to some embodiments of the present invention, R2 is a straight-chain alkyl group having 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14 carbon atoms, or R2 is a branched alkyl group having 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14 carbon atoms.

[0026] According to some embodiments of the present invention, R3 is a straight-chain alkyl group having 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14 carbon atoms, or R3 is a branched alkyl group having 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14 carbon atoms.

[0027] According to a preferred embodiment of the present invention, R1 is a straight chain alkyl group having 4 carbon atoms, R2 is a straight chain alkyl group having 2 or 3 carbon atoms, and / or R3 is a straight chain or branched alkyl group having 1, 2, 3 or 4 carbon atoms.

[0028] According to a preferred embodiment of the present invention, the aminosulfonic acid having an ether group can be prepared by reacting an amine having an ether group with a sulfoalkylating agent. According to some embodiments of the present invention, the amine having an ether group can be 3-n-butoxypropylamine, 3-isopropoxypropylamine or 2-methoxyethylamine, and according to some embodiments of the present invention, the sulfoalkylating agent can be 1,3-propane sultone or 1,4-butane sultone.

[0029] According to some embodiments of the present invention, the amount of the aminosulfonic acid with ether group is 0.3 to 25 weight %, such as 0.3 weight %, 0.5 weight %, 0.7 weight %, 1 weight %, 2 weight %, 3 weight %, 4 weight %, 5 weight %, 6 weight %, 7 weight %, 8 weight %, 9 weight %, 10 weight %, 11 weight %, 12 weight %, 13 weight %, 14 weight %, 15 weight %, 16 weight %, 17 weight %, 18 weight %, 19 weight %, 20 weight %, 21 weight %, 22 weight %, 23 weight %, 24 weight % or 25 weight %, based on the total weight of the polyisocyanate and the aminosulfonic acid with ether group. Correspondingly, the amount of the polyisocyanate is 75 weight % to 99.7 weight %, based on the total weight of the polyisocyanate and the aminosulfonic acid with ether group.

[0030] As mentioned above, the water-based hardener of the present invention is obtained by modifying the polyisocyanate compound with an aminosulfonic acid compound having an ether group, and the matting property can be controlled by adjusting the amount of aminosulfonic acid. Compared with the matting principle of the prior art, the polyurethane resin obtained by the polymerization reaction of the above-mentioned water-based hardener and polyol has a soft segment (polyol) and a hard segment (polyisocyanate), which will cause microphase separation in the cross-linked structure and produce a matting effect. Because the polarity of the polyisocyanate modified with the aminosulfonic acid compound having an ether group is higher, the degree of microphase separation of the polyurethane resin structure is more obvious, and the matting effect is better. Therefore, the water-based hardener of the present invention can obtain a coating film with a matting effect without adding a matting agent or the paint film is not roughened by a mechanical method. Compared with the matting principle of the prior art, the surface of the matting coating film obtained by the present invention is smoother, so the physical properties of the coating film, such as strength, can be maintained. In addition, compared to the prior art which requires two or more resins to achieve chemical matting, the polyurethane resin of the present invention can achieve the matting effect with only a single resin, without the need to design a unique chemical structure on the molecule, and is convenient to synthesize.

[0031] According to some embodiments of the present invention, the polyisocyanate may be any polyisocyanate, which is composed of at least two diisocyanates and is prepared by modifying simple aliphatic, cycloaliphatic, araliphatic and / or aromatic diisocyanates. The polyisocyanate has a uretdione, isocyanurate, allophanate, biuret, imino-oxadiazinedione, and / or oxadiazinedione structure, such as described in the following documents: DE1670666A, DE1954093A, DE2414413A, DE2452532A, DE2641380A, DE3700209A, DE3900053A, DE3928503A, EP0336205A, EP0339396A and EP0798299A, etc.

[0032] The diisocyanate used to prepare the aforementioned polyisocyanate can be obtained by phosgene or phosgene-free method, such as any diisocyanate obtained by thermal cracking of ethyl carbamate. According to a preferred embodiment of the present invention, the diisocyanate is a diisocyanate having a molecular weight range of 100 to 500 and having aliphatic, cycloaliphatic, aromatic aliphatic and / or aromatic groups, such as 1,4-diisocyanate butane, 1,6-hexamethylene diisocyanate (HDI), 2-methyl-1,5-diisocyanate pentane, 1,5-diisocyanate-2,2-dimethylpentane, 2,2,4- and 2,4,4-trimethyl-1,6-diisocyanate hexane, 1,10-diisocyanate decanane, 1,3- and 1,4-diisocyanate hexane, 1,3- and 1,4-bis(isocyanate)-1,4-diisocyanate ... diisocyanate (TDI), 2,4'- and 4,4'-diisocyanate diphenylmethane (MDI) and 1,5-diisocyanate naphthalene or mixtures thereof.

[0033] According to some embodiments of the present invention, the polyisocyanate is selected from the group consisting of aliphatic polyisocyanates, cycloaliphatic polyisocyanates, aromatic polyisocyanates, aromatic polyisocyanates, and combinations thereof. According to a preferred embodiment of the present invention, the polyisocyanate is an aliphatic and / or cycloaliphatic polyisocyanate. According to a more preferred embodiment of the present invention, the polyisocyanate has an isocyanurate structure and is prepared based on 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI) and / or 4,4'-dicyclohexylmethane diisocyanate (H12MDI).

[0034] The isocyanate of the polyisocyanate can undergo an addition reaction with the amino group of the aminosulfonic acid having an ether group to form a urea group. According to some embodiments of the present invention, since the polyisocyanate has a plurality of isocyanates, the adduct of the polyisocyanate and the aminosulfonic acid can be a modified polyisocyanate with different amounts of aminosulfonic acids, such as a modified polyisocyanate with 1, 2 or 3 aminosulfonic acids, depending on the amount of aminosulfonic acid used.

[0035] According to some embodiments of the present invention, the average isocyanate functionality of the aqueous hardener is at least 1.8 and at most 4.8, for example, 1.8, 2, 2.2, 2.5, 2.8, 3, 3.2, 3.3, 3.4, 3.5, 4, 4.5, 4.8. According to a preferred embodiment of the present invention, the average isocyanate functionality of the aqueous hardener is 2.5 to 4.5. According to a more preferred embodiment of the present invention, the average isocyanate functionality of the aqueous hardener is 3.0 to 3.5.

[0036] According to some embodiments of the present invention, the isocyanate group content (calculated as NCO; molecular weight = 42) is 4.0 to 26.0% by weight, such as 4.0%, 5.0%, 6.0%, 7.0%, 8.0%, 9.0%, 10.0%, 11.0%, 12.0%, 13.0%, 14.0%, 15.0%, 16.0%, 17.0%, 18.0%, 19.0%, 20.0%, 21.0%, 22.0%, 23.0%, 24.0%, 25.0% or 26.0% by weight, based on the weight of the aqueous hardener. According to a preferred embodiment of the present invention, the isocyanate group content (calculated as NCO; molecular weight = 42) is 15.0 to 26.0% by weight, based on the weight of the aqueous hardener. According to a more preferred embodiment of the present invention, the isocyanate group content (calculated as NCO; molecular weight = 42) is 20.0 to 21.0 wt % based on the weight of the aqueous hardener.

[0037] According to some embodiments of the present invention, the sulfonate group content (in terms of SO3 - % ; molecular weight = 80) is 0.1 to 7.7 wt%, for example 0.1 wt%, 0.3 wt%, 0.5 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt% or 7.7 wt%. According to a preferred embodiment of the present invention, the sulfonate group content (in terms of SO3 based on the weight of the aqueous hardener) is 0.1 to 7.7 wt%, for example 0.1 wt%, 0.3 wt%, 0.5 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt% or 7.7 wt%. - Calculated as; molecular weight = 80) is 0.1 to 1.7% by weight. According to a preferred embodiment of the present invention, based on the weight of the aqueous hardener, the sulfonate group content (as SO3 - Calculated; molecular weight = 80) is 0.8 to 1.0 wt%.

[0038] The present invention also provides a method for preparing the aforementioned aqueous hardener, which comprises reacting a polyisocyanate with an aminosulfonic acid having an ether group of formula (I) in the presence of a tertiary amine.

[0039] According to some embodiments of the present invention, the average functionality of the polyisocyanate used for reacting with aminosulfonic acid is 2.0 to 5.0, such as 2.0, 2.5, 3.0, 3.5, 4.0, 4.5 or 5.0. According to a preferred embodiment of the present invention, the average functionality of the polyisocyanate used for reacting with aminosulfonic acid is 3.5.

[0040] According to some embodiments of the present invention, the content of isocyanate groups in the polyisocyanate used for reacting with aminosulfonic acid (calculated as NCO; molecular weight = 42) is 8.0 to 27.0 weight%, for example, 8.0 weight%, 10.0 weight%, 12.0 weight%, 14.0 weight%, 16.0 weight%, 18.0 weight%, 20.0 weight%, 22.0 weight%, 24.0 weight%, 26.0 weight% or 27.0 weight%.

[0041] According to some embodiments of the present invention, based on the total weight of the polyisocyanate and the aminosulfonic acid having an ether group, the aminosulfonic acid is used in an amount of 0.3 to 25.0 wt %, for example, 0.3 wt %, 0.5 wt %, 1 wt %, 3 wt %, 5 wt %, 10 wt %, 15 wt %, 20 wt % or 25 wt %.

[0042] According to some embodiments of the present invention, the tertiary amine is a catalyst for the reaction of polyisocyanate with aminosulfonic acid having an ether group, and is used to neutralize the sulfonic acid group in the product water-based hardener to form a sulfonate. According to some embodiments of the present invention, the tertiary amine is an aliphatic and / or alicyclic substituted tertiary amine, and has an acyclic and / or cyclic structure. The tertiary amine includes monovalent tertiary amines, such as trimethylamine, triethylamine, tripropylamine, dimethylcyclohexylamine, N-methylmorpholine, N-methylquinoline and N-ethylquinoline, etc.; and divalent tertiary amines, such as 1,3-bis-(dimethylamino)-propane and N,N-dimethylpiperazine, etc. According to a preferred embodiment of the present invention, the tertiary amine is one or more of triethylamine, dimethylcyclohexylamine and N-methylmorpholine. According to a more preferred embodiment of the present invention, the tertiary amine is dimethylcyclohexylamine.

[0043] According to some embodiments of the present invention, the tertiary amine can also be mixed with a conventional catalyst commonly used in polyurethane synthesis, such as other tertiary amine catalysts: pyridine, picoline, benzyldimethylamine, N,N-dimethylpiperazine; organic metal catalysts: tri(ethyl-acetyl acetate)aluminum, tin octanoate, zinc octanoate, 2-ethyl-1-hexanoic acid tin (II), dibutyltin (IV) dichloride, dibutyltin (IV) diacetate, dibutyltin (IV) dilaurate, dioctyltin (IV) diacetate or a mixture of one or more of molybdenum glycolate. The conventional catalysts are used in an amount of 10 to 2000 ppm, such as 100 to 500 ppm, based on the total weight of the reactants.

[0044] According to some embodiments of the present invention, the amount of the tertiary amine is 0.2 to 2.0 equivalents based on the sulfonic acid group of the aminosulfonic acid with an ether group, such as 0.2 equivalents, 0.5 equivalents, 1 equivalent, 1.5 equivalents or 2.0 equivalents. According to a preferred embodiment of the present invention, the amount of the tertiary amine is 0.5 to 1.5 equivalents based on the sulfonic acid group of the aminosulfonic acid with an ether group. According to a preferred embodiment of the present invention, the amount of the tertiary amine is 1 equivalent based on the sulfonic acid group of the aminosulfonic acid with an ether group.

[0045] According to some embodiments of the present invention, the equivalent ratio of the isocyanate group of the polyisocyanate to the group reactive to the isocyanate group (e.g., the amine group in the aminosulfonic acid) is between 2:1 and 400:1, such as 2:1, 3:1, 4:1, 6:1, 10:1, 20:1, 50:1, 100:1, 200:1, 300:1, or 400:1. Since the equivalent ratio of the isocyanate group to the group reactive to the isocyanate group is greater than 1, there are still residual isocyanate groups in the product water-based hardener for subsequent polyurethane synthesis reaction. By adjusting the aforementioned equivalent ratio, a balance is sought between not affecting the properties of the final product and obtaining matting properties.

[0046] The water-based hardener of the present invention has a sulfonic acid group or a sulfonate, can be easily dissolved in water, and can maintain stability. The water-based hardener of the present invention can be used with most polyols to prepare water-based polyurethane resins. In addition, the water-based hardener of the present invention is obtained by modifying a polyisocyanate compound with an aminosulfonic acid compound having an ether group, and when used as a water-based polyurethane (PU) coating hardener, a matte coating film can be obtained.

[0047] The present invention also provides a polyurethane resin obtained by polymerization reaction of the aforementioned water-based hardener and polyol. The polyol has a plurality of hydroxyl groups, which can react with the isocyanate groups of the water-based hardener to form the polyurethane resin. According to some embodiments of the present invention, the ratio of the isocyanate groups (NCO) of the water-based hardener to the hydroxyl groups (OH) of all the polyols is 1.1 to 1.5 in moles.

[0048] Polyols can be roughly divided into polyacrylate polyols, polyether polyols and polyester polyols, and their molecular weight can range from 250 to 150,000, for example, 250, 500, 1,000, 2,000, 3,000, 5,000, 10,000, 20,000, 30,000, 50,000, 70,000, 80,000, 100,000, 120,000, 140,000 or 150,000.

[0049] The polyether polyols suitable for use in the present invention are not particularly limited, for example but not limited to: polyoxypropylene diol, polyoxypropylene triol, polytetramethylene ether glycol, polyethylene glycol, polytetramethylene ether glycol, tetramethylene ether glycol, tetramethylene ether glycol-propylene oxide copolymer glycol, or a combination thereof.

[0050] The polyester polyols suitable for use in the present invention are not particularly limited, and can be obtained by reacting a polycarboxylic acid with a polyol, such as but not limited to: aliphatic polyester diols, such as polyethylene adipate diol, polybutylene adipate diol, polyhexane adipate diol, or a combination thereof; aromatic polyester diols, such as polyethylene phthalate diol, polyneopentyl phthalate diol, polyhexane phthalate diol, or a combination thereof.

[0051] The polyacrylate polyol applicable to the present invention is not particularly limited, and can be obtained by polymerizing a hydroxyl-containing (meth)acrylate monomer with (meth)acrylic acid and / or other (meth)acrylate monomers.

[0052] According to some embodiments of the present invention, the polyol is a waterborne polyacrylate polyol, and is ETERSOL 1194-1 (solid content of 41.6%; hydroxyl value (based on solids) of 110 mg KOH / g) purchased from Changxing Materials.

[0053] According to some embodiments of the present invention, the prepared polyurethane resin may be a thermoplastic or thermosetting polymer. According to some embodiments of the present invention, the thermal decomposition temperature of the polyurethane resin is at least greater than 200° C. The polyurethane resin prepared by the present invention has good matting, toughness, acid resistance, adhesion, hardness, etc.

[0054] The present invention also provides a water-based matte coating composition, which comprises the above-mentioned water-based hardener. According to some embodiments of the present invention, the composition may further comprise other optional materials known in the formulation technology, such as chain extenders, colorants, plasticizers, wear-resistant particles, antioxidants, hindered amine light stabilizers, UV light absorbers and stabilizers, surfactants, flow control agents, thixotropic agents, fillers, water, organic solvents, reactive diluents, catalysts, grinding media, slip agents, dehumidifiers and other conventional additives. The water-based matte coating composition of the present invention has a self-matting effect, so there is no need to add a matte agent.

[0055] The composition of the present invention can be applied to substrates known in the industry, such as automobiles, marine substrates, outdoor walls, indoor walls, industrial substrates, containers, cement substrates, wood, wood floors, furniture, electronic products and sports equipment, etc., which can also be divided into metal or non-metal substrates.

[0056] According to some embodiments of the present invention, the composition of the present invention may be a two-component or multi-component composition, wherein the various components are kept separate just before application. The composition of the present invention may be applied by any standard means in the industry, such as electrocoating, spraying, electrostatic spraying, dipping, roller coating or brushing, and may be cured by any conventional means, such as by heating, forced ventilation, etc.

[0057] Example

[0058] The following examples are used to further illustrate the present invention, but are not used to limit the scope of the present invention. Any modifications and changes that can be easily achieved by those with ordinary knowledge in the art are included in the scope of the disclosure of the present invention and the appended claims.

[0059] The raw materials used in each preparation example and embodiment are shown in Table 1:

[0060] Table 1

[0061]

[0062] Preparation of aminosulfonic acid

[0063] Preparation Example 1: Synthesis of aminosulfonic acid A-1 (4-(3-n-butoxypropylamino)-butanesulfonic acid)

[0064] A mechanical stirrer, a thermometer, a reflux tube, a heating bag and a nitrogen inlet and outlet were set on a four-necked round-bottomed flask. Then the nitrogen was turned on. 48.5 ml of 1,4-dioxane was added as a solvent, and then 9.178 g of 3-n-butoxypropylamine and 10.000 g of 1,4-butane sultone were added to the round-bottomed flask. The reaction was heated to 80°C and stirred for 6 hours. At this time, a yellow viscous liquid was generated in the lower layer and separated from the solvent. Then, the upper layer solvent 1,4-dioxane was carefully removed, and 10 ml of acetone was added three times, stirred and washed, and the remaining solvent was finally removed using a vacuum system to obtain a yellow viscous liquid product. According to NMR analysis, the yellow viscous liquid was the expected product 4-(3-n-butoxypropylamino)-butanesulfonic acid, with a yield of 81%.

[0065] Preparation Example 2: Synthesis of aminosulfonic acid A-2 (4-(3-isopropoxypropylamino)-butanesulfonic acid)

[0066] The same as Preparation Example 1, except that 3-n-butoxypropylamine was replaced by 3-isopropoxypropylamine, and the added amount was 8.280 g, and the obtained product was a yellow viscous liquid. According to NMR analysis, it was the expected product 4-(3-isopropoxypropylamino)-butanesulfonic acid, and the yield was 75%.

[0067] Preparation Example 3: Synthesis of aminosulfonic acid A-3 (4-(2-methoxyethylamino)-butanesulfonic acid)

[0068] The same as Preparation Example 1, except that 3-n-butoxypropylamine was replaced by 2-methoxyethylamine, and the added amount was 5.253 g, and the obtained product was a yellow viscous liquid. According to NMR analysis, it was the expected product 4-(2-methoxyethylamino)-butanesulfonic acid, and the yield was 79%.

[0069] Preparation of water-based hardener

[0070] Preparation Example 4: Synthesis of water-based hardener B-1 (4-(3-n-butoxypropylamino)-butanesulfonic acid modified polyisocyanate)

[0071] A mechanical stirrer, a thermometer, a room temperature water bath and a nitrogen inlet and outlet were set on a four-necked round-bottomed flask. Then the nitrogen was turned on and 2.2951 g of aminosulfonic acid A-1, 1.0921 g of N,N-dimethylcyclohexylamine and 22.8 g of polyisocyanate were added. N 3300 (solid content 100%, NCO content 21.8%, average functionality 3.5) in a round bottom bottle, the reaction was heated to 80 ° C and stirred for 2 hours, then the reaction was cooled to room temperature and 54.0 g of polyisocyanate was added again N 3300, after stirring evenly, aminosulfonic acid modified polyisocyanate can be obtained, which is water-based hardener B-1.

[0072] Preparation Example 5: Synthesis of water-based hardener B-2 (4-(3-isopropoxypropylamino)-butanesulfonic acid modified polyisocyanate)

[0073] A mechanical stirrer, a thermometer, a room temperature water bath and a nitrogen inlet and outlet were set on a four-necked round-bottomed flask. Then the nitrogen was turned on and 2.1747 g of aminosulfonic acid A-2, 1.0921 g of N,N-dimethylcyclohexylamine and 22.8 g of polyisocyanate were added. N 3300 (solid content 100%, NCO content 21.8%, average functionality 3.5) in a round bottom bottle, the reaction was heated to 80 ° C and stirred for 2 hours, then the reaction was cooled to room temperature and 56.0 g of polyisocyanate was added again N 3300, after stirring evenly, aminosulfonic acid modified polyisocyanate can be obtained, which is water-based hardener B-2.

[0074] Preparation Example 6: Synthesis of water-based hardener B-3 (4-(2-methoxyethylamino)-butanesulfonic acid modified polyisocyanate)

[0075] A mechanical stirrer, a thermometer, a room temperature water bath and a nitrogen inlet and outlet were set on a four-necked round-bottomed flask. Then the nitrogen was turned on and 1.8140 g of aminosulfonic acid A-3, 1.0921 g of N,N-dimethylcyclohexylamine and 22.8 g of polyisocyanate were added. N 3300 (solid content 100%, NCO content 21.8%, average functionality 3.5) in a round bottom bottle, the reaction was heated to 80 ° C and stirred for 2 hours, then the reaction was cooled to room temperature and 51.0 g of polyisocyanate was added again N 3300, after being stirred evenly, aminosulfonic acid modified polyisocyanate can be obtained, which is water-based hardener B-3.

[0076] Table 2 lists the raw material amounts used to prepare the above-mentioned water hardeners B-1 to B-3:

[0077] Table 2

[0078]

[0079] Table 3 lists the solid content, NCO content, average NCO functionality and sulfonic acid content of the above aqueous hardeners B-1 to B-3.

[0080] Table 3

[0081] Water-based hardener B-1 B-2 B-3 Solid content (%) 100 100 100 NCO content (wt%) 20.29 20.45 20.46 Average NCO functionality 3.42 3.43 3.42 Sulfonic acid content (wt%) 0.86 0.84 0.90

[0082] Preparation of white color paste

[0083] Table 4 lists the raw material dosage for preparing white color paste:

[0084] Table 4

[0085]

[0086]

[0087] Preparing white paint

[0088] The formula of white paint is shown in Table 5 below. First, stir component I evenly, then add component II and continue stirring. After evenly mixing, let it stand to defoam, and then conduct coating application test.

[0089] Table 5

[0090]

[0091] 《Preparation of polyurethane resin coating》

[0092] The coatings obtained in Examples 1 to 3, Comparative Examples 1 and 2 in Table 5 were applied to the surface of the tinplate using a coating rod (RDS No. 65) to form a coating, which was allowed to stand at room temperature for 10 minutes, and then dried in an oven at 70° C. for 30 minutes to form a film (also called a dry film or paint film), obtaining a tinplate corresponding pattern with a dry film thickness of 100 to 110 μm.

[0093] 《Physical properties of each paint film sample》

[0094] Table 6 shows the physical properties of each paint film sample:

[0095] Table 6

[0096]

[0097] In Table 3 and Table 6, the measurement methods of various properties are as follows:

[0098] Measurement of solid content: First, weigh the empty aluminum dish and record the weight. Then weigh 1 to 2 g of the sample and place it in the aluminum dish. Wait for it to level. Then place it on a heating plate and bake it at 150°C for about 15 minutes until the weight no longer changes. Finally, weigh the weight (baked sample + aluminum dish) and calculate its solid content.

[0099] Solid content % = (baked sample + aluminum dish - empty aluminum dish) / weight of undried sample

[0100] Measurement of NCO content:

[0101] Step (1). Correction of the purity of dibutylamine: 25 ml of anhydrous toluene was added to a 250 ml conical flask, and then 10 ml of dibutylamine (weighed accurately and recorded as X1 g) was added. The conical flask was then covered and stirred for 15 minutes. Then 100 ml of isopropanol was added and stirred for another 5 minutes. Finally, 5 drops of bromophenol blue indicator were added and titrated with a calibrated 0.5N aqueous hydrochloric acid solution to a yellow-green endpoint (the titration amount was recorded as X2 ml). The number of amine equivalents per 1 gram of dibutylamine was calculated using the following formula:

[0102]

[0103] Step (2). Sample measurement: Weigh about 1 gram of sample (weigh accurately and record the weight as Y3 grams) and 25 milliliters of anhydrous toluene into a 250-ml conical flask, shake slowly to completely dissolve the resin, then add 10 milliliters of dibutylamine (weigh accurately and record the weight as Y1 grams), then cover the conical flask and stir for 15 minutes, then add 100 milliliters of isopropanol and stir again for 5 minutes, finally add 5 drops of bromophenol blue indicator, and titrate with a calibrated 0.5N aqueous hydrochloric acid solution to a yellow-green endpoint (record the titration amount as Y2 milliliters), and calculate NCO% using the following formula:

[0104]

[0105] Calculation of average NCO functionality and sulfonic acid content:

[0106] In Preparation Examples 4 to 6, the molecular weight of aminosulfonic acid is Z1 and the amount used is Z2 grams, and the amount of N,N-dimethylcyclohexylamine used is Z3 grams. N 3300 (solid content 100%; NCO content 21.8%; average functionality 3.5) is used in an amount of Z4 grams, and NCO is calculated based on a molecular weight of 42, sulfonic acid (SO3 - ) Based on a molecular weight of 80, the average NCO functionality and sulfonic acid content of the waterborne hardener are calculated using the following formula:

[0107]

[0108]

[0109] Color paste fineness measurement: measured according to the ASTM D1210 (Standard Test Method for Fineness of Dispersion of Pigment-Vehicle Systems by Hegman-Type Gage) test method established by the American Society for Testing and Materials.

[0110] Measurement of dry film thickness: measured according to the ASTM D7091 (Standard Practice for Nondestructive Measurement of Dry Film Thickness of Nonmagnetic Coatings Applied to Ferrous Metals and Nonmagnetic, Nonconductive Coatings Applied to Non-Ferrous Metals) test method established by the American Society for Testing and Materials.

[0111] Pencil hardness test: According to the ASTM D3363 (Standard Test Method for Film Hardness by Pencil Test) test method established by the American Society for Testing and Materials, the test was conducted using a Mitsubishi standard hardness test pencil under a load of 1 kg.

[0112] The evaluation criteria for paint film hardness are as follows:

[0113]

[0114] 100-grid adhesion test: According to the ASTM D3359 (Standard Test Methods for Rating Adhesion by Tape Test - Method B) test method established by the American Society for Testing and Materials, 3M Scotch 600 tape is used for testing. The adhesion evaluation standards are divided into 5B to 0B, where 5B means the removal area is 0%, 4B means the removal area is less than 5%, 3B means the removal area is between 5%-15%, 2B means the removal area is between 15%-35%, 1B means the removal area is between 35%-65%, and 0B means the removal area is greater than 65%.

[0115] Impact resistance test: According to the ASTM D2794 (Standard Test Method for Resistance of Organic Coatings to the Effects of Rapid Deformation (Impact)) test method established by the American Society for Testing and Materials, the test is conducted using an impact head with a radius of 1 / 4”, and the impact weight (g) and impact height (cm) are recorded.

[0116] The impact energy is calculated using the following formula:

[0117] Impact energy (J) = impact weight load (g) × impact height (cm) × 9.8 (m / s 2 )×10 -5

[0118] The impact resistance evaluation standards are as follows:

[0119]

[0120] Gloss measurement: Gloss is measured according to the ASTM D523 (Standard Test Method for Specular Gloss) test method established by the American Society for Testing and Materials, and graded according to the 60-degree angle gloss data.

[0121] The gloss grading standards are as follows:

[0122]

[0123] In Table 5, the white paint formula component I of Examples 1 to 3 and Comparative Example 1 are the same, that is, no matting powder is added, and the difference is that different water-based hardeners are used in component II. Examples 1 to 3 use the water-based hardeners B-1 to B-3 of the present invention respectively, while Comparative Example 1 uses the common water-based hardener XP 2655 on the market. From Table 6, it can be seen that the glossiness (60°) of the paint films obtained from Examples 1 to 3 is less than 20, which is a matting paint film with matting properties; while the glossiness (60°) of the paint film obtained from Comparative Example 1 is greater than 60, which is a high-gloss paint film without matting properties. The hardness, toughness, and adhesion to the substrate of the paint films obtained from Examples 1 to 3 and Comparative Example 1 are all excellent.

[0124] The only difference between the white paint formulas of Comparative Example 1 and Comparative Example 2 is that component I of Comparative Example 2 contains more matting powder, while component II uses the same water-based hardener XP 2655. Therefore, the paint film obtained in Comparative Example 1 is of high gloss type, i.e., the paint film gloss (60°)>60, while the paint film obtained in Comparative Example 2 is of matte type, i.e., the paint film gloss (60°)<20.

[0125] In addition, it can be found from Table 6 that the paint films obtained in Examples 1 to 3 and Comparative Example 2 are also matte paint films. However, since matte powder is added in Comparative Example 2, the hardness, toughness, and adhesion to the substrate of the paint film obtained are all poor.

[0126] Therefore, the paint film obtained by using the paint formulation of the water-based hardener of the present invention has a matting effect without adding a matting agent, and also has excellent physical properties.

Claims

1. A water-based matte coating composition comprising a water-based hardener, wherein the water-based hardener is an adduct of a polyisocyanate and an aminosulfonic acid having an ether group of formula (I), wherein R1 is a straight or branched alkyl group having 3 or 4 carbon atoms, wherein R2 is a straight chain alkyl group having 2 or 3 carbon atoms, R3 is a straight chain or branched chain alkyl group having 1, 3 or 4 carbon atoms, and the sum of the carbon atoms of R2 plus R3 is 3, 6 or 7; The amount of the aminosulfonic acid having an ether group is 2.4 to 5 weight % based on the total weight of the polyisocyanate and the aminosulfonic acid having an ether group; The aminosulfonic acid having an ether group of formula (I) is prepared by reacting an amine having an ether group with a sulfoalkylating agent.

2. The water-based matte coating composition according to claim 1, wherein the amine having an ether group is 3-n-butoxypropylamine, 3-isopropoxypropylamine or 2-methoxyethylamine, and wherein the sulfoalkylating agent is 1,3-propane sultone or 1,4-butane sultone.

3. The water-based matte coating composition according to claim 1, wherein the water-based hardener: A) an average isocyanate functionality of at least 1.8, B) an isocyanate group content of 4.0 to 26.0% by weight, based on the weight of the aqueous hardener, and C) The sulfonate group content is 0.1 to 7.7% by weight, based on the weight of the aqueous hardener.

4. The aqueous matte coating composition of any one of claims 1 to 3, wherein the polyisocyanate is selected from the group consisting of aliphatic polyisocyanates, cycloaliphatic polyisocyanates, araliphatic polyisocyanates, aromatic polyisocyanates, and combinations thereof.

5. A method for preparing the water-based matte coating composition as claimed in claim 1, comprising reacting the polyisocyanate with the aminosulfonic acid having an ether group in the presence of a tertiary amine.

6. The method of claim 5, wherein: The average functionality of the polyisocyanate is 2.0 to 5.0, and the content of isocyanate groups in the polyisocyanate is 8.0 to 27.0% by weight; The aminosulfonic acid is used in an amount of 2.4 to 5.0 wt % based on the total weight of the polyisocyanate and the aminosulfonic acid having an ether group; The tertiary amine is used in an amount of 0.2 to 2.0 equivalents based on the sulfonic acid group of the aminosulfonic acid having an ether group; and The equivalent ratio of the isocyanate groups of the polyisocyanate to the groups reactive toward isocyanate groups is between 2:1 and 400:

1.

7. The process as claimed in claim 5 or 6, wherein the tertiary amine is an aliphatic and / or alicyclic substituted tertiary amine.

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