A crack-effect textile coating and its preparation method

Abstract

This invention provides a textile coating with a cracked effect and its preparation method, relating to the field of textile coating technology. The textile coating with a cracked effect comprises, from bottom to top, a base layer, a cracked layer, and a protective layer, starting from a textile substrate; at least one of the base layer and the cracked layer contains 1,3-propanediol. This invention has found that adding 1,3-propanediol to the base layer and / or the cracked layer can significantly improve the flexural resistance of the textile coating with a cracked effect.

Description

Technical Field

[0001] This invention belongs to the field of textile coating technology, and relates to a crack-effect textile coating and its preparation method. Background Technology

[0002] Similar to the crackle pattern of Ru ware, crackle coatings possess a unique visual effect. Existing crackle coatings are generally applied to building surfaces. However, applying crackle coatings to textile surfaces presents significantly different requirements compared to building surfaces. This is primarily because textiles are frequently bent; for example, shoe uppers, according to GB / T 3903.1-2008 "Test Methods for Whole Footwear - Flexural Performance," require resistance to over 20,000 flexes. Therefore, crackle coatings need to possess excellent flexibility, adhesion, and flexural resistance; otherwise, they are prone to cracking or peeling after repeated flexing.

[0003] However, for crack-resistant coatings on textile surfaces, softness and crack formation are contradictory. The principle of crack formation is to increase the internal stress of the coating, causing stress concentration and cracking in the crack layer. However, increasing softness will reduce the internal stress of the coating, which is detrimental to crack performance. Summary of the Invention

[0004] Through extensive analysis and experimentation, the applicant discovered that the key technical points for improving the flexural resistance of cracked coatings mainly include: 1) improving the interlayer adhesion of the cracked layer in the cracked coating, and 2) balancing the flexibility and stress in the cracked layer. Based on this, the present invention proposes a cracked effect textile coating and its preparation method.

[0005] The technical solution of the present invention is as follows:

[0006] A textile coating with a cracked effect, starting from a textile substrate, comprises a base layer, a cracked layer, and a protective layer arranged sequentially from bottom to top;

[0007] At least one of the base layer and the crack layer contains 1,3-propanediol.

[0008] Preferably, the 1,3-propanediol in the at least one layer has a weight percentage of 1-15%;

[0009] Preferably, the base layer and the crack layer each contain 1,3-propanediol.

[0010] Preferably, there is a base adhesive layer between the base slurry layer and the crack layer;

[0011] The base layer contains cross-linked anionic polyurethane;

[0012] The weight percentage of 1,3-propanediol in the base layer is 1-10%.

[0013] Preferably, the base layer and the crack layer each contain cross-linked polyurethane.

[0014] The protective layer contains cross-linked acrylic resin.

[0015] More preferably, the crack layer also contains crack color paste.

[0016] Preferably, the thickness of the base slurry layer is 0.15-0.65 mm, the thickness of the crack layer is 0.1-0.3 mm, and the thickness of the protective layer is 0.05-0.5 mm.

[0017] A method for preparing a textile coating with a crackle effect, comprising:

[0018] A base paste is printed onto a textile substrate, and the base paste layer is obtained after the first drying.

[0019] A crack-forming paste is printed on the surface of the base layer, and a crack layer is obtained after a second drying.

[0020] A protective paste is printed on the surface of the cracked layer, and a protective layer is obtained after a third drying.

[0021] At least one of the base layer and the crack layer contains 1,3-propanediol.

[0022] Preferably, the raw material components of the substrate slurry include, by weight parts:

[0023] A-1) 85-95 parts of a first aqueous polyurethane dispersion, A-2) 1-5 parts of a first crosslinking agent, and optionally, A-3) 1-10 parts of 1,3-propanediol;

[0024] The raw material components of the crack slurry include, by weight, the following:

[0025] B-1) 85-95 parts crackle pigment, B-2) 1-5 parts second crosslinking agent, and optional B-4) 1-5 parts 1,3-propanediol;

[0026] The raw material components of the protective slurry include, by weight, 95-99 parts of glossy gold oil or matte gold oil and 1-5 parts of isocyanate curing agent (C-2).

[0027] More preferably, the conditions for the first drying are: drying at 65°C-70°C for 6-8 minutes.

[0028] The beneficial effects of this invention are:

[0029] (1) The present invention adds 1,3-propanediol to the base layer and / or crack layer, and finds that it can significantly improve the adhesion and flexibility of the base layer and / or crack layer, balance the stress and flexibility of the crack layer, improve the flexural resistance of the crack coating in textiles, and the crack coating can still maintain good stability after multiple flexing, without cracking, breaking or delamination, which is especially suitable for the footwear and apparel industry.

[0030] (2) An adhesive layer is set between the base layer and the crack layer, which can further improve the flexural properties of the crack coating. The crack coating can withstand more than 20,000 flexural cycles, such as 40,000 or even 100,000 cycles. Attached Figure Description

[0031] Appendix Figure 1 This is a diagram showing the crack effect of the textile coating obtained in Example 2.

[0032] Appendix Figure 2 This is a diagram showing the crack effect of the textile coating obtained in Example 7. Detailed Implementation

[0033] The technical solution of the present invention will be further explained and described below through specific embodiments.

[0034] To improve the flexural strength of cracked coatings and enhance their stability and durability on flexible substrates such as textiles, this invention proposes a textile coating with a cracked effect. Starting from a textile substrate, the coating comprises the textile substrate and a cracked coating. The cracked coating consists of a base layer, a cracked layer, and a protective layer arranged sequentially from bottom to top. The base layer is in direct contact with the textile substrate.

[0035] At least one of the base layer and the crack layer contains 1,3-propanediol.

[0036] This invention discovers that adding 1,3-propanediol to the base layer and / or crack layer can significantly improve the flexural resistance of the crack coating. Adding 1,3-propanediol to the base layer primarily improves its flexibility and adhesion to the crack layer and textile substrate, thereby enhancing the flexural resistance of the crack layer. Adding 1,3-propanediol to the crack layer, besides improving its adhesion to the base layer and protective layer, also balances the stress and flexibility of the crack layer. The crack layer has sufficient stress to create a cracking effect while avoiding excessive stress that could lead to cracking or detachment after repeated flexing, resulting in coating failure. To improve environmental friendliness, the 1,3-propanediol in this invention can be bio-based. Furthermore, this invention also finds that replacing 1,3-propanediol with 1,2-propanediol does not achieve the desired effect; that is, it fails to improve the flexural resistance of the crack coating or the improvement is minimal.

[0037] In some embodiments, the weight percentage of 1,3-propanediol in at least one layer is 1-15%, i.e., the weight percentage of 1,3-propanediol in the base layer is 1-15%, or the weight percentage of 1,3-propanediol in the crack layer is 1-15%, or both the base layer and the crack layer contain 1,3-propanediol, each with a weight percentage of 1-15%. For example, the weight percentage of 1,3-propanediol in the base layer can be 1%, 2%, 3%, 5%, 6%, 8%, 9%, 10%, 12%, 13%, 15%, etc., without particular limitation. Similarly, the weight percentage of 1,3-propanediol in the crack layer can be 1%, 2%, 3%, 5%, 6%, 8%, 9%, 10%, 12%, 13%, 15%, etc., without particular limitation. Furthermore, the weight percentage of 1,3-propanediol in the crack layer can be 1-5%, which can avoid the stress reduction or even disappearance that may be caused by too much increase in the flexibility of the crack layer, thus affecting the generation of crack effect.

[0038] In some embodiments, the base layer and the crack layer each contain 1,3-propanediol, i.e., both the base layer and the crack layer contain 1,3-propanediol, which can further improve the flexural strength of the crack coating.

[0039] In some embodiments, an undercoat layer is further provided between the base layer and the crack layer;

[0040] The primer layer contains cross-linked anionic polyurethane. The presence of anionic polyurethane in the primer layer enhances adhesion, further improving the performance stability of the cracked coating and its resistance to flexural deformation. Moreover, this invention has found that anionic polyurethane in the primer layer is more effective than nonionic or cationic polyurethane.

[0041] Furthermore, the weight percentage of 1,3-propanediol in the primer layer is 1-10%. The presence of 1,3-propanediol in the primer layer can further improve its flexibility and adhesion, thereby enhancing the flexural strength of the cracked coating. For example, the weight percentage of 1,3-propanediol in the primer layer can be 1%, 3%, 4%, 5%, 6%, 8%, 10%, etc., without particular limitation.

[0042] In some embodiments, the base layer and the crack layer each contain cross-linked polyurethane independently;

[0043] The protective layer contains cross-linked acrylic resin.

[0044] In this invention, both the base layer and the crack layer use cross-linked polyurethane as the main resin. Polyurethane has good flexibility and adhesion, which can improve the flexural resistance of the crack coating. The protective layer contains cross-linked acrylic resin, which can be used as the main resin or a combination of cross-linked acrylic resin and other polymers, such as cross-linked polyurethane. Because cross-linked acrylic resin has high hardness, high density, and good corrosion resistance, it can provide better protection.

[0045] In some embodiments, the crack layer also contains crack color paste. The crack layer uses crack color paste, which, when combined with a curing agent and cured, forms a cracked coating. Furthermore, the crack color paste is a pre-mixed formulation that can be directly used with the curing agent. Crack color paste can be purchased directly from the market, for example, from Xiamen Bateng Nanli Environmental Protection Technology Co., Ltd.

[0046] In some embodiments, the thickness of the base layer is 0.15-0.65 mm, the thickness of the crack layer is 0.1-0.3 mm, and the thickness of the protective layer is 0.05-0.5 mm. The aforementioned thicknesses of the base layer, crack layer, and protective layer can improve the performance of the cracked coating, resulting in good cracking effect and good flexural resistance. There are no particular restrictions on the thickness of the base slurry layer; for example, it can be any value from 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, etc. There are also no particular restrictions on the thickness of the crack layer; for example, it can be 0.1mm, 0.12mm, 0.13mm, 0.15mm, 0.18mm, 0.2mm, 0.22mm, 0.25mm, 0.27mm, 0.28mm, 0.3mm, etc. There are also no particular restrictions on the thickness of the protective layer; it can be 0.05mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, etc.

[0047] On the other hand, this invention proposes a method for preparing a textile coating with a cracked effect, which is obtained by layer-by-layer printing. First, a base paste is printed on the textile substrate to obtain a base paste layer, then a cracked paste is printed to obtain a cracked layer, and finally a protective paste is printed to obtain a protective layer, thus forming a cracked coating on the surface of the textile substrate. Specific steps may include:

[0048] A base paste is printed onto a textile substrate, and the base paste layer is obtained after the first drying.

[0049] A crack-forming paste is printed on the surface of the base layer, and a crack layer is obtained after a second drying.

[0050] A protective paste is printed on the surface of the cracked layer, and a protective layer is obtained after a third drying.

[0051] At least one of the base layer and the crack layer contains 1,3-propanediol.

[0052] At least one of the base layer and the crack layer contains 1,3-propanediol, which can improve the flexibility of the base layer and / or the crack layer, and improve interlayer adhesion and flexibility, thereby improving the flexural strength of the crack coating on the textile surface.

[0053] In some embodiments, the raw material components of the substrate include, by weight, the following:

[0054] A-1) 85-95 parts of a first aqueous polyurethane dispersion, A-2) 1-5 parts of a first crosslinking agent, and optionally, A-3) 1-10 parts of 1,3-propanediol;

[0055] The base slurry uses an aqueous polyurethane dispersion and a first crosslinking agent (such as an aqueous isocyanate crosslinking agent), resulting in good flexibility and adhesion to textile substrates. Adding 1,3-propanediol to the base slurry can further improve its flexibility and adhesion.

[0056] There are no particular restrictions on the first waterborne polyurethane dispersion and the first crosslinking agent mentioned above; they can be directly obtained from the market, such as Wanhua Chemical and Covestro. For the first waterborne polyurethane dispersion, it can be Wanhua Chemical's Adwel 1630B waterborne polyurethane dispersion, or Anhui Huatai's AH-1720A and AH-1618E, etc.; for the waterborne isocyanate curing agent, it can be Covestro's Imprafix 2794XP waterborne curing agent, BASF's Basonat HW 2100CN isocyanate curing agent, Covestro's Bayhydur 304 waterborne isocyanate curing agent, or Wanhua Chemical's Aquolin 278 water-dispersible isocyanate curing agent, etc.

[0057] In some embodiments, the raw material components of the crack slurry include, by weight parts:

[0058] B-1) 85-95 parts crackle pigment, B-2) 1-5 parts second crosslinking agent, and optional B-4) 1-5 parts 1,3-propanediol;

[0059] The crack slurry can be made by directly using commercially available crack color paste, combined with a second crosslinking agent (such as an aqueous isocyanate crosslinking agent), to form a coating with a crack effect and high interlayer adhesion. Adding 1,3-propanediol to the crack slurry can further improve the flexibility and adhesion of the crack layer, and controlling the amount of 1,3-propanediol added can avoid any adverse effects on the crack effect.

[0060] In some embodiments, the raw material components of the protective slurry include, by weight, 95-99 parts of glossy or matte gold oil and 1-5 parts of isocyanate curing agent (C-2). The protective slurry directly uses glossy or matte gold oil, which is readily available commercially. Combined with the isocyanate curing agent, it can form a protective layer with good protective effect, good adhesion to cracked layers, and good flexural resistance.

[0061] In some embodiments, the first drying conditions are: drying at 65°C-70°C for 6-8 minutes. This invention has found that insufficient or excessive first drying is detrimental to the formation of the cracked layer's cracking effect. If drying is insufficient, the underlying slurry layer may crack along with the cracked layer when the cracked layer develops its cracking effect, affecting the stability of the cracked coating. If drying is excessive, the underlying slurry layer becomes too hard, which can affect the cracking of the cracked layer, resulting in the cracked layer failing to form a cracking effect or having an indistinct cracking effect.

[0062] In some embodiments, a primer layer may be provided between the base layer and the crack layer. Specifically, after the first drying to obtain the base layer, primer paste is printed onto the surface of the base layer, and a primer layer is obtained after the fourth drying. Then, crack paste is printed onto the primer layer, and a crack layer is obtained after the second drying. Providing a primer layer can further improve the flexural strength of the crack coating and can avoid the negative impact on crack formation caused by insufficient or excessive drying of the base layer during the first drying. There are no particular limitations on the thickness of the primer layer, but preferably it can be 0.2-0.5 mm, such as any value among 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, and 0.5 mm.

[0063] For the primer layer, the raw material components may include the following by weight: D-1) 80-96 parts of aqueous anionic polyurethane dispersion, D-2) 1-5 parts of curing agent, and optionally D-3) 0.5-1 parts of leveling agent, D-4) 1-5 parts of dispersant, D-5) 0.5-1 parts of defoamer, D-6) 1-5 parts of thickener, and D-7) 1-15 parts of 1,3-propanediol. There are no particular limitations on the aqueous anionic polyurethane dispersion; for example, Covestro could be used. U54.

[0064] The technical solution of the present invention will be further described and illustrated below with reference to various embodiments. Unless otherwise specified, the parts mentioned in the following embodiments are parts by weight.

[0065] Example 1

[0066] In this embodiment, the textile coating is printed on a polyester substrate and includes, from bottom to top, a base layer, a crack layer, and a protective layer. The base layer is 0.12 mm thick, the crack layer is 0.15 mm thick, and the protective layer is 0.2 mm thick.

[0067] A base paste was printed onto a polyester substrate by screen printing and dried at 65°C for 7 minutes to obtain the base paste layer.

[0068] A cracked layer is obtained by screen printing crack paste onto the surface of the base layer and drying at 70°C for 10 minutes.

[0069] A protective paste is printed onto the surface of the cracked layer using a screen printing method, and then naturally dried to obtain a protective layer. The protective paste is printed in three layers, with each layer then allowed to dry naturally.

[0070] The base layer consists of 94 parts of waterborne polyurethane dispersion and 6 parts of waterborne isocyanate curing agent.

[0071] The crack layer consists of 95 parts crack color paste and 5 parts water-based isocyanate curing agent.

[0072] The protective layer consists of 96 parts glossy gold oil and 4 parts water-based isocyanate curing agent.

[0073] Example 2

[0074] The difference between this embodiment and Embodiment 1 is that in Embodiment 1, the composition of the base layer was adjusted to: 93 parts of waterborne polyurethane dispersion, 1 part of 1,3-propanediol, and 6 parts of waterborne isocyanate curing agent. The remaining steps remained unchanged.

[0075] The cracking effect of the textile coating obtained in this embodiment is shown in the attached figure. Figure 1 As shown.

[0076] Comparative Example 1

[0077] The difference between this comparative example and Example 2 is that in Example 2, 1,3-propanediol was replaced with an equal weight of 1,2-propanediol. The remaining steps remained unchanged.

[0078] Example 3

[0079] The difference between this embodiment and Embodiment 1 is that in Embodiment 1, the composition of the base layer was adjusted to: 86 parts of waterborne polyurethane dispersion, 8 parts of 1,3-propanediol, and 6 parts of waterborne isocyanate curing agent. The remaining steps remained unchanged.

[0080] Comparative Example 2

[0081] The difference between this comparative example and Example 3 is that in Example 3, 1,3-propanediol was replaced with an equal weight of 1,2-propanediol. The remaining steps remained unchanged.

[0082] Example 4

[0083] The difference between this embodiment and Embodiment 1 is that in Embodiment 1, the crack layer composition was: 94 parts crack color paste, 1 part 1,3-propanediol, and 5 parts aqueous isocyanate curing agent. The remaining steps remained unchanged.

[0084] Example 5

[0085] The difference between this embodiment and Embodiment 1 is that in Embodiment 1, the crack layer composition was: 90 parts crack color paste, 5 parts 1,3-propanediol, and 5 parts aqueous isocyanate curing agent. The remaining steps remained unchanged.

[0086] Example 6

[0087] The difference between this embodiment and Embodiment 1 is that in Embodiment 1, the crack layer composition was: 87 parts crack color paste, 8 parts 1,3-propanediol, and 5 parts aqueous isocyanate curing agent. The remaining steps remained unchanged.

[0088] Example 7

[0089] The difference between this embodiment and Embodiment 2 is that in Embodiment 2, an additional primer layer with a thickness of 0.3 mm is added between the base slurry layer and the crack layer. The remaining steps remain unchanged.

[0090] The composition of the primer coating used in the base coat is: 94.6 parts Covestro U54 waterborne anionic polyurethane dispersion, 4 parts waterborne isocyanate curing agent, 0.6 parts polyether modified silicone oil leveling agent, and 0.8 parts dimethyl defoamer.

[0091] The base coat is cured by baking at 70°C for 6 minutes.

[0092] The cracking effect of the textile coating obtained in this embodiment is shown in the attached figure. Figure 2 As shown.

[0093] Example 8

[0094] The difference between this embodiment and Embodiment 7 is that in Embodiment 7, the curing of the base coat was adjusted to: baking at 70°C for 12 minutes. The remaining steps remain unchanged.

[0095] Example 9

[0096] The difference between this embodiment and Embodiment 7 is that in Embodiment 7, the aqueous anionic polyurethane dispersion was adjusted from 94.6 parts to 92.6 parts, and 2 parts of 1,3-propanediol were added. The remaining steps remain unchanged.

[0097] Example 10

[0098] The difference between this embodiment and Embodiment 7 is that in Embodiment 7, the aqueous anionic polyurethane dispersion was adjusted from 94.6 parts to 86.6 parts, and 8 parts of 1,3-propanediol were added. The remaining steps remained unchanged.

[0099] Example 11

[0100] The difference between this embodiment and Embodiment 7 is that in Embodiment 7, the aqueous anionic polyurethane dispersion was adjusted from 94.6 parts to 80.6 parts, and 14 parts of 1,3-propanediol were added. The remaining steps remained unchanged.

[0101] Performance testing

[0102] Hydrolysis resistance test: Immerse the sample in a 10wt% sodium hydroxide solution for 24 hours, then remove it and observe whether the coating cracks, peels off or other abnormalities.

[0103] Flexural strength: Tested according to GB / T 3903.1-2008 "Test Methods for Flexural Performance of Whole Footwear", accurate to the nearest thousand.

[0104] Crack effect test: The area of ​​the coating surface with a clear crack is S1, and the total area of ​​the coating surface is S2. s = S1 / S2. Crack grade is determined as follows: Grade 1, s ≥ 95% - crack is obviously clear; Grade 2, 85% ≤ s < 95% - crack is clear; Grade 3, 70% ≤ s < 85% - crack is not clear; Grade 4, s < 70% - crack is severely unclear; Grade 5, no crack occurs.

[0105] The results are shown in Table 1 below.

[0106] Table 1

[0107] Hydrolysis resistance Flexural strength Crack grade Example 1 No abnormalities 2000 times Level 1 Example 2 No abnormalities 7000 times Level 1 Comparative Example 1 No abnormalities 3000 times Level 1 Example 3 No abnormalities 22,000 times Level 1 Comparative Example 2 No abnormalities 5000 times Level 1 Example 4 No abnormalities 14,000 times Level 1 Example 5 No abnormalities 25,000 times Level 1 Example 6 No abnormalities 32,000 times Level 2 Example 7 No abnormalities 41,000 times Level 1 Example 8 No abnormalities 38,000 times Level 1 Example 9 No abnormalities 65,000 times Level 1 Example 10 No abnormalities 82,000 times Level 1 Example 11 No abnormalities 103,000 times Level 1

[0108] As can be seen from the data in Table 1 above, the addition of 1,3-propanediol to the base layer and / or crack layer in the crack coating on the textile substrate of the present invention can significantly improve the number of flexural cycles; the addition of a base adhesive layer between the base layer and the crack layer can further significantly improve the number of flexural cycles.

[0109] As described above, the basic principles, main features, and advantages of the present invention have been shown and described. Those skilled in the art should understand that the present invention is not limited to the above embodiments, which are merely preferred embodiments and should not be construed as limiting the scope of the invention. All equivalent changes and modifications made in accordance with the scope of the patent and the description should still fall within the scope of the present invention. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A textile coating with a crack effect, characterized in that, Starting from the textile substrate, it includes, from bottom to top, a base layer, a crack layer, and a protective layer arranged sequentially. The raw material components of the base layer are arranged in parts by weight as follows: A-1) 85-95 parts of a first aqueous polyurethane dispersion, A-2) 1-5 parts of a first aqueous isocyanate curing agent, and optionally, A-3) 1-10 parts of 1,3-propanediol. The raw material components of the crack layer are arranged in parts by weight as follows: B-1) 85-95 parts crack color paste, B-2) 1-5 parts second aqueous isocyanate curing agent, and optionally, B-3) 1-5 parts 1,3-propanediol. At least one of the base layer and the crack layer contains 1,3-propanediol.

2. The textile coating with crack effect according to claim 1, characterized in that, The base layer and the cracked layer each contain 1,3-propanediol.

3. The textile coating with crack effect according to claim 1, characterized in that, There is also a base adhesive layer between the base slurry layer and the crack layer; The base layer contains cross-linked anionic polyurethane; The weight percentage of 1,3-propanediol in the base layer is 1-10%.

4. Textile coating with crack effect according to any of claims 1 to 3, characterized in that The base layer and the crack layer each contain cross-linked polyurethane. The protective layer contains cross-linked acrylic resin.

5. The textile coating with crack effect according to claim 1, characterized in that, The thickness of the base slurry layer is 0.15-0.65 mm, the thickness of the crack layer is 0.1-0.3 mm, and the thickness of the protective layer is 0.05-0.5 mm.

6. A method of producing the textile coating with crack effect according to claim 1, characterized in that, include: A base paste is printed onto a textile substrate, and the base paste layer is obtained after the first drying. A crack-forming paste is printed on the surface of the base layer, and a crack layer is obtained after a second drying. A protective paste is printed on the surface of the cracked layer, and a protective layer is obtained after a third drying. At least one of the base layer and the crack layer contains 1,3-propanediol.

7. The method for preparing a crack-effect textile coating according to claim 6, characterized in that, The raw material components of the protective slurry include, by weight, 95-99 parts of glossy or matte gold oil and 1-5 parts of isocyanate curing agent.

8. The method for preparing a crack-effect textile coating according to claim 7, characterized in that, The conditions for the first drying are: drying at 65℃-70℃ for 6-8 minutes.

Images