Ultra-high whiteness aqueous white color paste for digital textile printing ink and an ink composition using the same

Abstract

An ultra-high whiteness aqueous white color paste for digital textile printing ink is provided, which comprises: 40 wt % to 70 wt % of TiO.sub.2 powders; 1 wt % to 5 wt % of a wetting agent; 2 wt % to 12 wt % of a dispersant; and rest of water. Herein, the TiO.sub.2 powders are rutile TiO.sub.2 powders, the wetting agent is a fatty acid derivative, and the dispersant is an acrylic acid copolymer. In addition, the present disclosure thrther provides an ink composition using the aforesaid ultra-high whiteness aqueous white color paste.

Claims

1. An ultra-high whiteness aqueous white color paste for digital textile printing ink, comprising: 40 wt % to 70 wt % of TiO.sub.2 powders; 1 wt % to 5 wt % of a wetting agent; 2 wt % to 12 wt % of a dispersant; and rest of water, wherein the TiO.sub.2 powders are rutile TiO.sub.2 powders, the wetting agent is a fatty acid derivative, and the dispersant is an acrylic acid copolymer.

2. The ultra-high whiteness aqueous white color paste of claim 1, wherein the dispersant is an anionic dispersant, a non-ionic dispersant or a combination thereof.

3. The ultra-high whiteness aqueous white color paste of claim 2, wherein the dispersant is the anionic dispersant.

4. The ultra-high whiteness aqueous white color paste of claim 1, wherein a molecular weight of the fatty acid derivative is ranged from 500 to 2000.

5. The ultra-high whiteness aqueous white color paste of claim 1, wherein the acrylic acid copolymer is a random acrylic acid copolymer.

6. The ultra-high whiteness aqueous white color paste of claim 1, wherein Dv50 of the TiO.sub.2 powders is ranged from 200 nm to 320 nm, and Dv95 of the TiO.sub.2 powders is less than 500 nm.

7. The ultra-high whiteness aqueous white color paste of claim 1, wherein a content of the wetting agent is ranged from 1.5 wt % to 3 wt %.

8. The ultra-high whiteness aqueous white color paste of claim 1, wherein a CIE whiteness of the ultra-high whiteness aqueous white color paste is greater than 85.

9. The ultra-high whiteness aqueous white color paste of claim 1, wherein the ultra-high whiteness aqueous white color paste is prepared by pulverizing a mixture containing primary TiO.sub.2 powders, the wetting agent, the dispersant and the water through a milling process, wherein the milling process is a media milling process, a basket milling process, a high speed dispersion process, or a combination thereof.

10. An ink composition for digital textile printing, comprising: 15 wt % to 20 wt % of an ultra-high whiteness aqueous white color paste, wherein the ultra-high whiteness aqueous white color paste comprises: 40 wt % to 70 wt % of TiO.sub.2 powders based on a total weight of the ultra-high whiteness aqueous white color paste; 1 wt % to 5 wt % of a wetting agent based on the total weight of the ultra-high whiteness aqueous white color paste; 2 wt % to 12 wt % of a dispersant based on the total weight of the ultra-high whiteness aqueous white color paste; and rest of water based on the total weight of the ultra-high whiteness aqueous white color paste, wherein the TiO.sub.2 powders are rutile TiO.sub.2 powders, the wetting agent is a fatty acid derivative, and the dispersant is an acrylic acid copolymer; 20 wt % to 35 wt % of a resin; 1 wt % to 3 wt % of a cross-linking agent; 0.1 wt % to 0.5 wt % of a surfactant; 15 wt % to 30 wt % of a water soluble organic solvent, 0.1 wt % to 0.2 wt % of a biocide; and rest of water.

11. The ink composition of claim 10, wherein the dispersant is an anionic dispersant, a non-ionic dispersant or a combination thereof.

12. The ink composition of claim 11, wherein the dispersant is the anionic dispersant.

13. The ink composition of claim 10, wherein a molecular weight of the fatly acid derivative is ranged from 500 to 2000.

14. The ink composition of claim 10, wherein the acrylic acid copolymer is a random acrylic acid copolymer.

15. The ink composition of claim 10, wherein Dv50 of the TiO.sub.2 powders is ranged from 200 nm to 320 nm, and Dv95 of the TiO.sub.2 powders is less than 500 nm.

16. The ink composition of claim 10, wherein a content of the wetting agent is ranged from 1.5 wt % to 3 wt %.

17. The ink composition of claim 10, wherein a CIE whiteness of the ultra-high whiteness aqueous white color paste is greater than 85.

18. The ink composition of claim 10, wherein the ultra-high whiteness aqueous white color paste is prepared by pulverizing a mixture containing primary TiO.sub.2 powders, the wetting agent, the dispersant and the water through a milling process, wherein the milling process is a media milling process, a basket milling process, a high speed dispersion process, or a combination thereof.

Description

DETAILED DESCRIPTIO OF THE EMBODIMENT

[0017] The following embodiments when read with the accompanying drawings are made to clearly exhibit the above-mentioned and other technical contents, features and/or effects of the present disclosure. Through the exposition by means of the specific embodiments, people would further understand the technical means and effects the present disclosure adopts to achieve the above-indicated objectives. Moreover, as the contents disclosed herein should be readily understood and can be implemented by a person skilled in the art, all equivalent changes or modifications which do not depart from the concept of the present disclosure should be encompassed by the appended claims.

[0018] Unless specified otherwise, singular words a and the used in the present specification and claims include one or plural objects.

[0019] Unless specified otherwise, term or used in the present specification and claims include meaning of and/or.

[0020] In the following embodiments (Ex) and comparative embodiments (Comp. Ex) of the present disclosure, the mixture containing primary TiO.sub.2 powders, a wetting agent, a dispersant and water according to the formulation shown in the following Table 1 was pulverized by a media milling process, a basket milling process or a high speed dispersion process for 2 hours to disperse the TiO.sub.2 powders. After the milling process, aqueous white color pastes of the embodiments and the comparative embodiments were obtained.

[0021] Measurement of particle sizes

[0022] A particle size analyzer, Malvern Mastersizer 2000, was used to detect the particle sizes.

[0023] Herein, the symbol () refers to that Dv50 is ranged from 250 nm to 290 nm, and Dv95 is less than 450 nm. The symble refers to that Dv50 is ranged from 290 nm to 20 nm, and Dv95 is ranged from 450 nm to 500 nm. The symble refers to that Dv50 is ranged from 320 nm to 360 nm, and Dv95 is greater than 500 nm. The symble X refers to that Dv50 is greater than 360 nm, and Dv95 is greater than 600 nm.

[0024] Measurement of whiteness

[0025] The obtained aqueous white color paste was formulated into a white ink composition containing 10 wt % of TiO.sub.2, powders with a water soluble polyurethane dispersion (PUD). A black cloth treated with a pretreatment liquid was coated with the white ink composition by a scraper coating process with a coating machine (the wet film coating machine ZEHNTNER ZUA2000, and the electric coating machine ZERNTNER ZAA), wherein the coating rate was 5 mm/s, and the thickness of the coating film was set to be 150 m. Next, the coating film on the black cloth was fixed by a hot pressing process with a hot press machine at 165 C. for 90 sec. The black cloth coated with the white ink composition after the fixing process was detected with Datacolor400, the illumination source used herein was filtered to approximate D65, and the CIE whiteness was measured. Alternatively, the black cloth coated with the white ink composition after the fixing process was detected by visual inspection.

[0026] Herein, the results of the visual inspection are defined from level 1 to level 5, wherein the level 1 means the whiteness is the worst, the whiteness is getting better when the level is increased, and the level 5 means the whiteness is the best.

[0027] The results of the measurements of the particle sizes and the whiteness are listed in the following Table 1.

TABLE-US-00001 TABLE 1 Comp. Comp. Comp. Comp. Comp. Comp. Ex 1 Ex 2 Ex 3 Ex 4 Ex 5 Ex 6 Ex 1 Ex 2 Ex 3 TiO.sub.2 50 wt % 60 wt % (Primary particle size = X, ) BYK-190 12.5 wt % BYK-2010 12.5 wt % Joncryl HPD 11.5 wt % 196 Lutensol AT18 36 wt % solution Lutensol XP 37 wt % 99 Triethylene 5 wt % 5 wt % glycol monobutyl ether Diethylene 5 wt % glycol monobutyl ether Wetting agent 0 wt % 1.5 wt % 3 wt % 5 wt % TEGO Dispers652 Biocide 0.1 wt % IPA 5 wt % Water Adding water to 100 wt % Whiteness 1 1 1 1 3 5 5 5 5 (visual inspection) Whiteness 68.21 69.22 71.32 70.12 76.10 88.01 89.52 87.35 88.12 CIE value Particle sizes Dv50 and Dv95

[0028] As shown in Table 1, the white ink compositions prepared by the aqueous white color paste of the comparative embodiments 1 to 6 show poor particle sizes and/or whiteness. On the other hand, the white ink compositions prepared by the aqueous white color paste of the embodiments 1 to 3 show excellent particle sizes and whiteness. Particularly, the aqueous white color paste of the comparative embodiment 6 contains anionic acrylic acid copolymer dispersant but does not contain the wetting agent, and the particle sizes of the TiO.sub.2 powders are still large. However, the aqueous white color paste of the embodiments 1 to 3 contains the anionic acrylic acid copolymer dispersant and the wetting agent, the surface wettability of the TiO.sub.2 powders can be increased in the aqueous system, the dispersion of the TiO.sub.2 powders can be improved, and the particle sizes of the TiO.sub.2 powders are in a desirable range. When the particle sizes of the TiO.sub.2 powders are distributed to have small diameters, the TiO.sub.2 powders contained in the ink does not block the nozzle for digital textile printing. In addition, compared with the comparative embodiments 1 to 5, when the non-ionic acrylic acid copolymer is used as the dispersant in the aqueous white color paste of the embodiments 1 to 3, the whiteness can be increased two or three levels by visual inspection,

[0029] The particle sizes of the TiO.sub.2 powders in the aqueous white color paste of the embodiment 1 and in the commercial available white color pastes were measured. In addition, the whiteness of the white ink compositions prepared by the aqueous white color paste of the embodiment 1 and the commercial available white color pastes was also measured. The results are shown in the following Table 2.

TABLE-US-00002 TABLE 2 Dainichiseika Color & Chemicals Mfg. Co., Ltd. Dimond White color DIC FG White JW-062 PW066 Ex 1 paste Japan Japan England Particle sizes Dv50 = 466 nm Dv50 = 147 nm Dv50 = 165 nm Dv50 = 271 nm Dv50 and Dv95 Dv95 = 1202 nm Dv95 = 323 nm Dv95 = 332 nm Dv95 = 410 nm Whiteness 3 3 2 5 (visual inspection)

[0030] As shown in Table 2, the aqueous white color paste of the embodiment 1 shows better TiO.sub.2 powder particle size distribution and excellent whiteness.

[0031] Hereinafter, the influence of different contents of the TiO.sub.2 powders and different contents of the wetting agent on the TiO.sub.2 powder particle size distribution in the aqueous white color paste is compared. In the following Table 3, only the differences between the embodiments 4 to 5 and the embodiments l to 2 are listed. The particle size of the TiO.sub.2 powders, the species and the content of the dispersant, the species of the wetting agent, the species and the content of the biocide used in the embodiments 4 and 5 are the same as those used in the embodiments 1 and 2. The results are shown in the following Table 3.

TABLE-US-00003 TABLE 3 Particle size before storage TiO.sub.2 powders Wetting agent (nm) (wt %) (wt %) Dv50 Dv95 Comp. Ex 6 60 0 353 565 Ex 1 60 1.5 271 410 Ex 2 60 3 265 404 Ex 4 65 3 287 454 Ex 5 70 3 283 467

[0032] Hereinafter, the influence of different wetting agents on the TiO.sub.2 powder particle size distribution in the aqueous white color paste is compared. In the following Table 4, only the differences between the embodiments 6 to 7 and the embodiment 2 are listed. The rest, such as the particle size of the TiO.sub.2 powders and the species and the content of the biocide used in the embodiments 6 and 7 are the same as those used in the embodiment 2.

TABLE-US-00004 TABLE 4 Wetting agent (wt %) Dispersant TEGO EDAPLAN METOLAT TiO.sub.2 Joncryl Dispers652 915 390 Particle size powders HPD 196 Molecule Molecule Molecule (nm) (wt %) (wt %) weight: 1600 weight: 910 weight: 1950 Dv50 Dv95 Ex 2 60 11.5 3 265 404 Ex 6 60 11.5 3 266 402 Ex 7 60 11.5 3 296 424

[0033] According to the results shown in Table 4, when different fatty acid derivatives are used as the wetting agents, all the obtained aqueous white color pastes have good stability, dispersion and particle size distribution.

[0034] Hereinafter, the influence of different dispersants on the TiO.sub.2 powder particle size distribution in the aqueous white color paste is compared. In the following Table 5, only the differences between the embodiment 1 and the comparative embodiments 7 to 8 and between the embodiment 1 and the embodiments 8 to 9 are listed. The rest, such as the particle size of the TiO.sub.2 powders and the species and the content of the biocide used in the comparative embodiments 7 to 8 and the embodiments 8 to 9 are the same as those used in the embodiment 1. The results are shown in the following Table 5.

TABLE-US-00005 TABLE 5 TiO.sub.2 Dispersant Dispersant Wetting agent Particle size powders Joncryl 586 DISPERBYK-2015 TEGODispers652 (nm) (wt %) (wt %) (wt %) (wt %) Dv50 Dv95 Comp. 60 11.5 0 354 592 Ex 7 Ex 8 60 11.5 3 288 462 Comp. 60 11.5 0 332 552 Ex 8 Ex9 60 11.5 3 280 425

[0035] According to the results shown in Table 5, when different acrylic acid copolymer are used as the dispersants, all the obtained aqueous white color pastes have good stability, dispersion and particle size distribution. In addition, compared with the comparative embodiments 7 and 8, the aqueous white color pastes of the embodiments 8 and 9 have good dispersion and particle size distribution when the acrylic acid copolymer as the dispersant and the fatty acid derivatives as the wetting agents are used together.

[0036] According to the results shown in Table 1 to Table 4, when the random acrylic acid copolymer is used as the dispersant and the fatty acid derivative is used as the wetting agent in the aqueous white color paste of the present disclosure, the wetting agent in the aqueous white color paste can improve the surface wettability of the TiO.sub.2 powders to improve the dispersion of the TiO.sub.2 powders in the aqueous white color paste. Thus, the particle size of the aqueous white color paste can be significantly reduced. In addition, the obtained aqueous white color paste can show excellent stability and whiteness. Furthermore, the aqueous white color paste of the present disclosure has excellent storage stability and stably dispersion, and thus no flocculation or coagulation is generated in the aqueous white color paste of the present disclosure.

[0037] The aqueous white color paste prepared in the embodiment 1 was formulated into a white ink composition according to the formulation shown in the following Table 6. A black cloth treated with a pretreatment liquid was coated with the obtained white ink composition by an inkjet printing process with a printing machine (Epson 4880), and good inkjet printability can be obtained.

TABLE-US-00006 TABLE 6 White ink composition Content (wt %) Aqueous white color paste of 15-20 the embodiment 1 Ethylene Glycol 10-20 Glycerol 5-10 Dispersant BYK-349 0.1-0.5 Biocide 0.1-0.2 PUD(1010NHR) 20-35 Cross-linking agent 1-3 water Adding to 100%

[0038] After the tests on the washing fastness (AATCC 61 3A) and the dry/wet rubbing fastness (AATCC 8), the white pattern obtained by the inkjet printing process has the washing fastness at levels 4 to 5 and the dry/wet rubbing fastness at levels 4 to 5.

[0039] Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.