A WATER-BORNE PIGMENT PASTE COMPOSITION FREE OF RESIN, ITS PREPARATION METHOD AND ITS APPLICATION THEREOF

TECHNICAL FIELD

The present invention relates to a water-borne pigment paste composition free of resin. The present invention also relates to a preparation method of the water-borne pigment paste composition free of resin as well as its application.

BACKGROUND

Water-borne pigment paste compositions free of resin, especially those having high pigment contents are turning more and more attractive in the market. However, with the increase of pigment content in said composition, the pigment particles in the composition tend to agglomerate during storage, which may lead to gelation and sedimentation of the composition. And the performance of the composition could be even worse when the composition is stored at a high temperature.

To achieve stable storage and thereafter good performance, some approaches are explored, for example, CN108410268A disclosed a kind of resin-free aqueous pigment paste and a preparation method thereof. However, such composition is only stable at a low temperature.

Therefore, it is required to provide a new type of water-borne pigment paste compositions which is free of resin and has a high pigment content and furthermore is stable in storage especially at a high temperature.

SUMMARY OF THE INVENTION

In one aspect, the present invention provides a water-borne pigment paste composition free of resin, comprising components of:

(A) at least one pigment;

(B) at least one dispersant; and

(C) water, wherein the fineness of particles in the composition is no more than 9pm, preferably in a range of from 2pm to 8pm, more preferably in a range of from 3pm to 7.5pm, measured according to GB/T1724-79.

In another aspect, the present invention provides a preparation method for the composition of the present invention, comprising a step of grinding the particles in the composition to a fineness of no more than 9pm, preferably in a range of from 2pm to 8pm, more preferably in a range of from 3pm to 7.5pm, measured according to GB/T1724-79.

In another aspect, the present invention provides a use of the water-borne pigment paste composition of the present invention, in coatings, e.g., architectural coatings, industrial coatings, automotive coatings, and in leathers, inks, textiles, and papers. For example, the present invention provides the use of the water-borne pigment paste composition of the present invention in coating industry equipment and parts, automotive and parts, and rail transit equipment and parts. It is surprisingly found that the water-borne pigment paste composition of the present invention has greatly improved storage stability, even at high temperature, at the same time keeps high pigment content. Moreover, the water-borne pigment paste composition of the present invention is excellent in chemical resistance, compatibility, and applicability.

DETAILED DESCRIPTION OF THE INVENTION

The present invention now will be described more fully hereinafter, in which some, but not all embodiments of the invention are shown. Indeed, this invention can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements.

In the present disclosure, expressions “a”, “an”, “the”, when used to define a term, include both the plural and singular forms of the term.

The terms “comprise”, “comprising”, etc. are used interchangeably with “contain”, “containing”, etc. and are to be interpreted in a non-limiting, open manner. That is, e.g., further components or elements may be present. The expressions “consists of” or “consists essentially of” or cognates, if used, may be embraced within “comprises” or cognates.

In the present disclosure, the expression “water-borne pigment paste composition free of resin” means that the water-borne pigment paste composition does not have externally added filmforming resin. A polymeric dispersant, when used, is not encompassed by the concept of the resin in the expression.

In the present disclosure, the term “fineness” means the measured particle size of particles in the water-borne pigment paste composition, which is measured according to GB/T1724-79.

In the context of the present disclosure, any specific values mentioned for a feature (comprising the specific values mentioned in a range as the end point) can be recombined to form a new range.

One aspect of the present invention relates to a water-borne pigment paste composition free of resin, comprising components of:

(A) at least one pigment;

(B) at least one dispersant; and

(C) water, wherein the fineness of particles in the composition is no more than 9pm, measured according to GB/T1724-79, preferably in a range of from 2pm to 8pm, more preferably in a range of from 3pm to 7.5pm.

In the present invention, component (A) is a pigment. Pigment is a kind of materials that is applicable for coloring a substrate and is insoluble in a solvent and water. The pigment suitable for the present invention can be organic pigment, inorganic pigment and carbon black. Nonlimiting examples of suitable organic pigments may be selected from the group consisting of azo, azomethine, methine, anthraquinone, phthalocyanine, perinone, perylene, diketopyrrolopyrrole, thioindigo, dioxazine, iminoisoindoline, iminoisoindolinone, quinacridone, flavanthrone, indanthrone, anthrapyrimidine and quinophthalone pigments, or a mixture or solid solution.

For example, suitable organic pigments may include C.l. Pigment Red 202, C.l. Pigment Red 122, C.l. Pigment Red 179, C.l. Pigment Red 170, C.l. Pigment Red 144, C.l. Pigment Red 177, C.l. Pigment Red 254, C.l. Pigment Red 255, C.l. Pigment Red 264, C.l. Pigment Brown 23, C.l. Pigment Yellow 109, C.l. Pigment Yellow 110, C.l. Pigment Yellow 147, C.l. Pigment Yellow 154, C.l. Pigment Orange 61, C.l. Pigment Orange 71, C.l. Pigment Orange 73, C.l. Pigment Orange 48, C.l. Pigment Orange 49, C.l. Pigment Blue 15, C.l. Pigment Blue 60, C.l. Pigment Violet 23, C.l. Pigment Violet 37, C.l. Pigment Violet 19, C.l. Pigment Green 7, C.l. Pigment Green 36, C.l. Pigment Blue 15:2, the 2,9-dichloro-quinacridone in platelet form described in W008/055807, or a mixture or solid solution.

In some embodiments of the present invention, the organic pigments may be selected from C.l. Pigment Yellow 154, such as Hostaperm H3G from CLARIANT, Pigment Yellow 154 from Trust Chem Co., Ltd., Hangzhou, China, HF3G from HIFICHEM, Liaoning, China, YM07 from CINIC, Shanghai, China; C.l. Pigment Yellow 110, such as Irgazin Yellow L 2060 from BASF, Germany; Pigment Yellow 110 from Trust Chem Co., Ltd., 1103R from Wenzhou Jin Yuan Chemical Co., Ltd., Zhejiang, China; C.l. Pigment Red 254, such as Irgazin Red L 3660 HD from BASF, Germany, DR33 and DR32 from CINIC, Shanghai, China, D3G 70 from CLARIANT; C.l. Pigment Red 170, such as F5RK CN09 from CLARIANT, F3RK from Lily Group Co., Ltd., Zhejiang, China; C.l. Pigment Blue 15:2, such as Heliogen Blue L 6975 F from BASF, 152L from MAZDA COLOURS Ltd., India, M2L7 from Mallak, India; C.l. Pigment Green 36, such as Heliogen Green L 9361 from BASF, PG36 from Focus Chem, Taiwan, China, PG36 from Heubach, Germany; C.l. Pigment Violet 23, such as Cromophtal Violet D 5800 from BASF, HB- 256 from Lily Group Co., Ltd., Zhejiang, China.

In some embodiments of the invention, the organic pigments are preferably selected from a group consisting of Hostaperm H3G, Irgazin Yellow L 2060, Irgazin Red L 3660 HD, Heliogen Blue L 6975 F, Heliogen Green L 9361, and Cromophtal Violet D 5800.

When organic pigment is used as component (A) of the water-borne pigment paste composition of the invention, the amount may be in a range of from 20% to 50%, preferably from 25% to 45%, more preferably from 25% to 40% by weight, such as 30% to 40% by weight, based on the total weight of the composition.

Inorganic pigment may also be used as component (A) of the water-borne pigment paste composition of the invention. Examples of commercially available inorganic pigments are KRONOS 2310 from KRONOS, Germany; R996 from LOMON Group Co., Ltd, Sichuan, China; DuPont R-700, DuPont R-706, DuPont R-900, DuPont R-902, DuPont R-960 from DuPont; G313 from Langfang Yinma Pigment Co. Ltd., Hebei, China; BAYFERROX® 3920, BAYFERROX Yellow 3910, BAYFERROX® 920, BAYFERROX® 645T, BAYFERROX® 303T, BAYFERROX® 110, BAYFERROX® 110 M, from LANXESS, Germany; BAYFERROX 120, BAYFERROX 130 and BAYFERROX 4130 from LANXESS, Germany; and Y101 from Jiangsu Yuxing Industry & Trade Co., Ltd., Jiangsu China.

For example, suitable inorganic pigments are white pigments such as titanium dioxide, zinc white, zinc sulfide or lithopones; black pigments such as iron manganese black or spinel black; brown iron oxide; or iron oxide yellow, nickel titanium yellow, bismuth vanadate.

In some embodiments of the invention, component (A) is a titanium white having a particle size in a range of from 0.3pm to 0.5pm and an oil absorption in a range of less than 20, preferable less than 15. Preferably, component (A) is selected from a group consisting of KRONOS 2310 from KRONOS, Germany; R996 from LOMON Group Co., Ltd, Sichuan, China; and DuPont R- 700, DuPont R-706, DuPont R-900, DuPont R-902, DuPont R-960 from DuPont. More preferably, component (A) is DuPont R-706 or KRONOS 2310.

In some embodiments of the invention, component (A) is an iron oxide yellow having a particle size in a range of from 0.1pm to 0.4pm and an oil absorption in a range of less than 50, preferably less than 40. Preferably, component (A) is selected from a group consisting of BAYFERROX Yellow 3910 and BAYFERROX Yellow 3920 from LANXESS, Germany, G313 from Langfang Yinma Pigment Co. Ltd., Hebei, China. More preferably, component (A) is BAYFERROX Yellow 3920.

In some embodiments of the invention, component (A) is an iron oxide red having a particle size in a range of from 0.1pm to 0.3 pm and an oil absorption in a range of less than 30, preferably less than 25. Preferably, component (A) is selected from a group consisting of BAYFERROX 120, BAYFERROX 130 and BAYFERROX 4130 from LANXESS, Germany, Y101 from Jiangsu Yuxing Industry & Trade Co., Ltd., Jiangsu China. More preferably, component (A) is BAYFERROX 120.

When inorganic pigment is used as component (A) of the water-borne pigment paste composition of the invention, the amount may be in a range of from 40% to 80%, preferably from 45% to 75%, more preferably from 50% to 70% and even more preferably from 55% to 70% by weight, based on the total weight of the composition.

In the present invention, carbon black is used as a pigment independent from organic pigments and inorganic pigments above. In some embodiments of the invention, component (A) is a carbon black having an oil absorption in a range of less than 120, preferably less than 110 measured according to GB/T 5211.15-2014. Preferably, component (A) is selected from a group consisting of Orion FW255 and Orion FW200 from Orion Engineered Carbons Trading (Shanghai)Co. Ltd., Shanghai, China, Carbon Black R5000U3P from Birla carbon black Columbia Chemical (Jining) Co. Ltd., SB6 from Degussa AG, Germany. More preferably, component (A) is Orion FW255.

When carbon black is used as component (A) of the water-borne pigment paste composition of the invention, the amount may be in a range of from 10% to 35%, preferably in a range of from 10% to 30% and more preferably from 15% to 30% by weight, based on the total weight of the composition. The water-borne pigment paste composition of the invention comprises a dispersant as component (B), which can be selected by a skilled person according to practical application. Preferably, suitable dispersants are polymeric dispersants.

Polymeric dispersants include high molecular weight polymers with pigment affinic groups. Examples are: statistical co-polymers comprised from, for instance, styrene derivatives, (meth)acrylates and (meth)acrylamides, and such statistical co-polymers modified by post modification; block co-polymers and/or comb polymers comprised from, for instance, styrene derivatives, (meth)acrylates and (meth)acrylamides, and such block co-polymers and/or comb polymers modified by post modification; poly-ethylenimines; polyamines; and many kinds of (modified) polyurethanes.

In some embodiments of the present invention wherein component (A) is an inorganic pigment, component (B) may be selected from a group consisting of DISPERBYK-190 from BYK Chemie, Germany; TEGO Dispers 750 and TEGO Dispers 755 from Evonik Industries AG, Germany;

Borchi Gen 1252 from OM Group, Germany; and EFKA Dispex Ultra PX4575 from BASF. More preferably, in an embodiment of the present invention wherein component (A) is an inorganic pigment, the component (B) is DISPERBYK-190.

In the water-borne pigment paste composition of the invention, when component (A) is an inorganic pigment, component (B) may be used in an amount of from 2% to 25%, preferably from 3% to 20% and more preferably from 5% to 12% by weight, based on the total weight of the composition.

In some embodiments of the present invention wherein component (A) is an organic pigment, component (B) may be selected from a group consisting of DISPERBYK-2012 from BYK Chemie, Germany; EFKA Dispex Ultra PX4585 from BASF; and Borchi Gen 0851 from OM Group, Germany. More preferably, in an embodiment of the present invention wherein component (A) is an organic pigment, the component (B) is DISPERBYK-2012.

In the water-borne pigment paste composition of the invention, when component (A) is an organic pigment, component (B) may be used in an amount of from 5% to 35%, preferably from 6% to 30% and more preferably from 10% to 25% by weight, based on the total weight of the composition.

In some embodiments of the present invention wherein component (A) is carbon black, component (B) may be selected from a group consisting of DISPERBYK-2012 from BYK Chemie, Germany; EFKA Dispex Ultra PX4585 from BASF; and Borchi Gen 0851 from OM Group, Germany. More preferably, in an embodiment of the present invention wherein component (A) is carbon black, the component (B) is DISPERBYK-2012.

In the water-borne pigment paste composition of the invention, when component (A) is carbon black, component (B) may be used in an amount of from 20% to 55%, preferably from 25% to 52% and more preferably from 30% to 45% by weight, based on the total weight of the composition. Component (C)

The water-borne pigment paste composition of the present invention comprises water as component (C) in an amount of from 5% to 60% and preferably from 10% to 50% by weight, based on the total weight of the composition. Component (C) may be selected from a group consisting of deionized water, distilled water, tap water, and pure water. Preferably, component (C) is deionized water.

Water-borne pigment paste composition

The water-borne pigment paste composition of the present invention is free of resin, which means the water-borne pigment paste composition of the present invention does not have externally added film-forming resin. The water-borne pigment paste composition of the present invention has greatly improved storage stability at normal temperature and even at higher temperature and has high piment content. Furthermore, the water-borne pigment paste composition of the present invention is aqueous and contains a very small amount of organic solvent, which makes it environment-friendly. The water-borne pigment paste composition can find its use in many applications, such as applications in the field of coating materials, e.g., architectural coatings, industrial coatings, automotive coatings, and the like. The water-borne pigment paste composition of the present invention can also find its use in leathers, inks, textiles, and papers.

In preferred embodiments of the present invention, the water-borne pigment paste composition has a pH of from 7 to 9. More preferably, the water-borne pigment paste composition of the present invention has a pH of from 7.5 to 8.5.

In the 1 ^st embodiment, the water-borne pigment paste composition comprises:

(A) from 40% to 80% by weight of an inorganic pigment;

(B) from 2% to 25 % by weight of a dispersant; and

(C) from 5% to 60 % by weight of water, based on the total weight of the composition, wherein the fineness of particles in the water-borne pigment paste composition is no more than 9pm, preferably in a range of from 2pm to 8pm, more preferably from 3pm to 7.5pm.

In the 2 ^nd embodiment, the water-borne pigment paste composition comprises:

(A) from 45% to 75% by weight of an inorganic pigment;

(B) from 3% to 20% by weight of a dispersant; and

(C) from 10% to 50% by weight of water, based on the total weight of the composition, wherein the fineness of particles in the water-borne pigment paste composition is no more than 9pm, preferably in a range of from 2pm to 8pm, more preferably from 3pm to 7.5pm.

In the 3 ^rd embodiment, the water-borne pigment paste composition comprises:

(A) from 50% to 70% by weight of an inorganic pigment;

(B) from 5% to 15% by weight of a dispersant; and

(C) from 10% to 30% by weight of water, based on the total weight of the composition, wherein the fineness of particles in the water-borne pigment paste composition is no more than 9pm, preferably in a range of from 2pm to 8pm, more preferably from 3pm to 7.5pm. In the 4 ^th embodiment, the water-borne pigment paste composition comprises:

(A) from 55% to 70% by weight of an inorganic pigment;

(B) from 5% to 15% by weight of a dispersant; and

(C) from 10% to 30% by weight of water, based on the total weight of the composition, wherein the fineness of particles in the water-borne pigment paste composition is no more than 9pm, preferably in a range of from 2pm to 8pm, more preferably from 3pm to 7.5pm.

In the 5 ^th embodiment, the water-borne pigment paste composition comprises:

(A) from 62% to 68%, preferably from 62% to 65% by weight of a pigment comprising titanium white, preferably the titanium white pigment has a particle size in a range of from 0.3pm to 0.5pm and an oil absorption of less than 20, preferable less than 15;

(B) a dispersant; and

(C) from 10% to 30% by weight of water, based on the total weight of the composition, wherein the fineness of particles in the water-borne pigment paste composition is no more than 9pm, preferably in a range of from 2pm to 8pm, more preferably from 3pm to 7.5pm, wherein the amount of component (B) is in a range of from 3.5% to 5.5%, preferably from 4% to 5%, and more preferably from 4.5% to 5% by weight, based on the weight of component (A).

In the 6 ^th embodiment, the water-borne pigment paste composition comprises:

(A) from 55% to 65%, preferably from 58% to 63% by weight of an iron oxide pigment, such as iron oxide yellow pigment or iron oxide red pigment, preferably the iron oxide pigment has a particle size in a range of from 0.1pm to 0.4pm and an oil absorption of less than 50, more preferably the iron oxide pigment is an iron oxide yellow pigment having a particle size in a range of from 0.1pm to 0.4pm and an oil absorption of less than 50, preferably less than 40, or the iron oxide pigment is an iron oxide red pigment having a particle size in a range of from 0.1 pm to 0.3pm and an oil absorption of less than 30, preferably less than 25;

(B) a dispersant; and

(C) from 15% to 40% by weight of water, the weight percentages of components (A) and (C) are based on the total weight of the composition, wherein the fineness of particles in the water-borne pigment paste composition is no more than 9pm, preferably in a range of from 2pm to 8pm, more preferably from 3pm to 7.5pm, wherein the amount of component (B) is in a range of from 5.5% to 7.5%, preferably from 6% to 7% by weight, based on the weight of component (A).

In the 7 ^th embodiment, the water-borne pigment paste composition comprises:

(A) from 20% to 50% by weight of an organic pigment, preferably the organic pigment is selected from a group consisting of C.l. Pigment Yellow 154, C.l. Pigment Yellow 110, C.l. Pigment Red 254, C.l. Pigment Red 170, C.l. Pigment Blue 15:2, C.l. Pigment Green 36, and C.l. Pigment Violet 23;

(B) from 5% to 35% by weight of a dispersant; and

(C) from 5% to 60% by weight of water, based on the total weight of the composition, wherein the fineness of particles in the water-borne pigment paste composition is no more than 9pm, preferably in a range of from 2pm to 8pm, more preferably from 3pm to 7.5pm. In the 8 ^th embodiment, the water-borne pigment paste composition comprises:

(A) from 25% to 45% by weight of an organic pigment, preferably the organic pigment is selected from a group consisting of C.l. Pigment Yellow 154, C.l. Pigment Yellow 110, C.l. Pigment Red 254, C.l. Pigment Red 170, C.l. Pigment Blue 15:2, C.l. Pigment Green 36, and C.l. Pigment Violet 23;

(B) from 6% to 30% by weight of a dispersant; and

(C) from 10% to 50% by weight of water, based on the total weight of the composition, wherein the fineness of particles in the water-borne pigment paste composition is no more than 9pm, preferably in a range of from 2pm to 8pm and more preferably from 3pm to 7.5pm.

In the 9 ^th embodiment, the water-borne pigment paste composition comprises:

(A) from 25% to 40% by weight of an organic pigment, preferably the organic pigment is selected from a group consisting of C.l. Pigment Yellow 154, C.l. Pigment Yellow 110, C.l. Pigment Red 254, C.l. Pigment Red 170, C.l. Pigment Blue 15:2, C.l. Pigment Green 36, and C.l. Pigment Violet 23;

(B) from 8% to 30% by weight of a dispersant; and

(C) from 10% to 50% by weight of water, based on the total weight of the composition, wherein the fineness of particles in the water-borne pigment paste composition is no more than 9pm, preferably in a range of from 2pm to 8pm and more preferably from 3pm to 7.5pm.

In the 10 ^th embodiment, the water-borne pigment paste composition comprises:

(A) from 30% to 40% by weight of an organic pigment, preferably the organic pigment is selected from a group consisting of C.l. Pigment Yellow 154, C.l. Pigment Yellow 110, C.l. Pigment Red 254, C.l. Pigment Red 170, C.l. Pigment Blue 15:2, C.l. Pigment Green 36, and C.l. Pigment Violet 23;

(B) from 10% to 25% by weight of a dispersant; and

(C) from 30% to 50% by weight of water, based on the total weight of the composition, wherein the fineness of particles in the water-borne pigment paste composition is no more than 9pm, preferably in a range of from 2pm to 8pm and more preferably from 3pm to 7.5pm.

In the 11 ^th embodiment, the water-borne pigment paste composition comprises:

(A) from 35% to 40% by weight of an organic pigment, preferably the organic pigment is selected from a group consisting of C.l. Pigment Yellow 154, C.l. Pigment Yellow 110, C.l. Pigment Red 254, C.l. Pigment Red 170, C.l. Pigment Blue 15:2, C.l. Pigment Green 36, and C.l. Pigment Violet 23;

(B) a dispersant; and

(C) from 30% to 50% by weight of water, the weight percentage of components (A) and (C) are based on the total weight of the composition, wherein the fineness of particles in the water-borne pigment paste composition is no more than 9pm, preferably in a range of from 2pm to 8pm and more preferably from 3pm to 7.5pm, wherein the amount of component (B) is in a range of from from 15% to 30%, preferably from 18% to 27% and more preferably from 19% to 22% by weight, based on the weight of component (A). In the 12 ^th embodiment, the water-borne pigment paste composition comprises:

(A) from 10% to 35% by weight of a pigment comprising carbon black, preferably carbon black has an oil absorption in a range of less than 120, preferably less than 110 measured according to GB/T 5211.15-2014;

(B) from 20% to 55% by weight of a dispersant; and

(C) from 5% to 60% by weight of water, based on the total weight of the composition, wherein the fineness of particles in the water-borne pigment paste composition is no more than 9pm, preferably in a range of from 2pm to 8pm and more preferably from 3pm to 7.5pm.

In the 13 ^th embodiment, the water-borne pigment paste composition comprises:

(A) from 10% to 30% by weight of a pigment comprising carbon black, preferably the carbon black has an oil absorption in a range of less than 120, preferably less than 110 measured according to GB/T 5211.15-2014;

(B) from 25% to 52% by weight of a dispersant; and

(C) from 10% to 50% by weight of water, based on the total weight of the composition, wherein the fineness of particles in the water-borne pigment paste composition is no more than 9pm, preferably in a range of from 2pm to 8pm and more preferably from 3pm to 7.5pm.

In the 14 ^th embodiment, the water-borne pigment paste composition comprises:

(A) from 10% to 20% by weight of a pigment comprising carbon black, preferably the carbon black has an oil absorption in a range of less than 120, preferably less than 110 measured according to GB/T 5211.15-2014;

(B) from 28% to 50% by weight of a dispersant; and

(C) from 10% to 50% by weight of water, based on the total weight of the composition, wherein the fineness of particles in the water-borne pigment paste composition is no more than 9pm, preferably in a range of from 2pm to 8pm and more preferably from 3pm to 7.5pm.

In the 15 ^th embodiment, the water-borne pigment paste composition comprises:

(A) from 15% to 30% by weight of a pigment comprising carbon black, preferably the carbon black has an oil absorption in a range of less than 120, preferably less than 110 measured according to GB/T 5211.15-2014;

(B) from 30% to 45% by weight of a dispersant; and

(C) from 30% to 50% by weight of water, based on the total weight of the composition, wherein the fineness of particles in the water-borne pigment paste composition is no more than 9pm, preferably in a range of from 2pm to 8pm, more preferably from 3pm to 7.5pm.

In the 16 ^th embodiment, the water-borne pigment paste composition comprises:

(A) from 15% to 25% by weight, preferably from 15% to 20% by weight of a pigment comprising carbon black, preferably the carbon black has an oil absorption in a range of less than 120, preferably less than 110 measured according to GB/T 5211.15-2014;

(B) a dispersant; and

(C) from 30% to 50% by weight of water, the weight percentages of component (A) and (C) are based on the total weight of the composition, wherein the fineness of particles in the water-borne pigment paste composition is no more than 9pm, preferably in a range of from 2pm to 8pm, more preferably from 3pm to 7.5pm, wherein the amount of component (B) is in a range of from 90% to 130%, preferably from 95% to 120% and more preferably from 95% to 105% by weight, based on the weight of component (A).

Additives

The water-borne pigment paste composition of the present invention may further comprise additives, such as defoaming agents, wetting agents, bactericides, co-solvents, pH adjusting agents, anti-settling agents, and thickening agents.

Defoaming agents may be those conventionally used in the art. Suitable defoaming agents are preferably mineral oil defoaming agents, such as aliphatic mineral oil defoaming agents; polysiloxanes; organically modified polysiloxanes; polyether siloxanes; modified polyether siloxanes; fumed silica; silicones; vegetable oils; polymer-based defoaming agents such as modified fatty acids, polyethers, polyacrylates, silicon oils, or modified amides. In a preferred embodiment of the invention, the defoaming agent in the water-borne pigment paste composition is selected from TEGO 840, TEGO810 and TEGO 830 from Degussa AG, Germany.

When a defoaming agent is contained in the water-borne pigment paste composition of the present invention, the amount may be in a range of from 0 to 2%, preferably from 0.1% to 1.5% and more preferably from 0.2% to 1 % by weight, based on the total weight of the composition.

Wetting agents may be selected from a group consisting of polysiloxanes, such as polydimethylsiloxanes, modified polydisiloxanes, such as polyether-polysiloxane copolymers, nonionic surfactants, modified nonionic surfactants, such as alkynediol-modified nonionic surfactants, and fluorocarbon polymers. In a preferred embodiment of the invention, the wetting agent in the water-borne pigment paste composition is selected from BYK346, BYK348 from BYK Chemie, Germany; TEGO Wet 500 from EVON IK, Germany; and Surfynol 607 from Air Products, USA.

When a wetting agent is contained in the water-borne pigment paste composition of the present invention, the amount is in a range of from 0 to 3%, preferably from 0.1% to 2% and more preferably from 0.5% to 1.5% by weight, based on the total weight of the composition.

Bactericides may be selected from a group consisting of aqueous chloromethylisothiazolinone without N-/O- formal, aqueous methylisothiazolinone, and bronopol. In a preferred embodiment of the invention, the bactericide in the water-borne pigment paste composition is selected from Parmetol A28, Parmetol K20 from Schulke & Mayr GmbH, Germany, and the combination thereof.

When a bactericide is contained in the water-borne pigment paste composition of the present invention, the amount is in a range of from 0 to 2%, preferably from 0.1% to 1.5% and more preferably from 0.2% to 1% by weight, based on the total weight of the composition. Co-solvents may be selected from mono-or polyhydric alcohols, alkanolamines and glycol ethers. They are preferably ethanol, n-propanol or i-propanol, butanol, glycol, propanediol or butanediol, glycerol, diglycol, propyl or butyldiglycol, hexylene glycol, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol butyl ether, propylene glycol methyl, ethyl or propyl ether, dipropylene glycol monomethyl or monoethyl ether, diisopropylene glycol monomethyl or monoethyl ether, methoxy triglycol, Ethoxytriglycol or butoxytriglycol, 3-methyl-3-methoxybutanol, propylene glycol t-butyl ether, and mixtures thereof. Preferably, the co-solvents may be selected from a group consisting of propane diol, i- propanol, diethylene glycol butyl ether, and dipropylene glycol methyl ether. In a preferred embodiment of the invention, the co-solvent in the water-borne pigment paste composition is a 1 :5 mixture of propanediol and dipropylene glycol methyl ether.

When a co-solvent is contained in the water-borne pigment paste composition of the present invention, the amount is in a range of from 1% to 15%, preferably from 2% to 12% and more preferably from 3% to 10% by weight, based on the total weight of the composition. pH adjusting agents may be selected from a group consisting of ammonia, triethyl amine, and alcohol amines, preferably alcohol amines of no or thin smell. In a preferred embodiment of the invention, the pH adjusting agent in the water-borne pigment paste composition is AMP-95 from ANGUS Chemical Company, USA.

When a pH adjusting agent is contained in the water-borne pigment paste composition of the present invention, the amount is in a range of from 0.05% to 2%, preferably from 0.05% to 1.5% and more preferably from 0.1 % to 1 % by weight, based on the total weight of the composition.

Anti-settling agents may be selected from a group consisting of bentonite, fumed silica and wax emulsions. In a preferred embodiment of the invention, the anti-settling agent in the water-borne pigment paste composition is selected from a group consisting of R972 and A200 from Degussa AG, Germany, and H-15 and H-18 from Wacker Chemie AG, Germany.

When an anti-settling agent is contained in the water-borne pigment paste composition of the present invention, the amount is in a range of from 0.05% to 2%, preferably from 0.05% to 1.5% and more preferably from 0.1 % to 1 % by weight, based on the total weight of the composition.

Thickening agents may be selected from a group consisting of alkali-swelling thickeners and polyurethane thickeners. In a preferred embodiment of the invention, the thickening agent in the water-borne pigment paste composition is selected from a group consisting of ViscoPlus 3030 from TEGO, Germany; RHEOLATE 299 and RHEOLATE350D from Elementis, Shanghai, China.

When a thickening agent is contained in the water-borne pigment paste composition of the present invention, the amount is in a range of from 0.05% to 2%, preferably from 0.05% to 1.5% and more preferably from 0.1 % to 1 % by weight, based on the total weight of the composition. Process of producing the water-borne pigment paste composition

A further aspect of the present invention relates to a preparation method for a water-borne pigment paste composition, comprising a step of grinding the particles in the water-borne pigment paste composition to a fineness of no more than 9 pm, preferably in a range of from 2pm to 8pm, more preferably in a range of from 3pm to 7.5pm.

In a preferred embodiment of the present invention, the grinding step is carried by sanding with a sand mill.

In a preferred embodiment of the present invention, the process of the present invention comprises the steps of:

(i) dispersing component A and component B in water; and

(ii) grinding the composition obtained from step (i) to obtain a composition wherein the particles in the composition have a fineness of no more than 9pm, preferably in a range of from 2pm to 8pm, more preferably from 3pm to 7.5pm, measured according to GB/T1724-79.

In a preferred embodiment of the present invention, the process of the present invention comprises the steps of:

(i-1) dispersing a dispersant in water; then,

(i-2) adding an anti-settling agent under stirring; then,

(i-3) adding a pigment under stirring; and then,

(ii) grinding the dispersion obtained from step (i-2) to obtain a composition wherein the particles in the composition have a fineness of no more than 9pm, preferably in a range of from 2pm to 8pm, more preferably from 3pm to 7.5pm, measured according to GB/T1724-79.

In a preferred embodiment of the present invention, the process of the present invention comprises the steps of:

(i) dispersing, comprising sub-steps of:

(i-1) sequentially adding water; a dispersant; a defoaming agent; a wetting agent; a pH adjusting agent; and a co-solvent under stirring, and then

(i-2) adding an anti-settling agent under stirring, then

(i-3) adding a pigment under stirring, to obtain a pre-dispersed water-borne pigment paste composition;

(ii) grinding the pre-dispersed water-borne pigment paste composition with a grinding apparatus, to obtain the water-borne pigment paste composition having a fineness of no more than 9pm, preferably in a range of from 2pm to 8pm, more preferably in a range of from 3pm to 7.5pm;

(iii) optionally and preferably, post-treating the water-borne pigment paste composition obtained from step (ii), sequentially comprising one or more sub-steps of:

(iii-1) adding a thickening agent into the water-borne pigment paste composition from step (ii), under stirring,

(iii-2) adding a pH adjusting agent to adjust the pH of the obtained water-borne pigment paste composition to a value in a range of from 7 to 9, preferably in a range of from 7.5 to 8.5, and (iii-3) adding a bactericide to the obtained water-borne pigment paste composition; and

(iv) optionally, filtering the water-borne pigment paste composition from step (ii) or from step (iii).

Preferably, in sub-step (i-1), for the addition of each component, stirring may be carried out at a speed of from 300rpm to 1200rpm (revolution per minute), preferably from 400rpm to 1000rpm, more preferably from 500rpm to 800rpm, for from 3 minutes to 30 minutes, preferably from 3 minutes to 20 minutes, more preferably from 3 minutes to 15 minutes and even more preferably from 3 minutes to 10 minutes.

Preferably, in sub-step (i-1), water is selected from a group consisting of deionized water, distilled water, tap water, and pure water, preferably deionized water.

Preferably, in sub-step (i-2), stirring may be carried out at a speed of from 500rpm to 1500rpm (revolution per minute), preferably from 650rpm to 1200rpm, more preferably from 800rpm to 1000rpm, for from 3 minutes to 60 minutes, preferably from 10 minutes to 50 minutes, more preferably from 10 minutes to 40 minutes, and even more preferably from 10 miutes to 30 minutes.

Preferably, in sub-step (i-3), stirring may be carried out at a speed of from 800rpm to 2500rpm (revolution per minute), preferably from 850rpm to 2000rpm, more preferably from 1000rpm to 1500rpm, for from 5 minutes to 60 minutes, preferably from 10 minutes to 50 minutes, more preferably from 10 minutes to 40 minutes, even more preferably from 10 minutes to 30 minutes.

Preferably, in step (ii), the grinding apparatus is a sand mill. More preferably, an abrasive for grinding is added in a volume equal to that of the pre-dispersed water-borne pigment paste composition. In a preferred embodiment of the invention, the abrasive is a zirconia bead having particle size of 0.8mm.

Preferably, in step (ii), grinding may be carried out at a speed of 800rpm to 3000 rpm (revolution per minute), preferably from 1000rpm to 2500 rpm, more preferably from 1500rpm to 2000 rpm, for from 30 minutes to 10 hours, preferably from 30 minutes to 8 hours, more preferably from 1 hour to 5 hours, and even more preferably from 1 hour to 3 hours, such as 1 hour to 2 hours.

Preferably, at the end of step (ii), the grinding apparatus is flushed with water, such as deionized water, distilled water, tap water, and pure water, preferably deionized water, which may be combined with the water added during sub-step (i-1).

Preferably, in sub-step (iii-1), stirring may be carried out at speed of from 800rpm to 2500rpm (revolution per minute), preferably from 850rpm to 2000 rpm, more preferably from 1000rpm to 1500rpm, for from 10minutes to 60 minutes, preferably from 10minutes to 50 minutes, more preferably from 15minutes to 40 minutes, and even more preferably from 20minutes to 30 minutes.

Preferably, in a process of the present invention comprising step (iii), the ratio of pH adjusting agents added in sub-step (i-1) and sub-step(iii-2) is in a range of from 10:1 to 1 :5, preferably from 10:1 to 1:1 and more preferably from 8:1 to 1:1.

Preferably, in step (iv), filtering is carried out with a filter cloth of from 250 to 300 mesh.

EXAMPLES

The present invention will be better understood in view of the following non-limiting examples.

The examples do not limit the scope of the invention as described and claimed. Test Methods

In the present invention and examples, parameters were measured by the methods as follows. Fineness was measured according to GB/T1724-79.

Viscosity was measured according to GB/T9269-09.

Storage stability was measured according to GB6753-86 at 50°C.

Particle size was measured by dynamic light scattering according to 18013321 :2004.

Oil absorption was measured according to GB/T 5211.15-2014.

Solid content was measured according to GB/T1725-07.

Process of producing the water-borne pigment paste composition

Each water-borne pigment paste composition of the present invention in examples was prepared by the process comprising the steps of:

(i) dispersing, comprising sub-steps of:

(i-1) sequentially adding deionized water, a dispersant, a defoaming agent, a wetting agent, a pH adjusting agent, and a co-solvent under stirring at a speed of about 600rpm, wherein for the addition of each component, stirring was carried out for 5 minutes,

(i-2) adding an anti-settling agent under stirring at a speed of about 1000rpm for 15 minutes, (i-3) adding a pigment under stirring at a speed of about 1500rpm for about 30 minutes, to obtain a pre-dispersed water-borne pigment paste composition;

(ii) grinding the pre-dispersed water-borne pigment paste composition with a sand mill at a speed of about 2000rpm for 1 hour to obtain the water-borne pigment paste composition having particle fineness of no more than 7.5pm, wherein a zirconia bead having particle size of 0.8mm was used as the abrasive for grinding and was added in a volume equal to that of the predispersed pigment composition, and then flushing the sand mill with deionized water, wherein the deionized water obtained after flushing was combined in the composition; and

(iii) post-treating, sequentially comprising sub-steps of:

(iii-1) adding a thickening agent into the water-borne pigment paste composition from step (ii) under stirring at a speed of about 1000rpm for about 30 minutes,

(iii-2) adding a pH adjusting agent to adjust the pH of the obtained water-borne pigment paste composition to a value in a range of from 7.5 to 8.5, and

(iii-3) adding a bactericide to the obtained water-borne pigment paste composition and dispersing it uniformly, to form the finished water-borne pigment paste composition.

The comparative compositions in examples were prepared by the same process, except that different operation conditions were adopted such that in step (ii), the obtained fineness of particles in each comparative composition was 10 pm.

Example 1

A series of water-borne pigment paste compositions were prepared according to the components and amounts provided in table 1, wherein the pigment was R-706 from DuPont. Table 1

Property tests

Properties of the freshly prepared compositions were tested and results were provided in table 2.

able 2 est results on storage stability at 50°C of each composition were provided in table 3.

able 3

It shows that the inventive compositions in example 1 exhibited excellent results in storage stability test and kept the fineness of particles from being increased greatly during the storage for 30 days. The fineness of particles in the inventive compositions were kept less than 15pm during storage for 23 days. On the other hand, the fineness of particles in the comparative composition (3#) was increased greatly after storage for 15 days or more.

Example 2

A series of water-borne pigment paste compositions were prepared according to the components and amounts provided in table 4, wherein the pigment was BAYFERROX Yellow 3920 from LANXESS.

Table 4

Property tests Properties of the freshly prepared compositions were tested and results were provided in table 5. able 5 est results on storage stability at 50°C of each composition were provided in table 6.

able 6

It can be seen that the inventive compositions in example 2 exhibited excellent results in storage stability test, and kept the fineness of particles from being increased greatly during the storage for 30 days. The fineness of particles in the inventive compositions were kept < 15pm during storage for 30 days. On the other hand, the fineness of particles in the comparative composition (8#) was increased greatly after storage for 15 days or more.

Example 3

A series of water-borne pigment paste compositions were prepared according to the components and amounts provided in table 7, wherein the pigment was BAYFERROX 120 from LANXESS.

Table 7

Property tests Properties of the freshly prepared compositions were tested and results were provided in table 8. able 8 est results on storage stability at 50°C of each composition were provided in table 9.

able 9

It can be seen that the inventive compositions in example 3 exhibited excellent results in storage stability test, and kept the fineness of particles from being increased greatly during the storage for 30 days. The fineness of particles in the inventive compositions were kept < 15pm during storage for 30 days. On the other hand, the fineness of particles in the comparative composition (12#) was increased greatly after storage for 15 days or more.

Example 4

A series of water-borne pigment paste compositions were prepared according to the components and amounts provided in table 10, wherein the pigment was Hostaperm H3G from CLARIANT.

Table 10

Property tests Properties of the freshly prepared compositions were tested and results were provided in table 11. able 11 est results on storage stability at 50°C of each composition were provided in table 12.

able 12

It can be seen that the inventive compositions in example 4 exhibited excellent results in storage stability test, and kept the fineness of particles from being increased greatly during the storage for 30 days. The fineness of particles in the inventive compositions were kept < 15pm during storage for 23 days. On the other hand, the fineness of particles in the comparative composition (17#) was increased greatly after storage for 15 days or more.

Example 5

A series of water-borne pigment paste compositions were prepared according to the components and amounts provided in table 13, wherein the pigment was Irgazin Yellow L 2060 from BASF.

Table 13

Property tests Properties of the freshly prepared compositions were tested and results were provided in table 14. able 14 est results on storage stability at 50°C of each composition were provided in table 15.

able 15

It can be seen that the inventive compositions in example 5 exhibited excellent results in storage stability test, and kept the fineness of particles from being increased greatly during the storage for 30 days. The fineness of particles in the inventive compositions were kept < 15pm during storage for 23 days. On the other hand, the fineness of particles in the comparative composition (23#) was increased greatly after storage for 15 days or more.

Example 6

A series of water-borne pigment paste compositions were prepared according to the components and amounts provided in table 16, wherein the pigment was Irgazin Red L 3660 HD from BASF.

Table 16

Property tests Properties of the freshly prepared compositions were tested and results were provided in table 17. able 17 est results on storage stability at 50°C of each composition were provided in table 18.

able 18

It can be seen that the inventive compositions in example 6 exhibited excellent results in storage stability test, and kept the fineness of particles from being increased greatly during the storage for 30 days. The fineness of particles in the inventive compositions were kept < 15pm during storage for 23 days. On the other hand, the fineness of particles in the comparative composition (29#) was increased greatly after storage for 15 days or more.

Example 7

A series of water-borne pigment paste compositions were prepared according to the components and amounts provided in table 19, wherein the pigment was F5RK CN09 from CLARIANT.

Table 19

Property tests Properties of the freshly prepared compositions were tested and results were provided in table 20. able 20 est results on storage stability at 50°C of each composition were provided in table 21.

able 21

It can be seen that the inventive compositions in example 7 exhibited excellent results in storage stability test, and kept the fineness of particles from being increased greatly during the storage for 30 days. The fineness of particles in the inventive compositions were kept < 15pm during storage for 23 days. On the other hand, the fineness of particles in the comparative composition (35#) was increased greatly after storage for 15 days or more.

Example 8

A series of water-borne pigment paste compositions were prepared according to the components and amounts provided in table 22, wherein the pigment was Heliogen Blue L 6975 F from BASF.

Table 22

Property tests Properties of the freshly prepared compositions were tested and results were provided in table 23. able 23 est results on storage stability at 50°C of each composition were provided in table 24.

able 24

It can be seen that the inventive compositions in example 8 exhibited excellent results in storage stability test, and kept the fineness of particles from being increased greatly during the storage for 30 days. The fineness of particles in the inventive compositions were kept < 15pm during storage for 23 days. On the other hand, the fineness of particles in the comparative composition (41#) was increased greatly after storage for 15 days or more.

Example 9

A series of water-borne pigment paste compositions were prepared according to the components and amounts provided in table 25, wherein the pigment was Heliogen Green L 9361 from BASF.

Table 25

Property tests Properties of the freshly prepared compositions were tested and results were provided in table 26. able 26 est results on storage stability at 50°C of each composition were provided in table 27.

able 27

It can be seen that the inventive compositions in example 9 exhibited excellent results in storage stability test, and kept the fineness of particles from being increased greatly during the storage for 30 days. The fineness of particles in the inventive compositions were kept < 15pm during storage for 23 days. On the other hand, the fineness of particles in the comparative composition (47#) was increased greatly after storage for 15 days or more.

Example 10

A series of water-borne pigment paste compositions were prepared according to the components and amounts provided in table 28, wherein the pigment was Cromophtal Violet D 5800 from BASF.

Table 28

Property tests Properties of the freshly prepared compositions were tested and results were provided in table 29. able 29 est results on storage stability at 50°C of each composition were provided in table 30.

able 30

It can be seen that the inventive compositions in example 10 exhibited excellent results in storage stability test, and kept the fineness of particles from being increased greatly during the storage for 30 days. The fineness of particles in the inventive compositions were kept < 15pm during storage for 23 days. On the other hand, the fineness of particles in the comparative composition (53#) was increased greatly after storage for 15 days or more.

Example 11

A series of water-borne pigment paste compositions were prepared according to the components and amounts provided in table 31 , wherein the pigment was FW200 from Orion Engineered Carbons Trading (Shanghai) Co. Ltd..

Table 31

Property tests Properties of the freshly prepared compositions were tested and results were provided in table 32. Table 32

Test results on storage stability at 50°C of each composition were provided in table 33.

Table 33

It can be seen that the inventive compositions in example 11 exhibited excellent results in storage stability test, and kept the fineness of particles from being increased greatly during the storage for 30 days. The fineness of particles in the inventive compositions were kept < 15pm during storage for 30 days. On the other hand, the fineness of particles in the comparative composition (56#) was increased greatly after storage for 15 days or more.

Example 12 Performance tests Preparation of the coating composition

A series of coating compositions containing an water-borne pigment paste composition were prepared for testing the performance of the coating film formed from the coating composition.

The coating composition was prepared as follows: 1) preparing a paint composition by mixing an aqueous base composition having the components and amounts listed in table 34 and an water-borne pigment paste composition. The formed paint compositions were provided in table 35;

2) preparing a hardener composition having the components and amounts listed in table 36;

3) mixing the paint composition and the hardener composition with the ratio of 4:1 by weight by manually stirring to form a homogeneous mixture; and then

4) adding deionized water into the mixture from 3) to obtain a viscosity of 22 to 25s measured by No 4 Cup according to GB/T1723, thus obtaining the coating composition provided in table 37.

Preparation of the coating film

A coating film was prepared from a coating composition listed in table 37 by a process comprising:

1) sanding down a tin plate sized 15cm*7cm purchased from Biuged Laboratory Instruments (GuangZhou) Co., Ltd. with circular motions until there were overlapped circle patterns on the surface of the tin plate, to make sure oxides on the surface of the tin plate were removed;

2) cleaning the tin plate from step 1) with butyl acetate, and then drying, to obtain a dried clean tin plate;

3) spraying a coating composition on the dried clean tin plate from 2) to form a wet film having a thickness of about 50pm on the tin plate;

4) leveling the wet film for about 20 min, then putting the coated tin plate into an oven and baking it at 80°C for 45min; and then

5) taking out the coated tin plate and maintaining it at normal temperature for 7 days, to obtain a sample of the coating film for the performance tests.

Table 34 Aqueous base composition Table 35 Paint compositions

Table 36 Hardener composition Table 37 Coating compositions

The performance was tested in terms of the film color and appearance, water resistance, alkali resistance, acid resistance, diesel resistance, gasoline resistance, heat resistance, heatmoisture resistance, and MEK wiping resistance. Results were listed in table 38. able 38