Blue pigment color paste for gel pen ink, ink for gel pen and gel pen

Abstract

The present invention provides a blue pigment color paste for a gel pen, the blue pigment color paste contains a blue pigment, a nonionic surfactant, an acrylic resin and water, the nonionic surfactant is a polyoxyethylene polycyclic phenyl ether surfactant, and the acrylic resin is an acrylic resin having an aryl group. The pigment color paste provided by the invention has excellent storage stability, has excellent lubricity after being prepared into ink, and can realize good writing feeling.

Description

Technical Field

[0001] The present invention relates to the field of gel pen inks, and particularly to a blue pigment paste for gel pen inks, a blue ink, and a gel pen that can improve storage stability and the writing lubricity of the ink prepared using the paste. Background Art

[0002] Gel pens have been widely used in daily office work, study, writing, painting, and other fields due to their advantages such as smooth writing, clear handwriting, and non-bleeding on paper. The quality of gel pen ink directly affects the performance and writing experience of gel pens. As a key raw material for preparing gel pen ink, the performance of the pigment paste plays a decisive role in the quality of the ink.

[0003] In the process of preparing gel pen ink, it is a common and important process to pre-prepare a high-concentration pigment dispersion as a paste. The quality of the pigment paste is directly related to key performance indicators such as the color, uniformity, stability, and writing feel of the ink. High-quality pigment paste can ensure that the ink has bright and long-lasting colors, and maintains a good dispersed state during storage and use, avoiding the agglomeration and precipitation of pigment particles, thereby ensuring the smoothness of writing and the quality of handwriting.

[0004] However, during the storage of the paste, due to the intermolecular interaction forces, the pigment particles are prone to agglomeration. This will cause an increase in the particle size of the paste and a deterioration in the dispersion uniformity, and further affect the color and writing quality of the ink when it is prepared into ink. For example, when the pigment particles agglomerate into larger particles, they may clog the pen tip, resulting in poor writing or even ink breakage.

[0005] In Patent Document 1 (Chinese Patent Application CN103059646A), a special pigment paste for blue gel ink is disclosed, which contains 20-30 parts by weight of phthalocyanine blue, 36-58 parts by weight of deionized water, 0.5-1 part by weight of a lubricant, 0.05-0.2 part by weight of an emulsifier, 1.5-2.5 parts by weight of a dispersant, 0.5-1 part by weight of a wetting dispersant, and 20-30 parts by weight of polyethylene glycol. In Patent Document 2 (CN104804550A), a black gel ink composition is disclosed, which contains 20-50 parts by weight of pigment paste, 2-10 parts by weight of a viscosity regulator, 0-5 parts by weight of a viscosity stability regulator, 5-20 parts by weight of a humectant, 5-0.05-0.5 parts by weight of a preservative, 14-67.95 parts by weight of deionized water, and 0.5-5 parts by weight of a lubricant.

[0006] Although Patent Document 1 mentions its pigment ink, the pigment is not sufficiently dispersed, the thickening effect is poor, and after storage for a certain period of time, the pigment agglomerates, which is not conducive to the stable production of ink. Moreover, the ink prepared with this ink has poor line quality and insufficient lubricity during writing.

[0007] The black ink system disclosed in Patent Document 2 is not suitable for preparing blue ink, and the ink in this system has poor lubricity and poor writing feeling during writing.

[0008] The problems of poor stability of the ink and poor writing lubricity of the ink bring many troubles to both neutral pen manufacturers and consumers. For manufacturers, a large amount of time and cost are required to solve the stability problem of the ink and improve the quality stability of the ink. At the same time, due to the poor writing lubricity of the ink, the market competitiveness of the product may decline, affecting the economic benefits of the enterprise. For consumers, using a neutral pen with poor writing fluidity and easy ink breakage will affect the writing efficiency and mood, reducing the usage experience.

[0009] Therefore, it is of great practical significance and market value to develop a technology that can effectively improve the storage stability of pigment ink and the writing lubricity of the ink prepared with this ink. Summary of the Invention

[0010] The purpose of the present invention is to provide a blue pigment ink for neutral pens, which has excellent storage stability, and the neutral pen ink prepared with this pigment ink has excellent lubricity and can obtain a good writing feeling.

[0011] The inventor of the present invention found through repeated research that by using a specific thickening and dispersing system to prepare the blue pigment ink, not only can the ink have excellent storage stability, but also excellent lubricity and writing feeling can be obtained after being prepared into ink, thus completing the present invention.

[0012] Specifically, the present invention includes the following aspects.

[0013] [1] A blue pigment ink for neutral pens, which contains a blue pigment, a non-ionic surfactant, an acrylic resin and water, the non-ionic surfactant is a polyoxyethylene polycyclic phenyl ether surfactant, and the acrylic resin is an acrylic resin having an aryl group.

[0014] [2] The blue pigment ink for neutral pens according to [1], wherein the non-ionic surfactant is a polyoxyethylene styrenated phenyl ether surfactant.

[0015] [3] The blue pigment ink for neutral pens according to [1], wherein the acrylic resin is an acrylic resin having a phenyl group.

[0016] [4] For the blue pigment paste for gel pen described in [1], in the blue pigment paste, the content of the blue pigment is 10 to 30% by weight.

[0017] [5] For the blue pigment paste for gel pen described in [1], in the blue pigment paste, the content of the non-ionic surfactant is 1.0 to 8.0% by weight.

[0018] [6] For the blue pigment paste for gel pen described in [1], in the blue pigment paste, the content of the acrylic resin is 0.25 to 8.0% by weight.

[0019] [7] A blue ink for gel pen, in the blue ink, it contains 25 to 65% by weight of the blue pigment paste for gel pen described in any one of claims [1] to [6] and 0.3 to 2% by weight of a phosphate ester compound.

[0020] [8] A gel pen refill, which contains the blue ink for gel pen described in [7].

[0021] [9] A gel pen, which contains the gel pen refill described in [8].

[0022] Advantages of the Invention

[0023] The blue pigment paste for gel pen of the present invention has excellent storage stability, and the ink prepared using this paste has excellent lubricity during use, enabling a good writing feel. Detailed Embodiments

[0024] One embodiment of the present invention is a blue pigment paste for gel pen.

[0025] As a basic component of the ink, the dispersion stability and interfacial properties of the pigment paste directly affect the properties of the ink. Especially in blue ink, phthalocyanine blue is usually used as a colorant, which is prone to aggregation. Especially when preparing the pigment paste, due to the high concentration of the pigment in the paste composition, the aggregation of the pigment is more likely to occur, resulting in poor storage stability of the paste.

[0026] The blue pigment paste for gel pen of the present invention contains a blue pigment, a non-ionic surfactant, an acrylic resin and water. The non-ionic surfactant is a polyoxyethylene polycyclic phenyl-based surfactant, and the acrylic resin is an acrylic resin with an aryl group. By adopting the above specific dispersion system for the pigment paste of the present invention, the paste has excellent storage stability. Moreover, the blue ink prepared using the blue pigment paste of the present invention has excellent lubricity and can achieve a good writing feel.

[0027] In the blue pigment paste of the present invention, phthalocyanine blue is used as the pigment, and in the pigment paste, the content of the pigment is 10 to 30% by weight.

[0028] The nonionic surfactant used in the present invention is a polyoxyethylene polycyclic phenyl-based surfactant. The HLB value of the nonionic surfactant is 16 to 20, preferably 16 to 18. If the HLB value of the nonionic surfactant is less than the above range, the dispersion stability of the paste deteriorates and the lubricity of the ink becomes poor. By using such a nonionic surfactant, in an alkali-swellable thickening system, the paste can have excellent dispersion stability, and after being made into ink, it has excellent lubricity and can achieve a good writing feeling.

[0029] As such a nonionic surfactant, for example, polyoxyethylene styrenated phenyl ether-based surfactants can be cited. Such nonionic surfactants can use commercially available products, such as Neugen EA-207D and Neugen EA-197D produced by Dai-ichi Kogyo Seiyaku Co., Ltd. These surfactants can be used alone or in combination of two or more.

[0030] In the blue pigment paste, the content of the nonionic surfactant is 1.0 to 8.0% by weight, and from the viewpoint of improving lubricity, it is preferably 4 to 8% by weight.

[0031] The acrylic resin having an aryl group used in the present invention can be, for example, a copolymer of styrene and acrylic acid. The weight average molecular weight of the acrylic resin is preferably 7000 to 17000, and its acid value is preferably 150 to 250 mgKOH / g. As commercially available products of such acrylic resins, for example, SLX-200, 1173 produced by Axalta Coating Systems, Joncry series 679, 683, 690, 1552, HPD series 96, 196 produced by BASF SE, JSL-AC-750H of Polyplastics Co., Ltd., RT-AC-08 of Runtai Chemical Co., Ltd., SM-6109 of Mitsui Chemicals, Inc. can be cited. The content of the acrylic resin having an aryl group in the blue pigment paste is 0.25 to 8.0% by weight, preferably 0.5 to 4% by weight. By using such an acrylic resin in the paste, the paste can have excellent stability and excellent lubricity after being made into ink.

[0032] In addition, in the paste of the present invention, additives commonly used in ink, such as ethylene glycol, polyethylene glycol, defoaming agent, preservative, pH regulator and other conventional components, can be added as needed, and their addition amounts are the conventional addition amounts.

[0033] The color paste of the present invention can be prepared by the following method: Add deionized water into a prepared container, successively add additives such as non-ionic surfactant, acrylic resin, defoaming agent and preservative, fully stir well, then add pigment, continue to stir until the pigment is fully wetted, and then add grinding beads and use a dispersing machine to fully grind until the particle size D50 is less than 200 nm to obtain the color paste of the present invention.

[0034] Another embodiment of the present invention is a blue ink for gel pen. The ink of the present invention contains the pigment color paste and phosphate compound of the present invention as described above. In the ink of the present invention, the content of the pigment color paste is 25 to 65% by weight, and the content of the phosphate compound is 0.3 to 2% by weight, preferably 0.6 to 1.2% by weight.

[0035] The thickening system of the blue ink of the present invention uses an alkali-swellable thickener. As the alkali-swellable thickener, a thickener commonly used in gel pen inks is used, such as a cross-linked polymer formed by copolymerization of acrylate monomers, which contains carboxylic acid groups and swells under alkaline conditions to form a three-dimensional network structure to provide a thickening effect. The alkali-swellable thickener can be an alkali-swellable thickener commonly used in gel pen inks. As commercially available products, for example, HS1152, HS1162, HS1212, HS1332, AS1125, AS1188, AS1956 produced by BASF Chemical Industry in Germany, and alkali-swellable thickeners ASE-60, RM-5, RM-7, TT-615, TT-935, DR-73, DR-180 produced by Dow Chemical in the United States can be cited. The content of the thickener is adjusted according to the desired ink viscosity.

[0036] In the blue ink of the present invention, the phosphate compound and the non-ionic surfactant act synergistically to improve the stability and lubricity of the ink. As the phosphate compound, polyoxyethylene ether phosphate with 12 to 18 carbon atoms is usually used. Such phosphate compounds can be commercially available products, such as Phosphanol RD510Y, RS710, RS610, RS410, RD710 produced by Toho Chemical Co., Ltd.

[0037] In addition to the pigment color paste in the ink of the present invention, additives commonly contained in gel pen inks can be contained, such as diluents, preservatives, viscosity regulators and other conventional additives, and their addition amounts are the conventional addition amounts.

[0038] The preparation method of the ink of the present invention is not particularly limited. For example, deionized water, diluent, preservative, viscosity regulator, etc. can be successively added to the color paste and stirred well to obtain the ink of the present invention.

[0039] Examples

[0040] To more easily understand the technical concept of the present invention, the present invention will be described in more detail through the following embodiments. However, the following embodiments are merely exemplary examples, and the present invention is not limited to the following embodiments.

[0041] <Preparation of Color Paste>

[0042] Example 1-1

[0043] Add deionized water into a container, and successively add a diluent, a nonionic surfactant, an acrylic resin, an antifoaming agent, and a preservative according to the proportions shown in Table 1. After fully stirring, add a pigment. After the pigment is fully wetted, add grinding beads, and disperse with a disperser for 5 hours to obtain a pigment color paste.

[0044] Examples 1-2 to 1-10, Comparative Examples 1-1 to 1-6

[0045] Change the types or proportions of each component according to the proportions shown in Tables 1-1 to 1-3, and obtain a pigment color paste in the same manner as in Example 1-1 except for this.

[0046] Raw materials:

[0047] Pigment: Phthalocyanine Blue

[0048] Nonionic surfactant: Neugen EA-207D, produced by Dai-ichi Kogyo Seiyaku Co., Ltd., HLB value 18.7

[0049] Tween 20, HLB value 16.7

[0050] Tween 85, HLB value 11

[0051] OP-4, HLB value 8

[0052] Acrylic resin: Joncryl series 679 produced by BASF Chemical Co., Germany

[0053] Phosphate ester compound: Polyoxyethylene alkyl ether phosphate, Phosphanol RS610, produced by Toho Chemical Industry Co., Ltd.

[0054] Humectant: Polyethylene glycol

[0055] Preservative: Sodium pyrithione

[0056] <Evaluation of Pigment Color Paste>

[0057] 1. Use a cone-plate rotational viscometer to measure the viscosity of the color paste. The instrument is set at 25.0 ± 0.5 °C, 20 rpm × 1 min. Take 1.2 ± 0.05 ml of liquid and put it into the instrument for measurement. The measurement results are shown in Table 1.

[0058] 2. Measure the pigment particle size in the color paste using a nano-level particle size analyzer (FPAR-1000). Set the instrument at 25.0 ± 0.5 °C for 180 s.

[0059] 3. After allowing the prepared color paste to stand for 2 weeks at 50 °C, measure the viscosity of the color paste according to the above method. Evaluate the storage stability of the color paste based on the viscosity fluctuation. Samples with a viscosity increase of less than 50% are evaluated as having good stability, and samples with a viscosity increase of more than 50% are evaluated as having poor stability.

[0060] Table 1-1

[0061]

[0062] Table 1-2

[0063]

[0064] Table 1-3

[0065]

[0066] <Preparation of Ink>

[0067] Examples 2-1 to 2-13, Comparative Examples 2-1 to 2-5

[0068] Add the color paste to a container according to the ratios shown in Tables 2-1 to 2-3. Then add deionized water, a humectant, a preservative, and an acrylic emulsion as a viscosity modifier. After stirring well, obtain the ink samples for the examples and comparative examples.

[0069] Raw materials:

[0070] Humectant: polyethylene glycol, ethylene glycol, glycerol

[0071] Phosphate compound: polyoxyethylene alkyl ether phosphate, Phosphanol RS610, produced by Toho Chemical

[0072] Preservative: sodium pyrithione

[0073] Thickener: alkali-swellable thickener TT615 produced by The Dow Chemical Company, USA, alkali-swellable AS1125 produced by BASF Chemical, Germany, xanthan gum

[0074] <Ink Evaluation>

[0075] 1. Measure the viscosity of the ink using a cone-plate rotational viscometer. Set the instrument at 25.0 ± 0.5 °C, 1 rpm × 5 min. Take 1.2 ± 0.05 ml of the liquid and place it in the instrument for measurement. The results are shown in Tables 2-1 to 2-3.

[0076] 2. Writing lubricity: Using the writing lubricity detector of Jinan Kailedi Precision Instrument Co., Ltd., the pen tip is a bullet tip of 0.5 mm. Test conditions: 0.1 m / min, 0.6 m / min, 2.0 m / min, 4.5 m / min. Under the above measurement conditions, the friction coefficient of the pen tip is measured, and the results are shown in Tables 2-1 to 2-3.

[0077] Comparative Example 2-6

[0078] Prepare the pigment paste according to the formulation of Example 1 of Patent Document 1 (CN103059646A), prepare the ink according to the formulations of Examples 1-5 thereof, and conduct the above evaluations. The results are shown in Tables 1 and 2-2.

[0079] Comparative Example 2-7

[0080] Prepare the ink according to the formulation of Example 3 of Patent Document 2 (CN104804550A), and conduct the above evaluations. The results are shown in Table 2-2.

[0081] Comparative Example 2-8

[0082] Use xanthan gum to replace the alkali-swellable thickener, and prepare the ink in the same manner as in Example 2-3 except for this. Conduct the above evaluations. The results are shown in Table 2-2.

[0083] Comparative Example 2-9

[0084] Do not add a phosphate compound to the ink, and prepare the ink in the same manner as in Example 2-3 except for this. Conduct the above evaluations. The results are shown in Table 2-2.

[0085]

[0086] It can be seen from the results of Tables 2-1 to 2-3 that

[0087] The pigment paste of the present invention has a small dispersion particle size, a small viscosity fluctuation after long-term storage at high temperature, excellent lubricity of the prepared ink, and a good writing feeling.

[0088] From the results of Examples 2-1 to 2-5, as the amount of the nonionic surfactant increases, the lubricity has a tendency to increase.

[0089] From the results of Comparative Examples 2-1 to 2-4, in the case of using a nonionic surfactant other than the present application or not using a nonionic surfactant, although the dispersion of the pigment paste is also excellent, the lubricity of the prepared ink is poor.

[0090] From the results of Comparative Example 1-5, in the case of not using an acrylic resin having an aromatic ring, the storage stability of the pigment paste is poor.

[0091] From the results of Comparative Examples 2-5, when using a phosphate ester in place of the nonionic surfactant, although the dispersion and stability of the color paste are good, the lubricity of the resulting ink is poor.

[0092] From the results of Comparative Examples 2-8, when using xanthan gum in place of the alkali-swellable thickener, the writing performance of the ink during low-speed writing is poor.

[0093] From the results of Comparative Example 2-9, when no phosphate ester is added to the ink, the lubricity of the ink is poor.

[0094] Combining Comparative Examples 2-5 and 2-9, it can be seen that using a specific surfactant alone or using a phosphate ester compound alone cannot achieve an improvement in lubricity. In the present application, the combined use of a specific surfactant and a phosphate ester compound is crucial for achieving excellent lubricity.

[0095] From the results of Comparative Examples 2-6 and 2-7, the dispersion of the pigment paste in Patent Document 1 is poor, and after being made into an ink, the writing line is discontinuous during writing, while the lubricity of the ink in Patent Document 2 is poor.

[0096] Through the above examples and comparative examples, the technical idea of the present invention and the outstanding effects brought compared with the prior art can be clearly understood. However, the present invention is not limited to the technical solutions of the above examples.

Claims

1. A blue pigment paste for a gel pen, comprising a blue pigment, a nonionic surfactant, an acrylic resin and water, wherein the nonionic surfactant is a polyoxyethylene polycyclic phenyl ether surfactant, and the acrylic resin is an acrylic resin having an aromatic group.

2. The blue pigment paste for gel pens according to claim 1, wherein the nonionic surfactant is a polyoxyethylene styrenated phenyl ether surfactant. 3 . The blue pigment paste for gel pens according to claim 1 , wherein the acrylic resin is an acrylic resin having a phenyl group. 4 . The blue pigment paste for gel pen according to claim 1 , wherein the content of the blue pigment in the blue pigment paste is 10 to 30% by weight. 5 . The blue pigment paste for gel pens according to claim 1 , wherein the content of the nonionic surfactant in the blue pigment paste is 1.0 to 8.0% by weight. 6 . The blue pigment paste for gel pens according to claim 1 , wherein the content of the acrylic resin in the blue pigment paste is 0.25 to 8.0% by weight.

7. A blue ink for a gel pen, comprising 25 to 70% by weight of the blue pigment paste for a gel pen according to any one of claims 1 to 6 and 0.3 to 2% by weight of a phosphate compound.

8. A gel pen core comprising the blue ink according to claim 7.

9. A gel pen comprising the gel pen core according to claim 8.

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