Slow-setting ink composition, preparation method and application thereof

Abstract

The present invention discloses a slow-setting ink composition, its preparation method, and its application, belonging to the field of ink materials. The slow-setting ink composition comprises, by weight, 42 to 80 parts of a mixed resin, 10 to 30 parts of a solvent, 2.5 to 9 parts of an additive, and 2 to 5 parts of a curing agent. The mixed resin comprises a low-viscosity resin, a cross-linking resin, and a phenol resin. The slow-setting ink composition provided by the present invention can prolong the setting time of the ink and stabilize its fluidity.

Description

Technical Field

[0001] The present invention relates to the field of ink materials, and in particular to a retarding ink composition, a preparation method thereof and an application thereof. Background Art

[0002] With the rapid development of the smartphone industry, the design and manufacturing of phone back panels are receiving increasing attention. These panels not only protect internal components but also directly impact the phone's appearance and feel. Ink application is a key step in achieving color, patterns, and special effects during the manufacturing process. However, the ink's condensation properties significantly impact the printing quality of these panels.

[0003] While existing mobile phone backplate inks are designed with stability and fluidity in mind under specific conditions, rapid ink coagulation remains a common problem in actual applications. This impacts print quality: Rapid ink coagulation prevents even ink distribution during the printing process, resulting in uneven color and pattern on the phone backplate, impacting the overall aesthetics of the product. Production efficiency is limited: Rapid ink coagulation requires more frequent cleaning or ink changes on the printing press, increasing production downtime and limiting productivity. Material and cost waste: Due to ink coagulation, some ink cannot be used within its effective timeframe, resulting in wasted materials and increased production costs.

[0004] Therefore, there is currently a lack of inks with excellent retarding properties and stable flow properties. Summary of the Invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention proposes a retarding ink composition, a preparation method and an application thereof, aiming to solve the problem that there is currently no simple and easy method for removing both arsenic and carbon dioxide pollution in the air.

[0006] To achieve the above objectives, the present invention provides a retarding ink composition, comprising, by weight, 42 to 80 parts of a mixed resin, 10 to 30 parts of a solvent, 2.5 to 9 parts of an auxiliary agent, and 2 to 5 parts of a curing agent, wherein the mixed resin comprises a low-viscosity resin, a cross-linking resin, and a phenol resin, and the phenol resin comprises a poly(vinylphenol) and / or N-(4-hydroxyphenyl)maleimide copolymer.

[0007] Optionally, the mixed resin includes, by weight, 20 to 30 parts of low-viscosity resin, 20 to 30 parts of cross-linking resin, and 2 to 20 parts of phenol resin.

[0008] Optionally, the low-viscosity resin includes at least one of polyurethane acrylate, epoxy acrylate, and diglycidyl tetrachlorophthalate.

[0009] Optionally, the cross-linked resin skeleton is a polyhydroxy alcohol skeleton, and the cross-linked group is at least one unsaturated group selected from the group consisting of acryloyl, fumaryl, allyl ether, and isobornyl.

[0010] Optionally, the auxiliary agent includes a wetting agent, and the wetting agent includes a mixture of cyclohexanone and ethylene glycol butyl ether in a mass ratio of 1: (1-2).

[0011] The auxiliary agent includes pigments and fillers, and the pigments and fillers include at least one of talc powder, kaolin, porous powdered quartz, white carbon black, obsidian powder, tayma stone powder, and selenium ore powder.

[0012] At a temperature below 100° C., the retarding ink composition has a viscosity below 30 mPa·s and a surface tension below 0.0004 N / m at a shear rate of 5000 to 10000 times / second.

[0013] In order to achieve the above object, the present invention also provides a method for preparing a retarding ink composition, comprising the following steps:

[0014] S1: mixing a low-viscosity resin, a cross-linked resin and a phenol resin to obtain a mixed resin;

[0015] S2: adding a solvent and an additive to the mixed resin, shearing and mixing, to obtain a first mixture;

[0016] S3: Grinding the mixture and filtering it, adding a curing agent, heating and mixing it to reach a set viscosity and surface tension range to obtain a retarded ink composition.

[0017] Optionally, the filtration fineness is less than 2 μm.

[0018] In order to achieve the above-mentioned object, the present invention also proposes an application of a slow-setting ink composition, which is applied to a high-strength and drop-resistant mobile terminal glass back panel.

[0019] The beneficial effects of the present invention are as follows: The slow-setting ink composition provided by the present invention achieves slow setting of the resin by adjusting the type and ratio of the mixed resin and combining it with a wetting agent, which is beneficial for improving printing quality, increasing production efficiency, and avoiding raw material waste. The low-viscosity resin, cross-linked resin, and phenol resin of the present invention can provide a wide range of physical and chemical properties. The low-viscosity resin helps improve the fluidity of the ink, the cross-linked resin can enhance the stability and durability of the ink, and the poly(vinylphenol) and / or N-(4-hydroxyphenyl)maleimide copolymer in the phenol resin, due to the benzene ring and active hydroxyl groups in its structure, can improve the heat resistance and chemical resistance of the ink while maintaining the flexibility and adhesion of the ink. The mixed resin is combined with a solvent, an additive, and a curing agent to achieve an ink setting time of not less than 7 hours. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0021] Unless otherwise specified, all technical and scientific terms used herein have the common meanings in the art to which the claimed subject matter belongs, and all reagents used are of industrial or analytical purity.

[0022] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0023] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if the meaning of "and / or" appearing in the full text is to include three parallel schemes, taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0024] With the rapid development of the smartphone industry, the design and manufacturing of phone back panels are receiving increasing attention. These panels not only protect internal components but also directly impact the phone's appearance and feel. Ink application is a key step in achieving color, patterns, and special effects during the manufacturing process. However, the ink's condensation properties significantly impact the printing quality of these panels.

[0025] While existing mobile phone backplate inks are designed with stability and fluidity in mind under specific conditions, rapid ink coagulation remains a common problem in actual applications. This impacts print quality: Rapid ink coagulation prevents even ink distribution during the printing process, resulting in uneven color and pattern on the phone backplate, impacting the overall aesthetics of the product. Production efficiency is limited: Rapid ink coagulation requires more frequent cleaning or ink changes on the printing press, increasing production downtime and limiting productivity. Material and cost waste: Due to ink coagulation, some ink cannot be used within its effective timeframe, resulting in wasted materials and increased production costs.

[0026] Therefore, there is currently a lack of inks with excellent retarding properties and stable flow properties.

[0027] To solve the above problems, the present invention proposes a retarding ink composition, which comprises, by weight: 42 to 80 parts of a mixed resin, 10 to 30 parts of a solvent, 2.5 to 9 parts of an auxiliary agent, and 2 to 5 parts of a curing agent, wherein the mixed resin comprises a low-viscosity resin, a cross-linking resin, and a phenol resin, and the phenol resin comprises a poly(vinylphenol) and / or N-(4-hydroxyphenyl)maleimide copolymer.

[0028] In some embodiments, low-viscosity resins, cross-linked resins, and phenol resins can provide a wide range of physical and chemical properties. Low-viscosity resins help improve the fluidity of inks, cross-linked resins can enhance the stability and durability of inks, and poly(vinylphenol) and / or N-(4-hydroxyphenyl)maleimide copolymers in phenol resins can improve the heat resistance and chemical resistance of inks because of the benzene rings and active hydroxyl groups in their structures, while maintaining the flexibility and adhesion of the inks. The mixed resins are combined with solvents, additives, and curing agents to achieve an ink setting time of not less than 7 hours.

[0029] Furthermore, the mixed resin includes, by weight, 20 to 30 parts of low-viscosity resin, 20 to 30 parts of cross-linking resin, and 2 to 20 parts of phenol resin.

[0030] In certain embodiments, by adjusting the ratio of the three resins, cost optimization can be achieved while meeting performance requirements. Low viscosity resins and cross-linked resins are generally less expensive, while phenolic resins may be more expensive, and a reasonable ratio can balance performance and cost. The mixed resin is adjusted within the above-mentioned ratio range so that the ink can maintain good printing performance under various environments. By adjusting the ratio of the three resins, the drying speed of the ink can be controlled to adapt to different printing processes and equipment requirements, making the ink suitable for a variety of printing technologies and substrates, such as flexographic printing, gravure printing, screen printing, etc. In addition, an appropriate resin ratio can improve the thixotropy of the ink, that is, the ink has a higher viscosity when stationary to prevent sedimentation, and the viscosity is reduced under shear force for ease of printing. A reasonable resin ratio also helps to improve the stability of the ink during storage, reduces stratification and precipitation, and extends the shelf life of the ink.

[0031] Furthermore, the low-viscosity resin includes at least one of polyurethane acrylate, epoxy acrylate, and diglycidyl tetrachlorophthalate.

[0032] The combination of resins can improve the mechanical properties of inks, such as tensile strength, elasticity, and abrasion resistance. The complementary properties of these resins can provide a more balanced physical performance of the ink. Polyurethane acrylates and epoxy acrylates generally have good adhesion, while diglycidyl tetrachlorophthalate provides good crosslinking properties. The combination of these resins can enhance the adhesion of inks to various substrates. The blend of different resins can adjust the rheological properties of the ink, ensuring ideal fluidity and stability during the printing process while preventing sedimentation when the ink is still.

[0033] Furthermore, the cross-linked resin skeleton is a polyhydroxy alcohol skeleton, and the cross-linked group is at least one unsaturated group selected from the group consisting of acryloyl, fumaryl, allyl ether, and isobornyl.

[0034] In some embodiments, the cross-linking resin is preferably polyhydric alcohol acrylate, isobornyl acrylate.

[0035] In some embodiments, the crosslinking group of the crosslinking resin is allyl ether, a highly reactive unsaturated group that can undergo effective copolymerization with other unsaturated resins or monomers. Allyl ether crosslinking resins exhibit excellent crosslinking properties in free radical initiation systems, resulting in an ink film with good flexibility and adhesion.

[0036] Furthermore, the auxiliary agent includes a wetting agent, and the wetting agent includes a mixture of cyclohexanone and ethylene glycol butyl ether in a mass ratio of 1: (1-2).

[0037] Cyclohexanone can reduce the surface tension of inks and increase their wettability on substrates, thereby improving ink spreading and adhesion. Mixing cyclohexanone with ethylene glycol butyl ether can enhance the solubility of certain difficult-to-dissolve pigments and resins. Mixing cyclohexanone with ether can adjust the viscosity and fluidity of inks. A mixture of cyclohexanone and ether can reduce foaming during mixing or printing, thereby increasing production efficiency. A mixture of cyclohexanone and ether can also improve ink leveling and contribute to a higher surface gloss of printed materials.

[0038] In some embodiments, the wetting agent is preferably a mixture of cyclohexanone and ethylene glycol butyl ether in a mass ratio of 1:1.5.

[0039] Furthermore, the auxiliary agent includes pigments and fillers, and the pigments and fillers include at least one of talc powder, kaolin, porous powdered quartz, white carbon black, obsidian powder, tayma stone powder, and selenium ore powder.

[0040] Pigments and fillers can improve ink stability and reduce sedimentation or stratification during storage and use. Porous powdered quartz helps improve ink fluidity and printability. Harder pigments and fillers, such as obsidian powder, can enhance the wear resistance of printed surfaces. In some embodiments, talc or kaolin with specialized particle shapes or sizes can provide unique visual effects or textures.

[0041] Furthermore, at a temperature below 100°C, the retarding ink composition has a viscosity below 30 mPa·s and a surface tension below 0.0004 N / m at a shear rate of 5,000 to 10,000 times / second. By simultaneously adjusting the viscosity and surface tension of the ink, the retarding properties of the ink can be more effectively controlled. Reducing viscosity and surface tension can synergistically improve the fluidity and wettability of the ink and reduce coagulation. This solution utilizes the components and ratios of the resin, additives, solvent, and curing agent in the ink to achieve a synergistic effect, ensuring that the ink maintains excellent retarding properties.

[0042] To solve the above problems, the present invention further provides a method for preparing a retarding ink composition, comprising the following steps:

[0043] S1: mixing a low-viscosity resin, a cross-linked resin and a phenol resin to obtain a mixed resin;

[0044] S2: adding a solvent and an additive to the mixed resin, shearing and mixing, to obtain a first mixture;

[0045] S3: Grinding the mixture and filtering it, adding a curing agent, heating and mixing it to reach a set viscosity and surface tension range to obtain a retarded ink composition.

[0046] In some embodiments, the curing agent is m-xylylenediamine, and the heating curing temperature is 55°C to 65°C.

[0047] In some embodiments, diglycidyl tetrachlorophthalate can be used as a reactive diluent to promote the curing reaction of the ink and improve the curing efficiency.

[0048] Furthermore, the filtration fineness is less than 2 μm.

[0049] In order to solve the above problems, the present invention also proposes an application of a slow-setting ink composition, which is applied to a high-strength and drop-resistant mobile terminal glass back panel.

[0050] Urethane acrylate and epoxy acrylate resins possess excellent adhesion, improving the ink's adhesion to various substrates. Urethane acrylate resin also exhibits excellent flexibility, making printed materials less susceptible to cracking when bent or folded. It also possesses high abrasion resistance, contributing to enhanced durability. When the retarded ink in this solution is used on the glass backplane of a mobile device, the backplane surface must be well wetted by the retarded ink. To ensure even spreading and curing of the ink, the glass backplane may require surface treatment.

[0051] The technical solution of the present invention is further described in detail below with reference to specific embodiments.

[0052] Example 1:

[0053] S1: In parts by weight, 25 parts of diglycidyl tetrachlorophthalate, 20 parts of isobornyl acrylate, and 5 parts of poly(vinyl phenol) were mixed to obtain a mixed resin;

[0054] S2: adding 20 parts of solvent isobutanol, 5 parts of a mixture of cyclohexanone and ethylene glycol butyl ether in a mass ratio of 1:1.5, and 1 part of porous powdered quartz to the mixed resin, shearing and mixing to obtain a first mixture;

[0055] S3: After grinding the mixture, filter it to a fineness of less than 2 μm, add 3 parts of m-phenylenediamine, heat to 60° C. and mix evenly to make it reach the set viscosity and surface tension range (at a shear rate of 5000 times / second to 10000 times / second, the viscosity is less than 30 mPa·s and the surface tension is less than 0.0004 N / m) to obtain a retarding ink composition.

[0056] Example 2:

[0057] S1: In parts by weight, 30 parts of polyurethane acrylate, 20 parts of isobornyl acrylate and 5 parts of N-(4-hydroxyphenyl)maleimide copolymer were mixed to obtain a mixed resin;

[0058] S2: adding 30 parts of solvent isobutanol, 5 parts of a mixture of cyclohexanone and ethylene glycol butyl ether in a mass ratio of 1:1.5, and 1 part of porous powdered quartz to the mixed resin, shearing and mixing to obtain a first mixture;

[0059] S3: After grinding the mixture, filter it to a fineness of less than 2 μm, add 3 parts of m-phenylenediamine, heat to 60° C. and mix evenly to make it reach the set viscosity and surface tension range (at a shear rate of 5000 times / second to 10000 times / second, the viscosity is less than 30 mPa·s and the surface tension is less than 0.0004 N / m) to obtain a retarding ink composition.

[0060] Example 3:

[0061] S1: In parts by weight, 30 parts of epoxy acrylate, 20 parts of isobornyl acrylate and 10 parts of N-(4-hydroxyphenyl)maleimide copolymer were mixed to obtain a mixed resin;

[0062] S2: adding 30 parts of solvent isobutanol, 5 parts of a mixture of cyclohexanone and ethylene glycol butyl ether in a mass ratio of 1:1.5, and 1 part of porous powdered quartz to the mixed resin, shearing and mixing to obtain a first mixture;

[0063] S3: After grinding the mixture, filter it to a fineness of less than 2 μm, add 3 parts of m-phenylenediamine, heat to 60° C. and mix evenly to make it reach the set viscosity and surface tension range (at a shear rate of 5000 times / second to 10000 times / second, the viscosity is less than 30 mPa·s and the surface tension is less than 0.0004 N / m) to obtain a retarding ink composition.

[0064] Example 4:

[0065] S1: In parts by weight, 25 parts of diglycidyl tetrachlorophthalate, 20 parts of isobornyl acrylate, and 5 parts of poly(vinyl phenol) were mixed to obtain a mixed resin;

[0066] S2: adding 20 parts of solvent isobutanol, 3 parts of a mixture of cyclohexanone and ethylene glycol butyl ether in a mass ratio of 1:1, and 1 part of porous powdered quartz to the mixed resin, shearing and mixing to obtain a first mixture;

[0067] S3: After grinding the mixture, filter it to a fineness of less than 2 μm, add 3 parts of m-phenylenediamine, heat to 60° C. and mix evenly to make it reach the set viscosity and surface tension range (at a shear rate of 5000 times / second to 10000 times / second, the viscosity is less than 30 mPa·s and the surface tension is less than 0.0004 N / m) to obtain a retarding ink composition.

[0068] Example 5:

[0069] S1: In parts by weight, 30 parts of diglycidyl tetrachlorophthalate, 20 parts of isobornyl acrylate and 5 parts of poly(vinyl phenol) were mixed to obtain a mixed resin;

[0070] S2: adding 30 parts of solvent isobutanol, 7 parts of a mixture of cyclohexanone and ethylene glycol butyl ether in a mass ratio of 1:2, and 1 part of porous powdered quartz to the mixed resin, shearing and mixing to obtain a first mixture;

[0071] S3: After grinding the mixture, filter it to a fineness of less than 2 μm, add 3 parts of m-phenylenediamine, heat to 60° C. and mix evenly to make it reach the set viscosity and surface tension range (at a shear rate of 5000 times / second to 10000 times / second, the viscosity is less than 30 mPa·s and the surface tension is less than 0.0004 N / m) to obtain a retarding ink composition.

[0072] Comparative Example 1:

[0073] The same as Example 1, except that the resin component only includes a low-viscosity resin (diglycidyl tetrachlorophthalate) and no wetting agent is added.

[0074] Furthermore, ink retarding tests were performed on Examples 1-5 and Comparative Example 1. The tests included initial setting time and fluidity. The specific test contents included:

[0075] 1. Initial setting time: tested at a constant temperature of 50°C;

[0076] 2. Fluidity: Place a fluidity tester and the ink to be tested (the ink is first placed on the glass back panel of a test mobile phone) in an oven maintained at a constant temperature of 25°C for 400 minutes. Remove the ink and thoroughly mix it with a small ink spatula. Then, use an ink pipette to draw 0.1 ml of the ink onto the center of the lower glass. Place the upper glass on top, and then place a weight on top (simultaneously start a stopwatch or timer). Place the ink in the oven at a constant temperature for 50 minutes. Remove the weight and measure the diameter of the expanded ink circle with a transparent ruler.

[0077] The test results are summarized in the following table:

[0078]

[0079]

[0080] In the above data, Example 1, as the optimal example, achieved an ink slow setting time of 507 minutes, confirming that the slow setting ink composition provided by the present invention achieves slow setting of the resin by adjusting the type and ratio of the mixed resin and combining it with a wetting agent, which is beneficial to improving printing quality, improving production efficiency and avoiding waste of raw materials. The low-viscosity resin, cross-linked resin and phenol resin of the present invention can provide a wide range of physical and chemical properties. The low-viscosity resin helps to improve the fluidity of the ink, and the cross-linked resin can enhance the stability and durability of the ink. The poly(vinylphenol) and / or N-(4-hydroxyphenyl)maleimide copolymer in the phenol resin can improve the heat resistance and chemical resistance of the ink due to its structure containing benzene rings and active hydroxyl groups, while maintaining the flexibility and adhesion of the ink. The mixed resin is combined with a solvent, an additive and a curing agent to achieve a significant extension of the ink setting time.

[0081] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of the present invention.

Claims

1. A slow-setting ink composition, characterized in that: In parts by weight, it is prepared from the following raw materials: 42~80 parts of mixed resin, 10~30 parts solvent, 2.5 to 9 parts of additives, 2 to 5 parts of curing agent, wherein the mixed resin is composed of a low-viscosity resin, a cross-linked resin, and a phenol resin, and the phenol resin is selected from poly(vinylphenol) or N-(4-hydroxyphenyl)maleimide copolymer; In parts by weight, the mixed resin consists of 20 to 30 parts of a low-viscosity resin, 20 to 30 parts of a cross-linking resin, and 2 to 20 parts of a phenol resin; The low-viscosity resin is selected from any one of polyurethane acrylate, epoxy acrylate, and diglycidyl tetrachlorophthalate; The cross-linking resin is selected from isobornyl acrylate; The auxiliary agent includes a wetting agent, and the wetting agent is a mixture of cyclohexanone and ethylene glycol butyl ether in a mass ratio of 1: (1-2); The curing agent is m-xylenediamine; At a temperature below 100° C., the retarding ink composition has a viscosity below 30 mPa·s and a surface tension below 0.0004 N / m at a shear rate of 5000 to 10000 times / second.

2. The slow-setting ink composition according to claim 1, wherein The auxiliary agent includes pigments and fillers, and the pigments and fillers are selected from porous powdered quartz.

3. A method for preparing the slow-setting ink composition according to any one of claims 1 to 2, characterized in that: The following steps are involved: S1: mixing a low-viscosity resin, a cross-linked resin and a phenol resin to obtain a mixed resin; S2: adding a solvent and an additive to the mixed resin, shearing and mixing, to obtain a first mixture; S3: Grinding the mixture and filtering it, adding a curing agent, heating and mixing it to reach a set viscosity and surface tension range to obtain a retarded ink composition.

4. The method for preparing the slow-setting ink composition according to claim 3, wherein: The filtration fineness is less than 2 μm.

5. A use of the slow-setting ink composition according to any one of claims 1 to 2, characterized in that: Used in high-strength and drop-resistant mobile terminal glass back panels.

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