Noise-reducing black ink for PET (Polyethylene Terephthalate) material

Abstract

The noise-reducing black ink for the PET material comprises the following components in percentage by weight: 1-2 parts of anti-settling wax slurry; 5-7 parts of a medium dry solvent A; 25 to 32 parts of polyurethane resin; 8 to 12 parts of polyester polyol; 20-24 parts of a middle dry solvent B; 0.2 to 0.5 part of a dispersant; 0.5 to 1 part of carbon black; 0.1 to 0.3 part of iron blue powder; 10-25 parts of light calcium carbonate; 1-4 parts of silicon dioxide matting powder; 0.2 to 0.4 part of a catalyst; 8-15 parts of nitrocotton; 8-13 parts of a quick-drying solvent; 4-7 parts of an isocyanate curing agent; wherein the nitrocotton is provided in a liquid form, and the isocyanate curing agent is a normal-temperature curing agent and is added before use.

Description

Technical Field

[0001] The invention relates to conductive ink, in particular to a noise reduction black ink for PET materials. Background Art

[0002] ET film materials have a wide range of applications, including mobile phones, computers, monitors, panels, screens, plastic shells, nameplates, signs, polarizers, membrane switches, diffusers, FPCs, glass, lenses; die-cutting, electronics, electrical appliances, packaging, printing, composites, hardware, plastics, optoelectronics, metals and other industries;

[0003] Among them, battery components used in electronic products usually have battery labels or packaging films on the surface of the battery packaging during production, installation and normal use. When the battery label is used, when the battery is pressed or shaken, the battery label or battery packaging will produce a "crunching" sound, which usually comes from the PET film material. When installing the battery label and battery packaging film, the noise generated by the film will affect the judgment of the integrity of the film fit. If the battery label or battery packaging generates noise during the use of the battery, it will affect the quality of the entire electronic product, especially electronic products with acoustic devices. Therefore, noise reduction black ink for PET materials is worth developing.

[0004] There are many types of inks currently coated on PET materials, usually polyester, polyurethane, acrylic, and epoxy systems. Among them, polyester, acrylic, and epoxy system resins usually make the coating harder and harder due to post-curing during the application process, which in turn causes the film material to make more and more noise over time. Polyurethane system resins with higher hardness will also have the phenomenon of increasing noise after long-term storage. Resins with very low hardness have poor alcohol resistance. At the same time, since the resin itself is relatively soft, there is a huge risk of anti-sticking during the use of the ink after it is made.

[0005] Existing black inks used on PET materials have several disadvantages:

[0006] The existing black ink applied to PET materials usually does not have a noise reduction effect. It is usually applied for covering, hue, chemical resistance, scratch resistance, protection, etc., but has little effect on reducing the noise of the original PET film when it is shaken;

[0007] When the Tg point of the existing black ink applied to PET materials is high (Tg point>20°C), the coating after the ink film is usually brittle, so the ink layer will also increase the vibration sound of the PET material, not only failing to reduce the noise, but usually increasing the noise;

[0008] When the Tg point of the existing black ink applied to PET materials is low (Tg point < 20°C), the ink layer has the risk of sticking due to the soft resin itself during application, even if the surface is made matte by adding matting powder. At the same time, after the ink is dried, it has a certain noise reduction effect initially, but over time, the hardness of the ink layer will gradually increase, which will lead to a decrease and deterioration of the noise reduction effect.

[0009] If the existing black ink used on PET materials is made of polyurethane system resin with a lower Tg point, the noise reduction performance of the ink will be improved, but the alcohol and chemical resistance of the ink layer will be relatively weak, which is not conducive to the subsequent application of the product. At the same time, because the resin itself is relatively soft, there will also be a risk of anti-sticking.

[0010] Therefore, it is necessary to provide a noise reduction black ink for PET material to solve the above problems. Summary of the invention

[0011] The object of the present invention is to provide a noise-reducing black ink for PET material.

[0012] The present invention achieves the above object through the following technical solutions:

[0013] One of the technical solutions:

[0014] A noise reduction black ink for PET material, comprising the following components in percentage:

[0015]

[0016] Among them, nitrocellulose is provided in liquid form, and isocyanate curing agent is a room temperature curing agent, which is added before use.

[0017] Furthermore, the medium-dry solvent A and the medium-dry solvent B are added at different steps during the preparation process.

[0018] Furthermore, polyurethane resin has high adhesion to PET material and good softness. Since the reaction of some monomers is particularly suppressed during the synthesis process, a large amount of hydroxyl groups will remain in the resin molecules. The remaining hydroxyl groups will cross-link after reacting with the isocyanate curing agent, making the coating have a certain alcohol resistance effect, which can usually reach more than 500gf / 10 times in the standard dust-free cloth test.

[0019] Furthermore, polyester polyol is a linear polyester resin with a large molecular weight linear structure, which can provide a very soft and cottony effect. At the same time, the hydroxyl value of this resin reaches 77mgKOH / g, and the alcohol resistance is excellent after the isocyanate curing agent reacts completely. After the polyester polyol resin reacts with the isocyanate, the coating has both the flexibility of the polyol resin and excellent alcohol resistance, which can usually reach more than 500gf / 50 times in the standard dust-free cloth test;

[0020] Since polyurethane resin and polyester polyol resin can provide long-term softness, the noise reduction performance can be maintained for a long time. The long-term noise reduction effect can keep the membrane material vibration noise less than 40 decibels.

[0021] Furthermore, the use of a large amount of light calcium carbonate as a filler has two main effects: first, after comparing with a series of filler materials such as heavy calcium carbonate, barium sulfate, talcum powder, PMMA powder, silica powder, magnesium aluminum silicate, diatomaceous earth, etc., light calcium carbonate has the best effect on promoting noise reduction, and the noise reduction effect can keep the vibration noise of the membrane material less than 40 decibels;

[0022] Second, the addition of a large amount of light calcium carbonate has no effect on the adhesion of the ink, and at the same time can enhance the anti-sticking effect of the ink itself.

[0023] Furthermore, the medium-drying solvent is butyl acetate and the fast-drying solvent is butanone. The combination of the medium-drying solvent and the fast-drying solvent ensures that when the ink layer thickness is 18-21 μm, the solvent in the ink can produce gradient volatilization without being trapped in the coating and difficult to volatilize due to the surface drying too quickly, which has a certain promoting effect on the anti-sticking risk of the ink layer.

[0024] Furthermore, the nitrocellulose is AM type nitrocellulose with a nitrogen content of 11.4%. The purpose of adding the nitrocellulose is to increase the initial drying speed of the ink and prevent anti-sticking.

[0025] Furthermore, the amount of isocyanate curing agent used is calculated based on the hydroxyl content of the polyurethane resin and the polyester polyol resin. When the amount of isocyanate curing agent used is small, the alcohol resistance of the ink layer after curing is poor. When the amount of isocyanate curing agent used is large, the structure after the reaction of hydroxyl group and isocyanate NCO group is a rigid structure, which will reduce the flexibility of the ink and thereby reduce the noise reduction and silencing effect of the ink.

[0026] Compared with the prior art, the resin selected in the present invention is a special polyurethane resin, a polyester polyol resin compatible therewith, and nitrocellulose. After being adjusted and compounded in a certain proportion, the ink resin part respectively shows the effects of long-term softness, alcohol resistance, and no anti-stickiness after drying; since the main advantage of the present invention is the long-term noise reduction and sound elimination effect, and the black PET film is mainly used as the main application material, the amount of carbon black added during formula design is relatively low, and there are no special requirements. The addition of iron blue powder is mainly for the visual blue phase effect after the ink is formed into a film, and the visual effect is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a noise result report for samples coated with noise reduction ink.

[0028] Figure 2 This is the noise result report for the black PET original film sample. DETAILED DESCRIPTION

[0029] Example:

[0030] A noise reduction black ink for PET material, comprising the following components in percentage:

[0031]

[0032] Among them, nitrocellulose is provided in liquid form.

[0033] The preparation process is:

[0034] 1. Dilute and stir the quantitative anti-settling wax slurry with a certain amount of medium dry solvent until there is no paste and no large lumps of wax slurry;

[0035] 2. In step 1, add the polyurethane resin, polyester polyol resin, medium dry solvent and dispersant in the formula in sequence, and stir and disperse the mixture using a high-speed disperser at a speed of 600-800r / min for 10 minutes;

[0036] 3. After step 2, add the carbon black, iron blue powder and light calcium carbonate in the formula in order according to the formula amount. Use a high-speed disperser to stir and disperse the mixture at a speed of 600-800r / min for 10 minutes. After dispersion, use a sand mill to sand grind 4 times until the ink fineness is less than 5μm.

[0037] 4. After step 3 is completed, add the silicon dioxide matting powder in the formula according to the formula amount, and use a high-speed disperser to stir and disperse the mixture at a speed of 600-800r / min for 5 minutes. After dispersion, use a sand mill to sand grind once, and tie a 300-mesh filter cloth to the sand mill outlet for filtering;

[0038] 5. Add the remaining catalyst, nitrocellulose, and quick-drying solvent to the semi-finished product obtained in step 4 to obtain a noise reduction and silencing ink product;

[0039] 6. When using the ink, pre-disperse the ink product and isocyanate curing agent in a ratio of 100:5. Add an appropriate amount of diluent according to the actual situation, and start coating after dispersing for 5-10 minutes.

[0040] The medium-dry solvent A and the medium-dry solvent B are added at different steps during the preparation process.

[0041] Polyurethane resin has high adhesion to PET material and good softness. Since the reaction of some monomers is particularly suppressed during the synthesis process, a large amount of hydroxyl groups will remain in the resin molecules. The remaining hydroxyl groups will cross-link after reacting with the isocyanate curing agent, making the coating have a certain alcohol resistance effect, which can usually reach more than 500gf / 10 times in the standard dust-free cloth test.

[0042] Polyester polyol is a linear polyester resin with a large molecular weight linear structure. It can provide a very soft and cottony effect. At the same time, the hydroxyl value of this resin reaches 77mgKOH / g. After the isocyanate curing agent reacts completely, it has excellent alcohol resistance. After the polyester polyol resin reacts with the isocyanate, the coating has both the flexibility of the polyol resin and excellent alcohol resistance. It can usually reach more than 500gf / 50 times in the standard dust-free cloth test.

[0043] Since polyurethane resin and polyester polyol resin can provide long-term softness, the noise reduction performance can be maintained for a long time. The long-term noise reduction effect can keep the membrane material vibration noise less than 40 decibels.

[0044] There are two main reasons why a large amount of light calcium carbonate is used as filler: First, compared with a series of filler materials such as heavy calcium carbonate, barium sulfate, talcum powder, PMMA powder, silica powder, magnesium aluminum silicate, diatomaceous earth, etc., light calcium carbonate has the best effect on promoting noise reduction, and the noise reduction effect can keep the vibration noise of the membrane material less than 40 decibels;

[0045] Second, the addition of a large amount of light calcium carbonate has no effect on the adhesion of the ink, and at the same time can enhance the anti-sticking effect of the ink itself.

[0046] The medium-drying solvent is butyl acetate and the fast-drying solvent is butanone. The combination of the medium-drying solvent and the fast-drying solvent is to ensure that when the ink layer thickness is 18-21μm, the solvent in the ink can produce gradient volatilization instead of being trapped in the coating and difficult to volatilize due to the surface drying too quickly, which has a certain promoting effect on the anti-sticking risk of the ink layer.

[0047] The nitrocellulose is AM type nitrocellulose with a nitrogen content of 11.4%. The purpose of adding nitrocellulose is to increase the initial drying speed of the ink and prevent anti-sticking.

[0048] The dosage of isocyanate curing agent is calculated based on the hydroxyl content of the polyurethane resin and the polyester polyol resin. When the dosage of isocyanate curing agent is small, the alcohol resistance of the ink layer after curing is poor. When the dosage of isocyanate curing agent is large, the structure after the reaction of hydroxyl group and isocyanate NCO group is a rigid structure, which will reduce the flexibility of the ink and thus reduce the noise reduction and silencing effect of the ink.

[0049] Correspondingly, conduct product performance testing;

[0050] Specifically includes performance indicator charts.

[0051] For performance testing after preparation, refer to the following table:

[0052] Table: Performance of a noise reduction black ink for PET material

[0053]

[0054] See also Figure 1 Noise result report of the sample coated with noise reduction ink and Figure 2 The noise result report of the black PET original film sample can clearly show:

[0055] The resin selected in the present invention is a special polyurethane resin, a polyester polyol resin compatible therewith, and nitrocellulose. After being adjusted and compounded in a certain proportion, the ink resin part respectively shows the effects of long-term softness, alcohol resistance, and no anti-stickiness after drying; since the main advantage of the present invention is the long-term noise reduction and sound elimination effect, and the black PET film is mainly used as the main application material, the amount of carbon black added during formula design is relatively low, and there is no special requirement, and the addition of iron blue powder is mainly for visually viewing the blue phase effect after the ink is formed into a film, and the visual effect is good.

[0056] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the creative concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A noise reduction black ink for PET material, characterized by: In percentage, it contains the following components: Among them, nitrocellulose is provided in liquid form, and isocyanate curing agent is a room temperature curing agent, which is added before use.

2. The noise reduction black ink for PET material according to claim 1, characterized in that: Urethane resin has high adhesion to PET materials and good softness. Since the reaction of some monomers is particularly suppressed during the synthesis process, a large amount of hydroxyl groups will remain in the resin molecules. The remaining hydroxyl groups will cross-link after reacting with the isocyanate curing agent, making the coating have a certain alcohol resistance effect, which can usually reach more than 500gf / 10 times in the standard dust-free cloth test.

3. The noise reduction black ink for PET material according to claim 1, characterized in that: Polyester polyol is a linear polyester resin with a large molecular weight linear structure. It can provide a very soft and cottony effect. At the same time, the hydroxyl value of this resin reaches 77mgKOH / g, and it has excellent alcohol resistance after the isocyanate curing agent reacts completely. After the polyester polyol resin reacts with the isocyanate, the coating has both the flexibility of the polyol resin and excellent alcohol resistance, which can usually reach more than 500gf / 50 times in the standard dust-free cloth test.

4. The noise reduction black ink for PET material according to claim 3, characterized in that: Since polyurethane resin and polyester polyol resin can provide long-term softness, the noise reduction performance can be maintained for a long time. The long-term noise reduction effect can keep the membrane material vibration noise less than 40 decibels.

5. The noise reduction black ink for PET material according to claim 1, characterized in that: There are two main reasons why a large amount of light calcium carbonate is used as filler: First, compared with a series of filler materials such as heavy calcium carbonate, barium sulfate, talcum powder, PMMA powder, silica powder, magnesium aluminum silicate, diatomaceous earth, etc., light calcium carbonate has the best effect on promoting noise reduction, and the noise reduction effect can keep the vibration noise of the membrane material less than 40 decibels; Second, the addition of a large amount of light calcium carbonate has no effect on the adhesion of the ink, and at the same time can enhance the anti-sticking effect of the ink itself.

6. The noise reduction black ink for PET material according to claim 1, characterized in that: The medium-drying solvent is butyl acetate and the fast-drying solvent is butanone. The combination of the medium-drying solvent and the fast-drying solvent is to ensure that when the ink layer thickness is 18-21μm, the solvent in the ink can produce gradient volatilization instead of being trapped in the coating and difficult to volatilize due to the surface drying too quickly, which has a certain promoting effect on the anti-sticking risk of the ink layer.

7. The noise reduction black ink for PET material according to claim 1, characterized in that: The nitrocellulose is AM type nitrocellulose with a nitrogen content of 11.4%. The purpose of adding nitrocellulose is to increase the initial drying speed of the ink and prevent anti-sticking.

8. The noise reduction black ink for PET material according to any one of claims 1 to 7, characterized in that: The dosage of isocyanate curing agent is calculated based on the hydroxyl content of the polyurethane resin and the polyester polyol resin. When the dosage of isocyanate curing agent is small, the alcohol resistance of the ink layer after curing is poor. When the dosage of isocyanate curing agent is large, the structure after the reaction of hydroxyl group and isocyanate NCO group is a rigid structure, which will reduce the flexibility of the ink and thus reduce the noise reduction and silencing effect of the ink.

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