CN112625497A - Gravure ink for PET mobile phone membrane and preparation method thereof - Google Patents

Abstract

The invention relates to the technical field of printing ink, in particular to gravure printing ink for PET mobile phone diaphragms and a preparation method thereof. The gravure printing ink for the PET mobile phone membrane is prepared from the following components in parts by weight: 0.5-1.5 parts of cellulose acetate, 30-40 parts of polyurethane resin, 30-55 parts of solvent, 8-30 parts of pigment and 1-5 parts of assistant. The gravure ink does not actively add halogen, the single limit of halogen of the ink is less than or equal to 600ppm, and the total limit of halogen of the ink is less than or equal to 900 ppm; coating UV (ultraviolet) adhesive after printing ink is printed, testing the adhesive force of hundreds of cases when no ink is dissolved before and after visual inspection and curing, repeatedly pulling 3 times at the same position by using 3M adhesive tape, wherein the adhesive force is not less than 4B; after the ink is boiled in water, the adhesive force of the visual inspection lattice is not less than 4B, and the visual inspection ink has no obvious color change.

Description

Gravure ink for PET mobile phone membrane and preparation method thereof

Technical Field

The invention relates to the technical field of printing ink, in particular to gravure printing ink for PET mobile phone diaphragms and a preparation method thereof.

Background

With the development of the mobile phone market, the requirements of consumers on the delicacy of the mobile phone are increasingly improved, and the PET decorative film adhered to the back of the 3D glass and the transparent injection molding piece becomes the mainstream. At present, in the prior art, the coloring layer of the mobile phone PET membrane before film coating is obtained by adopting the modes of silk screen printing, offset printing and printing, and the method has the following defects: firstly, the silk-screen printing ink is limited by the mesh number of the screen plate, and a transition area is not fine and smooth during the color-changing overprinting, so that the yield is low and the cost is high; secondly, most of the offset printing ink is of a photocuring type, halogen-containing raw materials are used in a water-oil balance formula, and the UV texture transfer printing adhesive after coating after curing is not easy to adhere and has high performance and environmental protection risk; and thirdly, the point-by-point construction mode of printing ink has extremely low productivity and extremely high cost. Fourthly, the existing gravure printing ink is mostly applied to packaging materials, the coating layers are few, and the performance and the environmental protection performance can not meet the requirements of mobile phones.

The high speed and high precision of roller gravure meet the requirements of production appearance and capacity of PET mobile phone diaphragms, but the existing gravure ink is mostly applied to packaging materials, has different requirements on environment protection and performance, and cannot meet the requirements on performance and environment protection of mobile phones, for example, the adhesive force is poor after halogen-containing and UV texture transfer printing glue.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Disclosure of Invention

Aiming at the existing problems, the invention aims to provide a gravure ink for PET mobile phone diaphragms and a preparation method thereof, so as to solve the problem that although the existing roller gravure can meet the requirements of production appearance and capacity of PET mobile phone diaphragms, the gravure ink cannot meet the requirements of performance and environmental protection on mobile phones.

In order to achieve the purpose, the invention provides the following technical scheme:

the gravure printing ink for the PET mobile phone membrane is prepared from the following components in parts by weight: 0.5-1.5 parts of cellulose acetate, 30-40 parts of polyurethane resin, 30-55 parts of solvent, 8-30 parts of pigment and 1-5 parts of assistant.

Preferably, the cellulose acetate has a viscosity of 0.5-20s, a Tg value of 120-80000 ℃ and a molecular weight of 30000-80000.

Preferably, the cellulose acetate contains 2-15% by mass of acetyl, 35-45% by mass of propionyl and 1-3% by mass of hydroxyl.

Preferably, the polyurethane resin is ester-soluble polyurethane, the molecular weight is 40000-50000, the solid content is 28-32%, and the viscosity is 800-1600mPa.s 25 ℃.

In addition, the invention also provides a method for preparing the gravure ink for the PET mobile phone film, which comprises the following steps:

(1) preparing a semi-finished product, namely completely dissolving cellulose acetate in a solvent to prepare the semi-finished product with the mass fraction of 10-15%;

(2) pre-dispersing raw materials: fully stirring and dispersing the semi-finished product obtained in the step (1) with 25-40% of solvent, pigment and 1-3% of auxiliary agent until the pigment is uniformly dispersed in the mixture;

(3) grinding: pumping the mixture treated in the step (2) into a sand mill for grinding to obtain color paste with the particle size of not more than 10 mu;

(4) adjusting and packaging: adding polyurethane resin, the rest of the auxiliary agent and the solvent into the color paste for dispersion adjustment, inspecting and packaging.

The invention further provides an application of the gravure ink for the PET mobile phone diaphragm in gravure ink printing.

Compared with the prior art, the invention has the following beneficial effects:

(1) the gravure ink does not actively add halogen, the single limit of halogen of the ink is less than or equal to 600ppm, and the total limit of halogen of the ink is less than or equal to 900 ppm.

(2) After the gravure ink is printed, the UV adhesive is coated, ink dissolving does not occur before and after visual inspection and curing, the adhesive force of the hundred grids is tested, the 3M adhesive tape is repeatedly pulled at the same position for 3 times, and the adhesive force is more than or equal to 4B; after the ink is boiled in water, the adhesion force of the visible grids is more than or equal to 4B, and the visible ink has no obvious color change.

Detailed Description

In the following, the technical solutions of the present invention will be described clearly and completely, and it is obvious that the described embodiments are some, not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The gravure printing ink for the PET mobile phone membrane is prepared from the following components in parts by weight: 1.2g of cellulose acetate, 35g of polyurethane resin, 33.3g of solvent, 28g of pigment and 2.5g of auxiliary agent;

in this example, the cellulose acetate had a viscosity of 1.2s, a Tg of 134 deg.C, a molecular weight of 3000, an acetyl group content of 2.5%, a propionyl group content of 45%, and a hydroxyl group content of 2.6%; the polyurethane resin is ester-soluble polyurethane, the molecular weight is 40000, the solid content is 30%, and the viscosity is 1200mPa.s 25 ℃; the solvent is ethylene glycol butyl ether acetate; the pigment is rutile titanium dioxide; the auxiliary agent is sodium dodecyl benzene sulfonate.

The preparation method of the gravure ink for the PET mobile phone film comprises the following steps:

(1) preparing a semi-finished product, namely completely dissolving cellulose acetate in a solvent to prepare the semi-finished product with the mass fraction of 12%;

(2) pre-dispersing raw materials: fully stirring and dispersing the semi-finished product obtained in the step (1) with 30% of solvent, pigment and 1.5% of auxiliary agent until the pigment is uniformly dispersed in the mixture;

(3) grinding: pumping the mixture treated in the step (2) into a sand mill for grinding to obtain color paste with the particle size of not more than 10 mu;

(4) adjusting and packaging: adding polyurethane resin, the rest of the auxiliary agent and the solvent into the color paste for dispersion adjustment, inspecting and packaging.

Example 2

The gravure printing ink for the PET mobile phone membrane is prepared from the following components in parts by weight: 1.2g of cellulose acetate, 35g of polyurethane resin, 50.8g of solvent, 8g of pigment and 5g of auxiliary agent;

in this example, the cellulose acetate had a viscosity of 1.8s, a Tg of 130 ℃, a molecular weight of 7000, an acetyl group content of 2.5%, a propionyl group content of 45%, and a hydroxyl group content of 2.6%; the polyurethane resin is ester-soluble polyurethane, the molecular weight is 43000, the solid content is 31 percent, and the viscosity is 1400mPa.s 25 ℃; the solvent is ethylene glycol butyl ether acetate; the pigment is carbon black, the auxiliary agent is 4g of diethylethanolamine, 0.3g of matte powder and kaolin which is added to complement 5 g.

The preparation method of the gravure ink for the PET mobile phone film comprises the following steps:

(1) preparing a semi-finished product, namely completely dissolving cellulose acetate in a solvent to prepare the semi-finished product with the mass fraction of 15%;

(2) pre-dispersing raw materials: fully stirring and dispersing the semi-finished product obtained in the step (1) with 40% of solvent, pigment and 3% of auxiliary agent until the pigment is uniformly dispersed in the mixture;

(3) grinding: pumping the mixture treated in the step (2) into a sand mill for grinding to obtain color paste with the particle size of not more than 10 mu;

(4) adjusting and packaging: adding polyurethane resin, the rest of the auxiliary agent and the solvent into the color paste for dispersion adjustment, inspecting and packaging.

Performance testing

The gravure inks of examples 1 and 2 were tested according to the gravure composite plastic film ink QB/T2024-2012, and the test results are shown in table 1 below.

TABLE 1 test results for gravure inks according to the invention

As can be seen from Table 1, the fineness, drying speed, shallow screen transition, adhesion and anti-sticking performance of the gravure ink of the invention meet the requirements of gravure printing, the requirements of UV glue coating and water boiling in the subsequent process can meet the application requirements, and the environmental protection and halogen can also meet the industrial requirements.

Comparative examples

The gravure inks of examples 1 and 2 of the present invention were compared with conventional screen printing inks and the existing gravure back printing inks on the market, and the comparison results are shown in table 2 below.

TABLE 2 comparison of gravure inks of the present invention with conventional inks

As can be seen from table 2, the gravure ink of the present invention is superior to the existing screen printing ink and gravure inner printing ink in each test index, indicating that the gravure ink of the present invention can be used to replace the existing ink.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and its practical application to enable one skilled in the art to make and use various exemplary embodiments of the invention and various alternatives and modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims and their equivalents.

Claims (6)

1. The gravure printing ink for the PET mobile phone membrane is characterized by being prepared from the following components in parts by weight: 0.5-1.5 parts of cellulose acetate, 30-40 parts of polyurethane resin, 30-55 parts of solvent, 8-30 parts of pigment and 1-5 parts of assistant.

2. The gravure ink for PET mobile phone films as claimed in claim 1, wherein the viscosity of the cellulose acetate is 0.5-20s, the Tg value is 120-150 ℃, and the molecular weight is 30000-80000.

3. The gravure ink for PET mobile phone membranes as claimed in claim 2, wherein the cellulose acetate contains acetyl in an amount of 2 to 15% by mass, propionyl in an amount of 35 to 45% by mass, and hydroxyl in an amount of 1 to 3% by mass.

4. The gravure ink for PET mobile phone films as claimed in claim 1, wherein the polyurethane resin is ester-soluble polyurethane, the molecular weight is 40000-50000, the solid content is 28-32%, and the viscosity is 800-1600mPa.s 25 ℃.

5. A method for preparing gravure ink for PET mobile phone films as claimed in any one of claims 1 to 4, which comprises the following steps:

(1) preparing a semi-finished product, namely completely dissolving cellulose acetate in a solvent to prepare the semi-finished product with the mass fraction of 10-15%;

(2) pre-dispersing raw materials: fully stirring and dispersing the semi-finished product obtained in the step (1) with 25-40% of solvent, pigment and 1-3% of auxiliary agent until the pigment is uniformly dispersed in the mixture;

(3) grinding: pumping the mixture treated in the step (2) into a sand mill for grinding to obtain color paste with the particle size of not more than 10 mu;

(4) adjusting and packaging: adding polyurethane resin, the rest of the auxiliary agent and the solvent into the color paste for dispersion adjustment, inspecting and packaging.

6. Use of the gravure ink for PET mobile phone film sheets as claimed in any one of claims 1 to 4 for preparing gravure ink.