CN114410148B

CN114410148B - Low-temperature thermosetting 4D hot bending and stretching forming ink and preparation method thereof

Info

Publication number: CN114410148B
Application number: CN202111583854.3A
Authority: CN
Inventors: 蓝宏昌; 包亚群
Original assignee: Guangzhou 1s Environmental Protection Technology Co ltd
Current assignee: Guangzhou 1s Environmental Protection Technology Co ltd
Priority date: 2021-12-22
Filing date: 2021-12-22
Publication date: 2023-03-24
Anticipated expiration: 2041-12-22
Also published as: CN114410148A

Abstract

The invention discloses a low-temperature thermosetting 4D hot bending and stretching forming ink and a preparation method thereof. A low-temperature thermosetting 4D hot bending and stretching forming ink comprises the following components: saturated polyester resin, a dispersing agent, a wetting agent, a defoaming agent, a thickening agent, carbon black, a filler and a solvent; the saturated polyester resin comprises a saturated polyester resin with Tg of 45-50 ℃ and a saturated polyester resin with Tg of 5-8 ℃. The ink can be thermally set at a low temperature of 75-85 ℃, can be normally used as common ink, and has the functions of covering, protecting, decorating plates and the like of the common ink. Compared with common ink, the ink disclosed by the invention is better in flexibility and better in adhesive force on a plate coating layer. When the ink is applied to 4D hot bending and stretching forming, the ink does not crack, become brittle, adhere to a mold and fall off; lines are clearer during CNC cutting, edges do not jump, and the like.

Description

Low-temperature thermosetting 4D hot bending and stretching forming ink and preparation method thereof

Technical Field

The invention relates to the field of fine chemical engineering, in particular to low-temperature thermosetting 4D hot bending stretch forming ink and a preparation method thereof.

Background

In the mobile phone cover plate material, glass and ceramic are high in cost and are fragile, large-scale production and yield are limited, the mobile phone cover plate material is only suitable for middle-high end flagship models, plastic PC + PMMA cover plates are mainly used for middle-low end models, the markets of the middle and low ends in the sea and the outside are rapidly developed, the mobile phone middle frame consuming time and materials are required to be attached to the mobile phone rear cover formed by 2.5D or 3D hot bending of a plastic PC + PMMA plate, the mobile phone rear cover formed by integrally forming the 4D hot bending middle frame and the rear cover solves the problem that the middle frame needs to be attached to a 2.5D and 3D forming process, and the mobile phone rear cover is more solid and beautiful, is an innovative process and has a certain market prospect.

The plastic plate is an ideal material for the mobile phone cover plate because of the advantages of light weight, easy processing and forming, low cost, weak signal interference, impact resistance and the like, and the processing procedures of the mobile phone rear cover generally comprise: cleaning → printing LOGO → UV transfer → coating → printing 4D hot bending ink → hot bending molding → CNC cutting. Although the existing printing ink process is mature, complete equipment and skilled technical workers are provided, the common printing ink can only be used for the process of a planar or slightly bent mobile phone rear cover, and the phenomena of cracking, breakage, even falling off and the like are caused during the hot bending forming of the printing ink due to the reasons of toughness, compression resistance, high stretchability, compactness and the like during the 4D hot bending and stretching forming; the bad phenomena such as edge breakage of the ink layer on the plastic plate and the like are easily caused in the CNC cutting process. The 2.5D or 3D hot bending printing ink has the undesirable phenomena that an ink layer is cracked, fragile and even falls off due to the limitation of the printing ink during 4D hot bending stretching forming, the technological requirement of 4D hot bending forming cannot be met, workpieces are poor, and meanwhile, because the surface of the plastic plate material is not repairable, damaged workpieces can only be discarded, and unnecessary waste and loss are caused. Furthermore, because the corner of the 4D hot bending forming machine shell presents a 90-degree right-angle side stereoscopic effect, higher requirements are provided for flexibility, compressive deformation resistance, high stretchability, compactness and the like of printing ink.

Disclosure of Invention

In order to solve the problem that the existing ink in the prior art cannot meet the requirement of a 4D hot bending and stretching forming process, the invention provides a low-temperature thermosetting 4D hot bending and stretching forming ink, the second purpose of the invention is to provide a preparation method of the low-temperature thermosetting 4D hot bending and stretching forming ink, the third purpose of the invention is to provide application of the low-temperature thermosetting 4D hot bending and stretching forming ink, and the fourth purpose of the invention is to provide a 4D hot bending and stretching forming method.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a low-temperature thermosetting 4D hot bending and stretching forming ink comprises the following components: saturated polyester resin, a dispersing agent, a wetting agent, a defoaming agent, a thickening agent, carbon black, a filler and a solvent; the saturated polyester resin comprises a saturated polyester resin with Tg of 45-50 ℃ and a saturated polyester resin with Tg of 5-8 ℃; tg is the glass transition temperature.

The hardness of the high Tg (glass transition temperature) saturated polyester resin Gao Yifa is brittle, and the poor phenomena of brittleness, edge breakage, cracking and the like are easily caused in the hot bending and stretching forming process; the low Tg saturated polyester has low hardness, soft resin, high viscosity, low drying speed, poor chemical resistance and easy generation of bad phenomena such as mucosa, mold sticking and the like in the hot bending forming process. The inventor finds that when the Tg45-50 ℃ saturated polyester resin is matched with the Tg5-8 ℃ saturated polyester resin, the ink has excellent mechanical properties, does not crack or be mucous membrane during 4D hot bending and stretching forming, has excellent matching property and adhesive force on a plastic composite board, and can be applied to 4D hot bending and stretching by being matched with other components.

Preferably, the low-temperature thermosetting 4D hot bending and stretching forming ink comprises the following components in parts by mass: 35-60 parts of Tg45-50 ℃ saturated polyester resin, 5-20 parts of Tg5-8 ℃ saturated polyester resin, 0.8-1.4 parts of dispersing agent, 0.08-1.6 parts of wetting agent, 0.8-1.6 parts of defoaming agent, 4-12 parts of thickening agent, 6-12 parts of carbon black, 4-17 parts of filler and 4-12 parts of solvent; further preferably, the composition comprises the following components in parts by mass: 40-55 parts of saturated polyester resin with Tg of 45-50 ℃, 10-15 parts of saturated polyester resin with Tg of 5-8 ℃, 1-1.2 parts of dispersing agent, 0.1-1.5 parts of wetting agent, 1-1.5 parts of defoaming agent, 5-10 parts of thickening agent, 8-10 parts of carbon black, 5-10 parts of filler and 5-10 parts of solvent.

Preferably, in the low-temperature thermosetting 4D hot bending and stretching forming ink, the dispersant is an amino acid ester copolymer dispersant; further preferably, the dispersant is 20000 hyperdispersant; the dispersant can improve the dispersibility and stability of the carbon black in the ink, increase the storage stability of the filler, improve the rheological property and enable the ink to be more stable in the dispersing and grinding process.

Preferably, in the low-temperature thermosetting 4D hot-bending stretch forming ink, the wetting agent comprises at least one of a fluorocarbon polymer wetting agent and a polyether organic silicon wetting agent; the wetting agent aims at improving the wetting spreadability of the ink on a substrate and preventing the occurrence of undesirable phenomena such as shrinkage cavity, edge shrinkage and the like, the consumption of the wetting agent is critical, adverse effects on recoating can be caused by excessive consumption, and the wetting spreading effect cannot be realized by too little consumption.

Preferably, in the low-temperature thermosetting 4D hot bending and stretching forming ink, the defoaming agent is an organic silicon defoaming agent; the defoaming agent is mainly used for inhibiting and eliminating foams generated in the production and construction processes of the printing ink, the consumption of the defoaming agent is very critical, the defoaming effect is poor when the consumption is too small, and the problems of shrinkage, poor recoatability and the like can be caused when the consumption is too large.

Preferably, in the low-temperature thermosetting 4D hot-bending stretch forming ink, the thickening agent comprises at least one of fumed silica and modified bentonite; further preferably, the thickener is fumed silica; the thickening agent aims at adjusting the viscosity of the product, improving the stability of the product, has a certain extinction effect, provides a matte effect for the ink, and plays roles in thickening, thixotropy, extinction and improving the screen printing performance of the ink.

Preferably, in the low-temperature thermosetting 4D hot bending and stretching forming ink, the particle size of carbon black is 15-25nm; the carbon black is amorphous carbon, is light, loose and superfine black powder inorganic pigment, and plays roles of coloring, covering and decorating in the ink and improving the printability of the ink.

Preferably, in the low-temperature thermosetting 4D hot bending and stretching forming ink, the filler comprises at least one of talcum powder, barium sulfate and calcium carbonate; further preferably, the filler comprises at least one of talc powder and calcium carbonate; still further preferably, the filler is ultrafine talcum powder; when the filler is used in the ink, the hardness of the ink printing paint film can be improved, the stability and the weather resistance of the ink can be improved, and meanwhile, the manufacturing cost of the ink can be reduced due to low price.

Preferably, in the low-temperature thermosetting 4D hot-bending stretch forming ink, the solvent comprises at least one of isophorone, dibasic ester, propylene glycol methyl ether and dipropylene glycol dimethyl ether; more preferably, the solvent is at least one of isophorone and dibasic ester; still further preferably, the solvent is isophorone; isophorone (3,5,5-trimethyl-2-cyclohexenone), a colorless or white to yellow low-volatility liquid, can effectively prevent the defects of too fast drying of ink, net sealing and the like when used for screen printing due to the fact that isophorone has a high boiling point and low hygroscopicity, enables patterns to be clear, complete and plump, is strong in dissolving capacity, good in dispersibility and good in leveling property, and can be used as a dissolving and dispersing solvent for saturated polyester.

The invention also provides a preparation method of the low-temperature thermosetting 4D hot bending and stretching forming ink, which comprises the following steps: and mixing and stirring the saturated polyester resin, the dispersing agent and the solvent, adding the wetting agent, the defoaming agent, the thickening agent, the carbon black and the filler, and stirring to obtain the low-temperature thermosetting 4D hot bending and stretching forming ink.

Preferably, the preparation method of the low-temperature thermosetting 4D hot bending and stretching forming ink further comprises a grinding step, wherein a grinder is used for grinding the ink until the grain diameter is less than or equal to 9 microns.

Further preferably, the preparation method of the low-temperature thermosetting 4D hot bending and stretching forming ink adopts a grinder to grind the ink until the grain diameter is less than or equal to 8 microns; still more preferably, the particles are ground to a particle size of 7 μm or less.

The invention also provides application of the low-temperature thermosetting 4D hot bending stretch forming ink in decorative plates or 4D stretch hot bending forming.

The invention also provides a 4D hot bending and stretching forming method, which comprises the following steps:

1) Printing the low-temperature thermosetting 4D hot bending and stretching forming ink on the surface of the plate, and baking and curing each layer of the printed ink to obtain the plate printed with the ink;

2) And (5) carrying out 4D hot bending and stretching on the plate printed with the ink.

Preferably, in the 4D hot-bending stretch forming method, in step 1), the number of printed layers is 2-10, and the number of printed layers may be 2, 3, 4, 5, 6, 7, 8, 9, 10.

Preferably, in the 4D hot bending and stretching forming method, in the step 1), the baking temperature is 75-85 ℃, and the baking temperature can be 75 ℃,78 ℃,80 ℃,82 ℃ and 85 ℃.

Preferably, in the 4D hot bending and stretching forming method, in the step 1), the baking time is 20-140min.

Further preferably, in the 4D hot bending stretch forming method, in step 1), the baking time after printing of each layer is 20-40min except for the last layer, and the baking time after printing of the last layer is 100-140min; still further preferably, the baking time after printing of each layer is 25-35min except the last layer, and the baking time after printing of the last layer is 115-125min.

Preferably, in the 4D hot bending and stretching forming method, in the step 2), the temperature of hot bending and stretching is 120-140 ℃; further preferably, the temperature of hot bending and stretching is 125-135 ℃; the temperature of the hot bend drawing in some preferred embodiments of the invention is 130 ℃.

Preferably, in the 4D hot bending and stretching forming method, in the step 2), the pressure of hot bending and stretching is 3-4MPa.

Preferably, in the 4D hot bending and stretching forming method, in the step 2), hot bending and stretching are carried out for 4-7 seconds, and 4D hot bending and stretching forming is completed; further preferably, the hot bending and stretching are carried out for 5-6 seconds, and 4D hot bending and stretching forming is completed.

The invention has the beneficial effects that:

the low-temperature thermosetting 4D hot bending and stretching forming ink can be thermosetting at a low temperature of 75-85 ℃, can be normally used as common ink, and has the functions of covering, protecting, decorating plates and the like of the common ink.

Compared with common ink, the ink disclosed by the invention is better in flexibility and better in adhesive force on a plate coating layer.

The ink disclosed by the invention is oily, low in VOC (volatile organic compounds), and the emission of the ink meets the national standard.

When the ink is applied to 4D hot bending and stretching forming, the ink does not crack, become brittle, adhere to a mold and fall off in the hot bending and stretching forming process at the temperature of 120-140 ℃; lines are clearer during CNC cutting, edges do not jump, and the like.

The ink of the invention widens the application range of the ink and is suitable for the market environment with higher requirements.

Detailed Description

The present invention will be described in further detail with reference to specific examples. The starting materials or the apparatus used in the examples are, unless otherwise specified, either conventionally commercially available or may be obtained by methods known in the art. Unless otherwise indicated, the testing or testing methods are conventional in the art.

In the embodiment of the present invention, the first and second substrates,

resins with Tg points of 45-50 ℃ available from Toyo Boseki brand (TOYOBO) GK810;

resins with Tg points 5-8 ℃ available from Toyo textile brand (TOYOBO) GK670;

the type of the dispersant is: 20000 Hyperdispersant, available from Lu Borun;

the wetting agent is BYK-345;

the model of the defoaming agent is as follows: TSA750S, available from mayform chemical;

the thickener is degussel OK607

Carbon black type 4A, available from Degussa;

the talcum powder is 8000-mesh superfine talcum powder

The solvent is a dibasic ester.

Example 1

The ink of the embodiment comprises the following components in parts by mass:

55 parts of Tg45-50 ℃ saturated polyester resin, 15 parts of Tg5-8 ℃ saturated polyester resin, 1 part of dispersing agent, 0.5 part of wetting agent, 1.5 parts of defoaming agent, 5 parts of thickening agent, 8 parts of carbon black, 9 parts of talcum powder and 5 parts of solvent.

The ink of this example was prepared as follows:

adding saturated polyester resin into a dispersion stirrer, adding a dispersing agent and a solvent while stirring, and then adding a wetting agent, a defoaming agent, a thickening agent, carbon black and talcum powder; firstly, uniformly stirring the resin liquid, the dispersing agent, the solvent and the defoaming agent, and then adding the carbon black, the thickening agent and the talcum powder while stirring until the mixture is uniformly stirred; grinding with three-roll grinder for 3-4 times to fineness below 7 μm.

20000 hyperdispersant is selected in the examples, which improves the dispersibility, stability and rheological property of carbon black and filler in the ink, and makes the ink more stable in the dispersion grinding process.

In the embodiment, the talcum powder is selected as the filler, so that the hardness of the printing ink film can be improved, the stability and the weather resistance of the printing ink can be improved, the price is low, and the production cost can be reduced.

In the examples, 8 to 10% of carbon black was added to the ink, and the ink covering power and printing performance were excellent.

In the embodiment, the consumption of the defoaming agent is critical, the defoaming effect is poor when the consumption is too small, and the problems of shrinkage cavity, poor recoatability and the like are caused when the consumption is too large.

Example 2

The ink of the embodiment comprises the following components in parts by mass:

70 parts of saturated polyester resin with the Tg of 45-50 ℃,1 part of dispersing agent, 0.5 part of wetting agent, 1.5 parts of defoaming agent, 5 parts of thickening agent, 8 parts of carbon black, 9 parts of talcum powder and 5 parts of solvent.

The ink of this example was prepared as follows:

adding saturated polyester resin into a dispersion stirrer, adding a dispersing agent and a solvent while stirring, and then adding a wetting agent, an antifoaming agent, a thickening agent, carbon black and talcum powder; firstly, uniformly stirring the resin liquid, the dispersing agent, the solvent and the defoaming agent, and then adding the carbon black, the thickening agent and the talcum powder while stirring until the mixture is uniformly stirred; grinding with three-roller grinder for 3-4 times to fineness of below 7 μm.

Example 3

The ink of the embodiment comprises the following components in parts by mass:

70 parts of saturated polyester resin with the Tg of 5-8 ℃,1 part of dispersing agent, 0.5 part of wetting agent, 1.5 parts of defoaming agent, 5 parts of thickening agent, 8 parts of carbon black, 9 parts of talcum powder and 5 parts of solvent.

The ink of this example was prepared as follows:

The inks prepared in examples 1-3 were tested for performance.

The inks obtained in examples 1 to 3 were subjected to viscosity tests, the results of which are shown in Table 1 below.

Adding a D-110N isocyanate curing agent (purchased from Mitsui corporation) into the ink, wherein the mass ratio of the curing agent to the glass ink is 1: printing 4 layers on the PC surface of the plastic plate by using an ink screen printing machine, and baking each layer for 30 minutes at 80 ℃ during the printing of the previous 3 layers; the 4 th layer can be completely cured after being baked for 120 minutes at 80 ℃; the printed plastic plates 4D of examples 1-3 were hot-bent to be boiled in water and folded in half respectively by a special high-pressure forming machine (new bridged brand) of a PC/PMMA high-pressure forming machine matched with a customer for proofing, applying a silicone mold, raising the temperature to about 130 ℃, blowing air at high pressure and low pressure to press 35KG, and maintaining the pressure at high pressure and low pressure for 5-6 seconds (the specific hot bending parameters are adjusted according to the field conditions), and the test results are shown in Table 1 below.

Table 1 examples 1-3 performance test results

The result shows that the printed plastic plate 4D in the example 1 is completely hot-bent and formed without cracks, the printed plastic plate 4D in the example 2 is poor in crack at the corner of hot-bent and formed, and the printed plastic plate 4D in the example 3 is poor in watermark-shaped back adhesion on the ink surface of hot-bent and formed, so that the 4D hot-bent ink disclosed by the invention not only meets the requirement of 4D hot-bent and stretching forming, but also has the adhesive force of 4B after being boiled in water, and the ink printed on the plate does not fall off after being folded for 180-5 times, and can adapt to a 90-degree right-angle and 120-140-degree hot-bent and stretching forming process.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, and equivalents thereof are intended to be included within the scope of the present invention.

Claims

1. The low-temperature thermosetting 4D hot bending and stretching forming ink is characterized by comprising the following components in parts by mass: 35-60 parts of Tg45-50 ℃ saturated polyester resin, 5-20 parts of Tg5-8 ℃ saturated polyester resin, 0.8-1.4 parts of dispersing agent, 0.08-1.6 parts of wetting agent, 0.8-1.6 parts of defoaming agent, 4-12 parts of thickening agent, 6-12 parts of carbon black, 4-17 parts of filler and 4-12 parts of solvent;

the wetting agent comprises at least one of a fluorocarbon polymer wetting agent and a polyether organic silicon wetting agent;

the defoaming agent is an organic silicon defoaming agent;

the thickening agent comprises at least one of fumed silica and modified bentonite.

2. The low temperature thermosetting 4D hot-bending stretch-forming ink as claimed in claim 1, wherein the filler comprises at least one of talc, barium sulfate and calcium carbonate.

3. The low temperature thermosetting 4D hot-bendable stretch-formable ink according to claim 1, wherein the solvent comprises at least one of isophorone, dibasic ester, propylene glycol methyl ether, dipropylene glycol dimethyl ether.

4. A method for preparing the low-temperature thermosetting 4D hot-bending stretch-forming ink according to any one of claims 1 to 3, comprising the following steps: and mixing and stirring saturated polyester resin, a dispersing agent and a solvent, adding a wetting agent, a defoaming agent, a thickening agent, carbon black and a filler, and stirring to obtain the low-temperature thermosetting 4D hot bending and stretching forming ink.

5. Use of the low temperature thermosetting 4D hot-bending stretch-forming ink according to any one of claims 1 to 3 for decorative sheet materials or 4D stretch-bending.

6. A4D hot bending and stretching forming method is characterized by comprising the following steps:

1) Printing the low-temperature thermosetting 4D hot-bending stretch forming ink as claimed in any one of claims 1 to 3 on the surface of a plate, and baking and curing the printed layer of the ink to obtain the plate printed with the ink;

2) 4D hot bending and stretching the plate printed with the printing ink;

in the step 2), the pressure of hot bending and stretching is 3-4MPa.