Application of the hottest two-dimensional ink mak

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The application of two-dimensional ink making method in packaging and printing

for a long time, The "technical stacking method" of adding and subtracting in the manufacturing of packaging and printing ink and the "intrinsic viscosity method" usually used in the formulation design of ink (weigh a certain amount of polymer dissolved in solvents with different solubility parameters, measure its intrinsic viscosity at a certain temperature, and the maximum intrinsic viscosity system obtained can be determined that the solubility parameter of the polymer is equal to the solubility parameter value of the system) and "Equilibrium swelling method" (swelling the crosslinked polymer in a solvent with different solubility parameters at a certain temperature, and measuring the solubility parameter of the solvent system after reaching equilibrium is the solubility parameter of the polymer). These two methods are relatively simple and intuitive methods for determining the solubility parameter of polymer compounds at present, and are far from meeting the requirements of modern packaging and printing technology

one of the "two-dimensional ink making methods" described in this paper is to judge whether the resin is dissolved in solvent or mixed solvent and the mutual solubility of ink and substrate based on the principle that solubility parameters are the same or similar and can be mutually soluble

the second is to predict the mutual solubility between two solvents or inks and the substrate based on the principle that the solubility parameters are the same or similar

the third is based on the solubility parameters, which can estimate the mutual solubility of two or more resins (the parameters cannot be greater than 1.5) and the adhesion of substrate

the fourth is to use the dissolution of the resin in the packaging and printing ink system in a series of solvents with known solubility parameters, and the range value of the solubility parameters between the resin and the substrate can be determined through experiments

fifth, we can judge the solvent resistance of the ink film after printing according to the solubility parameter

the sixth is that the adhesion, flexibility, wear resistance and heat resistance of printing ink after film formation can be estimated according to the resin of ink system, dissolved hydrogen bond force and softening point

seventh, according to the parameters of dissolved hydrogen bond force, cheap resins and solvents can be selected in the process of packaging and printing inks, so as to control the material cost of packaging and printing inks

however, two or more resins or mixed solvents are often used in packaging and printing ink products. The calculation method must be based on its dissolved hydrogen bond force, surface tension and volatilization rate to accurately obtain the ideal (i.e. non tile effect) viscosity of mixed solution, so as to achieve high-quality and low-cost ink products, that is, the solubility of solvents and resins and the hydrogen bond force of ink solution and substrate (referred to as dissolved hydrogen bond force for short)

(Note: due to the compatibility of speed and speed, the mixed solvent forms a volatile gradient balance, and the volatile rate is faster than any single solvent component. At the same time, higher dissolved hydrogen bond force can be obtained during the heating process of ink film, and pinholes, shrinkage and whitening of ink film can be prevented.)

on the other hand, under the principle of solvation, the swelling and dissolution of its high polymer are related to the solvation, that is, when the polymer and solvent are in contact, the force generated by the solvent molecules on the polymer molecules. This force is greater than the cohesion between polymer molecules, so polymer molecules can be separated from each other and dissolved in solvents. The mutual attraction of polar solvent molecules and polar groups of polymers can produce solvation and dissolve the polymer. As we all know, this effect is often simply explained as: acidic solvents can dissolve alkaline polymers, otherwise vice versa. Theoretically, it is often explained that the electron acceptor can dissolve the electron donor

the solvent evaporates and dries from the ink film, which is called the evaporation rate. Although it has been proposed that the boiling point of a solvent can be used as a basis for predicting its volatility, only homologues or petroleum solvents conform to this law. Therefore, it is no longer scientific to use it as a general method, mainly because it is ineffective and inaccurate. One of the main reasons is the influence of hydrogen bond. For example, the boiling points of ethanol and benzene are close, while the volatilization rate of benzene is twice that of ethanol. The boiling point of butanol is lower than that of n-butyl acetate, and the volatilization rate is also low. From this, it can be seen that hydrogen bond plays an important role in limiting the volatilization of ink film of dissolving dosage form printing ink

of course, temperature, humidity, surface area of ink film, molecular weight of high molecular polymer, surface tension, etc. all directly affect the drying speed of ink film of packaging printing ink, especially the adhesion fastness after internal printing compound (aging), etc

1. Ink basic theory - "two-dimensional method"

has been promoting the "two-dimensional method" for more than two years, and its Fan Si focuses on Shanghai, Jiangsu, Anhui, Zhejiang, Fujian, Shandong, Shanxi, Sichuan, etc. This paper introduces the application of "two-dimensional method" in packaging printing ink. It mainly refers to the system without heat or endothermic when non-polar molecules are mixed, which is derived by Hurd. For the system composed of strong polar molecules, it is due to the formation of hydrogen bonds, which will release heat when mixed, so the derivation result is not applicable to packaging and printing inks. Therefore, according to Leiberman's assumption, the hydrogen bond force is quantified by the characterization average value (relative value) of hydrogen bond strength. According to its setting, the average value of weak hydrogen bond is 0, the average value of medium hydrogen bond is 1.0, and the average value of strong hydrogen bond is 1.7. The calculation formulas Q1 and Q2 are the characterization average values of hydrogen bond force of solvents a and B. Later, when we judge whether a resin is dissolved in a solvent (or mixed solvent) from burr, we must first confirm the grade of the hydrogen bond force between the resin and the solution, and then judge whether the resin is dissolved in the solvent according to the principle of whether the solubility parameters of the resin and the solvent in the same hydrogen bond grade are the same or similar, and the gloss and adhesion of the printed ink film are to make the test piece straight in the process of the experiment, In this way, the molecular polarity and the effect of hydrogen bonding force on solubility and printability are taken into account. Compared with the single judgment from solubility (including volatilization rate, surface tension, etc.), the accuracy is as high as 95%. Therefore, after more than two years of promotion and application, it has achieved certain results. It is unlikely that it will consume human and material resources by adding and subtracting "stacking" technology as before, especially when time is up. Sometimes it also adopts casting structure (cast steel, cast aluminum, etc.)

2. Examples of ink design common sense

in addition to the basic principles usually needed by people, the "two-dimensional ink making method" mainly keeps in mind the solubility of raw materials, hydrogen bonding force, surface tension and evaporation rate. For example:

(1) the solubility of PA is 10.5, the hydrogen bond force is 25.92, the surface tension is 460, and the volatilization rate is 2.8

(2) the solubility of CN is 10.7, the hydrogen bonding force is 12.7, the surface tension is 420 ~ 450, and the volatilization rate is 3.8

(3) the solubility of PE is 7.9 ~ 8.1, the hydrogen bonding force is 16.10, and the surface tension is 310

(4) the solubility of PP is 7.9 ~ 8.6, the hydrogen bonding force is 16.16, and the surface tension is 310

(5) the solubility of pet is 10.7, the hydrogen bonding force is 21.89, the surface tension is 400 ~ 430, and the volatilization rate is 2.67

(Note: the solubility is generally controlled at not more than 1 or not less than 1. More importantly, the pH index of various materials is close to the pH index of solvents. Of course, there is a relationship between chlorine content and solubility, such as CN nitrocellulose. Generally speaking, almost all solvents cannot be dissolved after the nitrogen content exceeds 12.5%)

3. The formation rate of printing ink film and the drying speed of printing machinery

determine the speed of printing. For convenience of application,

(1) 0.7 ~ 0.9 30m/min (2) 0.9 ~ 1.350m/min (3) 1.3 ~ 1.9 80m/Min

(4) 1.9 ~ 2.4 100M/min (5) 2.4 ~ 2.8120m/min (6) 2.8 ~ 3.150m/min

(7) 3.3 ~ 3.6 180m/min(8) 3.6 ~ 4.5200m/min

in addition, the height and size of workshop temperature and humidity, And the viscosity of the ink should be taken into account here. 4. Examples of general composite ink formula

titanium dioxide 20.0 hardle-15-lp 7.0 butanone 17.0 toluene 56.0 (Note: ① kilospeed: 2.58 ② solubility: 8.99 ③ hydrogen bond force: 18.4 ④ surface tension: 27.61)

reprinted from: China Packaging News

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