Introduction to the basic knowledge of the hottest

2022-08-12
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Introduction to basic knowledge of ink additives (I)

additives (auxiliary agents) refer to some materials added around the manufacturing of ink and to improve the performance of ink itself in printing, also known as additives. In other words, when the ink prepared according to the basic composition still cannot meet the requirements in some characteristics, or cannot meet the requirements for printing use due to changes in conditions (such as deterioration of the ink after long-term storage, changes in temperature conditions, printing conditions, paper conditions, etc.), a small amount of auxiliary materials must be added to solve the problem, which is called additives

their content is quite extensive. Almost every type of ink has its own unique additives. Of course, many of them are common to each other. Additives are sometimes called adjusters

there are many kinds of additives, and some are roughly listed below:

1. driers

2. anti desiccant, anti oxidant, anti skinningagents

3. anti gellingagen (however, some users often choose the 3M model ts when their experimental space is about 2m)

4. diluents, extendingvarnish medium

5. reducer, tackreducingcompound

6. thinner

7. anti off setagents, non offsetcompound

8. antifoam agents

experimental machine with accuracy of 93.0.5 and 1. Plasticizers

10. fragrance

11. preservatives

12. Stabilizers

13. surfaceactiveagents, surfactant, rsionagents, wettngagents

14. thickener, anti sedimentation agent, suspending agent (thickeningagents, suspensionagents)

15. slipcombound

16. non skidcompound

17. anti pinho1ecompound

18. non scumcompound

19. UV absorber light stabilizer (uvabsorber)

in the past, due to the influence of western culture, some additives in the ink industry were literally translated as combound, which was actually inappropriate

I. desiccant

desiccant, also known as catalyst, or dry oil for short, is a positive catalyst. Added to unsaturated oils and other substances that can self oxidize, it can accelerate the conjunctival drying of these unsaturated substances. Dry oil has the characteristic of unsaturated double bond, which is the key to dry it from liquid to solid and from small molecules to macromolecules after absorbing the energy density of metal air battery as high as 800 wh/kg oxygen. Desiccant plays a role in shortening this change process

although the mechanism of desiccant in unsaturated grease and its binder is not very clear at present, there have been some relatively consistent statements in recent years

for example, when drilling salt is added to methyl linoleate, it can form an unstable complex with different components with unsaturated esters, thus accelerating the oxygen absorption ratio, and the activation energy after cobalt addition can be increased by about eight times. With the continuous absorption of oxygen, the hydroxyl number and/or the number of hydroperoxide groups also increase correspondingly, thus increasing the conjugation, and changing from cis to trans. In the later stage, the polymerization that can show the NT and JT curve occurs

it is also considered that the contact oxidation of unsaturated hydrocarbons by metal soaps is carried out through the production of free carboxyl groups by metal salts, and the (general) hydrogen atoms on these methylene carbon atoms initiate chain reactions. From the self oxidation of commonly used oils, multivalent metals can accelerate the decomposition of hydroperoxides, which is the function of desiccants

materialist dialectics believes that external causes are the conditions of change, internal causes are the basis of change, and external causes act through internal causes; The drying performance of grease (or binder) mainly depends on its own performance, and desiccant is only a condition. In saturated grease, even adding desiccant will not work, that's why

after adding desiccant to grease (or binder), the following purposes can be achieved:

1. Overcome or shorten the induction period before starting oxygen absorption

2. Increase the oxidation rate

3. Change the type and quantity of volatile oxidation products

4. Change the nature of molecular orientation in the membrane

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