Surfactant composition, dampening solution for printing of tissue paper and method for its preparation

Abstract

The application belongs to the technical field of printing dampening solution, and particularly relates to a surfactant composition, a dampening solution for printing of extra-thin paper and a preparation method thereof. A star-shaped structure organic silicon polyether is designed and synthesized, wherein a polyether EO chain segment is hydrophilic, a siloxane skeleton is hydrophobic, after the number of EO of a side arm is increased, the enrichment ratio of the siloxane hydrophobic skeleton of the molecule at an ink-water interface is reduced, the surface tension is slightly increased, the interface spreading capacity is reduced, the compatibility of the siloxane hydrophobic skeleton with non-polar components such as rosin resin in offset printing ink is excellent, and an excessive amount leads to a significant increase in emulsification rate. The star-shaped organic silicon polyether and acetylenic diol polyether are used in combination to reduce the emulsification rate of cyan, magenta, yellow and black four colors, balance the surface tension and the emulsification rate, and the advantage is more obvious in the scene of high-speed printing and rapid spreading, and the star-shaped organic silicon polyether is very suitable for being used as a wetting agent of a 16g ultra-thin paper printing dampening solution.

Description

Technical Field

[0001] This application belongs to the field of printing dampening solution technology, and specifically relates to a surfactant composition, a dampening solution for printing on ultrathin paper, and a method for preparing the same. Background Technology

[0002] 16g ultrathin paper is characterized by its extremely thinness, loose fibers, low sizing, and extremely fast water absorption. Its thickness is only about one-quarter that of ordinary offset paper, making it a highly breathable and absorbent thin paper. Therefore, the requirements for the amount and characteristics of dampening water are extremely stringent. The dampening agent must possess extremely high wetting performance, allowing it to quickly spread into a continuous water film upon contact with the printing plate at low water supply levels. Its low static surface tension can resolve pinholes and dirty printing, eliminating the need for manual water addition during printing and maintaining a stable dampening water supply. Simultaneously, the ink emulsification rate needs to be controlled between 16-20% to avoid problems such as reduced ink viscosity or unstable water supply, thereby resolving defects such as poor ink color and uneven paper curling.

[0003] Currently available acetylenol polyether surfactants (such as Surfynol FS-85) have strong dynamic wetting properties and can maintain a minimum water content for a long time when added to the dampening solution. However, their static surface tension is relatively high, which makes the oxidized plate easy to get dirty. Operators are forced to add water, resulting in dull, wrinkled, and ghosted prints that do not meet quality requirements. Summary of the Invention

[0004] The present invention aims to overcome the shortcomings of the prior art and provide a solution for compounding a surfactant composition and using it in a dampening solution composition. By compounding acetylenic diol polyether with star-shaped organosilicon polyether, a balance between surface tension and ink emulsification rate is achieved, which is suitable for dampening solutions of 16g ​​ultrathin paper.

[0005] To achieve the above technical objectives, the technical solution adopted in this application is as follows: In a first aspect, a surfactant composition includes an acetylenic diol polyether and a star-shaped silicone polyether; The star-shaped organosilicon polyether is obtained by hydrosilylation reaction of hydrogen-containing cyclosiloxane with alkyl-terminated allyl polyether. The general structural formula of alkyl-terminated allyl polyethers is CH2=CH-CH2-O-(CH2CH2O). n -R, where n is a positive integer greater than or equal to 1, and R is selected from alkyl groups with 1 to 4 carbon atoms; Preferably, n=3-5; Preferably, R is methyl; Preferably, the acetylenol polyether is selected from Surfynol FS-85; Preferably, the hydrogen-containing cyclosiloxane is selected from at least one of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, and decamethylcyclopentasiloxane; Preferably, the hydrogen-containing cyclosiloxane is selected from octamethylcyclotetrasiloxane.

[0006] In the hydrosilylation reaction, the molar ratio of (Si-H) groups in the hydrogen-containing cyclosiloxane to (CH2=CH-) groups in the alkyl-terminated allyl polyether is 1:(1-1.15). Preferably, in the hydrosilylation reaction, the molar ratio of (Si-H) groups in the hydrogen-containing cyclosiloxane to (CH2=CH-) groups in the alkyl-terminated allyl polyether is 1:(1-1.1). Preferably, a platinum catalyst is used in the hydrosilylation reaction; Preferably, the platinum catalyst is selected from Karstedt catalysts.

[0007] Furthermore, after the hydrosilylation reaction is completed, the platinum catalyst is removed first, and then the solvent is removed by vacuum distillation. Furthermore, after the hydrosilylation reaction is completed, activated carbon is added to adsorb the platinum catalyst, and then the activated carbon is removed by filtration. Preferably, the activated carbon is selected from those with an iodine value ≥1000 mg / g and a specific surface area ≥1000 m². 2 / g of activated carbon.

[0008] Secondly, the use of the above-described surfactant composition as a wetting agent in dampening solutions.

[0009] Thirdly, a damping solution includes 2-6 parts by weight of damping stock solution, 94-98 parts by weight of deionized water, and 0.8-1.5 parts by weight of the surfactant mentioned above.

[0010] Dampening solution forms a stable, uniform water film on the blank areas of the printing plate, maintaining its hydrophilic and oleophobic properties and ensuring clear printed images and a clean plate surface.

[0011] The dampening solution is selected from STDSD H-9000; The deionized water meets the Class III water standard in GB / T 6682-2008; The mass ratio of acetylenic diol polyether to star-shaped organosilicon polyether in the surfactant is 1:(0.1-0.6); Preferably, the mass ratio of acetylenic diol polyether to star-shaped organosilicon polyether in the surfactant is 1:(0.2-0.5).

[0012] Fourthly, the preparation method of the above-mentioned dampening solution includes: adding a surfactant to the dampening stock solution, followed by dilution with deionized water.

[0013] Fifthly, the use of the dampening solution described above in printing on 16g ultrathin paper.

[0014] The beneficial effects of the technical solution proposed in this application are: designing and synthesizing star-shaped organosilicon polyethers, wherein the polyether EO segments are hydrophilic and the siloxane skeleton is hydrophobic. After increasing the number of EOs in the side arms, the enrichment ratio of the siloxane hydrophobic skeleton at the ink-water interface decreases, the surface tension increases slightly, and the interfacial spreading ability is reduced. However, the siloxane hydrophobic skeleton has excellent compatibility with non-polar rosin resin and other components in offset printing inks. If the amount used is too high, the emulsification rate will be significantly increased.

[0015] This star-shaped organosilicon polyether, when combined with acetylenic diol polyether, can reduce the emulsification rate of cyan, magenta, yellow, and black, achieving a balance between surface tension and emulsification rate. Its advantages are more pronounced in high-speed printing and rapid spreading scenarios, making it very suitable as a wetting agent for 16g ultrathin paper printing dampening solution. Detailed Implementation

[0016] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present invention. It should be noted that the terminology used herein is only for describing specific implementation methods and is not intended to limit the exemplary implementation methods according to the present invention.

[0017] Unless otherwise specified, the experimental conditions used in the examples are generally in accordance with conventional conditions in the art or the conditions recommended by the reagent company. Unless otherwise specified, the materials and reagents used in the examples can be purchased commercially.

[0018] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings: The terms "and / or," "or / and," and "and / or" as used herein include any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. It should be noted that when at least three items are connected by at least two conjunctions selected from "and / or," "or / and," and "and / or," it should be understood that in this application, the technical solution undoubtedly includes technical solutions connected by "logical AND," and also undoubtedly includes technical solutions connected by "logical OR." For example, "A and / or B" includes three parallel solutions: A, B, and A+B. For example, the technical solution of "A, and / or, B, and / or, C, and / or, D" includes any one of A, B, C, and D (that is, a technical solution that is connected by "logical OR"), as well as any and all combinations of A, B, C, and D, that is, combinations of any two or three of A, B, C, and D, and also combinations of all four of A, B, C, and D (that is, a technical solution that is connected by "logical AND").

[0019] In this application, the terms "multiple", "various", "multiple times", "multi-dimensional", etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more than or equal to two.

[0020] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0021] In this application, the technical features described in an open-ended manner include both closed technical solutions composed of the listed features and open technical solutions composed of the listed features.

[0022] Preparation Example 1 Synthesis of star-shaped organosilicon polyether: 216.2 g of methyl-terminated allyl polyether (EO=3, Hangzhou Danwei Technology) was added to a four-necked flask equipped with a condenser. Then, 150 mL of toluene and 0.6 mL of platinum catalyst PT-5000 (Karstedt catalyst, Guangzhou Siyou New Materials) were added. The reaction vessel was heated to 85 °C, and 60 g of hydrogen-containing silicone oil 1,3,5,7-tetramethylcyclotetrasiloxane (D4H), pre-dissolved in 60 mL of toluene, was added dropwise with stirring. The addition was completed over 2 hours, and the temperature was further increased to 90 °C and maintained for 6 hours. Sampling and testing were then performed. 1 The complete disappearance of the absorption peak at 4.60-4.65 ppm in H-NMR indicates that the Si-H bond reaction is complete.

[0023] 1 The 1H-NMR spectral data are as follows (CDCl3, 400 MHz): δ 0.33 (12H, s), 0.99 (8H, t, J =7.50 Hz), 1.93 (8H, tt, J = 7.50, 7.30 Hz), 3.21 (12H, s), 3.33 (8H, t, J =7.30 Hz), 3.54-3.71 (48H, 3.60 (t, J = 4.19 Hz), 3.64 (t, J = 4.19 Hz), 3.64(t, J = 4.23 Hz), 3.64 (t, J = 4.23 Hz), 3.64 (t, J = 3.10 Hz), 3.65 (t, J =3.10 Hz).

[0024] 13 The C-NMR spectral data are as follows (CDCl3, 100 MHz): δ 0.6, 29.5, 39.2, 59.0, 70.1, 70.5, 70.8 (12C), 71.2, 71.9.

[0025] After the reaction is complete, add 2.5g of activated carbon (Mulinsen activated carbon, 200-325 mesh, iodine value ≥1050mg / g, specific surface area ≥1000 m²). 2 / g), after stirring at 80℃ for 1h, filter while hot, take the filtrate and remove the solvent by vacuum distillation at 90℃, slowly add 1100g of deionized water while stirring, and continue stirring for 1h to obtain an aqueous dispersion of star-shaped organosilicon polyether surfactant with a solid content of about 20wt%.

[0026] Preparation Example 2 Methyl-terminated allyl polyether (EO=4, Hangzhou Danwei Technology) was used as the reaction raw material, with an amount of 262.9 g. Subsequently, deionized water was added to prepare an aqueous solution of star-shaped organosilicon polyether surfactant with a theoretical solid content of 20 wt%. The remaining raw materials and synthesis steps were the same as in Preparation Example 1.

[0027] Preparation Example 3 74.4 g of methyl-terminated allyl polyether (EO=4, Hangzhou Danwei Technology) and 221.9 g of methyl-terminated allyl polyether (EO=5, Hangzhou Danwei Technology) were used as reactants. Subsequently, deionized water was added to prepare an aqueous solution of star-shaped organosilicon polyether surfactant with a theoretical solid content of 20 wt%. The remaining raw materials and synthesis steps were the same as in Preparation Example 1.

[0028] Example 1 The dampening solution composition, by weight, comprises: 3.5 parts by weight of dampening stock solution STDSD H-9000 (Shanghai Yingyang Chemical Technology Co., Ltd.), 96.5 parts by weight of deionized water, 1.0 part by weight of acetylenol polyether Surfynol FS-85 (Evonik Specialty Chemicals), and 0.24 parts by weight (based on effective content) of the organosilicon nonionic surfactant prepared in Preparation Example 1.

[0029] Example 2 The dampening solution composition uses 0.24 parts by weight (based on effective content) of the organosilicon nonionic surfactant prepared in Preparation Example 2, and the remaining components and amounts are the same as in Example 1.

[0030] Example 3 The dampening solution composition uses 0.24 parts by weight (based on effective content) of the organosilicon nonionic surfactant prepared in Preparation Example 3, and the remaining components and amounts are the same as in Example 1.

[0031] Example 4 The dampening solution composition uses 0.48 parts by weight (based on effective content) of the organosilicon nonionic surfactant prepared in Preparation Example 1, and the remaining components and amounts are the same as in Example 1.

[0032] Example 5 The dampening solution composition uses 0.48 parts by weight (based on effective content) of the organosilicon nonionic surfactant prepared in Preparation Example 2, and the remaining components and amounts are the same as in Example 1.

[0033] Example 6 The dampening solution composition uses 0.48 parts by weight (based on effective content) of the organosilicon nonionic surfactant prepared in Preparation Example 3, and the remaining components and amounts are the same as in Example 1.

[0034] Comparative Example 1 The dampening solution composition, by weight, comprises: 3.5 parts by weight of dampening stock solution STDSD H-9000, 96.5 parts by weight of deionized water, and 1.0 part by weight of acetylenol polyether Surfynol FS-85.

[0035] Comparative Example 2 The dampening solution composition comprises: 3.5 parts by weight of dampening stock solution STDSD H-9000, 96.5 parts by weight of deionized water, and 0.48 parts by weight (based on effective content) of the organosilicon nonionic surfactant prepared in Preparation Example 1.

[0036] Comparative Example 3 The dampening solution composition comprises: 3.5 parts by weight of dampening stock solution STDSD H-9000, 96.5 parts by weight of deionized water, 1.0 part by weight of acetylenol polyether Surfynol FS-85, and 0.24 parts by weight of hydroxyl-terminated polyether modified silicone oil SF 8427 FLUID (Dow Corning, based on effective content).

[0037] In the above examples and comparative examples, the dampening stock solution used was the commercially available finished product STDSD H-9000 (Shanghai Yingyang Chemical Technology Co., Ltd.). The product manual provided by the supplier discloses its component information as follows: diethylene glycol monobutyl ether 30wt%, water 28wt%, propylene glycol butyl ether 15wt%, gum arabic 10wt%, a mixture of 5-chloro-2-methyl-3(2H)isothiazolidinone and 2-methyl-3(2H)isothiazolidinone 7wt%, glycerol 5wt%, and citric acid 5wt%. This batch of stock solution was used consistently in the experiments of this application. The basic physicochemical parameters (pH, conductivity) of the stock solution remained unchanged; the only variable was the added organosilicon surfactant and the acetylenic glycol polyether compound system.

[0038] Test section The surfactant was added to the dampening stock solution and mixed evenly, and then diluted with deionized water to prepare the dampening solution. The conductivity was tested using a conductivity meter, and the surface tension was tested according to the standard SY / T5370-2018.

[0039] The prepared dampening solution was stirred with four-color printing inks respectively. The emulsification rate of the four inks was tested according to the standard QB / T 5487-2020. Each sample was tested three times, and the average value was taken. The inks used in the test were offset glossy fast-drying four-color resin inks. The mass ratio of dampening solution to ink was 1:4. The inks were stirred at 1200 r / min for 5 min. After centrifugation, the emulsification rate was calculated. The temperature of the test environment was controlled at (23℃±2)℃.

[0040] The test results of Examples 1-6 and Comparative Examples 1-3 are recorded in Table 1.

[0041] Table 1 Analysis of the data in Table 1 shows that the surface tension of Examples 1-3 is between 29 and 33 mN·m. -1 Between these values, the surface tension is significantly lower than that of ordinary dampening solutions (35-40 mN·m).-1 The risk of pinholes is lower, making it suitable for spreading on low-energy printing plates with a high process tolerance. The emulsification rate of the four colors—cyan, magenta, yellow, and black—is maintained at around 16-19%, which perfectly matches the exclusive emulsification rate range of 16g ​​ultrathin paper. Ultrathin paper is characterized by thin fibers, low ink absorption, and poor resistance to deformation, resulting in an emulsification rate window narrower than that of ordinary thick paper (15-25%). Excessive emulsification rate significantly reduces ink viscosity, intensifies dot spreading, and easily exceeds the dot range required for fine printing; conversely, insufficient ink transfer rate leads to insufficient solid density, uneven coloring, and a tendency for dirty printing plates. In Examples 4-6, increasing the amount of star-shaped silicone polyether further reduces the surface tension of the corresponding system, but simultaneously increases the emulsification rate of the four colors. The number of EOs on the side arms of the star-shaped silicone polyether is controlled within a suitable range of n=3-5, avoiding excessive reduction of surface tension to prevent uncontrolled emulsification rate while ensuring sufficient hydrophilic spreading ability, achieving the optimal performance balance when compounded with acetylsene glycol polyether.

[0042] Comparative Example 1 uses commercially available FS-85 alone, which has a higher surface tension and a greater risk of pinholes and dirty printing plates. Therefore, the star-shaped organosilicon polyether synthesized in Examples 1-3 was selected for compound preparation. Under the premise that the emulsification rate does not exceed 20%, the surface tension is further reduced, taking into account both low surface tension and low emulsification rate for cyan, magenta, yellow and black.

[0043] Comparative Example 2 completely removed the commercially available FS-85 and added a star-shaped silicone polyether surfactant to the dampening solution. Although this could further reduce the surface tension, the corresponding ink emulsification rate significantly exceeded 20%, making it unsuitable for use on 16g ultrathin paper.

[0044] Comparative Example 3, based on FS-85, was compounded with a commercially available linear structure dual-terminated hydroxyl polyether modified silicone oil. Although the emulsification rate was similar, the surface tension was significantly higher than that of the star-shaped structure organosilicon polyether, which was not conducive to spreading on low-energy printing plates. The reason is that the siloxane main chain of SF8427 has a straight chain structure, which has a larger contact area with the ink resin. Under the same emulsification rate, the surface tension is higher. If its dosage is increased to reduce the surface tension, the corresponding emulsification rate will be higher.

[0045] Finally, it should be noted that the above-described embodiments are merely illustrative of several implementation methods of this application, facilitating a detailed and specific understanding of the technical solutions of this application, but should not be construed as limiting the scope of protection of the patent application. It should be pointed out that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. Furthermore, it should be understood that after reading the above teachings of this application, those skilled in the art can make various alterations or modifications to this application, and the equivalent forms obtained also fall within the scope of protection of this application. It should also be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided in this application through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims. Therefore, the scope of protection of this patent application should be determined by the content of the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. A surfactant composition, characterized in that, Including acetylenic diol polyether and star-shaped organosilicon polyether; The star-shaped organosilicon polyether is obtained by hydrosilylation reaction of hydrogen-containing cyclosiloxane with alkyl-terminated allyl polyether. The general structure of the alkyl-capped allyl polyether is CH2=CH-CH2-O-(CH2CH2O) n -R, n is a positive integer greater than or equal to 1, and R is selected from alkyl groups of 1 to 4 carbon atoms; In the hydrosilylation reaction, the molar ratio of (Si-H) groups in the hydrogen-containing cyclosiloxane to (CH2=CH-) groups in the alkyl-terminated allyl polyether is 1:(1-1.15).

2. The surfactant composition according to claim 1, characterized in that, n=3-5； And / or, R is methyl.

3. The surfactant composition according to claim 1, characterized in that, The acetylenol polyether is selected from Surfynol FS-85.

4. The surfactant composition according to claim 1, characterized in that, The hydrogen-containing cyclosiloxane is selected from at least one of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane; And / or, the hydrosilylation reaction uses a platinum catalyst.

5. The surfactant composition according to claim 1, characterized in that, After the hydrosilylation reaction is completed, the platinum catalyst is removed first, and then the solvent is removed by vacuum distillation.

6. The surfactant composition according to claim 1, characterized in that, After the hydrosilylation reaction is completed, activated carbon is added to adsorb the platinum catalyst, and then the activated carbon is removed by filtration.

7. Use of a surfactant composition as a wetting agent in a dampening solution according to any one of claims 1-6.

8. A dampening solution, characterized in that, It comprises 2-6 parts by weight of dampening stock solution, 94-98 parts by weight of deionized water, and 0.8-1.5 parts by weight of the surfactant composition according to any one of claims 1-6; The dampening solution is selected from STDSD H-9000; The deionized water meets the Class III water standard in GB / T 6682-2008; The mass ratio of acetylenic diol polyether to star-shaped organosilicon polyether in the surfactant is 1:(0.1-0.6).

9. A method for preparing the dampening solution as described in claim 8, characterized in that, The surfactant is added to the dampening stock solution, and then diluted with deionized water to obtain the solution.

10. The use of the dampening solution as described in claim 8 in printing on 16g ultrathin paper.

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