Hard-water-resistant alcohol-free fountain solution and preparation method thereof

Abstract

The invention discloses a hard-water-resistant alcohol-free fountain solution and a preparation method thereof. The formula of the fountain solution comprises PVA-g-AA copolymer water-soluble resin, a pH buffering agent, a polyhydric alcohol wetting agent, an alcohol ether wetting agent, a surfactant, an antibacterial agent, other additives and deionized water. The preparation method comprises the following steps: 1, synthesizing PVA-g-AA copolymer water-soluble resin; 2, preparing raw materials; step 3, premixing the raw materials; step 4, adding a functional auxiliary agent; according to the formula, PVA-g-AA copolymer water-soluble resin is adopted, the molecular weight and proportion of the resin are regulated and controlled by introducing an acrylic acid component, and the problem that the spreading rate of a water film is decreased due to winding of a resin molecular chain is solved; the water-soluble resin is compounded with a pH buffering agent, so that precipitation of hard water is inhibited, and long-acting pH stability is realized; in addition, the water-soluble resin can be in synergistic effect with the surfactant, so that stable control on the emulsification rate of the printing ink is realized.

Description

Technical Field

[0001] The present invention relates to the field of printing technology, and specifically to a hard-water resistant and alcohol-free dampening solution and a preparation method thereof. Background Art

[0002] Offset printing is based on the principle of immiscibility between oil and water. The hydrophilic area of the printing plate forms a water film through the dampening solution, while the hydrophobic area adsorbs the ink, thus achieving the transfer of graphics and texts. The dampening solution is an aqueous liquid, and its main function is to form a uniform water film between the printing plate and the paper during the printing process, thereby improving the printing quality and efficiency. The core functions of the dampening solution include: controlling the wettability of the printing plate surface: by reducing the surface tension of the water phase, rapidly spreading to form a uniform water film, isolating the non-graphic area from the ink; adjusting the ink-water balance: maintaining an appropriate viscosity and pH value, promoting the emulsification of the ink and inhibiting excessive diffusion; protecting the printing plate: buffering acidic components to prevent the oxidation of the printing plate and extending the printing durability.

[0003] The composition and performance of the dampening solution have a crucial impact on its effect. Existing alcohol-based dampening solutions contain low-boiling-point alcohol or isopropyl alcohol, and during use, the emissions of volatile organic compounds seriously exceed the standard, posing environmental and health risks; moreover, the wettability decays rapidly, the stability is poor, and alcohol will accelerate the swelling of the rubber blanket, so there are problems such as low printing durability and poor resistance to hard water. To replace isopropyl alcohol, some technologies use gum arabic, polyethylene glycol, hydroxyethyl cellulose, etc. as thickeners, and are combined with polyols, alcohol ethers, and surfactants as wetting agents to replace traditional alcohol-based dampening solutions, but the following problems still exist during actual use: 1. The contradiction between viscosity and the spreading rate of the water film: Natural water-soluble cellulose and gum arabic can increase the viscosity, but they have a high molecular weight, and the entanglement of molecular chains leads to a decrease in the spreading rate of the water film. Low-molecular-weight thickeners such as glycerol have a good spreading rate, but insufficient viscosity, increasing the risk of water film rupture during high-speed printing. In addition, when the content of the thickener is too high, the drying rate of the ink becomes slower, easily causing sticking of the subsequent process; 2. Poor system compatibility: Strongly ionized pH buffer systems such as phosphates and citrates, and water-soluble ionic thickeners such as sodium carboxymethyl cellulose, have poor miscibility with wetting agents, and phase separation is likely to occur during formulation, so there is a problem of poor storage stability; 3. Poor hard-water resistance: Hard water contains a large amount of calcium and magnesium ions. Due to the above compatibility problems, the pH buffer capacity of the existing alcohol-free dampening solution system is insufficient, resulting in unstable pH during the use of the dampening solution, easily causing abnormal printing quality; in addition, flocculants are easily generated during long-term use, thus clogging the circulation filtration system and increasing the replacement frequency of the filter screen; 4. Stable control of wettability: A large amount of wetting agent needs to be added to the alcohol-free dampening solution to improve the wetting effect of the system and achieve rapid spreading of the water film during the printing process. However, blindly increasing the content of the wetting agent will cause problems such as excessive ink emulsification, reduced printing durability, printing plate grid drift, and even dot loss. Summary of the Invention

[0004] The object of the present invention is to provide a hard water resistant and alcohol-free dampening solution and its preparation method to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: A hard water resistant and alcohol-free dampening solution, the formula of which includes: PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water. The mass percentage contents of each component are respectively: 8-12% of PVA-g-AA copolymer water-soluble resin, 1-5% of pH buffer, 10-20% of polyol humectant, 20-40% of alcohol ether wetting agent, 0.5-3% of surfactant, 0.1-1% of antibacterial agent and 0-0.5% of other additives, and the balance is deionized water.

[0006] Preferably, the PVA-g-AA copolymer water-soluble resin is obtained by copolymerizing three components of polyvinyl alcohol, polyacrylic acid and polymethacrylic acid, and its structural general formula is as follows:

[0007]

[0008] Among them, x, y, and z are respectively the mass parts of polyvinyl alcohol, polyacrylic acid, and polymethacrylic acid in the resin.

[0009] Preferably, the pH buffer is one or a combination of more than one of sodium dihydrogen phosphate, disodium hydrogen phosphate, sodium hydrogen phosphite, sodium dihydrogen phosphite, sodium phosphate, sodium citrate, sodium oxalate, sodium carbonate, triethylamine, sodium formate, sodium acetate, sodium benzoate, and potassium hydrogen phthalate.

[0010] Preferably, the polyol humectant is one or a combination of more than one of ethylene glycol, 1,2-propanediol, 1,3-propanediol, glycerol, 1,4-butanediol, 1,3-butanediol, dipropylene glycol, polyethylene glycol, sorbitol, and xylitol.

[0011] Preferably, the alcohol ether wetting agent is one or a combination of more than one of ethylene glycol monobutyl ether, ethylene glycol monopropyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether.

[0012] Preferably, the surfactant is one or a combination of more than one of alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, sodium dodecyl sulfate, sodium dodecyl sulfonate, cetyltrimethylammonium bromide, N-octylpyrrolidone, N-dodecylpyrrolidone, sulfonyl104, sulfonyl420, sulfonyl440, and surfynol465.

[0013] Preferably, the antibacterial agent is one or a combination of more than one of Kathon, chloromethyl isothiazolinone, methyl isothiazolinone, sodium benzoate, and polyhexamethylene guanidine.

[0014] Preferably, the other additives include an antifoaming agent and a quick-drying agent. The ratio of the antifoaming agent to the quick-drying agent is 1:1. The antifoaming agent is one or a combination of more than one of polydimethylsiloxane, calcium stearate, oleic acid amide, polyether L61, and polyether F68. The quick-drying agent is one of ammonium nitrate and magnesium nitrate.

[0015] A preparation method of a hard water-resistant alcohol-free dampening solution includes Step 1: synthesizing a PVA-g-AA copolymer water-soluble resin; Step 2: preparing raw materials; Step 3: pre-mixing the raw materials; Step 4: adding functional additives.

[0016] Among them, in the above Step 1, prepare polyvinyl alcohol, acrylic acid, methacrylic acid, deionized water, and an initiator according to the formula of the PVA-g-AA copolymer water-soluble resin. Add polyvinyl alcohol to deionized water, heat up to 80 - 90 °C, stir until completely dissolved, cool to 40 - 50 °C, add the initiator, stir and dissolve, then pass nitrogen to deoxidize for 15 - 30 min. Slowly drop the mixed solution of acrylic acid and methacrylic acid into the polyvinyl alcohol solution, heat up to 60 - 70 °C, and react for 2 - 4 h to form a PVA-g-AA copolymer. After cooling to room temperature, filter to obtain the PVA-g-AA copolymer water-soluble resin.

[0017] Among them, in the above Step 2, based on the sum of the mass percentage contents of each component being 1, prepare the PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol ether wetting agent, surfactant, antibacterial agent, other additives, and deionized water according to the formulation ratio of the dampening solution.

[0018] Among them, in the above Step 3, at room temperature of 23 ± 2 °C, mix and stir the PVA-g-AA copolymer water-soluble resin, pH buffer, and polyol humectant evenly to obtain a basic mixed system.

[0019] Among them, in the above Step 4, in the basic mixed system obtained in Step 3, sequentially add the alcohol ether wetting agent, surfactant, antibacterial agent, other additives, and deionized water, and continue to stir for 30 - 40 min until a clear solution is formed in the system to obtain a concentrated dampening solution.

[0020] Preferably, in the first step, in the water-soluble resin formula of PVA-g-AA copolymer, the mass parts of each component are as follows: 100-200 parts of polyvinyl alcohol, 50-150 parts of acrylic acid, 5-20 parts of methacrylic acid, and 300-500 parts of deionized water. Among them, the dosage of the initiator accounts for 0.5-3% of the total mass of the monomers. The initiator is one or a combination of ammonium persulfate, potassium persulfate, sodium persulfate, benzoyl peroxide, azodiisobutyramidine hydrochloride, and azodiisobimidazoline hydrochloride. The polyvinyl alcohol is one or a combination of PVA0388, PVA0488, PVA0588, PVA1788, PVA2488, PVA0599, PVA1799, and PVA2499. The molecular weight of the prepared PVA-g-AA copolymer water-soluble resin is 10,000-100,000.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: The water-soluble resin of PVA-g-AA copolymer is adopted in the formula of the present invention. By introducing acrylic acid components, the molecular weight and ratio of the resin are regulated, and the problem of the decrease in the water film spreading rate caused by the entanglement of resin molecular chains is solved. The water-soluble resin is compounded with a pH buffer to inhibit the precipitation of hard water and achieve long-term pH stability. And the water-soluble resin can act synergistically with surfactants to achieve stable control of the ink emulsification rate. Description of the Drawings

[0022] Figure 1 It is a flowchart of the method of the present invention. Detailed Embodiments

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0024] Please refer to the attached Figure 1 , a technical solution provided by the present invention:

[0025] Example 1:

[0026] Synthesis of PVA-g-AA copolymer water-soluble resin: Prepare raw materials according to the formula of PVA-g-AA copolymer water-soluble resin. The mass fractions of each component in the formula are as follows: 90 parts of PVA2488, 10 parts of PVA2499, 50 parts of acrylic acid, 20 parts of methacrylic acid, and 300 parts of deionized water. Among them, the dosage of the initiator accounts for 3% of the total mass of the monomers, and the initiator is ammonium persulfate. Add polyvinyl alcohol to deionized water, heat up to 80 - 90 °C, stir until completely dissolved, cool to 40 - 50 °C, add the initiator, stir to dissolve, then introduce nitrogen to deoxygenate for 15 - 30 min. Slowly drop the mixed solution of acrylic acid and methacrylic acid into the polyvinyl alcohol solution, heat up to 60 - 70 °C, and react for 2 - 4 h to form PVA-g-AA copolymer. After cooling to room temperature, filter to obtain PVA-g-AA copolymer water-soluble resin with the model number P1.

[0027] Example 2:

[0028] Synthesis of PVA-g-AA copolymer water-soluble resin: Prepare raw materials according to the formula of PVA-g-AA copolymer water-soluble resin. The mass fractions of each component in the formula are as follows: 100 parts of PVA1788, 20 parts of PVA1799, 120 parts of acrylic acid, 5 parts of methacrylic acid, and 300 parts of deionized water. Among them, the dosage of the initiator accounts for 2.5% of the total mass of the monomers, and the initiator is benzoyl peroxide. Add polyvinyl alcohol to deionized water, heat up to 80 - 90 °C, stir until completely dissolved, cool to 40 - 50 °C, add the initiator, stir to dissolve, then introduce nitrogen to deoxygenate for 15 - 30 min. Slowly drop the mixed solution of acrylic acid and methacrylic acid into the polyvinyl alcohol solution, heat up to 60 - 70 °C, and react for 2 - 4 h to form PVA-g-AA copolymer. After cooling to room temperature, filter to obtain PVA-g-AA copolymer water-soluble resin with the model number P2.

[0029] Example 3:

[0030] Synthesis of PVA-g-AA copolymer water-soluble resin: Prepare raw materials according to the formula of PVA-g-AA copolymer water-soluble resin. The mass fractions of each component in the formula are as follows: 100 parts of PVA0588, 50 parts of PVA0599, 100 parts of acrylic acid, 15 parts of methacrylic acid, and 300 parts of deionized water. Among them, the dosage of the initiator accounts for 1% of the total mass of the monomers, and the initiator is sodium persulfate. Add polyvinyl alcohol to deionized water, heat up to 80 - 90 °C, stir until completely dissolved, cool to 40 - 50 °C, add the initiator, stir to dissolve, then introduce nitrogen to deoxygenate for 15 - 30 min. Slowly drop the mixed solution of acrylic acid and methacrylic acid into the polyvinyl alcohol solution, heat up to 60 - 70 °C, and react for 2 - 4 h to form the PVA-g-AA copolymer. After cooling to room temperature, filter to obtain the PVA-g-AA copolymer water-soluble resin with the model number P3.

[0031] Example 4:

[0032] Synthesis of PVA-g-AA copolymer water-soluble resin: Prepare raw materials according to the formula of PVA-g-AA copolymer water-soluble resin. The mass fractions of each component in the formula are as follows: 180 parts of PVA0488, 150 parts of acrylic acid, 10 parts of methacrylic acid, and 300 parts of deionized water. Among them, the dosage of the initiator accounts for 0.5% of the total mass of the monomers, and the initiator is azodiisobutyramidine hydrochloride. Add polyvinyl alcohol to deionized water, heat up to 80 - 90 °C, stir until completely dissolved, cool to 40 - 50 °C, add the initiator, stir to dissolve, then introduce nitrogen to deoxygenate for 15 - 30 min. Slowly drop the mixed solution of acrylic acid and methacrylic acid into the polyvinyl alcohol solution, heat up to 60 - 70 °C, and react for 2 - 4 h to form the PVA-g-AA copolymer. After cooling to room temperature, filter to obtain the PVA-g-AA copolymer water-soluble resin with the model number P4.

[0033] Example 5:

[0034] Synthesis of PVA-g-AA copolymer water-soluble resin: Prepare raw materials according to the formula of PVA-g-AA copolymer water-soluble resin. The mass fractions of each component in the formula are as follows: 200 parts of PVA0388, 120 parts of acrylic acid, 15 parts of methacrylic acid, and 300 parts of deionized water. Among them, the dosage of the initiator accounts for 0.5% of the total mass of the monomers, and the initiator is 2,2'-azobis(2-methylpropionamidine) dihydrochloride. Add polyvinyl alcohol to deionized water, heat up to 80 - 90 °C, stir until completely dissolved, cool to 40 - 50 °C, add the initiator, stir to dissolve, then pass nitrogen to deoxygenate for 15 - 30 min. Slowly drop the mixed solution of acrylic acid and methacrylic acid into the polyvinyl alcohol solution, heat up to 60 - 70 °C, and react for 2 - 4 h to form PVA-g-AA copolymer. After cooling to room temperature, filter to obtain PVA-g-AA copolymer water-soluble resin with the model number P5.

[0035] Example 6:

[0036] A hard water-resistant alcohol-free dampening solution, the formula includes: PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol ether wetting agent, surfactant, antibacterial agent, other additives, and deionized water. The mass percentage contents of each component are respectively: 10% of PVA-g-AA copolymer water-soluble resin, 3% of pH buffer, 15% of polyol humectant, 30% of alcohol ether wetting agent, 2% of surfactant, 0.5% of antibacterial agent, 0.5% of other additives, and 39% of deionized water. The specific raw material components in the formula are: the model number of PVA-g-AA copolymer water-soluble resin is P1, the pH buffer is sodium dihydrogen phosphite, the polyol humectants are ethylene glycol and glycerol, the alcohol ether wetting agent is propylene glycol butyl ether, the surfactants are alkylphenol polyoxyethylene ether and surfynol465, the antibacterial agent is chloromethyl isothiazolinone, and other additives include defoamer and quick-drying agent. The defoamer is polyether L61, and the quick-drying agent is ammonium nitrate;

[0037] A preparation method of a hard water-resistant alcohol-free dampening solution, including Step 1, synthesizing PVA-g-AA copolymer water-soluble resin; Step 2, preparing raw materials; Step 3, pre-mixing raw materials; Step 4, adding functional additives;

[0038] Among them, in the above Step 1, referring to Example 1, synthesize PVA-g-AA copolymer water-soluble resin with the model number P1;

[0039] Among them, in the above Step 2, based on the sum of the mass percentage contents of each component being 1, prepare PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol ether wetting agent, surfactant, antibacterial agent, other additives, and deionized water according to the formula ratio of the dampening solution;

[0040] Among them, in Step 3 above, at room temperature of 23±2°C, the PVA-g-AA copolymer water-soluble resin is mixed and stirred evenly with the pH buffer and the polyol humectant to obtain a basic mixed system;

[0041] Among them, in Step 4 above, in the basic mixed system obtained in Step 3, an alcohol ether wetting agent, a surfactant, an antibacterial agent, other additives and deionized water are added in sequence, and stirring is continued for 30-40 minutes until a clear solution is formed in the system to obtain a fountain solution concentrate of Model S01.

[0042] Example 7:

[0043] A hard water-resistant alcohol-free fountain solution, the formula of which includes: PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water. The mass percentage contents of each component are respectively: 8% of PVA-g-AA copolymer water-soluble resin, 3% of pH buffer, 15% of polyol humectant, 30% of alcohol ether wetting agent, 2% of surfactant, 0.5% of antibacterial agent, 0.5% of other additives and 41% of deionized water; the specific raw material components in the formula are: the model of PVA-g-AA copolymer water-soluble resin is P1, the pH buffer is sodium dihydrogen phosphite, the polyol humectant is 1,3-propanediol and glycerol, the alcohol ether wetting agent is ethylene glycol propyl ether and diethylene glycol ethyl ether, the surfactant is alkylphenol polyoxyethylene ether and N-octyl pyrrolidone, the antibacterial agent is polyhexamethylene guanidine, and other additives include defoaming agent and quick-drying agent. The defoaming agent is polyether L61, and the quick-drying agent is ammonium nitrate;

[0044] A preparation method of a hard water-resistant alcohol-free fountain solution, which includes Step 1, synthesizing PVA-g-AA copolymer water-soluble resin; Step 2, raw material preparation; Step 3, raw material premixing; Step 4, adding functional additives;

[0045] Among them, in Step 1 above, referring to Example 1, PVA-g-AA copolymer water-soluble resin of Model P1 is synthesized;

[0046] Among them, in Step 2 above, based on the sum of the mass percentage contents of each component being 1, PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water are prepared according to the formula ratio of the fountain solution;

[0047] Among them, in Step 3 above, at room temperature of 23±2°C, the PVA-g-AA copolymer water-soluble resin is mixed and stirred evenly with the pH buffer and the polyol humectant to obtain a basic mixed system;

[0048] In the above step 4, in the basic mixed system obtained in step 3, an alcohol-ether wetting agent, a surfactant, an antibacterial agent, other additives and deionized water are successively added, and stirring is continued for 30 - 40 min until a clear solution is formed in the system, obtaining a fountain solution concentrate of model S02.

[0049] Example 8:

[0050] A hard water-resistant alcohol-free fountain solution, the formula of which includes: PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol-ether wetting agent, surfactant, antibacterial agent, other additives and deionized water. The mass percentage contents of each component are respectively: 12% of PVA-g-AA copolymer water-soluble resin, 3% of pH buffer, 15% of polyol humectant, 30% of alcohol-ether wetting agent, 2% of surfactant, 0.5% of antibacterial agent, 0.5% of other additives and 37% of deionized water; the specific raw material components in the formula are: the model of PVA-g-AA copolymer water-soluble resin is P2, the pH buffer is sodium dihydrogen phosphite, the polyol humectant is 1,4-butanediol, the alcohol-ether wetting agents are propylene glycol methyl ether and diethylene glycol butyl ether, the surfactants are alkylphenol polyoxyethylene ether and N-dodecylpyrrolidone, the antibacterial agent is chloromethyl isothiazolinone, and other additives include defoamer and quick-drying agent. The defoamer is polyether L61, and the quick-drying agent is ammonium nitrate;

[0051] A preparation method of a hard water-resistant alcohol-free fountain solution includes step 1, synthesizing PVA-g-AA copolymer water-soluble resin; step 2, raw material preparation; step 3, raw material premixing; step 4, adding functional additives;

[0052] In the above step 1, referring to Example 2, synthesize PVA-g-AA copolymer water-soluble resin of model P2;

[0053] In the above step 2, based on the sum of the mass percentage contents of each component being 1, prepare PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol-ether wetting agent, surfactant, antibacterial agent, other additives and deionized water according to the formula ratio of the fountain solution;

[0054] In the above step 3, at room temperature of 23 ± 2 °C, mix and stir the PVA-g-AA copolymer water-soluble resin with the pH buffer and the polyol humectant evenly to obtain a basic mixed system;

[0055] In the above step 4, in the basic mixed system obtained in step 3, an alcohol-ether wetting agent, a surfactant, an antibacterial agent, other additives and deionized water are successively added, and stirring is continued for 30 - 40 min until a clear solution is formed in the system, obtaining a fountain solution concentrate of model S03.

[0056] Example 9:

[0057] A hard water-resistant and alcohol-free dampening solution, the formula of which includes: PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water. The mass percentage content of each component is respectively: 10% of PVA-g-AA copolymer water-soluble resin, 5% of pH buffer, 10% of polyol humectant, 20% of alcohol ether wetting agent, 2% of surfactant, 0.5% of antibacterial agent, 0.5% of other additives and 52% of deionized water; The specific raw material components in the formula are: the model of PVA-g-AA copolymer water-soluble resin is P2, the pH buffer is sodium citrate, the polyol humectant is 1,2-propanediol and glycerol, the alcohol ether wetting agent is propylene glycol methyl ether and propylene glycol butyl ether, the surfactant is fatty alcohol polyoxyethylene ether and sodium dodecyl sulfate, the antibacterial agent is polyhexamethylene guanidine, and other additives include defoamer and quick-drying agent. The defoamer is polyether L61, and the quick-drying agent is ammonium nitrate;

[0058] A preparation method of a hard water-resistant and alcohol-free dampening solution, which includes Step 1, synthesizing PVA-g-AA copolymer water-soluble resin; Step 2, preparing raw materials; Step 3, pre-mixing raw materials; Step 4, adding functional additives;

[0059] Among them, in the above Step 1, referring to Example 2, synthesize PVA-g-AA copolymer water-soluble resin of model P2;

[0060] Among them, in the above Step 2, based on the sum of the mass percentage contents of each component being 1, prepare PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water according to the formula ratio of the dampening solution;

[0061] Among them, in the above Step 3, at room temperature of 23±2°C, mix and stir the PVA-g-AA copolymer water-soluble resin with the pH buffer and polyol humectant evenly to obtain a basic mixed system;

[0062] Among them, in the above Step 4, in the basic mixed system obtained in Step 3, add alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water in sequence, and continue to stir for 30 - 40 min until the system forms a clear solution to obtain a dampening solution concentrate of model S04.

[0063] Example 10:

[0064] A hard water-resistant alcohol-free dampening solution, the formula of which includes: PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water. The mass percentage contents of each component are respectively: 10% of PVA-g-AA copolymer water-soluble resin, 3% of pH buffer, 20% of polyol humectant, 30% of alcohol ether wetting agent, 1% of surfactant, 0.5% of antibacterial agent, 0.5% of other additives and 35% of deionized water; the specific raw material components in the formula are: the model of PVA-g-AA copolymer water-soluble resin is P3, the pH buffer is sodium oxalate, the polyol humectant is 1,3-butanediol and dipropylene glycol, the alcohol ether wetting agent is ethylene glycol monobutyl ether and propylene glycol monobutyl ether, the surfactant is fatty alcohol polyoxyethylene ether and sodium dodecyl sulfonate, the antibacterial agent is methylisothiazolinone, and other additives include defoamer and quick-drying agent. The defoamer is polyether L61, and the quick-drying agent is ammonium nitrate;

[0065] A preparation method of a hard water-resistant alcohol-free dampening solution, which includes Step 1, synthesizing PVA-g-AA copolymer water-soluble resin; Step 2, preparing raw materials; Step 3, pre-mixing raw materials; Step 4, adding functional additives;

[0066] Among them, in the above Step 1, referring to Example 3, synthesize PVA-g-AA copolymer water-soluble resin with the model of P3;

[0067] Among them, in the above Step 2, taking the sum of the mass percentage contents of each component as 1, prepare PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water according to the formula ratio of the dampening solution;

[0068] Among them, in the above Step 3, at room temperature of 23±2°C, mix and stir the PVA-g-AA copolymer water-soluble resin with the pH buffer and polyol humectant evenly to obtain a basic mixed system;

[0069] Among them, in the above Step 4, in the basic mixed system obtained in Step 3, sequentially add alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water, and continue to stir for 30-40 minutes until the system forms a clear solution to obtain a dampening solution concentrate with the model of S05.

[0070] Example 11:

[0071] A hard water-resistant and alcohol-free dampening solution, the formula of which includes: PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water. The mass percentage content of each component is respectively: 8% of PVA-g-AA copolymer water-soluble resin, 3% of pH buffer, 10% of polyol humectant, 40% of alcohol ether wetting agent, 1% of surfactant, 0.5% of antibacterial agent, 0.5% of other additives and 37% of deionized water; the specific raw material components in the formula are: the model of PVA-g-AA copolymer water-soluble resin is P3, the pH buffer is sodium carbonate, the polyol humectant is xylitol, the alcohol ether wetting agents are ethylene glycol propyl ether and diethylene glycol butyl ether, the surfactant is fatty alcohol polyoxyethylene ether and cetyl trimethyl ammonium bromide, the antibacterial agent is polyhexamethylene guanidine, and other additives include defoamer and quick-drying agent. The defoamer is polyether L61, and the quick-drying agent is magnesium nitrate;

[0072] A preparation method of a hard water-resistant and alcohol-free dampening solution, including Step 1, synthesizing PVA-g-AA copolymer water-soluble resin; Step 2, preparing raw materials; Step 3, pre-mixing raw materials; Step 4, adding functional additives;

[0073] Among them, in the above Step 1, referring to Example 3, synthesize PVA-g-AA copolymer water-soluble resin with the model of P3;

[0074] Among them, in the above Step 2, based on the sum of the mass percentage contents of each component being 1, prepare PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water according to the formula ratio of the dampening solution;

[0075] Among them, in the above Step 3, at room temperature of 23±2°C, mix and stir the PVA-g-AA copolymer water-soluble resin with the pH buffer and polyol humectant evenly to obtain a basic mixed system;

[0076] Among them, in the above Step 4, in the basic mixed system obtained in Step 3, sequentially add alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water, and continue to stir for 30 - 40 min until the system forms a clear solution to obtain a dampening solution concentrate with the model of S06.

[0077] Example 12:

[0078] A hard water-resistant and alcohol-free dampening solution, the formula of which includes: PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water. The mass percentage contents of each component are respectively: 9% of PVA-g-AA copolymer water-soluble resin, 5% of pH buffer, 20% of polyol humectant, 35% of alcohol ether wetting agent, 0.5% of surfactant, 1% of antibacterial agent, 0.5% of other additives and 29% of deionized water. The specific raw material components in the formula are: the model of PVA-g-AA copolymer water-soluble resin is P4, the pH buffer is ammonium formate, the polyol humectant is sorbitol, the alcohol ether wetting agent is propylene glycol butyl ether, the surfactant is N-octyl pyrrolidone, the antibacterial agent is methylisothiazolinone, and other additives include defoamer and quick-drying agent. The defoamer is polyether L61, and the quick-drying agent is ammonium nitrate;

[0079] A preparation method of a hard water-resistant and alcohol-free dampening solution, which includes Step 1, synthesizing PVA-g-AA copolymer water-soluble resin; Step 2, preparing raw materials; Step 3, pre-mixing raw materials; Step 4, adding functional additives;

[0080] Among them, in the above Step 1, referring to Example 4, synthesize PVA-g-AA copolymer water-soluble resin of model P4;

[0081] Among them, in the above Step 2, taking the sum of the mass percentage contents of each component as 1, prepare PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water according to the formula ratio of the dampening solution;

[0082] Among them, in the above Step 3, at room temperature of 23±2°C, mix and stir the PVA-g-AA copolymer water-soluble resin with the pH buffer and polyol humectant evenly to obtain a basic mixed system;

[0083] Among them, in the above Step 4, in the basic mixed system obtained in Step 3, sequentially add alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water, and continue to stir for 30-40 min until the system forms a clear solution to obtain a dampening solution concentrate of model S07.

[0084] Example 13:

[0085] A hard water-resistant and alcohol-free dampening solution, the formula of which includes: PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water. The mass percentage contents of each component are respectively: 12% of PVA-g-AA copolymer water-soluble resin, 1% of pH buffer, 14% of polyol humectant, 22% of alcohol ether wetting agent, 2% of surfactant, 0.5% of antibacterial agent, 0.5% of other additives and 48% of deionized water; the specific raw material components in the formula are: the model of PVA-g-AA copolymer water-soluble resin is P4, the pH buffer is sodium acetate, the polyol humectant is ethylene glycol and 1,2-propanediol, the alcohol ether wetting agent is ethylene glycol monobutyl ether, the surfactant is sulfonyl440 and surfynol465, the antibacterial agent is methylisothiazolinone, and other additives include defoamer and quick-drying agent. The defoamer is polyether L61, and the quick-drying agent is magnesium nitrate;

[0086] A preparation method of a hard water-resistant and alcohol-free dampening solution, including Step 1, synthesizing PVA-g-AA copolymer water-soluble resin; Step 2, preparing raw materials; Step 3, pre-mixing raw materials; Step 4, adding functional auxiliaries;

[0087] Among them, in the above Step 1, referring to Example 4, synthesize PVA-g-AA copolymer water-soluble resin with the model of P4;

[0088] Among them, in the above Step 2, taking the sum of the mass percentage contents of each component as 1, prepare PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water according to the formula ratio of the dampening solution;

[0089] Among them, in the above Step 3, at room temperature of 23±2°C, mix and stir the PVA-g-AA copolymer water-soluble resin with the pH buffer and polyol humectant evenly to obtain a basic mixed system;

[0090] Among them, in the above Step 4, in the basic mixed system obtained in Step 3, successively add alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water, and continue to stir for 30-40 minutes until the system forms a clear solution to obtain a dampening solution concentrate with the model of S08.

[0091] Example 14:

[0092] A hard water-resistant and alcohol-free dampening solution, the formula of which includes: PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water. The mass percentage content of each component is as follows: 12% of PVA-g-AA copolymer water-soluble resin, 3% of pH buffer, 10% of polyol humectant, 26% of alcohol ether wetting agent, 1% of surfactant, 0.5% of antibacterial agent, 0.5% of other additives and 47% of deionized water. The specific raw material components in the formula are: the model of PVA-g-AA copolymer water-soluble resin is P5, the pH buffer is sodium benzoate, the polyol humectant is ethylene glycol and glycerol, the alcohol ether wetting agent is ethylene glycol monobutyl ether, the surfactant is sulfonyl440 and surfynol465, the antibacterial agent is methylisothiazolinone, and other additives include defoamer and quick-drying agent. The defoamer is polyether L61 and the quick-drying agent is magnesium nitrate;

[0093] A preparation method of a hard water-resistant and alcohol-free dampening solution, which includes Step 1, synthesizing PVA-g-AA copolymer water-soluble resin; Step 2, preparing raw materials; Step 3, pre-mixing raw materials; Step 4, adding functional additives;

[0094] Among them, in the above Step 1, referring to Example 5, synthesize PVA-g-AA copolymer water-soluble resin with the model of P5;

[0095] Among them, in the above Step 2, based on the sum of the mass percentage contents of each component being 1, prepare PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water according to the formula ratio of the dampening solution;

[0096] Among them, in the above Step 3, at room temperature of 23±2°C, mix and stir the PVA-g-AA copolymer water-soluble resin with the pH buffer and polyol humectant evenly to obtain a basic mixed system;

[0097] Among them, in the above Step 4, in the basic mixed system obtained in Step 3, sequentially add alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water, and continue to stir for 30-40 min until the system forms a clear solution to obtain a dampening solution concentrate with the model of S09.

[0098] Example 15:

[0099] A hard water-resistant alcohol-free dampening solution, the formula of which includes: PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water. The mass percentage contents of each component are respectively: 11% of PVA-g-AA copolymer water-soluble resin, 3% of pH buffer, 18% of polyol humectant, 35% of alcohol ether wetting agent, 2% of surfactant, 0.5% of antibacterial agent, 0.5% of other additives and 30% of deionized water; the specific raw material components in the formula are: the model of PVA-g-AA copolymer water-soluble resin is P5, the pH buffer is sodium phthalate, the polyol humectant is ethylene glycol, polyethylene glycol, glycerol, the alcohol ether wetting agent is ethylene glycol monobutyl ether, the surfactant is sulfonyl440, the antibacterial agent is methylisothiazolinone, chloromethylisothiazolinone, and other additives include defoamer and quick-drying agent. The defoamer is polyether L61, and the quick-drying agent is ammonium nitrate;

[0100] A preparation method of a hard water-resistant alcohol-free dampening solution, including Step 1, synthesizing PVA-g-AA copolymer water-soluble resin; Step 2, preparing raw materials; Step 3, pre-mixing raw materials; Step 4, adding functional additives;

[0101] Among them, in the above Step 1, referring to Example 5, synthesize PVA-g-AA copolymer water-soluble resin with the model of P5;

[0102] Among them, in the above Step 2, taking the sum of the mass percentage contents of each component as 1, prepare PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water according to the formula ratio of the dampening solution;

[0103] Among them, in the above Step 3, at room temperature of 23±2°C, mix and stir the PVA-g-AA copolymer water-soluble resin with the pH buffer and polyol humectant evenly to obtain a basic mixed system;

[0104] Among them, in the above Step 4, in the basic mixed system obtained in Step 3, sequentially add alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water, and continue to stir for 30-40 min until the system forms a clear solution to obtain a dampening solution concentrate with the model of S10.

[0105] Experimental Example 1:

[0106] Take the samples of the dampening solution concentrates of models S01 to S10 prepared in the above examples, and dilute them to 3 - 5% respectively with ultrapure water. Then, conduct tests on pH value, surface tension, hard water resistance, drying time, and antibacterial property. The test methods are shown in Table 2, and the performance test results are shown in Table 3. Among them, the determination of the pH value is specifically as follows: Take 15 mL of the diluted dampening solution concentrate sample. Under room temperature conditions, completely immerse the probe of the pH acidimeter into the sample solution, start the determination under continuous stirring, observe the change of the pH acidimeter value, and record the reading after it shows stability. Repeat the above operation 3 times, and take the average of the 3 measurement results as the pH value determination result of this sample; the determination of the conductivity is specifically as follows: Take 20 mL of the diluted dampening solution concentrate sample. Under room temperature conditions, completely immerse the probe of the conductivity meter into the sample solution, and stir continuously at the same time. Start the conductivity test, and read the data when the value shown by the conductivity meter tends to be stable. Similarly, repeat the measurement 3 times, and take the average of the 3 measurement values as the final conductivity determination result of this sample; the determination of the dynamic surface tension is specifically as follows: Take 15 mL of the diluted dampening solution concentrate sample, inject it into the sample cell of the dynamic surface tension meter, and conduct the determination at room temperature environment to obtain the dynamic surface tension (γ) of the sample, and draw the relationship curve between γ and the surface lifetime t (ms).

[0107] Experimental Example 2:

[0108] Testing of ink emulsification rate: Weigh 50 g of commercially available dampening solution and the samples of the dampening solution concentrates of models S01 to S10 prepared in the above examples respectively. Put each dampening solution sample and 50 g of offset printing ink into a container equipped with a stirring device, set the stirring speed to 300 r / min, and stir continuously for 10 min to ensure that the dampening solution and the ink are fully mixed and emulsified. After the stirring ends, pour out the dampening solution in the container, and use an ink knife to squeeze out as much residual dampening solution in the emulsified offset printing ink as possible. Weigh the total mass / g of the poured out and squeezed out dampening solution, and then calculate the ink emulsification rate according to the following formula. The results are shown in Table 4:

[0109]

[0110] Experimental Example 3:

[0111] On a Heidelberg CD102 - 4 type four - color offset printing press, use the above dampening solution for printing tests. The dampening solution is diluted and mixed with deionized water at a ratio of 4%. Use DIC series inks, and the substrate is selected as 157 g / m 2 copperplate paper. The set parameters of the printing press are as follows: The temperature of the dampening solution is controlled at 12 - 15 °C, the water roller pressure and the ink roller pressure are set to the standard pressure provided by the equipment supplier, the printing speed is 13,000 sheets per hour, and it runs continuously for 48 hours. Sample and inspect the printed patterns every 2 hours, and compare with the existing commercial dampening solutions A, B, and C. The printing test results are shown in Table 4.

[0112] Experimental Example 4:

[0113] Samples of fountain solution concentrates of models S01, S2, S7, and S8 prepared in the above examples were taken for hazardous substance testing. The test items included: diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), bis(2-ethylhexyl) phthalate (DEHP), di-n-octyl phthalate (DNOP), diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), and methanol. The specific test method was as follows: The sample was diluted to 5% with ultrapure water, and the content of hazardous substances was determined by inductively coupled plasma mass spectrometry. The detection limit of the method was 1 ppm, and N.D. indicated that the test result was less than the detection limit. The test results are shown in Table 5.

[0114] Table 1 Molecular Weight and pH Value of PVA-g-AA Copolymer Water-Soluble Resin

[0115] Resin model Molecular weight pH P1 85643 4.2 P2 56906 3.8 P3 45632 3.6 P4 32187 3.4 P5 25074 3.6

[0116] Table 2 Test Items

[0117]

[0118] Table 3 Performance Test Results

[0119]

[0120] Table 4 Ink Emulsification Rate Test and Printing Test Results

[0121]

[0122]

[0123] Table 5 Hazardous Substance Test Results

[0124]

[0125] Based on the above, the advantages of the present invention are as follows: The PVA-g-AA copolymer water-soluble resin is adopted in the formula of the present invention. This resin uses polyvinyl alcohol as the main chain skeleton to provide water solubility and film-forming property, uses acrylic acid as the hydrophilic monomer to introduce carboxylic acid groups, and uses methacrylic acid to regulate the spreading and water resistance of the molecular chain. By controlling the molecular weight and ratio of the resin, the problem of the decrease in the spreading rate of the water film caused by the entanglement of the resin molecular chains is solved; The PVA-g-AA copolymer water-soluble resin is compounded with a pH buffer to inhibit the precipitation of hard water and achieve long-term pH stability, controlling the pH fluctuation within ±0.5. The PVA-g-AA copolymer water-soluble resin may cooperate with surfactants to achieve stable control of the ink emulsification rate.

[0126] It is obvious to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, in all respects, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

Claims

1. A hard water-resistant and alcohol-free dampening solution, the formula of which comprises: PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water, characterized in that: the mass percentage contents of each component are respectively: 8-12% of PVA-g-AA copolymer water-soluble resin, 1-5% of pH buffer, 10-20% of polyol humectant, 20-40% of alcohol ether wetting agent, 0.5-3% of surfactant, 0.1-1% of antibacterial agent and 0-0.5% of other additives, and the balance is deionized water.

2. A hard water-resistant alcohol-free dampening solution according to claim 1, characterized in that: The PVA-g-AA copolymer water-soluble resin is obtained by copolymerizing three components of polyvinyl alcohol, polyacrylic acid, and polymethacrylic acid, and its structural general formula is as follows: Among them, x, y, and z are the mass parts of polyvinyl alcohol, polyacrylic acid, and polymethacrylic acid in the resin respectively.

3. A hard water-resistant alcohol-free dampening solution according to claim 1, wherein: The pH buffer is one or a combination of more of sodium dihydrogen phosphate, disodium hydrogen phosphate, sodium hydrogen phosphite, sodium dihydrogen phosphite, sodium phosphate, sodium citrate, sodium oxalate, sodium carbonate, triethylamine, sodium formate, sodium acetate, sodium benzoate, potassium hydrogen phthalate.

4. A hard water-resistant and alcohol-free dampening solution according to claim 1, wherein: The polyol humectant is one or a combination of more of ethylene glycol, 1,2-propanediol, 1,3-propanediol, glycerol, 1,4-butanediol, 1,3-butanediol, dipropylene glycol, polyethylene glycol, sorbitol, xylitol.

5. A hard water-resistant and alcohol-free dampening solution according to claim 1, wherein: The alcohol ether wetting agent is one or a combination of more of ethylene glycol butyl ether, ethylene glycol propyl ether, propylene glycol methyl ether, propylene glycol butyl ether, diethylene glycol ethyl ether, diethylene glycol butyl ether.

6. A hard water-resistant alcohol-free dampening solution according to claim 1, characterized in that: The surfactant is one or a combination of more of alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, sodium dodecyl sulfate, sodium dodecyl sulfonate, cetyltrimethylammonium bromide, N-octylpyrrolidone, N-dodecylpyrrolidone, sulfonyl104, sulfonyl420, sulfonyl440, surfynol465.

7. A hard water-resistant alcohol-free dampening solution according to claim 1, characterized in that: The antibacterial agent is one or a combination of more of Kathon, chloromethylisothiazolinone, methylisothiazolinone, sodium benzoate, polyhexamethylene guanidine.

8. A hard water-resistant and alcohol-free dampening solution according to claim 1, characterized in that: The other additives include defoaming agent and quick-drying agent, and the ratio of defoaming agent to quick-drying agent is 1:

1. The defoaming agent is one or a combination of more of polydimethylsiloxane, calcium stearate, oleic acid amide, polyether L61, polyether F68, and the quick-drying agent is one of ammonium nitrate and magnesium nitrate.

9. A preparation method of a hard water-resistant alcohol-free dampening solution, including Step 1, synthesizing PVA-g-AA copolymer water-soluble resin; Step 2, preparing raw materials; Step 3, pre-mixing raw materials; Step 4, adding functional auxiliaries, characterized in that: In the above step 1, polyvinyl alcohol, acrylic acid, methacrylic acid, deionized water and an initiator are prepared according to the formula of the PVA-g-AA copolymer water-soluble resin. The polyvinyl alcohol is added to the deionized water, and the temperature is raised to 80-90 °C and stirred until completely dissolved. After cooling to 40-50 °C, the initiator is added. After stirring and dissolving, nitrogen is introduced to deoxygenate for 15-30 min. The mixed solution of acrylic acid and methacrylic acid is slowly added dropwise to the polyvinyl alcohol solution, and the temperature is raised to 60-70 °C and reacted for 2-4 h to form a PVA-g-AA copolymer. After cooling to room temperature, the PVA-g-AA copolymer water-soluble resin is obtained by filtration; In the above step 2, based on the sum of the mass percentage contents of each component being 1, the PVA-g-AA copolymer water-soluble resin, pH buffer, polyol humectant, alcohol ether wetting agent, surfactant, antibacterial agent, other additives and deionized water are prepared according to the formulation ratio of the dampening solution; In the above step 3, at room temperature of 23±2 °C, the PVA-g-AA copolymer water-soluble resin is mixed and stirred evenly with the pH buffer and polyol humectant to obtain a basic mixed system; In the above step 4, in the basic mixed system obtained in step 3, an alcohol ether wetting agent, a surfactant, an antibacterial agent, other additives and deionized water are sequentially added, and stirring is continued for 30-40 min until a clear solution is formed in the system to obtain a concentrated dampening solution.

10. The preparation method of a hard water-resistant alcohol-free dampening solution according to claim 9, characterized in that: In the formula of the PVA-g-AA copolymer water-soluble resin in step 1, the mass parts of each component are as follows: 100-200 parts of polyvinyl alcohol, 50-150 parts of acrylic acid, 5-20 parts of methacrylic acid and 300-500 parts of deionized water. Among them, the dosage of the initiator accounts for 0.5-3% of the total mass of the monomers. The initiator is one or a combination of ammonium persulfate, potassium persulfate, sodium persulfate, benzoyl peroxide, azodiisobutyramidine hydrochloride, azodiisobimidazoline hydrochloride, etc. The polyvinyl alcohol is one or a combination of PVA0388, PVA0488, PVA0588, PVA1788, PVA2488, PVA0599, PVA1799, PVA2499, etc. The molecular weight of the prepared PVA-g-AA copolymer water-soluble resin is 10,000-100,000.

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