JPS59502097A - Lithographic printing aqueous reservoir solution concentrate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Lithographic printing aqueous reservoir 921. Mi liquid concentrate technology field The present invention can be mixed with water to form a lithographic printing reservoir solution (lithographic printing reservoir solution). aqueous concentrates that produce untain so]-utions).

Background technology In web offset printing and lithographic printing, lithographic printing plates (planog) are used. [rapic peates], and the printing plate blankets the ink. The ink is transferred to a roller, which in turn transfers the ink to the support to form a printed image. Form. Since the image area and the non-image area are in the same plane, this printing plate is a lithographic printing plate. It is called a printing plate.

This printing plate is made by suitable treatment to make the image area hydrophobic and oleophilic, making it receptive to ink. It is designed to be easy to use. The non-image area is hydrophilic and therefore easily absorbs water. stomach. Maintains the hydrophilic properties of the non-image areas and prevents ink from accumulating in the non-image areas. To prevent this, the printing plate must be continuously bathed in a water-based reservoir solution. It is necessary to process it accordingly. The water reservoir solution is placed in a separate roll prior to inking. Therefore, it can be applied to a printing plate. Or Dahlgren (Dahlgr) It is also possible to apply the ink and the reservoir solution at the same time, as in the case of the en) type system. 1. It is also possible to use qualified tap water as the reservoir solution, but a person skilled in the art can As is well known in Sometimes it's good. Low-boiling alcohols such as isopropanol and ethanol and various surfactants to lower the surface tension and reduce the stiffness of printing plates. Good 2 It is also well known that Acid or buffer to achieve a pH range of 4°0-60 It is also known to use agents. Adding a polyol such as glycerin to the reservoir solution a thin layer of water on the hydrophilic areas of the printing plate, acting as a humectant and lubricant. Let them help you keep it. Biocides such as fungicides and algicides are Added to control the growth of organisms.

Generally, the reservoir solution is prepared at the printing site by mixing the reservoir solution concentrate with tap water. prepared.

The use of a reservoir solution has many beneficial effects in the printing process, such as water-ink emulsion formation. Decrease in raw material, decrease in scum formation, decrease in paper fiber detachment, decrease in paper breakage, acceleration of drying, marking It is known that printing operations take a longer time.

Typical reservoir solutions well known to those skilled in the art include ethyl alcohol or improvised alcohol. kohl, glycerin, surfactants, fungicides or algicide, in varying amounts. Acidifying agents such as phosphoric acid.

and water.

U.S. Pat. No. 4,247,328 discloses a lithographic printing reservoir containing a desensitizing agent. Solution concentrates are disclosed. Preferred desensitizers disclosed include acids, e.g. For example, citric acid, phosphoric acid, and tartaric acid.

and a salt of ethylenediaminetetraacetic acid (EDTA). During the above period, IiI] , we mentioned that acids can be used as desensitizers, but salts are preferred. Ru. Salt acts as a buffer, counteracting the effects of using acidic or alkaline tap water. It is from. The specification also states that the reservoir solution concentrate contains at least 50% organic solvent. It is necessary to use a drug.

US Pat. No. 4,150,996 discloses that sulfanilic acid, formaldehyde discloses a reservoir solution concentrate containing , sodium hydroxide, and gum arabic. . Gum arabic is used to make printing plates and rolls rubbery and glossy, as well as to prevent bacteria and algae. It has been found to have a number of deleterious effects, such as promoting the growth of.

U.S. Pat. No. 4,278,467 discloses that isopropyl alcohol is substituted with The reservoir solution used is disclosed.

U.S. Pat. No. 4,416,896 discloses that acidic acid Disclosed is a reservoir solution that prevents harmful precipitation in alcohol/water reservoir solutions.

Therefore, what is needed in the art is to Strong buffering capacity brings improvements to the printing process by maintaining a pH range of An improved reservoir solution with Additionally, this improved reservoir solution contains alcohol. It must be free of alcohol or must have a significantly reduced alcohol content.

Disclosure of invention A concentrated reservoir solution with a strong buffer obtained by reacting a polycarboxylic acid with an organic base. When a concentrate is prepared and the concentrate is mixed with water at a weight ratio of about 1.0 to 6.0, it becomes an excellent buffer. A reservoir that is active and contains no alcohol or only a very small amount of alcohol. It is known that a liquid solution can be obtained. The reservoir solution thus obtained from the concentrate When used in lithographic printing presses, the following unexpected and remarkable improvements have been made: Ru. i.e. longer print runs, less scum, less ink/water emulsion. , reduced fiber waste generation and fiber detachment, reduced support breakage, improved drying, strike This reduces ink and improves the ink/water balance.

The present invention relates to concentrates for use in lithographic printing reservoir solutions.

This concentrate is a blend of buffer, polyol, water, and alcohol. da This concentrate, used in lithographic presses using the Dardalene wet system, is Does not include rules. The concentrates of the invention may further contain fungicides or algicides, and Surfactants may be included. This concentrate is mixed with tap water and the concentrate becomes a reservoir solution. Prepare a reservoir solution with a concentration of 1-6%.

The buffer used in the present invention is a salt of a polycarboxylic acid and an organic base (amine).

The polycarboxylic acid has a pKa of 3 to 6, and the base has a pKb of 2 to 9. There must be. This polycarboxylic acid may have at least one hydroxyl group. can.

Detailed description of the invention With respect to the aqueous concentrate used in the Haritogelaf printing reservoir solution of the present invention, the concentrate is about 1 ．． (Mix with water in an amount of 1 to 60% by weight to produce a reservoir solution. Concentrate the reservoir solution.) The thing is water; A polycarboxylic acid having a pKa of 3 to 6 and an organic base having a Kb of 2 to 9. A buffer salt consisting of a salt of; a low molecular weight alcohol; Hygroscopic substances 2 such as glycerin or equivalent polyols (such as polysaccharides or their derivatives (e.g. carboxymethyl cellulose)) still polymerization of vinyl pyrotone The product obtained in

or colloidal silicic acid; and Various optional ingredients such as surfactants, bactericides and/or algae side and the reservoir solution prepared by mixing said concentrate with water is , pH of about 47-53, and It has a surface tension of about 32 x 10" to 52 o-3 N/m. This surface tension Adjusted according to system type.

For standard wet systems (water-based systems), the surface tension is approximately 44X10 = ~5 It is preferable to set it to 2×1O-3N/m. For alcohol-wet systems, see the table below. The surface tension is preferably approximately 32X1.0-3 to 37X1O-3N/m. . In the latter case, the wet system can be improved by selecting and using appropriate reservoir solution additives. The amount of alcohol commonly used can be reduced or suppressed. need If so, the surface tension can be adjusted by adding a non-foaming surfactant.

Sufficient strength of the buffer is 5 CC (D O, I N When adding HGl, 5cc of O, ], N, NaOH, the change in pH was It is something like 1 unit or less.

The concentrate of the present invention is mixed with water to account for 1 to 6 volumes of the reservoir solution. like this The resulting reservoir solution has a pH of about 47-53 and a pH of about 32 x 10-3-52. X has a surface tension of 1O-3N/m.

The reservoir solution prepared in accordance with the present invention may have either a strong base or a strong acid added to the solution. buffering effect such that the change in pH is smaller than 1 unit of pH even when have For example, 5cc of 01N NaOH is still 0. IN H (J 1.0O When a force of cc of the inventive solution is applied, the change in pH is less than 1 unit. Book Invention preference 6 In some new embodiments, the change in pH is less than 0.5 units under the same conditions. You can make it smaller.

The carboxylic acid that can be used to produce the buffer salt of the present invention is citric acid.

malic acid, glutaric acid, succinic acid, azelaic acid, and has a pKa of about 3-6. It is a similar polyacid. The polyacids used in the production of buffer salts contain other functional groups such as hydroxyl. It may have a group. The organic base used in the present invention is an amine, such as a first base. Second and tertiary amines, polyamines such as hydrazine and ethylenediamine, ring amines, and amino alcohols. These amines are about 2-9. preferred It has a pKb of 3 to 6.

A particularly useful buffer is the salt of citric acid and dimethylamine.

The pKa of a polycarboxylic acid-amine salt solution is Therefore, it changes depending on the number of acid roots that have been neutralized. In the present invention, the reservoir A sufficient number of acid groups on the polycarboxylic acid molecules are unreacted to obtain the desired pH value of the solution. It is preferable to obtain a buffer salt that is resistant to oxidation.

In addition to the buffering agent mentioned above, the reservoir solution of the present invention contains a hygroscopic solution that homogenizes the various components. substances, alcohol, and additives, such as disinfectants or algicide, and detergents. agents such as N-methylpyrrolidone or various surfactants.

The moisture absorbent may be glycerin or an equivalent polyol such as polysaccharide. or one of its derivatives (e.g. carboxymethylcellulose) or vinylpyro It can be a lydone polymer or a colloidal 9-silicic acid. Moisture absorption material is printed Used to maintain a constant amount of water deposited on the plate and blanket. actual , a thick water film on the printing plate, and a very thin water film due to the low surface tension of the reservoir solution of the present invention. It becomes. Therefore, the amount of reservoir solution used is reduced during normal printing operations.

Another important point is that the amount of water required is reduced by using the present invention. An important technical consequence is that the printed product dries faster. With the concentrate of the invention The fungicide and/or algicide used can be any commercially available product. . As used herein, the term biocide refers to fungicides, algicides, or shall mean a combination of

A particularly useful and preferred embodiment of the invention is a concentrated solution for use in lithographic printing reservoir solutions. When the concentrate is mixed with water in an amount of about 6% by weight, the concentration is 4.7 to 6% by weight. pH of 53, surface tension of 32X 10-3 to 52X10”N7m, and strong acid or a buffer strength sufficient to reduce the pH change by more than 1 unit when a strong base is added. It is like producing a reservoir solution with a water content of 587% by weight.

A 20.5 weight scale buffered salt solution consisting of a salt of citric acid and dimethylamine.

7% by weight polyvinylpyrrolidone.

5.3 wt- of ethanol.

35% by weight of isoprene.

5% by weight biocide It consists of

As previously mentioned, the reservoir solution prepared from the concentrate of the present invention can be used in the lithographic printing process. When used in Reduces shrinkage and fiber waste.

Improved abrasion resistance, reduced use of reservoir solution, and reduced use of alcohol. You can get the following effect. The reason for this unexpected effect is not clear The interaction of the reservoir solution with the ink, paper support, and lithographic plate surface is controlled. This seems to be a factor. As is well known to those skilled in the art, the reservoir solution, ink and paper The interaction of the two influences the printing properties and the properties of the printing method. The new invention When used in lithographic printing, the reservoir solution is applied very thinly to the hydrophilic areas of the printing plate. It was unexpectedly revealed that the water layer was maintained by a thin layer of water. Furthermore, the present invention The strong buffering action of buffering agents allows for pH change characteristics of various inks and paper supports. gender is compensated. Deviation from the ideal pH range of 460 to 60 is due to drying time and printing plate feel. It can have various other negative effects. Reservoir solutions generally contain up to 15% by weight of low molecular weight alcohol, but the reservoir solution prepared using the concentrate of the present invention The amount of alcohol used in the liquid is extremely small (0.04-12% by weight); For Dahlgren products, use no alcohol or significantly reduce the amount of alcohol used. be able to.

The concentration of buffer salts in the reservoir solution concentrates of the present invention ranges from about 70 to 35.0% by weight. It is in. The concentration of buffer salts in the reservoir solutions of the present invention ranges from about 0.07 to 21% by weight. It is surrounded by To obtain the required buffering effect, each buffer salt or combination of buffer salts must be or using a combination of buffer salts and acids to prepare the reservoir solution concentrates of the present invention. can do.

The reservoir solution concentrate of the present invention has the following component composition.

40.0 to 89.0 weight water.

7.0-35.0% by weight buffer.

50-200% by weight polyol.

00-10.0% by weight low molecular weight alcohol.

0.0-01% by weight surfactant.

00-60% by weight biocide Description of preferred embodiments The following examples are provided to explain the present invention in more detail; It is not limited to.

Example 1 A buffer salt is created by reacting 1 mole of citric acid (monohydrate) with 2 moles of dimethylamine. Prepared. Mix 0.6 g of salt in 100 g of water to form an aqueous solution with the following properties: Prepared.

pH=5.3.

Buffering effect 5cc 0. When adding IN sodium hydroxide, the pH starts from 5.3. It changed to 58. 5cc of 0. When IN hydrochloric acid was added, the pH changed from 53 to 49. It became.

Surface tension: Approximately 4.7.3 x 1O-3N/m0 In this example, quench Two acid roots of the acid are neutralized (pKa of the second acid root is 4.7 to 4..8) ).

Example 2 Buffer salts are prepared by reacting 1 mole of monohydrate citric acid with 2 moles of ethanolamine. did. 0.69 of this buffer salt is mixed with 100 g of water to form an aqueous solution with the following properties: A liquid was prepared.

pH=5.25 10 Buffering effect: pH increases to 58 by adding 5 cc of 00IN sodium hydroxide did. 5cc of 0. Addition of IN hydrochloric acid lowered the pH to 48.

Surface tension: approximately 42.6 x 1O-3N/m.

Example 3 By reacting 1 mol of malic acid with 1.1 mol of dimethylamine, a Prepared salt solution. 0.6g of salt mixed with 100g of water has the following properties An aqueous solution was prepared.

pH=4.3 Buffering effect 5cc 0. Addition of IN sodium hydroxide increases pH to 4.7 did. 5cc of 0. Addition of IN hydrochloric acid lowered the pH to 41.

Surface tension: approx. 54.9 x 1.0””’N7m.

In this example, slightly more than 1 (/c) of the acid radicals of malic acid are neutralized. (the pKa of the first acidic function is 34 , the pKa of the second acid root is approximately 51).

Example 4 By reacting 1 mole of monohydrate citric acid with 2 moles of cyclohexylamine Thus, buffer salts were prepared. 0.69 of this salt is mixed with 100g of water and has the following properties. Prepare an aqueous solution with a buffering effect of 5cc of 0. By adding IN sodium hydroxide The pH rose to 6.2. 5cc of 0. By adding IN hydrogen chloride, the pH is 4. ．． It dropped to 9.

Surface tension approximately 50.4 x 10 = N7m0 Example 5 A buffer salt is prepared by reacting 1 mole of adipic acid with 1 mole of piperidine. Manufactured. 0.6, this salt of S7 is mixed with 100 g of water to form water with the following properties: A solution was prepared.

, I) H=5 Buffering effect 0.1 of 5cc. The pH increased to 53 by adding sodium hydroxide. rose. Addition of 5 cc of O,],N hydrogen chloride lowered the pH to 47.

Example 6 buffer salt by reacting 1 mole of adipic acid with 1 mole of dimethylamine was prepared. 0.6.9 of this salt is mixed with 100 g of water to form water with the following properties: A solution was prepared.

pH=4.9 Buffering effect 5cc 0. (IN hydroxide) The pH increased to 51 by adding IJium. rose. 5cc of 0. After addition of IN hydrogen chloride, the pH decreased to 47.

Example 7 Results comparable to those obtained in Examples 1-6 were obtained using the following acids and bases.

Glutaric acid (1 mol) Cyclohexylamine (1 mol) Succinic acid (1 mol) Ethylenediamine (05 mol) Azelain (] mol) Triethylamine (1 mol) ) Example 8 reservoir solution concentrate 2 A reservoir solution concentrate was prepared by combining the following ingredients: The proportion of ingredients is Expressed in parts. Buffer salt of AB Examples 1 to 7 30.0 32.2 Glycerin 1 8.0 13.6 Ethyl alcohol 5.4 4.5 Isopropyl alcohol 3.6 2.8 Disinfectant 09 09 Concentrates prepared according to formulations A and B are mixed with water in a ratio of 1 to 6 parts of concentrate and 100 parts of water. A reservoir solution was prepared by mixing with

Example 9 Other reservoir solution concentrates were prepared by blending the following ingredients into the buffers of Examples 1-7. Salt 7,4 20.5 Polyvinylpyrrolidone 50 70 Ethyl alcohol 29 53 Inpropyl alcohol 1.9 3.5 Disinfectant 30 50 Surfactant 0.08 0.05 Wednesday 79.72 58.65 Total 100.00100.00 Combination C,! : The concentrate prepared according to D was mixed in a ratio of 1 to 6 parts of concentrate and 100 parts of water. A reservoir solution was prepared by mixing with water.

The use of the reservoir solutions of Examples 8 and 9 significantly reduced the number of species compared to conventional reservoir solutions. The following unexpected improvements were made to similar printing presses.

3 a.) Reduced paper damage h) Reduces fiber waste generation and fiber detachment, and stops cleaning the blanket. It has become less.

C) Reduced paper adhesion to the blanket d) Reduction of ink/water emulsion C) Shortening drying time f) Improving the abrasion resistance of printed materials.

Although the present invention has been disclosed and explained using various embodiments, those skilled in the art will be able to easily understand it. It will be understood that there may be no departure in embodiment or detail from the spirit and scope of the invention. Various modifications are possible.

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Claims (1)

[Claims] (1) Lithographic printing reservoir solution containing water, buffer, phoriol and surfactant An improved water dilutable concentrate for use in. The buffering agent is at least one salt of (a) polycarboxylic acid and (bl organic amine). an improved buffer comprising: the polycarboxylic acid having a pKa of about 3 to 6; the organic amine has a pKb of about 2-9; When the concentrate is mixed with water in an amount of about 1 to 6 parts by weight, the concentrate pH of about 4.7-5.3. providing a reservoir solution with a surface tension of about 32×10−” to 52×10−3 N/m; and the reservoir solution contains 5 cc of 0.5 cc to 100 cc of the reservoir solution. IN NaOH also When 5cc of 0.1N HO2 is added, the pH change of the reservoir solution is about 1 unit. Have sufficient buffering effect to be lower than the pH Full featured concentrate. (2) Claim 1 further containing 4 to 10% by weight of low molecular weight alcohol Concentrates. (3) The polycarboxylic acid is citric acid and the organic amine is dimethylamine. A concentrate according to item 1 of the claimed scope. (4) The concentrate of claim 2 further comprising 05-60% by weight of biocide. (5) a disinfectant selected from the group consisting of algicides, fungicides, and combinations thereof; Claim 5 further comprising 0.5 to 60% by weight of crude drug Concentrate according to paragraph 3. (6) The concentrated polycarboxylic acid according to claim 1, wherein the polycarboxylic acid contains at least one hydroxyl group. shrinkage. (7) Low molecular weight alcohols include ethanol, isopropamel and mixtures thereof. 3. A concentrate according to claim 2, wherein the concentrate is selected from the group consisting of: (8) IJ) A water-dilutable concentrate for use in a graph printing reservoir solution, comprising: 58.7% water by weight 20.5% by weight buffer salt consisting of a salt of citric acid and dimethylamine 7% by weight polyvinylpyrrolidone 5.3% by weight ethanol 35% by weight Improper Tools 50% biocide by weight Karaseishi, When this concentrate is mixed with water at about 1-6% by weight, the pH is about 47-53, about 32X A reservoir solution with a surface tension of 10-3 to 52X10-3 N/m is obtained and To 100 cc of cloudy solution, add 5 cc of 0, IN NaOH or 0. I　N　H When Cl is added, the change in pH is smaller than about 1 unit of pH. The reservoir solution has a negative effect. A concentrate characterized by. (9) Improved lithographic printing reservoir containing water, buffer, polyol and surfactant a solution, 16 The buffering agent contains at least one of (a) JIJ carboxylic acid and (A) organic amine. an improved buffer comprising a salt, wherein the polycarboxylic acid has a pKb of about 3-6; the organic amine has a pKb of about 2-9; The reservoir solution has a pH of about 47-53, about 32 x 10 - 52 x 1 O-3 N/m surface tension and 5cc of 0. IN NaOH or 0.1N HGI When J is added to 100 CC of the above-mentioned reservoir solution, 7) the change in H is about 1 unit of pH. have a sufficient buffering effect to reduce the A reservoir solution with all features. (10) Claim 9 further contains 4 to 10 weight percent low molecular weight alcohol. Reservoir solution. 0υ Claim that the polycarboxylic acid is citric acid and the organic base is dimethylamine The reservoir solution according to item 9. 02) The reservoir solution according to claim 9, further comprising a biocide of 05 to 60% by weight. . (13) selected from the group consisting of algizides, fungicides or combinations thereof; 10. The reservoir solution of claim 9 further comprising a biocide of 0.05 to 6.0 weight fraction. 0.4) The polycarboxylic acid according to claim 9, wherein the polycarboxylic acid contains at least one hydroxyl group. Reservoir solution. (15) Low molecular weight alcohols include ethanol, isopropanol and their 11. A reservoir solution according to claim 10 selected from the group consisting of combinations. 06) Water dilutable reservoir solution concentration containing water, buffer, phoriols and surfactants Prepare a reservoir solution by mixing about 1.0 to 60 parts by weight of the product in water, and then Treating a lithographic printing plate with the reservoir solution to render the non-image areas of the printing plate hydrophilic; This consists of preventing ink from adhering to the area and improving the printing process. In lithographic printing or web offset printing processes, buffering in the reservoir solution is the agent comprises at least one salt of (a) a polycarboxylic acid and (b) an organic amine. In an improved buffer, the h61J carboxylic acid has a pK& of about 3-6, and the organic amino acid has a pKb of about 2~); The reservoir solution has a pH of about 47-53, about 32×], O-3-52×10 It has a surface tension of "N/m, and 5CC of 0.1N HGl is 100CC of When added to the reservoir solution, the change in pH is less than about 1 unit of 7)H. have sufficient buffering effect for A printing method characterized by 07) Claim that the reservoir solution further contains 40 to 100% by weight of low molecular weight alcohol The printing method according to item 16 within the scope of . 08) The claim that the buffer salt in the reservoir solution is a salt of citric acid and dimethylamine. The printing method described in paragraph 16. (19) Claim 16, wherein the reservoir solution further contains a biocide in an amount of 0.5 to 60% by weight. Printing method described. (The 201 reservoir solution is a group consisting of algicite, fungicides, and combinations thereof. Claim 16 further comprising 05-6.0% by weight of a biocide selected from Printing method. Cυ Polycarboxylic acid 8 used to prepare buffer salts for reservoir solutions 17. The printing method according to claim 16, wherein said hydroxyl group contains at least one hydroxyl group. (22) Low molecular weight alcohols include ethanol, impropatol and their combinations. 18. The printing method of claim 17, wherein the printing method is selected from the group consisting of: