JP3304158B2 - Cleaning fluid for printing machines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil-in-water rotary offset printing press, for example, a satellite type offset multi-color rotary printing press of a newspaper company or the like for removing ink and paper dust deposits on a multicolor common cylinder and rollers. The present invention relates to a cleaning liquid for a printing press comprising a water-in-oil emulsion or a water-in-oil emulsion.

[0002]

2. Description of the Related Art When printing on a base material such as paper, plastic, or fabric by various printing methods, the printing cylinder is temporarily stopped for color change, plate change, machine adjustment, or the like, or when the printing is completed. In some cases, it is necessary to wash ink, paper powder, and the like adhering to satellite impression cylinders, ink rollers, and the like.

For this purpose, conventionally, tap water, alkaline dampening water or kerosene is used as a washing liquid, which is sprayed from a brush or a nozzle onto a washing roller to wash off ink and paper powder adhering to a satellite impression cylinder or the like. I was

[0004] However, kerosene or washing oil has the drawback of bleeding into the paper surface, has a strong odor, and has the drawback of being dangerous in terms of the Fire Service Law and hygiene. On the other hand, there is a disadvantage that it is difficult to remove ink and oil with tap water or alkaline dampening water.

In recent years, in order to solve such disadvantages caused by using oil or water alone, various washing liquids for printing presses comprising an oil-in-water emulsion or a water-in-oil emulsion by adding water to oil have been proposed. It has become. For example, as such a washing liquid for a printing press, one for the purpose of forming a stable emulsion of hydrocarbon and water (Japanese Patent Publication No.
Japanese Patent Application Laid-Open No. 1-4081) and oil-soluble dirt such as ink and hydrophilic dirt such as paper powder and clay powder are both types of dirt adhering to the impression cylinder. There is one developed as desirably to remove dirt with a cleaning solution (Japanese Patent Publication No. 3-79399). In these cases, a statutory third type organic solvent is used as an oil component in order to maintain high washing performance.

[0006]

However, the cleaning solutions for emulsion-type printing presses proposed so far contain organic solvents such as mineral spirits, which are prescribed in the Ordinance on Prevention of Organic Solvent Poisoning under the Labor Standards Law. Although it is a cleaning liquid for a printing machine having a high cleaning ability, if the cleaning liquid is volatilized in a printing room or scatters or floats in a continuous use during printing, a state unfavorable in hygiene occurs. Therefore, in a printing room or a work site with a small air volume, there is a legal limitation in using such a cleaning liquid.

[0007] Therefore, an object of the present invention is to exhibit high cleaning ability without using an organic solvent specified in the Ordinance for Prevention of Organic Solvent Poisoning of the Labor Standards Law, and to be free from legal restrictions in equipment and work. Another object of the present invention is to provide a cleaning liquid for a printing press that does not attack a rubber roller or the like.

[0008]

To achieve SUMMARY OF to the above objects, printing machine cleaning solution of the present invention, a weight ratio of 9 / 1-3 /
7 to a composition of a hydrocarbon solvent and water,
3 to 10% by weight based on a water-in-oil emulsion emulsified with 10% by weight of a nonionic surfactant
The following expression,

Embedded image (Wherein R is a nonyl group or octyl group, and n is 4-16
Polyoxyethylene alkylpheny represented by
And emulsified by adding 3% by weight or more of water
Cleaning fluid for printing press consisting of oil-in-water emulsion
A petroleum distillate in which the 50% distillation temperature of the hydrocarbon solvent exceeds 180 ° C., wherein the aromatic hydrocarbon content in the composition is 1% by weight or less .

[0009]

Hereinafter, the present invention will be described more specifically. In the following description, “%” representing the composition,
“Parts” and “ratio” are based on weight unless otherwise specified. As the hydrocarbon-based solvent constituting the mother phase of the first printing press cleaning liquid of the present invention or the dispersed phase of the second printing press cleaning liquid of the present invention, a petroleum fraction whose 50% distillation temperature exceeds 180 ° C. It is a residue. Such petroleum distillates do not fall under the category of organic solvents specified in the Ordinance for the Prevention of Organic Solvent Poisoning in the Labor Standards Act. The hydrocarbon-based solvent must have a low aroma content in the composition, and is preferably 1% or less. Further, the flash point of such a hydrocarbon-based solvent is preferably a temperature exceeding 70 ° C.

Examples of such low-aromatic hydrocarbon solvents include naphthesol L (manufactured by Nippon Oil Co., Ltd.) having a flash point of 57 ° C. and an aroma content of 1% or less, and an aroma content of 86 ° C. Naphthesol M (manufactured by Nippon Oil Co., Ltd.) of 1% or less, MCW-8 oil having a flash point of 162 ° C. and substantially containing no aroma (manufactured by Idemitsu Kosan Co., Ltd.), and the like.

These have a flash point of Class 4 Petroleum 2 or Class 4 Petroleum 3 under the Fire Service Law, but none of them after emulsification. Therefore, it differs greatly from the conventionally used, for example, mineral spirits which have a flash point equivalent to Class 4 and Class 2 petroleum under the Fire Service Law even after emulsification, and regulates the amount of storage or storage location and uses. There are no restrictions on the above notes. Further, since the hydrocarbon solvent according to the present invention has a low aroma content, it does not attack the rubber roller and the like. In the present invention, the hydrocarbon solvent is preferably an industrial liquid paraffin specified in JIS K2231, and particularly preferably MCW-8 oil (manufactured by Idemitsu Kosan Co., Ltd.).

Meanwhile, as the water for the printing machine cleaning liquid to be used have you to the present invention, generally tap water, ground water, it may be used ion-exchanged water or distilled water.

When the water-in-oil emulsion is prepared in the first washing liquid for a printing press of the present invention, the mixing ratio of the hydrocarbon solvent to water is 9/1 to 3/7, preferably 8/2 to 2/7.
It is within the range of 7/3. If the proportion of water is less than this range, the stability of the emulsion is good, but the effect is poor in terms of lowering flammability, removing hydrophilic stains, and improving economic efficiency, which is not preferable. On the other hand, when the amount of water exceeds the above range, the emulsion becomes unstable and the viscosity increases, and the washing effect of lipophilic soil is reduced, which is not preferable.

The first cleaning liquid for a printing press of the present invention is obtained by emulsifying the above-mentioned composition of a hydrocarbon solvent and water with a nonionic surfactant. This nonionic surfactant is only sorbitan fatty acid ester,
Alternatively, it is a mixture of a sorbitan fatty acid ester and an ethylene oxide-added nonionic activator.

The sorbitan fatty acid ester is a fatty acid ester of sorbitan including sorbit intramolecular dehydrates, including 1,4-sorbitan, 3,6-sorbitan, 1,5-sorbitan, and 1,4,3,6-sorbide. As a fatty acid, a fatty acid is used which comprises a saturated or unsaturated fatty acid having 10 to 18 carbon atoms, such as lauric acid, palmitic acid, stearic acid, oleic acid, capric acid, and myristic acid. be able to. Those having an HLB (hydrophilic-lipophilic balance) of less than 10, particularly in the range of 1.8 to 8.6 can be suitably used.

Examples of the ethylene oxide-added nonionic activator include ethers such as alkyl ethers, alkyl aryl ethers and alkyl thioethers, esters such as alkyl esters and sorbitan fatty acid esters, and alkylamines and amides. Those obtained by adding about 5 to 20 moles of ethylene oxide to adjust the HLB within the range of 3 to 20, especially 7 to 18 can be suitably used.

The sorbitan fatty acid ester and the ethylene oxide-added nonionic activator can be used in combination of two or more. Although the first washing liquid for a printing press of the present invention can be obtained by using only the sorbitan fatty acid ester, the sorbitan fatty acid ester and the ethylene oxide-added nonionic activator are preferably used in an amount of 9/1 to 6 /.
4, more preferably at a ratio of 8.5 / 1.5 to 7/3. If the above ratio is greater than 9/1 and the sorbitan fatty acid ester is in excess, phase separation of the washing solution may occur, and the required emulsion stability may not be obtained. On the other hand, when the above ratio is less than 6/4 and the amount of the ethylene oxide-added nonionic activator becomes excessive, the emulsion becomes thick and the desired fluidity cannot be obtained, and the adequacy of the washing liquid cannot be obtained.

Further, the first cleaning liquid for a printing press of the present invention comprises:
The nonionic surfactant is contained in a range of 0.5 to 10%, preferably 3 to 8%. If this amount is too small, a stable emulsion cannot be obtained, while if it is too large, the surfactant remains on the plate cylinder even after the solvent and water are removed after washing.
It remains on the surface of an inking roller, blanket impression cylinder, or the like, mixes with ink at the time of reprinting, and emulsifies, causing undesirable phenomena such as background stain and floating stain. Such inconveniences associated with the use of an excessive amount of surfactant should be particularly avoided in the case of an automatic cleaning system in which printing is performed immediately after washing with a washing solution without washing with water.

The first cleaning liquid for a printing press of the present invention can be used in an amount of 5 to 100 cps suitable for automatic cleaning involving spraying of the cleaning liquid through a spray nozzle by appropriately controlling the type and amount of the nonionic surfactant. The viscosity can be as low as possible.

The first washing liquid for a printing press of the present invention contains, in addition to the above-mentioned nonionic surfactant, other ordinary nonionic surfactants such as propylene oxide addition type and allyl ether or alkyl ether of polyethylene glycol. Can be added as needed, but in that case also the total amount of surfactant should not exceed the above range. The use of anionic or cationic surfactants should be avoided as much as possible because safety is likely to be impaired and there is a problem of corroding components such as a printing plate or a washing device.

Next, an example of the first method for producing a cleaning liquid for a printing press of the present invention will be described below. First, a hydrocarbon solvent is taken into a tank equipped with a homogenizer and a jacket for heating or warming, heated to about 45 to 55 ° C., the nonionic surfactant is added therein, and the homogenizer is used. After mixing and dissolving, without stopping the rotation of the homogenizer, a predetermined amount of water heated to substantially the same temperature as above is gradually added to prepare a water-in-oil emulsion. Further, after stirring is continued for 30 to 60 minutes while keeping the temperature at the above temperature, the mixture is cooled to room temperature and filled in a container. Temperature fluctuations up to the preparation of the emulsion should be avoided as much as possible, and it is preferable that the temperature difference between the solvent and water before mixing and the temperature difference during stirring after mixing be kept within ± 2 ° C.

Next, a description will be given of an oil-in-water emulsion cleaning liquid for a second printing press of the present invention, which is obtained by reverse emulsification of the water-in-oil emulsion cleaning agent of the present invention. The inverse emulsification is carried out by the following formula of 3 to 10% by weight based on the water-in-oil emulsion detergent of the present invention,

Embedded image (Wherein R is a nonyl group or octyl group, and n is 4-16
) And 3% by weight or more of water. As such polyoxyethylene alkyl phenyl ether, for example, the above polyoxyethylene nonyl phenyl ether and polyoxyethylene octyl phenyl ether wherein n is 8 are preferable.

The second cleaning liquid for a printing press of the present invention contains a polyoxyethylene alkylphenyl ether, which is a nonionic surfactant, in an amount of 3 to 10%, preferably 5 to 8%. If the amount is too small, a stable emulsion cannot be obtained, while if the amount is too large, the surfactant will remain on the plate even after the solvent and water have been removed after washing, as in the case of the first printing press washing liquid. Undesirable phenomena such as remaining on the surface of the body or the like occur.

In addition, the amount of water added at the time of reverse emulsification is as follows:
If the amount is less than 3% by weight, it is difficult to form an inverted emulsion. Incidentally, the washing liquid of the oil-in-water emulsion of the present invention,
When used, it can be diluted with a large amount of water, but the amount of water added during production is preferably 50% by weight or less from the viewpoint of economy. More preferably, 20 to 40
% By weight.

In the second method for producing a cleaning liquid for a printing press of the present invention, the cleaning liquid for a first printing press of the present invention produced as described above is placed in a tank provided with a homogenizer and a jacket for heating or warming. Heat to about 45-55 ° C,
The above polyoxyethylene alkylphenyl ether was added therein, and after sufficiently mixing with a homogenizer, without stopping the rotation of the homogenizer, a predetermined amount of water heated to substantially the same temperature as above was gradually added. Create an oil-in-water emulsion. Further, while keeping the temperature at the above temperature, 30
After stirring is continued for ６０60 minutes, the mixture is cooled to room temperature and filled in a container. As in the case of the first cleaning liquid for a printing press of the present invention, temperature fluctuations up to the preparation of the emulsion should be avoided as much as possible, and the temperature difference between the solvent and water before mixing and the temperature difference during stirring after mixing are ± It is preferable to keep the temperature within 2 ° C.

[0027]

Although the first and second cleaning liquids of the present invention can exhibit a high cleaning ability, they do not use a statutory Class 3 organic solvent, so that the equipment and work are regulated. You are not subject to the above restrictions.

The first printing press cleaning liquid of the present invention is a water-in-oil emulsion, which is particularly suitable for automatic cleaning of a blanket cylinder of an offset rotary printing press. That is, there are both oil-soluble stains such as ink and hydrophilic stains such as paper powder and clay powder as dirt attached to the blanket body surface. Washing is preferred. In this regard, a water-in-oil emulsion that can preferentially remove dirt that is difficult to remove among the dirt is ideal.

Further, when a part of the cleaning liquid remaining on the metal impression cylinder surface and the blanket cylinder surface during the cleaning adheres to the printing paper, if the printing paper is relatively poor in the aqueous predominant oil-in-water emulsion, the paper breaks. And it may not be possible to continue the cleaning operation thereafter. In this regard, since the first cleaning liquid for a printing press of the present invention is a water-in-oil emulsion, the problem of paper breakage during the cleaning operation can be almost completely prevented.

On the other hand, a water-in-oil emulsion, when diluted with water, tends to separate into an oil phase and an aqueous phase with time, and cannot be diluted with a large amount of water. It has an aspect that it is disadvantageous compared to the oil type emulsion. Thus, the second solution for printing press of the present invention has overcome this point. Since this is an oil-in-water emulsion instead of a water-in-oil emulsion, it can be diluted with water and is suitable for cleaning both lipophilic and oil-soluble stains.

The first and second cleaning liquids for a printing press of the present invention can be suitably used, for example, in an automatic cleaning apparatus disclosed in Japanese Utility Model Application Laid-Open No. 56-173450.

[0032]

Reference Example 1 155 parts of naphthesol L (manufactured by Nippon Oil Co., Ltd.) were taken as a hydrocarbon solvent in a tank equipped with a homogenizer, and 50
° C, and 10 parts of Nonion LP20R (manufactured by NOF Corporation), 3 parts of Nonion OT-221 (manufactured by NOF Corporation) and Pelletex N (manufactured by Miyoshi Corporation) as nonionic surfactants. (Made of oils and fats) and stirred at this temperature for 10 minutes at low speed.

Then, without stopping the homogenizer, 155 parts of water preheated to 50 ° C. was gradually added, and the mixture was stirred at a high speed for 30 minutes to obtain a water-in-oil emulsion. It was confirmed that this cleaning solution for a printing press was excellent in dissolving power, emulsifying and dispersing properties, and permeability.

[0034] Reference Examples 2 and 3 except that the above 50 parts the amount of water of Example 1 and 100 parts by following the procedure of Reference Example 1, Reference Example 2 and 3
A water-in-oil emulsion was obtained. It was confirmed that these cleaning fluids for printing machines were excellent in dissolving power, emulsifying dispersibility, and permeability.

[0035] Reference Example 4, Example 1 First, except for using a hydrocarbon-based solvent as MCW8 oil (Co., Ltd. Idemitsu Kosan) following the procedure of Reference Example 1, water-in-oil Reference Example 4 An emulsion was obtained. It was confirmed that this emulsion was excellent in dissolving power, emulsifying dispersibility, and permeability. Next, 15 parts of polyoxyethylene nonylphenyl ether (Nonal 208, manufactured by Toho Chemical Industry Co., Ltd.) was added to the emulsion of Reference Example 4, and the mixture was stirred at this temperature for 10 minutes at low speed.

Next, without stopping the homogenizer, water preheated to 50 ° C. was gradually added, and high-speed stirring was performed at this temperature for 30 minutes to obtain an oil-in-water emulsion of Example 1 . It was confirmed that this emulsion was excellent in dissolving power, emulsifying dispersibility, and permeability.

[0037] Examples 2 and 3 above Reference Example water-in-oil emulsion or found in Example 1 of 4
When preparing an oil-in-water emulsion of
The same operation as in Example 1 was carried out except that 0 parts and 400 parts were used, whereby oil-in-water emulsions of Examples 2 and 3 were obtained. These cleaning fluids for printing machines have dissolving power, emulsifying dispersibility,
It was confirmed that it had excellent permeability.

The cleaning performance of each of the above Reference Examples 1 to 4 and Examples 1 to 3 was evaluated. The evaluation method is as follows. 5 parts of newsprint paper powder was added to and mixed with 100 parts of the offline ink, and the mixture was spread thinly on a metal plate with a roller and heated in an oven at 150 ° C. for 20 minutes. Next, the metal plate was cut into a small width and immersed in a test cleaning solution for 1 hour, and the surface in contact with the cleaning solution was wiped with a cloth, and the cleaning ability was evaluated from the cleaned state of the metal surface. In addition, as a comparative example, the conventional one using only water (Comparative Example 1) and the one using mineral spirits as the organic solvent (Comparative Example 2) were also evaluated. The results obtained are shown in Table 1 below.

[0039]

[Table 1]

As can be seen from Table 1, it was confirmed that the cleaning liquid for a printing press of the present invention exhibited the same high cleaning ability as the cleaning liquid using a legal organic solvent for both the water-in-oil emulsion and the oil-in-water emulsion. Was done.

[0041]

As described above, the cleaning liquid for a printing press of the present invention is defined as a hydrocarbon-based solvent in both a water-in-oil type emulsion and an oil-in-water type emulsion in accordance with the Ordinance on the Prevention of Organic Solvent Poisoning of the Labor Standards Act. A petroleum distillate that does not fall under the category of organic solvents, and uses an organic solvent with a low aroma content in the composition.Therefore, equipment and operations are not restricted by laws and regulations, and they can also damage rubber rollers, etc. Absent. Nevertheless, it is possible to exhibit the same high cleaning performance as a cleaning liquid for an emulsion type printing press using a legal organic solvent.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI C11D 7:50 C11D 7:50 7:26) 7:26) (56) References JP-A-59-33396 (JP, A) JP-A-60-38499 (JP, A) JP-A-63-133000 (JP, A) JP-A-57-202399 (JP, A) JP-A-5-331492 (JP, A) JP-A-54-63108 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C11D ^7/ 00-7/50 B41N 3/06 B41F 35/00

Claims (3)

(57) [Claims] 1. An oil obtained by emulsifying a composition of a hydrocarbon solvent and water in a weight ratio of 9/1 to 3/7 with 0.5 to 10% by weight of a nonionic surfactant. Water type d
The following formula of 3 to 10% by weight with respect to the marsion : (Wherein R is a nonyl group or octyl group, and n is 4-16
Polyoxyethylene alkylpheny represented by
And emulsified by adding 3% by weight or more of water
Cleaning fluid for printing press consisting of oil-in-water emulsion
And a petroleum distillate having a hydrocarbon solvent having a 50% distillation temperature of more than 180 ° C., wherein an aromatic hydrocarbon content in the composition is 1% by weight or less . 2. The composition according to claim 1, wherein the nonionic surfactant is 9% by weight.
The cleaning liquid for a printing press according to claim 1, wherein the cleaning liquid is a mixture of a sorbitan fatty acid ester of / 1/6/4 and an ethylene oxide-added nonionic activator. 3. The cleaning liquid for a printing press according to claim 1, wherein the hydrocarbon solvent is industrial liquid paraffin.