JP3195092B2 - Cleaning agent for blanket of offset printing press - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning agent for a blanket of an offset printing machine. More specifically, an offset printing machine that is inexpensive, has high detergency against ink and paper powder, has good drying properties, has good workability such as not swelling blanket rubber, and has extremely low toxicity and environmental pollution. And a hydrocarbon-based cleaning agent for blankets.

[0002]

2. Description of the Related Art In an offset printing press, it is necessary to wash and remove ink stains when the printing press is stopped. However, in addition to ink, contaminants such as paper powder adhere to the blanket portion. It is necessary to wash and remove paper powder and the like together with the ink. Here, the blanket is made of rubber, and its cleaning requires different considerations from those of a normal printing press. Conventionally, hydrocarbon oils such as gasoline, mineral spirits and kerosene, and chlorine solvents such as trichloroethylene have been used as blanket cleaners for offset printing presses. However, hydrocarbon oils such as kerosene have a poor effect of removing paper dust, swell the blanket rubber, and have problems such as flammability and toxicity.
If a high-boiling hydrocarbon oil is used to ensure safety such as flammability, the cleaning effect becomes insufficient and the drying property after cleaning deteriorates. On the other hand, a chlorine-based solvent has a cleaning effect, but is not preferable because it has a problem of environmental pollution. In order to solve these problems, conventionally, for example, the printing ink is first removed with a hydrocarbon oil, and then the paper powder is washed with water.
A step cleaning method is employed, which results in a long cleaning time and poor workability.

Therefore, as a cleaning agent for washing in one step, for example, Japanese Patent Publication No. 3-79399 proposes an emulsion comprising a hydrocarbon solvent, water and a surfactant. JP-A-60-179499 discloses a boiling point of 15
A cleaning agent containing alcohol and water in a petroleum hydrocarbon at 0 to 300 ° C has been proposed. However, although these cleaning agents can be washed in one step, they are not always satisfactory in terms of workability and economy because they are mixed solvents. Further, in the case of the above-mentioned Japanese Patent Application Laid-Open No. 60-179499, since kerosene, which is a mere petroleum fraction, is used, alcohol or water must be added in order to exert sufficient detergency. There was nothing.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a single solvent, which is capable of washing and removing paper powder at the same time as ink, has good drying properties after washing, and swells blanket rubber. An object of the present invention is to provide a cleaning agent for a blanket of an offset printing press, which can develop a cleaning agent which is less flammable and less toxic, and which can shorten the cleaning time, improve the workability, and reduce the cost of cleaning.

[0005]

Means for Solving the Problems The present inventors have made intensive studies in view of the above problems, and as a result, have found that the above problems can be solved by using a cleaning agent comprising a specific hydrocarbon mixture solvent. It came to accomplish. That is, the present invention provides a method for converting petroleum using a metal catalyst for hydrogenation of an aromatic nucleus at a pressure of 30 to 100 kg / cm ² and a temperature of 100 to 3 kg.
An offset consisting of a hydrocarbon mixture solvent having an aromatic hydrocarbon content of 3% or less and a boiling point in the range of 150 to 200 ° C. obtained by subjecting to a nuclear hydrogenation treatment at 00 ° C. and then performing precision distillation. It is a blanket cleaner for printing presses. ADVANTAGE OF THE INVENTION According to the cleaning agent of this invention, it is possible to wash ink and paper dust dirt simultaneously with one liquid, the drying property after washing is good, there is little swelling of a blanket rubber etc., and the flammability is relatively low. It is low and has little toxicity because it contains almost no aromatic components.

[0006] The cleaning agent of the present invention is obtained by hydrogenating a petroleum fraction such as kerosene under high pressure with a metal catalyst for the nuclear hydrogenation of aromatic nuclei, and hydrogenating an aromatic compound contained in petroleum to obtain naphthene. It is obtained by a production method such as precision distillation after conversion into a system or other hydrocarbon. As the catalyst, any conventionally known aromatic hydrogenation catalyst can be preferably used. For example, nickel, nickel oxide, nickel / diatomaceous earth, Raney nickel, nickel / copper, platinum, platinum oxide, platinum / activated carbon, platinum / rhodium, platinum / alumina, platinum / lithium / alumina, rhodium / activated carbon, palladium / cobalt, Raney cobalt, ruthenium, tungsten sulfide / nickel sulfide / alumina, cobalt / molybdenum and the like can be preferably used.

The pressure is 30 to 100 kg / cm ² and the temperature is 100 to 300 ° C. At a pressure lower than 30 kg / cm ² or at a temperature lower than 100 ° C., the hydrogenation does not proceed sufficiently, and at a pressure higher than 100 kg / cm ² or at a temperature higher than 300 ° C., side reactions such as decomposition take precedence. . The processing time is determined as appropriate. Hydrogenation can be appropriately performed in two or more stages.

[0008] The aromatic component needs to be 3% or less. If it exceeds 3%, the cleaning property is reduced, and it becomes impossible to sufficiently clean paper dust. Moreover, it is not preferable in terms of toxicity. As the fraction, the boiling point is 150 to 200
It is important that the hydrocarbon mainly contains hydrocarbons in the range of ° C. If the boiling point is lower than this, flammability increases and there is a safety problem. On the other hand, if the boiling point is higher than this range, the detergency deteriorates and the drying property after the cleaning deteriorates. The boiling point range of the fraction is 50 ° C. or lower, preferably 30 ° C. or lower. The narrower the boiling point range, the higher the detergency of paper powder and the like, and the better the drying property after cleaning. The boiling point range of the fraction indicates the difference between the initial boiling point and the dry point by ASTM distillation (simple distillation).

The cleaning agent of the present invention may contain trace amounts of components normally contained in petroleum, such as sulfur compounds and nitrogen compounds other than hydrocarbons. Further, other components such as alcohols and surfactants may be added for use. Further, the method of using the cleaning agent of the present invention can be performed in one step in the same manner as in the conventional cleaning agent.

[0010]

The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. First, the test method used in the examples will be described. (Detergency test) Using an actual printing machine, the printed ink was adhered onto blanket rubber after printing, and dried ink and paper powder were wiped off with a cleaning agent contained in a cloth, and evaluated by the number of wiping operations until completely removed. The smaller the number of wiping operations, the higher the cleaning power. (Dryability test) Put 0.3 ml of detergent into a glass dish,
The weight loss was measured and measured in a room at 3 ° C. and a humidity of 43%. And it evaluated by the rate of evaporation and drying. (Rubber Swelling Test) A blanket rubber for a printing press and a test piece of a rubber roller were immersed in a cleaning agent, and the weight change before and after immersion at room temperature (25 ° C.) for a predetermined time was evaluated.

(Production Example) A kerosene fraction having a boiling range of 150 to 280 ° C. obtained by distillation of crude oil (aromatic hydrocarbon 1)
0% by weight) at 280 ° C. and 90 kg / cm ² under hydrogenation using a nickel / tungsten catalyst, and the resulting product is subjected to precision distillation using a precision distillation apparatus to obtain a product having a boiling point range of 150 to 179 ° C. A fraction was obtained. The aromatic content of this fraction was 1.9%. The difference between the initial boiling point and the dry point was 29 ° C.

(Example) In the above production example, the aromatic content obtained by catalytic hydrogenation of kerosene was 1.9%, and the boiling point was 150-1.
A detergency test was performed using a hydrocarbon oil at 79 ° C. The results were evaluated by the number of times of wiping and are shown in Table 1. As a result, both the ink and the paper dust could be easily removed. Further, a drying test of the hydrocarbon oil was performed. The results are shown in FIG. 1, and it is clear that the drying speed is high. Further, the results of a rubber swelling test of the hydrocarbon oil were performed. The results are shown in Table 2, and it is clear that the degree of swelling is small.

Comparative Example 1 White kerosene having a boiling point of 175 to 285 ° C. (aromatic content 10.2%, difference between initial boiling point and dry point is 11)
(0 ° C.). The results are also shown in Table 1 in the same manner as in the examples. However, although the ink could be easily removed, paper dust was not able to be removed even by wiping 20 times. The drying test results of the above white kerosene were performed. The results are also shown in FIG. 1, but the drying speed was lower than in the examples. The rubber swelling test of the white kerosene was performed. Table 2 shows the results
As described above, the degree of swelling is large for both the blanket rubber and the rubber for the rubber roller.

Comparative Example 2 White kerosene 10 used in Comparative Example 1
0 parts by volume of 5 parts by volume of n-butanol and 20 parts of water
Table 1 also shows the results of a detergency test conducted using the mixed solvent to which 0 parts by volume was added. Although this mixed solvent had good detergency against ink and paper powder, water was separated and storage and workability were poor.

[0015]

[Table 1]

[0016]

[Table 2]

[0017]

EFFECT OF THE INVENTION The cleaning agent for a blanket of an offset printing machine according to the present invention has excellent detergency against both ink and paper powder, has good drying properties, and does not swell blanket rubber. In addition, since it is made of a single solvent, it has good workability, and has low toxicity and is inexpensive, so that it has great industrial utility value.

[Brief description of the drawings]

FIG. 1 is a graph showing a drying rate of a cleaning solvent.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C11D 7/50 B41N 3/06 C11D 7/24

Claims (1)

(57) [Claims] 1. A method according to claim 1, wherein the petroleum is subjected to a pressure of 30 to 100 kg / cm ² and a temperature of 100 using a metal catalyst for hydrogenation of an aromatic nucleus.
The content of aromatic hydrocarbon obtained by nuclear hydrogenation treatment at ~ 300 ° C and then precision distillation is 3%
A cleaning agent for a blanket of an offset printing press, comprising: a hydrocarbon mixture solvent having a boiling point in the range of 150 to 200 ° C.