JPS5842213B2 - Inkroll manufacturing method - Google Patents

Description

[Detailed description of the invention] The present invention relates to a novel method for manufacturing ink rolls.

More specifically, a porous body with continuous ultra-fine pores is obtained by producing irregularly shaped fine powder of thermoplastic elastomer, and then sintering the fine powder. It is about the manufacturing method of large ink rolls, and includes desk calculators and typewriters.
, Register, 7-L/Tice This invention provides an improved ink roll for supplying ink to the typeface of printers incorporated into various devices such as computers.

In recent years, line printers have been increasingly adopted due to the demand for high-speed typing.

However, in line printers, which are completely different from conventional typing methods, it is necessary to supply ink to the entire surface of the type incorporated in a drum that rotates at high speed, and the ink roll used for this is also rotated at high speed and inside the drum. It must be such that the ink contained in it can be constantly oozed out in an appropriate proportion, neither excessive nor insufficient, and the ink-containing capacity must be sufficient, and it must be durable in itself. It is required to be of excellent quality.

As described above, ink rolls used in single-type line printers are required to have the above-mentioned specific performance. To date, there has been no satisfactory solution.

The inventor of the present invention has conducted various researches in order to obtain ink rolls used especially in one-type line printers.
We have discovered that a porous body with continuous ultra-fine pores obtained by sintering irregularly shaped fine powder of thermoplastic elastomer has all the performances necessary for an ink roll used in a one-type line printer, and we have published this book. He completed his invention.

The present invention sprays an organic solvent solution of a thermoplastic elastomer to form fine particles, removes the organic solvent contained in the fine particles to obtain irregularly shaped fine powder, and then sinters the fine powder to make it continuous. The present invention relates to a method for manufacturing an ink roll made of a porous body characterized by scaling a porous body having ultra-fine pores.

The present invention can be applied, for example, when a dimethylformamide solution of a polyester-type thermoplastic polyurethane elastomer is sprayed into water to form fine particles, and the dimethylformamide contained in the fine particles is extracted with water, or when a polyester-type thermoplastic polyurethane elastomer is After adding a foaming agent to the polyurethane elastomer, it is dissolved in dimethylformamide, which is sprayed to form a fine powder, and the dimethylformamide contained in the fine powder is removed by heating to form a fine powder, which is then heated and foamed. The knowledge that the fine powder obtained by this process becomes fine powder of various irregular shapes as shown in Fig. 1, and the fact that the fine powder obtained as described above is filled into a certain mold. (Irregularly shaped fine powders may be packed by collecting pieces of the same shape, or may be filled by mixing pieces of irregular shapes) The porous body is heated and sintered to form a sponge structure. The knowledge that it has irregular continuous ultra-fine pores based on the irregular shape of the powder (butadiene rubber, styrene-butadiene rubber, acrylonitrile-
The same phenomenon was observed for butadiene rubber).

The ink roll obtained by the method of the present invention is made from a porous body having continuous ultra-fine pores obtained by first turning a thermoplastic elastomer into irregularly shaped fine powder and then heating and sintering it. It should be noted that an ink roll having the various features of the present invention cannot be obtained without the steps of obtaining such irregularly shaped fine powder and further heating and sintering it.

Next, an ink roll obtained by the method of the present invention will be explained based on FIG.

FIG. 2 is a sketch showing one embodiment of the ink roll, which includes a roll 1 made of a continuous porous material and having an appropriate length, and a shaft 2 provided in the center according to the purpose. Consisting of

Thermoplastic elastomers used in the present invention include acrylonitrile-butadiene rubber, styrene-butadiene rubber, butadiene rubber, and polyester-type and polyether-type polyurethane elastomers.

Among the polyurethane elastomers, polyester-type diphenylmethane diisocyanate-crosslinked polyurethane elastomers, which have particularly good heat resistance and cold resistance, and are physically and chemically stable, are preferably used.

Note that these thermoplastic elastomers can be used as a mixture of two or more types depending on the type, and
A thermoplastic synthetic resin such as polyvinyl chloride or vinyl chloride-vinyl acetate copolymer may be appropriately mixed with these thermoplastic elastomers.

Next, a method for obtaining irregularly shaped fine powder will be explained.

As exemplified above, irregularly shaped fine powder can be obtained by, for example, (1) dissolving a thermoplastic elastomer in an organic solvent and spraying it without melting the thermoplastic elastomer, and what is the solvent that melts the thermoplastic elastomer? A method is to spray the thermoplastic elastomer into a compatible solvent to make it into fine particles and extract the organic solvent contained in the fine particles, or to make the thermoplastic elastomer into fine particles by first spraying the organic solvent solution onto the roll surface, etc. (2) Adding a blowing agent to a thermoplastic elastomer, dissolving it in an organic solvent, and blowing it with a spray. Attach it to make it into fine particles,
It can be obtained by removing the organic solvent contained in the fine particles and then heating and foaming them.

In the present invention, the organic solvents used to dissolve the thermal elastomer include dimethylformamide, dimethylacetamide, tetrahydrofuran,
Tetrachloroethylene, methyl ethyl ketone, etc. may be used alone or in combination of two or more thereof.

In addition, as a solvent used to extract the organic solvent, that is, a solvent that does not dissolve the thermoplastic elastomer and is compatible with the solvent that dissolves the thermoplastic elastomer, there are types of organic solvents that dissolve the thermoplastic elastomer. Water or alcohols are particularly preferably used because they are inexpensive and have good compatibility with the solvent that dissolves the thermoplastic elastomer.

In addition, the size of the fine powder is such that the average particle size is 1 to 500μ,
In particular, it is preferable to set the thickness to 10 to 200μ.

If the average particle size of the fine powder is smaller than the above range, the fine powder will become spheroidal and will not be able to maintain its irregular shape; The pore diameter of the resulting continuous porous material becomes too large, and when an ink roll made from the continuous porous material is used, it tends to become impossible to print clearly.

Next, the fine powder obtained as described above is filled into a certain mold and heated and sintered. Regarding the type of fine powder, particle size, shape, etc., the same type of fine powder can be used alone, or two or more types of different types can be used as a mixture.

The conditions for heating and sintering are 150 to 200°C, which is the melting temperature of thermoplastic elastomer fine powder that is normally sintered.
The method is applied for about 5 to 30 minutes within the temperature range of .

In the present invention, the ink roll is produced by forming the porous body having continuous ultra-fine pores obtained as described above into a roll shape to form the roll 1, or by filling a roll-shaped mold with fine powder during sintering. sintered to make roll 1, which was then attached to shaft 2.
It can be obtained by fitting the powder into a mold, or by filling a roll molding die equipped with a shaft 2 with fine powder and sintering it.

In the ink roll obtained by the method of the present invention, the roll 1 is made of a porous material having irregularly shaped continuous ultra-fine pores, so it has a large ink-containing capacity and capillary action is easy to act. It is durable because it can continuously ooze out in the right amount, and it has unique features such as extremely clear printing, and is highly elastic, oil resistant, heat resistant, dimensionally stable, It also has excellent abrasion resistance.

Next, the present invention will be explained with reference to Examples.

Example 1 Polyester type thermoplastic polyurethane elastomer (
Diphenylmethane diisocyanate cross-linked type) 21 was dissolved in 98 grams of dimethylformamide to obtain a dimethylformamide solution of polyurethane elastomer with a concentration of 2% (weight 6 or less).

While maintaining the solution at 30°C, spray at a temperature of 30°C.
The particles were sprayed into a 10% dimethylformamide aqueous solution to form fine particles, the dimethylformamide contained in the fine particles was extracted, the fine particles were collected, washed with water, dried at a temperature of 60°C for 30 minutes, and the average particle size was A fine powder of about 20μ was obtained.

Next, the obtained fine powder 3.51 was filled into a roll forming mold with a space volume of 10 m1 equipped with a shaft with a diameter of 15 mm and a length of 55 mm, and sintered at a temperature of 150°C for 30 minutes to form continuous ultra-fine pores. An ink roll made of a porous body with high elasticity and high porosity was obtained.

Example 2 A solution of the same polyurethane elastomer in dimethylformamide as in Example 1 was sprayed onto the surface of a stainless steel roll having an irregular surface with fine irregularities, and the irregular irregularities on the roll surface were transferred. Make it into fine particles,
It is introduced into water and peeled off from the roll surface to collect the fine particles, and then immersed in a 10-polymer dimethylformamide aqueous solution at a temperature of 30°C to extract the dimethylformamide contained in the fine particles, and then collect the fine particles. , washed with water, and dried at a temperature of 60° C. for 30 minutes to obtain a fine powder with an average particle size of about 50 μm.

Next, the obtained fine powder was sintered in the same manner as in Example 1 to obtain an ink roll similar to that in Example 1.

Example 3 A dimethylformamide solution of the same polyurethane elastomer as in Example 1 was sprayed onto the roll surface as in Example 2 while supplying water to transfer irregular irregularities on the roll surface into fine particles. Thereafter, by the same method as in Example 2, a fine powder with an average particle size of about 550 μm was obtained.

Next, the obtained fine powder was sintered in the same manner as in Example 1 to obtain an ink roll similar to that in Example 1.

Example 4 Polyester type thermoplastic polyurethane elastomer 1
Add 10g of powdered sodium bicarbonate to 001 and make 40-5
After kneading on a roll heated to 0° C., the mixture was dissolved in dimethylformamide to make a solution with a concentration of approximately 0%.

This was sprayed into a sealed container at 50 to 100° C., and the resulting fine particles were subjected to slight vibrations to evaporate the solvent while avoiding fusion, thereby mixing and dispersing the foaming agent.

This fine material was rapidly foamed at 130-150° C. for 5-10 minutes and rapidly cooled to obtain a fine powder with an average particle size of about 180 μm.

Next, the obtained fine powder was sintered in the same manner as in Example 1 to obtain an ink roll similar to that in Example 1.

Comparative example polyvinyl chloride powder 20? , Dioctylphthalate 10L? , 251 parts of calcium carbonate, 431 parts of baking soda, and 2 grams of white carbon were mixed and kneaded with two rolls to make a paste, which was filled into the same mold by the same method as in Example 1 and heated at 180°C for 30 minutes. Heated.

After cooling, the mold was removed and immersed in a heated 6N hydrochloric acid aqueous solution to extract calcium carbonate. After washing with water, the mold was heated at 50°C.
After drying for 24 hours, an ink roll was obtained.

Test Examples The ink rolls obtained in Examples 1 to 4 and Comparative Examples were impregnated with appropriate inks, and the ink content was measured. Results of printing with each ink roll using a desktop printer and clear characters were obtained. Table 1 shows the results of measuring the limit values and the density of characters printed at temperatures of -20°C and 80°C.

As shown in Table 1, the ink rolls obtained by the method of the present invention are highly durable, have little difference in print density between -20°C and 80°C, and have excellent heat resistance and cold resistance.

Further, in general, the higher the temperature, the softer the roll becomes, the more ink oozes out, and the printed characters tend to become thicker and smudged.This problem was not observed in the ink roll of the present invention.

[Brief explanation of drawings]

FIG. 1 is an enlarged sectional view of a fine powder of a polyester type thermoplastic polyurethane elastomer according to the present invention, and FIG. 2 is a sketch showing an embodiment of an ink roll according to the present invention. Symbols in the drawing: 1: Roll, 2: Axis.

Claims (1)

[Claims] 1 Spray an organic solvent solution of a thermoplastic elastomer to form fine particles, remove the organic solvent contained in the fine particles to obtain irregularly shaped fine powder, and then sinter the fine powder to form continuous ultra-fine pores. A method for producing an ink roll made of a porous body characterized by scales.