JP6673548B2 - Fabric ribbon for dot impact printer - Google Patents

Description

  The present invention relates to a fabric ribbon for a dot impact printer.

  Dot impact printers have been widely used in recorders, time card recorders, financial terminals, etc. because they have high operational stability and are easy to maintain, such as requiring less frequent replacement of supplies such as fabric ribbons. I have.

  As described above, in various usage methods, particularly in use in a time card recorder or a financial terminal, a recording medium such as a time card or a bankbook is repeatedly inserted into the slot of the time recorder or the financial terminal each time it is used, Printing is carried out after being transported to the predetermined position of the built-in dot impact printer by the transport rubber roll, and then transported by the transport rubber roll in the same transport path as the insertion direction in the opposite direction and discharged from the insertion slot for discharge. Is done. In this manner, in a time card recorder or a financial terminal having a printing mechanism for performing printing by repeatedly using a recording medium and performing insertion and ejection by a rubber roll for conveyance, a printing surface of a recording medium and a rubber roll for conveyance are used. In order to make repeated contact, the ink adheres little by little to the transfer rubber roll from the printing surface, and the oil and the like contained in the attached ink are absorbed by the transfer rubber roll, so that the transfer rubber roll swells and the transfer rubber roll If the outer diameter increases and the outer diameter of the transfer rubber roll increases beyond a certain level, an error occurs in the control of the transfer position of the recording medium, and printing is performed in a place different from the place where printing should originally be performed. In some cases, printing defects occurred.

  Particularly, in recent years, inexpensive ethylene-propylene-diene terpolymer (EPDM) which is excellent in abrasion resistance and weather resistance and is inexpensive from urethane rubber which has been conventionally used as a rubber used for a rubber roll for transporting a printer. The thing which used system rubber has come to be used a lot. However, EPDM rubber has excellent properties as described above, but has a disadvantage that it is inferior in oil resistance. Therefore, when ink adheres to the transfer rubber roll as described above, the transfer rubber roll easily swells, The problem that a printing defect is caused as a result frequently occurs.

  In order to solve such a printing problem caused by the swelling of the conveying rubber roll by the oil agent, in JP-A-2014-133382 and the like, a feed roller made of EPDM is immersed in various oil agents and fed. The oil agent that reduces the outer diameter swelling ratio of the roller is selected, and as a result, an oil agent containing at least one of castor oil fatty acid ester, trimet acid ester, aluminum coupling agent, and sorbite fatty acid ester as the oil agent in the ink is used. Ink ribbons for impact printers have been proposed.

JP-A-2014-133382

  The present invention further examines an oil agent which does not easily swell EPDM rubber with respect to an oil agent which is a main component of an ink vehicle used for a fabric ribbon as in Patent Literature 1, and relates to a dot impact printer using EPDM rubber for a transfer rubber roll. It is a main object to provide a fabric ribbon for a dot impact printer impregnated with ink which causes less printing defects due to swelling of a transport rubber roll by an oil agent.

  In order to solve these problems, the present inventor has developed a fabric ribbon for a dot impact printer which is composed of at least a colorant, a surfactant, and an oil agent, and the main component of the oil agent is an ink impregnated with a medium-chain fatty acid triglyceride. Invented. With this configuration, the amount of ink absorbed by the EPDM rubber transport rubber roll is small, and it is possible to suppress the occurrence of printing defects due to swelling of the EPDM rubber transport rubber roll due to the oil contained in the ink.

  When the fabric ribbon for a dot impact printer of the present invention is used, in a dot impact printer using EPDM rubber for a transfer rubber roll, even if ink adheres to the transfer rubber roll, the transfer rubber roll swells due to the oil agent in the ink. As a result, printing defects caused by swelling of the transfer rubber roll do not occur.

  The ink used for the fabric ribbon in the present invention is composed of at least a colorant such as a dye or a pigment, a surfactant that functions for dispersion of the pigment or stability of the paint, and an oil agent that is a main component of the vehicle of the ink.

  Further, depending on the need for required quality and applications, as a raw material of the ink, various inorganic fillers and organic fillers, organic acids such as fatty acids as dye solubilizers, various oil-soluble resins and various elastomers, various dispersion aids, Various lubricants, various additives, and the like may be added, but are not limited thereto.

  Various dyes and various pigments can be used as the colorant used in the ink of the fabric ribbon of the present invention. The ink for fabric ribbon in the present invention may be any of a dye-based ink using only a dye, a pigment-based ink using only a pigment, and a dye-pigment-based ink using both a dye and a pigment.

  As the dye used in the ink for fabric ribbon of the present invention, one or more dyes such as nigrosine dye, methyl violet and oil black can be used.

  When a dye is used as a colorant for an ink, it is common to use various long-chain fatty acids such as oleic acid and stearic acid as a dye dissolving agent, and dissolve the dye in the long-chain fatty acid. Since EPDM rubber has poor resistance to organic acids such as fatty acids, it is preferable to use a dye dissolving agent as little as possible when using it in inks. It is preferable to keep it to 20%.

  As the pigment used for the ink of the fabric ribbon of the present invention, one or more of inorganic pigments such as carbon black and organic pigments such as aniline black, phthalocyanine blue and disazo yellow can be used.

  The amount of the colorant used in the ink of the fabric ribbon of the present invention is not particularly limited, but is preferably in the range of 10 to 40% by mass, more preferably 20 to 30% by mass of the whole ink. More preferred. When the amount of the coloring agent added is within the above range, it is easy to obtain an ink having an appropriate print density and an appropriate ink fluidity and hardly causing a reduction in print life.

  As the surfactant used for the ink of the fabric ribbon of the present invention, various known surfactants can be used. Surfactants serve not only as a wetting agent / dispersing agent to improve the wetting / dispersing properties of solid fine particles such as pigments, but also as a pigment dispersing agent and for imparting stability to paints. It also serves as a regulator, dye dissolving agent, compatibilizer, solubilizer, and antistatic agent.

  Examples of the surfactant that can be used in the ink of the fabric ribbon of the present invention include, for example, various carboxylate surfactants, various sulfonate surfactants, and various sulfate ester surfactants as anionic surfactants. Activators, various phosphate ester type surfactants and the like can be used. As the cationic surfactant, an alkylamine salt type surfactant, a quaternary ammonium salt type surfactant and the like can be used in the ink for fabric ribbon of the present invention. As the amphoteric surfactant, a carboxybetaine type surfactant, a 2-alkylimidazoline derivative type surfactant, a glycine type surfactant, an amine oxide type surfactant and the like can be used for the ink for fabric ribbon of the present invention. Examples of nonionic surfactants include ester surfactants such as glycerin fatty acid ester, sorbitan fatty acid ester and sucrose fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene polyoxypolypropylene glycol, and the like. Ether surfactants, ester ether surfactants such as fatty acid polyethylene glycol and fatty acid polyoxyethylene sorbitan, and alkanolamide surfactants such as fatty acid alkanolamide can be used in the fabric ribbon ink of the present invention. The above-mentioned surfactants can be used alone or in combination of two or more depending on the intended use, and usable surfactants are not limited to the above-mentioned surfactants.

  The amount of the surfactant used in the ink of the fabric ribbon of the present invention is preferably in the range of 5 to 40% by mass, more preferably 10 to 30% by mass of the whole ink. When the amount of the surfactant is within the above range, it is possible to obtain an ink excellent in pigment dispersion and paint stability.

  Depending on the type of surfactant used in the ink of the fabric ribbon of the present invention, there is a substance which greatly affects swelling of EPDM rubber or shrinkage due to elution of components in EPDM rubber. It is necessary to consider in advance the use of a surfactant that does not swell or shrink the rubber, and it is preferable to keep the addition amount to the minimum necessary.

  The oil agent in the ink of the fabric ribbon of the present invention is a main component of the vehicle that greatly affects the viscosity, viscosity, storage stability, dispersibility of pigments and dyes of the ink. The amount of addition is not particularly limited, but is generally added in an amount of about 30 to 70% by mass of the entire ink.

  Oil agents used in general fabric ribbon inks are liquid, hydrophobic and non-drying substances at room temperature, and specific examples thereof include various known vegetable oils such as olive oil and various kinds of oils. Animal oils, various mineral oils such as liquid paraffin, various poly-α-olefin synthetic oils, various hydrocarbon ester synthetic oils such as polyol esters such as monoesters, diesters and fatty acid triglycerides, etc. One or more of these oil agents may be selected and used.

  As a result of intensive studies conducted by the present inventors, the use of medium-chain fatty acid triglyceride as an oil agent used as an oil agent in the fabric ribbon ink of the present invention can suppress swelling of EPDM rubber by the ink. found.

  The medium-chain fatty acid triglyceride used as an oil agent in the ink for fabric ribbon of the present invention refers to an oil formed by ester-bonding glycerin and three medium-chain fatty acids having 8 to 12 carbon atoms. Medium-chain fatty acid triglycerides are a type of fatty acid ester often contained in natural fats and oils such as coconut oil and coconut oil, but if they are used as they are, they will also contain a large amount of impurities and triglycerides composed of long-chain fatty acids, leading to variations in performance. Or, since the solid or fluidity at room temperature becomes extremely poor and the usability is poor, the ratio of the medium-chain fatty acid composition to the entire fatty acid composition of fatty acid triglyceride from natural coconut oil or the like is used as the oil agent used in the present invention. It is preferable to use a refined medium-chain fatty acid triglyceride oil purified to at least 90% or more, or a synthetic medium-chain fatty acid triglyceride oil having 100% of medium-chain fatty acid triglyceride chemically synthesized from glycerin and medium-chain fatty acid.

  The component of the medium-chain fatty acid triglyceride used in the ink for a fabric ribbon of the present invention is not particularly limited, but is more preferably a medium-chain fatty acid triglyceride comprising at least one of caprylic capric acid triglyceride or caprylic capric laurate triglyceride. Preferably, it is used, and more preferably, caprylic capric triglyceride is used. Use of these medium-chain fatty acids makes it possible to produce fabric ribbons with less swelling of EPDM rubber, good pigment dispersibility and paint stability, and inks with appropriate viscosity and long print life. Becomes

  The viscosity of the medium-chain fatty acid triglyceride used in the ink of the fabric ribbon of the present invention is not particularly limited, and any viscosity can be used as long as it is liquid at room temperature and has an appropriate fluidity. The viscosity can be measured using a vibration viscometer according to JIS Z8803 (2011). The viscosity at 25 ° C. is preferably in the range of 1 to 80 mPa · s, and more preferably in the range of 1 to 40 mPa · s. When the viscosity of the medium-chain fatty acid triglyceride is within the above range, the prepared ink has an appropriate viscosity, the fluidity of the ink is secured, and it becomes easy to prepare a fabric ribbon having a long printing life.

  The amount of medium-chain fatty acid triglyceride used in the ink of the fabric ribbon of the present invention is not particularly limited, but is preferably 30 to 70% by mass, more preferably 40 to 60% by mass of the whole ink. It is more preferable to be performed. At this time, the medium-chain fatty acid triglyceride needs to be added at least 50% by mass or more of the whole oil agent, more preferably 90% by mass or more, and most preferably the whole amount of the oil agent is medium-chain fatty acid triglyceride. . When the amount of the medium-chain fatty acid triglyceride added to the ink is within the above range, it is easy to produce a fabric ribbon having a small print swelling, a moderate viscosity of the ink, and a long printing life.

The following is a summary of typical ink formulations used in the above-described fabric ribbon for a dot impact printer of the present invention.
<Components><% by mass>
Colorant (pigment / dye) 10-40
Surfactant (dispersant, wetting agent, viscosity modifier) 5-40
Oil agent 30-70
Dye solubilizer (organic acid, etc.) 0-20
Oil-soluble resin / rubber / elastomer 0-10
Various additives 0-5

  The ink used for the fabric ribbon of the present invention is prepared by kneading and dispersing the above-described raw materials of the ink mixture using a three-roll mill or the like. In general, the viscosity of the ink impregnated in the fabric ribbon is required to be within a certain range, and if the viscosity is too low, the paper may become dirty due to slight contact between the fabric ribbon and the paper, There is a tendency that the transferability of the ink is too good and the print life is shortened. Conversely, if the viscosity of the ink is too high, the fluidity of the ink will be too poor. And a problem such as shortening of the printing life tends to occur. It is preferable that the ink prepared from the above have a viscosity within a certain range, and the viscosity of the ink used in the present invention is 100 to 6000 mPa · s at 25 ° C. by a vibration viscometer according to JIS Z8803 (2011). It is preferably in the range, and more preferably in the range of 200 to 5000 mPa · s. When the viscosity of the ink is within the above range, the ink has an appropriate viscosity, the fluidity of the ink is secured, and it is easy to produce a fabric ribbon having a long printing life.

The fabric ribbon in the present invention is completed by impregnating the fabric for fabric ribbon with the above-described ink using a coating machine. The fabric for the fabric ribbon is not particularly limited. For example, plain woven fabric of various synthetic fibers such as nylon and polyester can be used, but it is particularly preferable to use nylon 66 plain woven fabric having excellent mechanical strength. The basis weight of the fabric for the fabric ribbon is not particularly limited, but it is generally preferable to use a fabric weight of 40 to 80 g / m ² .

In the present invention, the amount of ink to be impregnated into the cloth is not particularly limited, but the amount of ink impregnated per unit area is preferably in the range of 6 to ²⁰ g / m ² . When the amount of ink impregnation is within the above range, it is possible to obtain a fabric ribbon having an appropriate print density and life and free from problems such as background contamination.

  Next, the present invention will be specifically described with reference to examples and comparative examples, but the present invention is not limited to the examples.

<Example 1>
Ink formulation 1 shown below was kneaded and dispersed by a three-roll mill to prepare an ink, and the ink was applied to a nylon 66 plain woven fabric having a width of 13 mm, a length of 38 m and a basis weight of 55 g / m ² by a coating machine. Impregnation coating was carried out in an amount of 11 g / m ² .
(Ink formulation 1)
Raw material component mass%
・ Synthetic medium-chain fatty acid triglyceride oil 52.0
(Caprylic capric triglyceride 100%)
・ Surfactant 20.0
・ Carbon 10.0
・ Organic pigment 18.0

<Example 2>
An ink was prepared by kneading and dispersing the following ink formulation 2 with a three-roll mill, and the ink was further applied to a nylon 66 plain woven fabric having a width of 13 mm, a length of 38 m and a basis weight of 55 g / m ² by a coating machine. Impregnation coating was carried out in an amount of 11 g / m ² .
(Ink formulation 2)
Raw material component mass%
-Refined medium-chain fatty acid triglyceride oil 52.0
(Caprylic capric acid lauric triglyceride 90%)
・ Surfactant 20.0
・ Carbon 10.0
・ Organic pigment 18.0

<Example 3>
An ink was prepared by kneading and dispersing the following ink formulation 3 with a three-roll mill, and the ink was further applied to a nylon 66 plain woven fabric having a width of 13 mm, a length of 38 m and a basis weight of 55 g / m ² by a coating machine. Impregnation coating was carried out in an amount of 11 g / m ² .
(Ink formulation 3)
Raw material component mass%
・ Synthetic medium-chain fatty acid triglyceride oil 49.0
(Caprylic capric triglyceride 100%)
・ Styrene resin 3.0
・ Surfactant 20.0
・ Carbon 10.0
・ Organic pigment 18.0

<Comparative Example 1>
An ink was prepared by kneading and dispersing Ink Formulation 4 shown below with a three-roll mill, and the ink was further applied to a nylon 66 plain woven fabric having a width of 13 mm, a length of 38 m and a basis weight of 55 g / m ² by a coating machine. Impregnation coating was carried out in an amount of 11 g / m ² .
(Ink formulation 4)
Raw material component mass%
・ Liquid paraffin 52.0
・ Surfactant 20.0
・ Carbon 10.0
・ Organic pigment 18.0

<Comparative Example 2>
An ink was prepared by kneading and dispersing the following ink formulation 5 using a three-roll mill, and then applying the ink to a nylon 66 plain woven fabric having a width of 13 mm, a length of 38 m and a basis weight of 55 g / m ² by a coating machine. Impregnation coating was carried out in an amount of 11 g / m ² .
(Ink formulation 5)
Raw material component mass%
・ Poly-α-olefin synthetic oil 52.0
・ Surfactant 20.0
・ Carbon 10.0
・ Organic pigment 18.0

<Comparative Example 3>
Ink formulation 6 shown below was kneaded and dispersed by a three-roll mill to prepare an ink, and the ink was further applied to a nylon 66 plain woven fabric having a width of 13 mm, a length of 38 m and a basis weight of 55 g / m ² by a coating machine. Impregnation coating was carried out in an amount of 11 g / m ² .
(Ink formulation 6)
Raw material component mass%
・ Octyl oleate 52.0
・ Surfactant 20.0
・ Carbon 10.0
・ Organic pigment 18.0

<Comparative Example 4>
An ink was prepared by kneading and dispersing the following ink formulation 7 with a three-roll mill, and the ink was further applied to a nylon 66 plain woven fabric having a width of 13 mm, a length of 38 m and a basis weight of 55 g / m ² by a coating machine. Impregnation coating was carried out in an amount of 11 g / m ² .
(Ink formulation 7)
Raw material component mass%
・ Olive oil 52.0
・ Surfactant 20.0
・ Carbon 10.0
・ Organic pigment 18.0

<Test for immersion of EDPM rubber transfer rubber roll in oil agent>
Approximately 100 cc of the various oils used in Examples and Comparative Examples were weighed into each container, and the entire EPDM rubber transfer rubber roll of the dot impact printer using the fabric ribbon of the present invention was completely immersed in the oil at 60 ° C. And stored for 400 hours. Measure the increase or decrease in the mass of the EPDM rubber transport rubber roll before and after storing the oil agent immersion, and use the EPDM rubber transport rubber roll as a guide for how much each oil agent has penetrated into the EPDM rubber transport rubber roll. Was determined. The mass change rate (%) of the EDPM rubber transfer rubber roll is determined by the following equation.
“Mass change rate (%) of EDPM rubber transport rubber rolls = ((mass of EDPM transport rubber rolls after storage in oil solution) − (mass of EDPM transport rubber rolls before storage in oil solution)) 浸漬 (oil solution immersion) Mass of EDPM transport rubber roll before storage) x 100 "
By knowing the rate of change in mass of the EPDM rubber transfer rubber roll, it is possible to know how much the oil agent is absorbed by the EPDM rubber.

<Ink immersion storage test of EDPM rubber transfer rubber roll>
About 100 cc of each ink prepared in Examples and Comparative Examples was weighed into each container, and the entire EPDM rubber transfer rubber roll of the dot impact printer using the fabric ribbon of the present invention was completely immersed in the ink at 60 ° C. And stored for 400 hours. Based on the results of measuring the outer diameter of the EDPM rubber transfer rubber roll before and after the ink immersion storage, the outer diameter change rate of the EDPM rubber transfer rubber roll for each ink was determined. The outer diameter change rate (%) of the EDPM rubber transfer rubber roll is obtained by the following equation.
"Change rate of outer diameter of transfer rubber roll made of EDPM rubber (%) = ((outer diameter of transfer rubber roll made of EDPM after storage immersed in ink)-(outer diameter of transfer rubber roll made of EDPM before storage dipped in ink))} (Outside diameter of EDPM transport rubber roll before ink immersion storage) x 100 "
From the results of the printing tests so far, if the rate of change in the outer diameter of the transfer rubber roll of the dot impact printer is in the range of 0 to 5.0%, no printing defect due to the swelling of the transfer rubber roll occurs at all. If the rate of change in outer diameter is more than 5.0% and not more than 7.0%, there is a possibility that a printing defect due to swelling of the transfer rubber roll may occur slightly, but it can withstand use. In addition, it has been found that when the outer diameter change rate exceeds 7.0%, printing defects due to swelling of the transfer rubber roll tend to occur frequently.

<Viscosity of oil and ink>
The viscosity of the oil agent and the ink was measured at 25 ° C. using a tuning fork vibrating viscometer SV series manufactured by A & D Co., Ltd. corresponding to JIS Z8803 (2011).

<Evaluation of print life>
The fabric ribbons prepared in Examples and Comparative Examples were used as Mobius rings, and loaded in a ribbon cassette to perform a printing test. Printing was performed on a stock home with a 24-pin wire dot printer, and the PCS print density (A filter) was measured using a densitometer PCM-II manufactured by Macbeth. The print life was measured by measuring the number of characters that could be printed before the PCS print density (A filter) reached 0.40, and evaluated according to the following evaluation criteria.
(Evaluation criteria)
A: 1.5 million characters or more B: 1 million characters or more and less than 1.5 million characters C: less than 1 million characters

  Table 1 shows various characteristic data and various evaluation results of the fabric ribbons of Examples and Comparative Examples of the present invention. (* In the table, medium chain fatty acid triglyceride oil is abbreviated as MCT, and triglyceride is abbreviated as TG.)

  From the results in Table 1, as shown in Examples 1 to 3, a fabric ribbon impregnated with an ink composed of at least a colorant, a surfactant, and an oil agent, and the main component of the oil agent is a medium-chain fatty acid triglyceride is used. This shows that the rate of change in outer diameter of the EPDM rubber transfer rubber roll of the dot impact printer after the oil immersion storage test is as small as 5.0% or less and the printing life is good. As shown in Examples, at least one of caprylic capric acid triglyceride or caprylic capric laurate triglyceride, which has a low penetration and a small swelling in an EPDM rubber carrier rubber roll, is particularly preferably used as the oil agent used in the ink. preferable.

  When the oil agents shown in Comparative Examples 1 to 4 are used for a fabric ribbon for a dot impact printer, there is no problem with the printing life, but the swelling of the EPDM rubber causes the rate of change in the outer diameter of the conveying rubber roll to exceed 7.0%. In addition, printing defects due to the swelling of the transfer rubber roll are likely to occur.

  The fabric ribbon for a dot impact printer according to the present invention can be used not only for a device incorporating a printer, such as a time clock or a financial terminal, which repeatedly uses a print-receiving medium, but also for various dot impact printers in general.

Claims (5)

  A fabric ribbon for a dot impact printer, comprising at least a coloring agent, a surfactant, and an oil agent, wherein the main component of the oil agent is impregnated with an ink of a medium-chain fatty acid triglyceride.   The fabric ribbon for a dot impact printer according to claim 1, wherein the medium-chain fatty acid triglyceride comprises at least one of caprylic capric triglyceride or caprylic capric laurate triglyceride.   The fabric ribbon for a dot impact printer according to claim 1 or 2, wherein the content of the medium-chain fatty acid triglyceride in the ink is 30 to 70% by mass.   The fabric ribbon for a dot impact printer according to any one of claims 1 to 3, wherein the ink has a viscosity at 25 ° C measured by a vibration viscometer according to JIS Z8803 (2011) of 100 to 6000 mPa · s.   When the EPDM rubber transport rubber roll is completely immersed in the ink at 60 ° C. and stored for 400 hours in a state of being completely immersed in the ink, the outer diameter change rate of the EPDM rubber transport rubber roll before and after the ink immersion storage is reduced. The fabric ribbon for a dot impact printer according to any one of claims 1 to 4, which is in a range of 0 to 7.0%.