JP2012131037A - Liquid supply tube and liquid ejecting apparatus equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid supply tube that prevents the occurrence of displacement of landing positions by reducing reaction force accompanying movement of a carriage.SOLUTION: The liquid supply tube for supplying liquid to a liquid ejecting head mounted on a carriage which reciprocates along a guide shaft includes a polypropylene series resin composition which contains a crystalline polypropylene component, and a noncrystalline polyolefin component containing propylene. The polypropylene series resin composition contains 5-40 wt.% of a crystalline polypropylene component, and 95-60 wt.% of a noncrystalline polyolefin component.

Description

  The present invention relates to a liquid supply tube.

  In the liquid ejecting apparatus, a material called styrene-ethylene-butadiene-styrene (SEBS) block copolymer resin is used as the liquid supply tube material (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2000-978

  However, if a liquid supply tube mainly composed of SEBS is used as a tube for supplying a liquid to a liquid jet head provided in a reciprocating carriage, the curvature of the curved portion of the tube cannot be made sufficiently small. If the curvature of the curved portion is reduced, the carriage tilts due to the reaction force of the liquid supply tube, the nozzle of the head mounted on the carriage tilts, and the landing position deviation of the liquid ejected from the nozzle occurs, and the landing accuracy There was a problem of having an adverse effect. Furthermore, since the tube mainly composed of SEBS is a hard material that easily generates a reaction force when the tube is bent, even if the tube is bent with a curvature that makes the landing position deviation below a predetermined value, There was a risk of difficulty in durability.

  The present invention has been made in view of such circumstances, and provides a liquid supply tube capable of suppressing the occurrence of landing position deviation by reducing the reaction force accompanying the movement of the liquid ejecting head, and the degree of freedom in design. It aims at improving.

  In order to solve the above problems, a liquid supply tube of the present invention is a liquid supply tube used for supplying a liquid to a liquid jet head mounted on a reciprocating carriage, and includes a crystalline polypropylene component, And an amorphous polyolefin component containing propylene, and the polypropylene resin composition has a content of the crystalline polypropylene component of 5 to 40% by weight, The amorphous polyolefin component content is 95 to 60% by weight.

  According to the liquid supply tube of the present invention, it is constituted by a polypropylene resin composition in which the content of the crystalline polypropylene component is 5 to 40% by weight and the content of the amorphous polyolefin component is 95 to 60% by weight. Therefore, the flexibility is improved and the reaction force generated in the liquid supply tube when the carriage moves can be suppressed. Accordingly, the carriage can be prevented from being tilted by the reaction force of the liquid supply tube, so that the nozzle of the head mounted on the carriage is prevented from being tilted, and the landing position deviation of the liquid ejected from the nozzle is prevented. Can be suppressed.

In the liquid supply tube, the polypropylene resin composition has a content of the crystalline polypropylene component of 5 to 10% by weight and a content of the amorphous polyolefin component of 95 to 90% by weight. More desirable.
In this way, since the content of the crystalline polypropylene component is 5 to 10% by weight and the content of the amorphous polyolefin component is 95 to 90% by weight, the polypropylene resin composition is used. It is possible to reduce the curvature of the curved portion of the liquid supply tube while suppressing the amount of liquid landing position deviation below a reference value.

Schematic which shows the structure of the liquid ejecting apparatus which concerns on this embodiment. FIG. 2 is a conceptual diagram illustrating a configuration of a liquid ejecting apparatus according to the embodiment. FIG. 3 is a side sectional view showing a configuration of a head. FIG. 3 is a cross-sectional view of a main part illustrating the configuration of the head. FIG. 3 is a block diagram illustrating an electrical configuration of the liquid ejecting apparatus. The figure which shows the result of evaluation experiment in order to confirm the effect of a liquid supply tube. The figure for demonstrating the definition of a landing deviation rate. The figure which shows the relationship between the content rate of a crystalline polypropylene component, and a landing deviation rate.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size.

  Hereinafter, a liquid supply tube and a liquid ejecting apparatus equipped with the same will be described as an embodiment of the present invention with reference to the drawings. FIG. 1 is a diagram illustrating a schematic configuration of the liquid ejecting apparatus PRT.

  The liquid ejecting apparatus PRT shown in FIG. 1 is an apparatus that ejects liquid onto the medium M while conveying the sheet-like medium M. The medium to which the liquid is ejected is not limited to paper such as recording paper, but may be other media such as a film, woven fabric, and non-woven fabric, or a work such as various substrates such as a glass substrate and a silicon substrate. Good.

  Moreover, it does not specifically limit as a liquid ejected from the liquid ejecting apparatus of this invention, It can be set as the liquid (including dispersion liquids, such as a suspension and an emulsion) containing the following various materials. Ink containing filter material for color filter, light emitting material for forming EL light emitting layer in organic EL device, fluorescent material for forming phosphor on electrode in electron emission device, fluorescence in PDP (Plasma Display Panel) device Fluorescent material for forming body, electrophoretic material for forming electrophoretic body in electrophoretic display device, bank material for forming bank on surface of substrate W, various coating materials, liquid electrode material for forming electrode Particle material constituting spacer for forming minute cell gap between two substrates, liquid metal material for forming metal wiring, lens material for forming microlens, resist material, light diffuser For example, a light diffusing material.

  The liquid ejecting apparatus PRT includes a housing PB, a liquid ejecting mechanism IJ that ejects liquid onto the medium M, a liquid supply mechanism IS that supplies liquid to the liquid ejecting mechanism IJ, a transport mechanism CV that transports the medium M, A maintenance mechanism MN that performs a maintenance operation of the liquid ejecting mechanism IJ and a control device CONT that controls these mechanisms are provided.

  Hereinafter, an XYZ rectangular coordinate system is set, and the positional relationship of each component will be described with reference to the XYZ rectangular coordinate system as appropriate. In this embodiment, the transport direction of the medium M is the X direction, the direction perpendicular to the X direction on the transport surface of the medium M is the Y direction, and the direction perpendicular to the plane including the X axis and the Y axis is the Z direction. To do. The rotation direction around the X axis is the θX direction, the rotation direction around the Y axis is the θY direction, and the rotation direction around the Z axis is the θZ direction.

  The housing PB is formed so that the Y direction is the longitudinal direction. Each part of the liquid ejecting mechanism IJ, the liquid supply mechanism IS, the transport mechanism CV, the maintenance mechanism MN, and the control device CONT is attached to the housing PB. A platen 13 is provided in the housing PB. The platen 13 is a support member that supports the medium M. The platen 13 is disposed in the central portion in the X direction of the housing PB. The platen 13 has a flat surface 13a oriented in the + Z direction. The flat surface 13a is used as a support surface that supports the medium M.

  The transport mechanism CV includes a transport roller and a motor that drives the transport roller. The transport mechanism CV transports the medium M into the housing PB from the −X side of the housing PB and discharges the medium M from the + X side of the housing PB to the outside of the housing PB. The transport mechanism CV transports the medium M so that the medium M passes over the platen 13 inside the housing PB. In the transport mechanism CV, the transport timing, transport amount, and the like are controlled by the control device CONT.

  The liquid ejecting mechanism IJ includes a liquid ejecting head H that ejects liquid and a liquid ejecting head moving mechanism AC that holds and moves the liquid ejecting head H. The liquid ejecting head H ejects liquid toward the medium M sent onto the platen 13. The liquid ejecting head H has an ejecting surface Ha that ejects liquid. The ejection surface Ha is directed in the −Z direction and is disposed so as to face the flat surface 13a of the platen 13.

  The liquid ejecting head moving mechanism AC has a carriage 4. The liquid ejecting head H is fixed to the carriage 4. The carriage 4 is in contact with a guide shaft 8 that extends in the longitudinal direction (Y direction) of the housing PB. The liquid ejecting head H and the carriage 4 are arranged in the + Z direction of the platen 13.

  In addition to the carriage 4, the liquid ejecting head moving mechanism AC is provided with a pulse motor 9, a driving pulley 10 that is rotationally driven by the pulse motor 9, and the driving pulley 10 on the opposite side in the width direction of the housing PB. An idle pulley 11 and a timing belt 12 spanned between the drive pulley 10 and the idle pulley 11 and connected to the carriage 4 are provided.

  The carriage 4 is connected to the timing belt 12. The carriage 4 is provided to be movable in the Y direction as the timing belt 12 rotates. When moving in the Y direction, the carriage 4 is guided by a guide shaft 8.

  The liquid supply mechanism IS supplies a liquid to the liquid ejecting head H. A plurality of liquid cartridges (liquid tanks) 6 are accommodated in the liquid supply mechanism IS. The liquid ejecting apparatus PRT of the present embodiment has a configuration in which the liquid cartridge 6 is accommodated in a position different from the liquid ejecting head H. The liquid supply mechanism IS has a liquid supply tube TB which is an embodiment of the liquid supply tube of the present invention as a liquid supply tube connecting the liquid jet head H and the liquid cartridge 6. The liquid supply mechanism IS has a pump mechanism (not shown) that supplies the liquid stored in the liquid cartridge 6 to the liquid ejecting head H via the liquid supply tube TB.

  The liquid supply tube TB is bent in various ways in the housing PB due to the size restriction of the liquid ejecting apparatus PRT. The liquid stored in the liquid supply mechanism IS passes through the first bending portion 100 and the second bending portion 101, and the third bending portion 102 and the fourth bending portion are located closer to the head than the binding portion 105 that binds the liquid supply tube TB. The liquid flows through the bending portion 103 and the fifth bending portion 104 to the liquid ejecting head H. A reaction force is generated in the liquid supply tube TB bent in this way. In particular, as shown in FIG. 2, when the second bending portion 101 exists in the vicinity of the carriage 4 on which the liquid ejecting head H is mounted, the carriage 4 is inclined with respect to the guide shaft 8 due to the reaction force of the liquid supply tube TB. There is a risk of landing position deviation.

  On the other hand, in the present embodiment, a polypropylene resin composition containing a crystalline polypropylene component and an amorphous polyolefin component containing propylene is used as a constituent material of the liquid supply tube TB.

  The amorphous polyolefin component has the role of a polypropylene polymer plasticizer, and can soften the polypropylene, and can maintain the same heat resistance as the base polypropylene even when softened. It has characteristics.

  In the present embodiment, the polypropylene resin composition has a crystalline polypropylene component content of 5 to 40% by weight and an amorphous polyolefin component content of 95 to 60% by weight.

  Generally, the outer diameter of the liquid supply tube TB in the liquid ejecting apparatus PRT is 0.9 to 3 mm. In the liquid supply tube TB having the outer diameter in such a range, in the configuration according to the embodiment of the present invention, the shape of the bending portion can be kept almost constant, and the bending diameter of the bending portion can be set at a portion where the reaction force fluctuation is small. It is also possible to fit within 2 mm. That is, the second curved portion 101, the third curved portion 102, the fourth curved portion 103, and the fifth curved portion are curved portions closer to the liquid supply mechanism IS than the bundling portion 105, and the curved portions are not significantly deformed by movement of the carriage. As for the portion 104, the bending diameter of the bending portion can be about 2 mm or a few mm with some margin.

  As for the second bending portion 101, the positional relationship between the position of the second bending portion 101 and the carriage 4 changes greatly as the carriage moves. That is, in FIG. 2 with respect to FIG. 1, the second bending portion 101 is located near the carriage 4. Therefore, in FIG. 1, the reaction force generated in the second bending portion 101 hardly affects the carriage 4, whereas in FIG. 2, the second bending portion 101 exerts a larger reaction force on the carriage 4 than in the state of FIG. As described above, the carriage 4 may be inclined with respect to the guide shaft 8. Then, the nozzle NZ of the head H mounted on the carriage 4 may be inclined and the landing position of the liquid ejected from the nozzle NZ may be shifted. Therefore, the bending diameter of the second bending portion 101 needs to be about several tens mm. Therefore, in a conventional tube mainly composed of SEBS, at a portion corresponding to the second bending portion 101, at least a bent diameter is set to 40 mm so that the landing position deviation is equal to or less than a predetermined value, and the tube curvature is reduced to reduce liquid ejection. There was a limit to the degree of freedom in designing the equipment.

  However, according to FIG. 8 to be described later, the second bending portion 101 in the liquid supply tube TB was able to have a bent diameter of 30 mm. Even when the curvature of the second bending portion 101 is R30 (meaning that the radius of curvature of the bending portion is 30 mm), the carriage 4 is inclined with respect to the guide shaft 8 by the reaction force of the liquid supply tube TB. Therefore, it is possible to obtain a good print quality by suppressing the amount of landing position deviation generated to a specified value or less. When the second curved portion 101 of the liquid supply tube TB is set to R40 or more as in the conventional case, when compared with the same curvature, the landing position deviation is reduced as compared with the conventional tube mainly composed of SEBS. Needless to say, the accuracy is improved.

  Further, when the required curvature of the curved portion is small due to the size restriction of the liquid ejecting apparatus PRT, the polypropylene resin composition constituting the liquid supply tube TB has a content of crystalline polypropylene component of 5 to 10% by weight. The content of the amorphous polyolefin component is desirably 95 to 90% by weight. In the polypropylene resin composition having such distribution, the carriage 4 is inclined with respect to the guide shaft 8 by the reaction force of the liquid supply tube TB even if the curvature of the curved portion of the liquid supply tube TB is R20 as described later. The amount of landing position deviation can be suppressed to a specified value or less by suppressing the above, and good print quality can be obtained.

  The maintenance mechanism MN is disposed at the home position of the liquid ejecting head H. This home position is set in an area outside the area where printing is performed on the medium M. In the present embodiment, the home position is set on the + Y side of the platen 13. The home position is a place where the liquid ejecting head H stands by when the power of the liquid ejecting apparatus PRT is off or when recording is not performed for a long time.

  The maintenance mechanism MN includes a capping mechanism CP that covers the ejection surface Ha of the liquid ejection head H, a wiping mechanism WP that wipes the ejection surface Ha, and the like. A suction mechanism SC such as a suction pump is connected to the capping mechanism CP. By the suction mechanism SC, the capping mechanism CP can suck the space on the ejection surface Ha while covering the ejection surface Ha. The waste liquid discharged from the head H to the maintenance mechanism MN side is collected by a waste liquid collection mechanism (not shown).

FIG. 3 is a side sectional view showing the configuration of the head H. As shown in FIG. FIG. 4 is a cross-sectional view of a main part for explaining the configuration of the liquid jet head H.
As shown in FIG. 3, the liquid ejecting head H includes an introduction needle unit 17, a head case 18, a flow path unit 19, and an actuator unit 20.

  Two liquid introduction needles 22 are attached to the upper surface of the introduction needle unit 17 side by side with the filter 21 interposed. A liquid introduction path 23 corresponding to each liquid introduction needle 22 is formed inside the introduction needle unit 17. The upper end of the liquid introduction path 23 is connected to the liquid introduction needle 22 via the filter 21. The lower end of the liquid introduction path 23 is connected to the case flow path 40 inside the head case 18 via the packing 24. A sub tank 2 is attached to each liquid introduction needle 22.

  The sub tank 2 is formed using a resin material such as polypropylene. The sub tank 2 is provided with a liquid chamber 27. The liquid chamber 27 has a concave portion 27a formed in a mortar shape. The recess 27a has an opening 27b. A transparent elastic sheet 26 is attached to the opening 27b. A communication hole 27c is formed at the bottom of the recess 27a. The communication hole 27c is formed so as to communicate between the recess 27a of the liquid chamber 27 and the liquid supply chamber 27d. The liquid supply chamber 27d is connected to the supply tube TB. A filter (not shown) or the like is provided at a connection portion of the liquid supply chamber 27d with the supply tube TB.

  The elastic sheet 26 is stuck so as to close the opening 27b. The elastic sheet 26 expands and contracts according to the pressure in the liquid chamber 27. When the pressure in the liquid chamber 27 becomes higher than the external pressure, the elastic sheet 26 expands toward the outside of the recess 27a, and the volume of the liquid chamber 27 increases. When the pressure in the liquid chamber 27 becomes lower than the external pressure, the liquid chamber 27 expands toward the inside of the recess 27a, and the volume of the liquid chamber 27 decreases.

  A valve 27 e is attached to the elastic sheet 26. The valve 27e is connected to the liquid supply chamber 27d from the recess 27a via the communication hole 27c, and is formed to open and close the communication hole 27c from the liquid supply chamber 27d side. The valve 27e opens and closes the communication hole 27c in conjunction with the expansion and contraction of the elastic sheet 26. Specifically, the communication hole 27c is opened when the elastic sheet 26 expands in the direction of decreasing the volume of the liquid chamber 27, and the communication hole when the elastic sheet 26 expands in the direction of increasing the volume of the liquid chamber 27. 27c is closed. An urging member 27f for applying a predetermined elastic force is attached to the valve 27e, and the opening / closing pressure of the communication hole 27c is adjusted.

  The sub tank 2 is connected to the needle connecting portion 28. The needle connection portion 28 is a portion that connects the sub tank 2 and the liquid introduction needle 22. A connection channel 29 connected to the needle connection portion 28 is formed in the recess 27 a of the liquid chamber 27. A sealing material 31 into which the liquid introduction needle 22 is fitted with almost no gap is provided in the internal space of the needle connection portion 28. Since the liquid introduction needle 22 is fitted into the sealing material 31, the sub tank 2 and the introduction needle unit 17 are connected with almost no leakage.

  As shown in FIG. 4, the head case 18 is formed using a synthetic resin or the like. The head case 18 is formed in a box shape so as to have a hollow portion. The head case 18 has an introduction needle unit 17 attached to the upper end side via a packing 24. A flow path unit 19 is joined to the lower end surface of the head case 18. The actuator unit 20 is accommodated in a hollow portion 37 formed inside the head case 18.

A case channel 40 is provided inside the head case 18 so as to penetrate the height direction.
The upper end of the case flow path 40 communicates with the liquid introduction path 23 of the introduction needle unit 17 through the packing 24. The lower end of the case flow path 40 communicates with the common liquid chamber 44 in the flow path unit 19. Therefore, the liquid L introduced from the liquid introduction needle 22 is supplied to the common liquid chamber 44 side through the liquid introduction path 23 and the case flow path 40.

  The actuator unit 20 supplies a plurality of piezoelectric vibrators 38 arranged in a comb shape, a fixed plate 39 that holds the piezoelectric vibrator 38, and a drive signal from the control device CONT to the piezoelectric vibrator 38. Flexible cable 40.

  The piezoelectric vibrator 38 is fixed so that the lower end portion in the figure protrudes from the lower end surface of the fixed plate 39. Thus, each piezoelectric vibrator 38 is mounted on the fixed plate 39 in a so-called cantilever state. The fixed plate 39 that supports each piezoelectric vibrator 38 is made of stainless steel having a thickness of about 1 mm. A surface of the fixing plate 39 different from the surface on which the piezoelectric vibrator 38 is fixed is bonded to the inner wall surface of the case that defines the hollow portion 37.

  The flow path unit 19 includes a vibration plate 41, a flow path substrate 42 and a nozzle substrate 43. The diaphragm 41, the flow path substrate 42, and the nozzle substrate 43 are bonded in a stacked state. The flow path unit 19 constitutes a series of liquid flow paths from the common liquid chamber 44 through the liquid supply port 45 and the pressure chamber 46 to the nozzle NZ. The pressure chamber 46 is formed such that the direction perpendicular to the arrangement direction (nozzle row direction) of the nozzles NZ is the longitudinal direction.

  The common liquid chamber 44 is connected to the case flow path 40. The common liquid chamber 44 is a chamber into which the liquid L from the liquid introduction needle 22 side is introduced. The common liquid chamber 44 is connected to the liquid supply port 45. The liquid L introduced into the common liquid chamber 44 is distributed to each pressure chamber 46 through the liquid supply port 45.

  The nozzle substrate 43 is disposed at the bottom of the flow path unit 19. A plurality of nozzles NZ are formed on the nozzle substrate 43 at a pitch (for example, 180 dpi) corresponding to the dot formation density of an image or the like formed on the medium M. As the nozzle substrate 43, a metal plate material such as stainless steel is used.

FIG. 5 is a block diagram showing an electrical configuration of the liquid ejecting apparatus PRT.
The liquid ejecting apparatus PRT includes a control device CONT that controls the operation of the entire liquid ejecting apparatus PRT. The control device CONT is connected to an input device 59 for inputting various information related to the operation of the liquid ejecting apparatus PRT, a storage device 63 storing various information related to the operation of the liquid ejecting apparatus PRT, and the like. The head moving mechanism AC, the maintenance mechanism MN, etc. are connected. The control device CONT can control the suction mechanism SC in the maintenance mechanism MN.

  The liquid ejecting apparatus PRT includes a drive signal generator 62 that generates a drive signal to be input to each piezoelectric vibrator 38. The drive signal generator 62 is connected to the control device CONT. The drive signal generator 62 receives data indicating the amount of change in the voltage value of the drive pulse input to the piezoelectric vibrator 38 of the liquid ejecting head H, and a timing signal that defines the timing for changing the voltage of the drive pulse. . The drive signal generator 62 is provided so that a drive signal can be individually supplied to each piezoelectric vibrator 38.

Next, the operation of the liquid ejecting apparatus PRT configured as described above will be described.
When performing the printing operation by the liquid ejecting head H, the control device CONT causes the transport mechanism CV to place the medium M on the −Z side of the liquid ejecting head H. After disposing the medium M, the control device CONT inputs a drive signal from the drive signal generator 62 related to the nozzle NZ to the piezoelectric vibrator 38 based on the image data while moving the liquid ejecting head H.

  When a drive signal is input to the piezoelectric vibrator 38, the piezoelectric vibrator 38 expands and contracts. Due to the expansion and contraction of the piezoelectric vibrator 38, the volume of the pressure chamber 46 changes, and the pressure of the pressure chamber 46 containing the liquid fluctuates. The liquid is ejected from the nozzle NZ due to the fluctuation of the pressure. A desired image is formed on the medium M by the liquid ejected from the nozzle NZ.

The control device CONT performs a flushing operation, a capping operation, a suction operation, and the like as a maintenance operation of the liquid ejecting head H.
When the flushing operation is performed, the control device CONT moves the liquid ejecting head H to the home position so that the ejecting surface Ha of the liquid ejecting head H and the cap member 33 face each other. In this state, the control device CONT finely adjusts the posture of the cap member 33 so that the ejection surface Ha of the liquid ejection head H is parallel to the cap member 33. After adjusting the posture of the cap member 33, the control device CONT vibrates the piezoelectric vibrator 38 via the drive signal generator 62. By this operation, the liquid is ejected from the nozzle NZ and discharged.

  Next, when the capping operation is performed, the control device CONT moves the liquid ejecting head H to the home position, and causes the liquid ejecting head H and the cap member 33 to face each other. At the same time, the control device CONT moves the cap member 33 toward the liquid ejecting head H by a driving mechanism (not shown) to press the ejecting surface Ha. By this operation, a gap is formed between the cap member 33 and the ejection surface Ha, and the capping operation is completed. In the cap member 33, a liquid absorbing portion that absorbs the liquid is disposed. Accordingly, the liquid absorbed by the liquid absorbing portion exerts a wetting effect on the liquid ejecting head H.

  After the capping operation, a suction operation for sucking the nozzle NZ of the liquid jet head H can be performed. After the cap member 33 is brought into contact with the liquid ejecting head H, the control device CONT operates the suction mechanism SC. By this operation, the space between the cap member 33 and the ejection surface Ha of the liquid ejection head H is sucked and becomes negative pressure. Due to the negative pressure, the liquid is discharged from the plurality of nozzles NZ of the head H in the −Z direction, and the viscosity of the liquid is appropriately maintained. After the liquid suction operation is completed, the control device CONT releases the negative pressure state in the cap member 33 by, for example, releasing the inside of the cap member 33 to the atmosphere, and the cap member 33 is ejected from the ejection surface of the liquid ejection head H. Separate from Ha. In this way, the suction operation is performed.

  As described above, since the liquid supply tube TB according to the present invention is composed of the polypropylene resin composition having the above-described blending ratio, the liquid supply tube TB has excellent flexibility and suppresses the reaction force generated in the liquid supply tube TB. Can do. Therefore, even when the liquid supply tube TB incorporated in the liquid ejecting apparatus PRT is bent with a small curvature (for example, R30 or R20), the carriage 4 is attached to the guide shaft 8 as shown in the experimental results described later. It is possible to suppress tilting. Therefore, it is possible to satisfactorily prevent occurrence of landing position deviation due to the inclination of the carriage 4 and to perform highly reliable printing processing.

(Experimental example)
Next, the evaluation experiment and the result conducted for confirming the effect of the liquid supply tube TB will be described. FIG. 6 shows the relationship between each condition of the liquid supply tube TB to be evaluated and each condition of the conventional liquid supply tube.

In FIG. 6, Examples 1 to 9 show cases where the composition ratios of the polypropylene resin compositions constituting the liquid supply tube TB according to the present invention are varied. As shown in FIG. 6, the polypropylene resin composition contains two types of components. Components A and B are respectively
Component A: crystalline polypropylene component,
Component B: formed from an amorphous polyolefin component containing propylene.

  What evaluated the barrier property and the flexibility about what differed the content rate of these two types of components was set as Examples 1-9. Further, as a comparison, a conventional liquid supply tube mainly composed of SEBS was evaluated for barrier properties and bendability as a comparative example.

  As an evaluation experiment, first, the moldability of the liquid supply tubes TB according to Examples 1 to 9 and the comparative example was evaluated. Specifically, the ease of molding was subjectively evaluated for the molding of the liquid supply tube TB by extrusion molding and injection molding. In this evaluation, “o” indicates a degree equivalent to the ease of molding in the comparative example, and “Δ” when difficulty in formability is recognized.

  As shown in FIG. 6, the moldability in Example 2-9 was “◯” for both extrusion molding and injection molding, and it was found that moldability comparable to that of the comparative example was obtained. However, in Example 1, the moldability was “Δ”, and it was found that molding was more difficult than in other Examples and Comparative Examples. This is probably because the blending ratio of component A was 0%, so that the material of the liquid supply tube became too soft, making it difficult to mold.

Next, as an evaluation experiment, barrier properties of the liquid supply tubes according to Examples 1 to 9 and the comparative example were evaluated. In this evaluation, as a barrier property, the transmittance of water vapor and air per hour was measured. In FIG. 6, the unit of the barrier property of water vapor is “g · mm / m ² · 24 hr”, and the unit of the air barrier property is “cc · mm / m ² · 24 hr · atm”. If the barrier property of water vapor is 3.0 g · mm / m ² · 24 hr or less, the barrier property of water vapor is good and the evaluation is “◎”, which is larger than 3.0 g · mm / m ² · 24 hr and 4.0 g · mm ^/ m 2 · 24hr or less the evaluation because there is no problem substantially and "○", slightly a difficulty barrier properties of water vapor is not more than larger 6.5g · ^mm / m 2 · 24hr than 4.0 Therefore, the evaluation is “Δ”, and if the value is larger than 6.5 g · mm / m ² · 24 hr, the barrier property of water vapor is difficult, and the evaluation is “x”.
Also, if the air barrier property is 0.7 c · mm / m ² · 24 hr · atm or less, the air barrier property is good, and therefore, it is evaluated as “◎”. 0.7 c · mm / m ² · 24 hr · atm If it is larger than 0.8 c · mm / m ² · 24 hr · atm, there is substantially no problem. Therefore, the evaluation is “◯”, and larger than 0.8 c · mm / m ² · 24 hr · atm and 0.9 c · m is less than mm ^/ m 2 · 24hr · atm evaluated for slightly a difficulty barrier properties of air as ^{"△", 0.9c · mm / m 2 ·} 24hr · atm greater than the barrier of the air Since difficulty arises, the evaluation is “x”.

  As shown in FIG. 6, the barrier properties of water vapor in Examples 1 to 9 were evaluated as “◎” in Examples 4-9 and Comparative Examples, and evaluated as “◯” in Examples 2 and 3. Example 1 was evaluated as “Δ”. Further, the air barrier properties in Examples 1 to 9 were evaluated as “◎” in Examples 3-9 and Comparative Examples, evaluated as “◯” in Example 2, and evaluated as “Δ” in Example 1. It was done. Therefore, from the viewpoint of barrier properties, the liquid supply tube TB is composed of a polypropylene resin composition having a component A content of 5 to 60% by weight and a component B content of 95 to 40% by weight. It was found that it is more desirable that the component A is composed of a polypropylene resin composition having a content of 15 to 60% by weight and a component B of 85 to 40% by weight.

  Subsequently, an evaluation experiment and a result thereof for confirming the effect that the liquid supply tube TB configured as described above can reduce the landing position deviation amount will be described.

  Here, the landing position deviation rate indicates a ratio of an experimental landing position deviation amount to an allowable value of the landing position deviation amount in the liquid ejecting apparatus PRT. Specifically, when the landing position deviation rate is larger than 0%, the vertical deviation amount S formed on the medium M by the droplets ejected from the nozzle NZ as shown in FIG. The situation exceeding the width W is shown. That is, {(S−W) / W} * 100> 0. In this case, the column becomes a meandering state, and the print quality is deteriorated.

  On the other hand, the case where the landing position deviation rate is 0% or less means a situation where the deviation amount S of the columns formed on the medium M is smaller than the column width W, as shown in FIG. That is, {(S−W) / W} * 100 ≦ 0. In this case, since the column is in a meandering state that cannot be visually recognized by human eyes, good print quality can be obtained.

  FIG. 8 shows the relationship between the landing position deviation rate and R in the second bending portion 101 of the liquid supply tube TB for each content of the crystalline polypropylene component of the polypropylene resin composition of the liquid supply tube TB to be evaluated. is there. In FIG. 8, the curve of A45 (A component means 45% and B component means 55%) corresponds to the curve of the landing position deviation rate that is almost the same as the conventional liquid supply tube mainly composed of SEBS. To do. At A40 or less, the landing position deviation rate at R40 is improved as compared with the tube mainly composed of A45 or SEBS. When A40 or less, the landing position deviation rate can be reduced to 0% or less even at R40 or less. Thus, it can be read that the curvature of the curved portion can be reduced. In particular, at A25 or less, the landing position deviation rate can be 0% or less even at R30, and particularly at A10 or less, the landing position deviation rate can be 0% or less even at R20. As shown in FIG. 8, it can be confirmed that the landing position deviation rate increases as the curvature of the curved portion of the liquid supply tube TB decreases from R40 to R20. This is because the reaction force increases when the curvature decreases, because the liquid supply tube TB is greatly curved.

  Moreover, when the curvature of the curved portion of the liquid supply tube TB is constant, it can be confirmed that the landing position deviation rate changes according to the content of the component A. This is because the flexibility of the liquid supply tube TB changes depending on the content of the component A, and the reaction force due to the liquid supply tube TB changes accordingly.

  In FIG. 8, as indicated by a solid line A, in order to suppress the landing position deviation rate by the liquid supply tube TB bent at R40 to 0% or less, the content of the component A in the liquid supply tube TB is set to 5 to 5%. It can be confirmed that the content needs to be 45% by weight. As described above, this is equivalent in performance to a liquid supply tube mainly composed of conventional SEBS. Therefore, by setting the content of component A in the liquid supply tube TB to 5 to 40% by weight, it is possible to improve the landing position deviation rate as compared with the conventional liquid supply tube mainly composed of SEBS.

  In FIG. 8, as indicated by a solid line B, in order to suppress the landing position deviation rate by the liquid supply tube TB bent at R30 to 0% or less, the content of the component A in the liquid supply tube TB is set to 5 to 5%. It can be confirmed that the content needs to be 25% by weight.

  In FIG. 8, as indicated by a solid line C, in order to suppress the landing position deviation rate by the liquid supply tube TB bent at R20 to 0% or less, the content of the component A in the liquid supply tube TB is set to 5 to 5%. It can be confirmed that the content needs to be 10% by weight.

  The liquid ejecting apparatus PRT has a limited space for the liquid supply tube TB due to its size restriction. Therefore, it is necessary to reduce the curvature of the curved portion of the liquid supply tube TB. In practice, the curvature of the curved portion is desirably smaller than R30.

From the above experimental results, if the liquid supply tube TB is composed of a polypropylene resin composition in which the content of the component A is 5 to 40% by weight and the content of the component B is 95 to 60% by weight, It was confirmed that when the curvature of the second bending portion 101 is R40, the landing position deviation rate can be improved as compared with the conventional liquid supply tube mainly composed of SEBS. Moreover, if it is liquid supply tube TB comprised by the polypropylene-type resin composition whose content of component A is 5-25 weight% and content of component B is 95-75 weight%, it will be 2nd curved part. It was confirmed that even when the curvature of 101 was R30, the landing position deviation rate could be 0% or less. Furthermore, if the liquid supply tube TB is composed of a polypropylene resin composition in which the content of the component A is 5 to 10% by weight and the content of the component B is 95 to 90% by weight, the second bending portion It was confirmed that even when the curvature of 101 was R20, the landing position deviation rate could be 0% or less.
In consideration of barrier properties, when R is designed between R30 and R40, the content of component A is 15 to 40% by weight, and the content of component B is 85 to 60% by weight. It is more desirable to be constituted by a certain polypropylene resin composition.

  Therefore, according to the liquid supply tube TB and the liquid ejecting apparatus PRT equipped with the liquid supply tube TB according to the above-described embodiment, the reaction force due to the liquid supply tube TB is suppressed. It was confirmed that the value could be kept below the specified value.

PRT ... Liquid ejecting device, TB ... Liquid supply tube, H ... Liquid ejecting head, 4 ... Carriage, 6 ... Liquid cartridge (liquid tank)

Claims (3)

A liquid supply tube that is used to supply liquid to a liquid ejecting head mounted on a reciprocating carriage and deforms following the carriage;
The liquid supply tube is composed of a polypropylene-based resin composition containing a crystalline polypropylene component and an amorphous polyolefin component containing propylene,
The polypropylene resin composition has a content of the crystalline polypropylene component of 5 to 40% by weight and a content of the amorphous polyolefin component of 95 to 60% by weight. .   2. The liquid supply tube according to claim 1, wherein a curvature radius of the curved portion that deforms following the movement of the carriage is 20 mm or more.   A liquid ejecting apparatus equipped with the liquid supply tube according to claim 1.

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