JP5014006B2 - ink cartridge - Google Patents

Description

  The present invention relates to an ink cartridge for an ink jet recording apparatus.

  As one of recording apparatuses for recording an image including characters or the like (hereinafter referred to as printing) on a recording medium such as paper or a plastic thin plate (OHP, etc.), a small ink droplet is ejected. There is an ink jet recording apparatus that performs printing or the like. Printing with an ink jet recording apparatus is capable of high-speed recording, easy recording of color images, printing on recording media such as paper as well as paper, low noise, and high-quality printing, etc. Have various advantages.

  As an ink supply source for various recording apparatuses such as an ink jet recording apparatus, an ink cartridge that is detachable from the recording apparatus is employed. Ink cartridges for ink jet recording apparatuses are roughly classified into the following two types.

  One is an ink cartridge (Patent Document 1) in which a recording head unit and an ink cartridge that supplies ink are integrated. On the other hand, the ink cartridge is a separate and replaceable ink cartridge that is separated and independent from the ink jet recording head portion and is connected to the ink jet recording head portion via an ink introduction tube.

  A porous ink absorber is provided in the ink cartridge for the ink jet recording apparatus, and a negative pressure is generated by utilizing the capillary force of the ink absorber. Leakage is suppressed and a necessary amount of ink is held in the ink absorber.

  The ink held by the ink absorber is guided to the ink jet recording head from the ink supply port provided in the ink cartridge by the capillary force of the nozzle of the ink jet recording head. In order to prevent ink from leaking from the recording head, and to maintain the ink meniscus so that normal ink ejection can always be performed during standby as an on-demand inkjet, the negative pressure is adjusted more appropriately. Has been.

  When such an ink cartridge is handled as a single unit in a distribution process or the like, a cap is attached to the ink supply port in order to prevent ink leakage from the ink supply port and facilitate transportation. In order to securely seal the ink supply port, an elastic seal member is provided so as to close the opening, and the cap and the ink cartridge are welded via the seal member to prevent liquid leakage. As a method of welding the cap and the ink cartridge, a plurality of welding portions are formed on the edge portion of the cap so as to protrude toward the ink cartridge, and the contact surface between the welding portion and the ink cartridge is welded by ultrasonic welding. The method is adopted.

  In addition, in any type of head cartridge integrated with a recording head or a separate type, positioning when an ink cartridge is mounted on a carriage or the like of an ink jet recording apparatus is also an important matter related to print quality. Various attachment / detachment mechanisms for positioning when these ink cartridges are mounted on a carriage or the like have been reported. For example, an ink cartridge (Patent Document 2) has been proposed in which an engaging portion is provided on one side of the ink cartridge and an elastic latch lever is provided on the other side, and these are engaged with a locking portion provided on the holder of the inkjet head. .

  In addition, in the ink jet recording apparatus, when the ink in the cartridge is consumed in the middle of the recording operation, the printed matter is wasted, and the ink may not be supplied. is there. For this reason, a mechanism for detecting the remaining amount of ink in the ink cartridge has been proposed. As a mechanism for detecting the remaining amount of ink in the ink cartridge, a mechanism has been developed in which an electrode is provided in the ink cartridge to detect a conduction state between the electrodes, and a mechanism for optical detection. In particular, the optical system detection apparatus is often applied because it has a simple configuration and does not require a large apparatus. Specifically, a light projecting / receiving unit provided in the ink jet recording apparatus and a prism of a light transmitting material are provided at the bottom of the ink cartridge, and the difference in refractive index between ink and air is utilized to emit light from the light emitting unit. An example is one in which the presence or absence of ink is detected by the reflected light that is introduced into the light receiving section through the prism reflection surface. (Patent Documents 3 and 4).

The following requirements are necessary for the material of such an ink jet ink cartridge.
1. Ink resistance that does not dissolve in the ink to be stored.
2. Do not change the composition of the ink components.
3. Since it is a supply product, material costs and processing costs are low.
4). In recent years, it must be recyclable due to the growing awareness of global environmental issues.
5. Have transparency.
6). It must be a rigid material.

  Examples of materials that satisfy these requirements include resins such as modified PPO (manufactured by GE Plastics, Asahi Kasei Chemicals, Mitsubishi Engineering Plastics, etc.), PS, PBT, PET, PP, and the like. Among these, propylene polymers are widely used as ink cartridge materials because they are inexpensive, have high gas barrier properties, and have high solvent resistance. These propylene polymers have different characteristics depending on the homopolymer and the copolymer. In general, propylene homopolymer is inexpensive, high rigidity, high heat resistance, ethylene-propylene random copolymer is highly transparent and flexible, ethylene-propylene block copolymer has characteristics such as high impact resistance, These are appropriately selected according to the purpose of use.

  A transparent ethylene-propylene random copolymer is used for an ink cartridge having a detection mechanism for detecting the presence or absence of ink by a light projecting / receiving device. However, the ethylene-propylene random copolymer has low elasticity and may lack attachment / detachment (rebound) to an ink jet recording apparatus. Further, it is flexible, and when the user presses the ink cartridge, the inside of the ink cartridge is pressurized, and there is a concern that the ink leaks from the supply port. Such leakage of ink can be prevented by increasing the wall thickness of the ink cartridge, but increasing the wall thickness increases the volume of the ink cartridge, which is disadvantageous in terms of space and cost. Further, the ethylene-propylene random copolymer has a low crystallization temperature, and there is a problem that a long time is required for the molding cycle and the welding tact with other members.

  On the other hand, propylene homopolymer is inexpensive and can provide a high crystallization temperature and rigidity that cannot be obtained with an ethylene-propylene random copolymer. Since the crystallization temperature is high, there is an advantage that a molding cycle can be shortened, tact-up can be performed, the production can be efficiently performed, and an inexpensive product can be provided. In addition, since the rigidity is high, ink leakage due to pressing of the ink cartridge can be suppressed. From these viewpoints, an ink cartridge using a propylene monopolymer is very promising, but cannot be used for an ink cartridge having an optical detection function because of its low transparency. Although it is known to add a nucleating agent in order to improve the transparency of the resin, there are the following problems. Conventionally, as a nucleating agent, a sorbitol-based nucleating agent represented by 2,4-dibenzylidenesorbitol has been generally used (Patent Document 10). This sorbitol-based nucleating agent is relatively easy to elute into the ink, and the eluting matter is deposited depending on the environmental conditions, and rarely deposits on the ink flow path filter or ink nozzle of the printer, which may adversely affect printing. .

By the way, it is also known to use an organophosphate nucleating agent in order to improve rigidity and transparency in a polypropylene molded product (Patent Documents 5 to 9), but it has been developed as a cartridge material for an ink jet recording apparatus. There was nothing that was done.
JP-A 63-87242 Patent Registration No. 2801149 JP-A-2-102062 Japanese Patent Laid-Open No. 7-218321 JP 2002-265710 A JP-A-5-222078 JP-A-10-298367 Japanese Patent Laid-Open No. 9-87452 JP-A-5-222250 Japanese Patent Laid-Open No. 2000-263813

  The problem of the present invention is that the interaction with the ink is low, the printing quality defect is suppressed regardless of the environmental change, the ink remaining amount detection accuracy is transparent, and the ink leakage due to pressing is rigid. Another object of the present invention is to provide an inexpensive ink cartridge that can be manufactured efficiently while preventing environmental disturbance.

  By using propylene monopolymer and a nucleating agent containing a specific organophosphate compound as the ink cartridge material, it has excellent transparency and can suppress the generation of deposits in the ink flow path due to environmental changes. The knowledge that an ink cartridge can be obtained was obtained. Based on this knowledge, the present invention has been completed.

That is, the present invention is, in the ink accommodating chamber for accommodating the dye ink, an ink cartridge for an ink jet recording apparatus provided with a part of the optical system detector for detecting the dye ink amount,
Some of the ink cartridge and the optical system detector, propylene homopolymer, a nucleating agent comprising an organic phosphate ester compound represented by formula (1), in that it is formed of a material containing Characteristic ink cartridge

Wherein R ¹ represents a divalent hydrocarbon group having 1 to 10 carbon atoms, R ² to R ⁵ independently represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and M represents 1 to 3 This represents a metal atom having any valence of valence or an atomic group containing the same, and m represents an integer of 1 to 3.

  The ink cartridge of the present invention has low interactivity with ink, suppresses poor print quality regardless of environmental changes, has high transparency in detecting the remaining amount of ink, and has rigidity for suppressing ink leakage due to pressing. Therefore, it is possible to manufacture efficiently and inexpensively.

The ink cartridge of the present invention, the ink chamber for containing the dye ink, an ink cartridge for an ink jet recording apparatus provided with a part of the optical system detector for detecting the dye ink amount, the ink cartridge and the part of the optical system detector is characterized propylene homopolymer, a nucleating agent comprising an organic phosphate ester compound represented by formula (1), in that it is formed of a material containing.

In the formula, R ¹ represents a divalent hydrocarbon group having 1 to 10 carbon atoms, R ² to R ⁵ independently represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and M represents a 1 to trivalent group. The metal atom which has any valence of these, or the atomic group containing this is shown, m shows the integer in any one of 1-3.

  The propylene monopolymer used for forming the ink cartridge of the present invention is preferably an isotactic polypropylene. As the polypropylene having an isotactic structure, a polymer having a higher isotactic pentad fraction is preferable.

The nucleating agent used for forming the ink cartridge of the present invention has a function of imparting transparency with low interaction with ink. Such a nucleating agent contains an organic phosphate ester compound represented by the formula (1). In the formula, R ¹ represents a hydrocarbon group having 1 to 10 carbon atoms, and R ² to R ⁵ independently represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. The alkyl group may be linear, branched or cyclic. In the formula, M represents a metal atom having any valence of 1 to 3 or an atomic group containing the same, and m represents an integer of 1 to 3. Examples of M include alkali metals such as sodium, potassium and lithium, alkaline earth metals such as calcium and magnesium, alkaline earth metals having a hydroxyl group, trivalent metals such as aluminum and indium, and these trivalent metals having a hydroxyl group. be able to. Specific examples of such organophosphate compounds include the following.
Sodium-2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphate.
Sodium-2,2'-methylene-bis (4-tert-butyl-6-methylphenyl) phosphate.
Sodium-2,2'-methylene-bis (4-tert-butyl-6-ethylphenyl) phosphate.
Sodium-2,2'-methylene-bis (4,6-di-i-propylphenyl) phosphate.
Sodium-2,2'-methylene-bis (4-i-propyl-6-methylphenyl) phosphate.
Sodium-2,2'-methylene-bis (4-di-i-propyl-6-ethylphenyl) phosphate.
Sodium-2,2'-methylene-bis (4,6-di-pentylphenyl) phosphate.
Sodium-2,2'-methylene-bis (4-pentyl-6-methylphenyl) phosphate.
Sodium-2,2'-methylene-bis (4-pentyl-6-ethylphenyl) phosphate.
Sodium-2,2'-ethylene-bis (4,6-di-t-butylphenyl) phosphate.
Sodium-2,2′-ethylene-bis (4-tert-butyl-6-methylphenyl) phosphate.
Sodium-2,2′-ethylene-bis (4-tert-butyl-6-ethylphenyl) phosphate.
Sodium-2,2'-ethylene-bis (4,6-di-i-propylphenyl) phosphate.
Sodium-2,2′-ethylene-bis (4-i-propyl-6-methylphenyl) phosphate.
Sodium-2,2'-ethylene-bis (4-di-i-propyl-6-ethylphenyl) phosphate.
Sodium-2,2'-ethylene-bis (4,6-dipentylphenyl) phosphate.
Sodium-2,2′-ethylene-bis (4-pentyl-6-methylphenyl) phosphate.
Sodium-2,2'-ethylene-bis (4-pentyl-6-ethylphenyl) phosphate.
Sodium-2,2'-trimethylene-bis (4,6-di-t-butylphenyl) phosphate.
Sodium-2,2'-tetramethylene-bis (4,6-di-t-butylphenyl) phosphate.
Sodium-2,2′-t-octylmethylene-bis (4,6-di-t-butylphenyl) phosphate.

Calcium-bis [2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphate].
Calcium-bis [2,2′-methylene-bis (4-tert-butyl-6-methylphenyl) phosphate].
Calcium-bis [2,2′-methylene-bis (4-tert-butyl-6-ethylphenyl) phosphate].
Calcium-bis [2,2′-methylene-bis (4,6-di-i-propylphenyl) phosphate].
Calcium-bis [2,2′-methylene-bis (4-i-propyl-6-methylphenyl) phosphate].
Calcium-bis [2,2′-methylene-bis (4-di-i-propyl-6-ethylphenyl) phosphate].
Calcium-bis [2,2′-methylene-bis (4,6-dipentylphenyl) phosphate].
Calcium-bis [2,2′-methylene-bis (4-pentyl-6-methylphenyl) phosphate].
Calcium-bis [2,2′-methylene-bis (4-pentyl-6-ethylphenyl) phosphate].
Calcium-bis [2,2′-ethylene-bis (4,6-di-t-butylphenyl) phosphate].
Calcium-bis [2,2′-ethylene-bis (4-tert-butyl-6-methylphenyl) phosphate].
Calcium-bis [2,2′-ethylene-bis (4-tert-butyl-6-ethylphenyl) phosphate].
Calcium-bis [2,2′-ethylene-bis (4,6-di-i-propylphenyl) phosphate].
Calcium-bis [2,2′-ethylene-bis (4-i-propyl-6-methylphenyl) phosphate].
Calcium-bis [2,2′-ethylene-bis (4-di-i-propyl-6-ethylphenyl) phosphate],
Calcium-bis [2,2′-ethylene-bis (4,6-dipentylphenyl) phosphate].
Calcium-bis [2,2′-ethylene-bis (4-pentyl-6-methylphenyl) phosphate].
Calcium-bis [2,2′-ethylene-bis (4-pentyl-6-ethylphenyl) phosphate].
Calcium-bis [2,2′-trimethylene-bis (4,6-di-t-butylphenyl) phosphate].
Calcium-bis [2,2′-tetramethylene-bis (4,6-di-t-butylphenyl) phosphate].
Calcium-bis [2,2′-t-octylmethylene-bis (4,6-di-t-butylphenyl) phosphate].

Aluminum-tris [2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate].
Aluminum-tris [2,2′-methylene-bis (4-tert-butyl-6-methylphenyl) phosphate].
Aluminum-tris [2,2′-methylene-bis (4-tert-butyl-6-ethylphenyl) phosphate].
Aluminum-tris [2,2′-methylene-bis (4,6-di-i-propylphenyl) phosphate].
Aluminum-tris [2,2′-methylene-bis (4-i-propyl-6-methylphenyl) phosphate].
Aluminum-tris [2,2′-methylene-bis (4-di-i-propyl-6-ethylphenyl) phosphate].
Aluminum-tris [2,2′-methylene-bis (4,6-dipentylphenyl) phosphate].
Aluminum-tris [2,2′-methylene-bis (4-pentyl-6-methylphenyl) phosphate].
Aluminum-tris [2,2′-methylene-bis (4-pentyl-6-ethylphenyl) phosphate].
Aluminum-tris [2,2′-ethylene-bis (4,6-di-t-butylphenyl) phosphate].
Aluminum-tris [2,2′-ethylene-bis (4-tert-butyl-6-methylphenyl) phosphate].
Aluminum-tris [2,2′-ethylene-bis (4-tert-butyl-6-ethylphenyl) phosphate].
Aluminum-tris [2,2′-ethylene-bis (4,6-di-i-propylphenyl) phosphate].
Aluminum-tris [2,2′-ethylene-bis (4-i-propyl-6-methylphenyl) phosphate].
Aluminum-tris [2,2′-ethylene-bis (4-di-i-propyl-6-ethylphenyl) phosphate].
Aluminum-tris [2,2′-ethylene-bis (4,6-dipentylphenyl) phosphate].
Aluminum-tris [2,2′-ethylene-bis (4-pentyl-6-methylphenyl) phosphate].
Aluminum-tris [2,2′-ethylene-bis (4-pentyl-6-ethylphenyl) phosphate].
Aluminum-tris [2,2′-trimethylene-bis (4,6-di-t-butylphenyl) phosphate].
Aluminum-tris [2,2′-tetramethylene-bis (4,6-di-t-butylphenyl) phosphate].
Aluminum-tris [2,2′-t-octylmethylene-bis (4,6-di-t-butylphenyl) phosphate].

Hydroxyaluminum-bis [2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphate].
Hydroxyaluminum-bis [2,2′-methylene-bis (4-tert-butyl-6-methylphenyl) phosphate].
Hydroxyaluminum-bis [2,2′-methylene-bis (4-tert-butyl-6-ethylphenyl) phosphate].
Hydroxyaluminum-bis [2,2′-methylene-bis (4,6-di-i-propylphenyl) phosphate].
Hydroxyaluminum-bis [2,2'-methylene-bis (4-i-propyl-6-methylphenyl) phosphate].
Hydroxyaluminum-bis [2,2'-methylene-bis (4-di-i-propyl-6-ethylphenyl) phosphate].
Hydroxyaluminum-bis [2,2'-methylene-bis (4,6-di-pentylphenyl) phosphate].
Hydroxyaluminum-bis [2,2'-methylene-bis (4-pentyl-6-methylphenyl) phosphate].
Hydroxyaluminum-bis [2,2'-methylene-bis (4-pentyl-6-ethylphenyl) phosphate].
Hydroxyaluminum-bis [2,2′-ethylene-bis (4,6-di-t-butylphenyl) phosphate].
Hydroxyaluminum-bis [2,2′-ethylene-bis (4-tert-butyl-6-methylphenyl) phosphate].
Hydroxyaluminum-bis [2,2′-ethylene-bis (4-tert-butyl-6-ethylphenyl) phosphate].
Hydroxyaluminum-bis [2,2′-ethylene-bis (4,6-di-i-propylphenyl) phosphate].
Hydroxyaluminum-bis [2,2'-ethylene-bis (4-i-propyl-6-methylphenyl) phosphate].
Hydroxyaluminum-bis [2,2′-ethylene-bis (4-di-i-propyl-6-ethylphenyl) phosphate].
Hydroxyaluminum-bis [2,2′-ethylene-bis (4,6-di-pentylphenyl) phosphate].
Hydroxyaluminum-bis [2,2′-ethylene-bis (4-pentyl-6-methylphenyl) phosphate].
Hydroxyaluminum-bis [2,2′-ethylene-bis (4-pentyl-6-ethylphenyl) phosphate].
Hydroxyaluminum-bis [2,2'-trimethylene-bis (4,6-di-t-butylphenyl) phosphate].
Hydroxyaluminum-bis [2,2′-tetramethylene-bis (4,6-di-t-butylphenyl) phosphate].
Hydroxyaluminum-bis [2,2′-t-octylmethylene-bis (4,6-di-t-butylphenyl) phosphate] and the like.

  These compounds can be used alone or in combination of two or more.

  Among these, hydroxyaluminum-bis [2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate] represented by the formula (2) can be mentioned as a preferable one. . Specifically, commercially available NA-21 (manufactured by ADEKA Corporation) or the like can be used.

  Further, sodium-2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate represented by the formula (3) can be mentioned as a preferable one.

The content of the nucleating agent containing such an organic phosphate ester compound in the cartridge forming material is 0.01 parts by mass or more and 1.0 parts by mass with respect to 100 parts by mass of propylene homopolymer (hereinafter also referred to as polypropylene ). It is preferable to contain in the ratio below mass part. More preferably, they are 0.05 mass part or more and 0.3 mass part or less. If the content of the nucleating agent is 0.01 parts by mass or more, transparency and mechanical strength can be obtained in the obtained cartridge, and if it is 1.5 parts by mass or less, sufficient transparency, Mechanical strength can be obtained and wasteful consumption can be suppressed.

  The particle size of the nucleating agent is preferably 1 μm or more and 10 μm or less. When the particle size of the nucleating agent is 1 μm or more, it is possible to suppress the nucleating agent from adhering to the manufacturing machine and to prevent the actual blending ratio in the ink cartridge from changing. As a result, variation in the transparency of the optical prism can be suppressed, erroneous detection of the remaining amount of ink can be suppressed, and deterioration in detection accuracy can be suppressed. On the other hand, if the particle diameter is 10 μm or less, the nucleating agent dispersibility is suppressed from being lowered, and uniform permeability and mechanical strength can be obtained in the ink cartridge.

The cartridge forming material preferably contains a neutralizing agent. The neutralizing agent is used to prevent the influence of the residual catalyst used during the polymerization of the propylene homopolymer. As such a neutralizing agent, it is preferable to use a hydrotalcite compound (basic aluminum magnesium carbonate). The hydrotalcite-type compound has little elution to the ink, and can suppress the generation of precipitates in the ink flow path connected to the ink jet head. Specific examples include Mg _4.3 Al ₂ (OH) _12.6 CO ₃ .mH ₂ O. The content of the hydrotalcite compound in the cartridge forming material is preferably 0.005 parts by mass or more and 1.5 parts by mass or less, more preferably 0.05 parts by mass with respect to 100 parts by mass of polypropylene. The amount is 0.5 parts by mass or less. If the hydrotalcite content is 0.005 parts by mass or more, a neutralization effect can be obtained, and if it is 1.5 parts by mass or less, a sufficient neutralization effect is obtained and wasteful consumption is suppressed. can do.

  Furthermore, the cartridge forming material preferably contains, for example, an antioxidant as long as the function of the substance is not impaired. Further, if necessary, an additive used for polypropylene, for example, an ultraviolet absorber, a filler, an antistatic agent, and the like can be contained within a range that does not impede the function of the substance.

  Examples of a method for molding an ink cartridge using the ink cartridge forming material include the following methods. The propylene homopolymer is added with a predetermined amount of the above-mentioned nucleating agent and, if necessary, various additives such as a neutralizing agent, mixed using a Henschel mixer, etc., melt-kneaded using an extruder, kneader, Banbury mixer, etc. A resin composition in which each component is uniformly dispersed and mixed is prepared. The resin composition is once formed into pellets, and then formed into an ink cartridge having a desired shape by a method such as injection molding, extrusion molding, or mold molding. Or it can also shape | mold without going through a pellet.

  It is preferable that the haze value (cloudiness) in a molded body having a thickness of 2 mm formed using the above material is 65% or less. By using a material having such a haze value, detection without error can be performed even when the optical system detection device is used to detect a decrease in the amount of ink stored in the ink cartridge.

  Here, as the haze value, a value measured according to JIS K7105 can be adopted.

Moreover, it is preferable that the bending elastic modulus in the molded object of 2 mm thickness formed using the said material is 1000 Mpa or more. By using a material having such a flexural modulus, ink leakage due to pressing in the ink cartridge can be suppressed.

  Here, as the flexural modulus, a measurement value at 2 mm / min and 23 ° C. can be adopted by a measurement method according to JIS K7203.

  The structure of the ink cartridge of the present invention may be any, but examples thereof include those shown in FIG. 1 and FIG. As shown in the schematic front sectional view of FIG. 1 and the schematic side view of FIG. 2, the main body of the ink cartridge 1 is separated by a partition wall 6 and has an ink storage chamber 4 and an absorber storage chamber 5. An air communication port (not shown) communicating with the atmosphere is connected to the upper portion of the absorber housing chamber 5, and an ink jet recording head (not shown) is connected to the lower portion of the absorber housing chamber 5 to receive ink. An ink supply unit 8 is provided. The ink storage chamber 4 communicates with the absorber storage chamber 5 only through the gas-liquid exchange passage 7, and the ink storage chamber 4 is provided by the porous absorber 2 having a capillary force provided inside the absorber storage chamber 5. The ink stored inside is absorbed and held in the absorbent body. An air introduction groove 6a is provided on the partition wall 6 on the absorber housing chamber 5 side so as to reach the gas-liquid exchange passage 7, and air flowing from the air communication port can be introduced into the ink containing chamber through the air introduction groove. It has become.

Ink supply from such an ink cartridge to the ink jet recording head is performed as follows. When ink is ejected from the ink ejection port of the head by a signal from the ink jet recording apparatus, an ink suction force is generated at the ink ejection port. This suction force is transmitted to the ink in the ink storage chamber 4 via the ink in the absorber storage chamber 5 and the ink present in the gas-liquid exchange passage 7, and an amount of ink corresponding to the amount discharged from the ink storage chamber 4. Is supplied. As the ink is supplied, the pressure inside the ink storage chamber 4 which is sealed except for the gas-liquid exchange passage 7 decreases, and a pressure difference is generated between the absorber storage chamber 5 into which air flows from the air communication port. . When the ink is continuously discharged, the pressure difference continues to rise, but the air that has flowed into the absorber housing chamber 5 enters the ink housing chamber 4 from the gas-liquid exchange passage 7 through the absorber 2. At this time, the pressure difference between the ink storage chamber 4 and the absorber storage chamber 5 is eliminated. This operation is repeated while the ink jet recording apparatus is driven. At this time, when air flows into the air introduction groove 6 a provided in the partition wall 6, ink is supplied from the ink storage chamber 4 to the absorber storage chamber 5 in the gas-liquid exchange passage 7 and the vicinity thereof. Since the meniscus is formed stably, it is performed smoothly. The inflow of air from the absorber housing chamber 5 to the ink housing chamber 4 is smoothly performed by constantly and promptly breaking the meniscus of ink and air formed in the gas-liquid exchange passage 7 and its vicinity. . In this way, while the ink discharge operation is continuously performed, the supply of ink from the ink storage chamber 4 to the absorber storage chamber 5 and the absorber storage chamber while maintaining a constant negative pressure in the cartridge. Thus, air can smoothly flow from 5 into the ink storage chamber 4.

  The ink cartridge is provided with a latch lever 9 that is an elastic lever having an engaging portion 9a so as to protrude from the outer wall of the ink cartridge. It can be easily positioned and installed on the carriage or the like of the ink jet recording head by the engaging portion of the latch lever, and is further detachable. When ink consumption is detected by an ink amount detection device, which will be described later, the ink cartridge is detached from the carriage or the like by operating the latch lever, and can be replaced with an ink cartridge filled with ink.

The ink cartridge of the present invention is provided with an optical detector that detects the amount of ink stored in the ink storage chamber. The optical system detector is, for example, disposed at the bottom of the ink containing chamber , and includes a prism 3 that is a part of the optical system detector, a light projecting unit that emits light to the prism, and a light receiving unit that receives light transmitted through the prism. A light projecting / receiving device (not shown) having a light receiving portion can be detected, and the remaining amount of ink can be detected by light received by the light receiving portion. The ink cartridge of the present invention has high transparency, facilitates optical detection of the remaining amount of ink, and can perform highly accurate detection without erroneous detection.

As the ink that can be stored in the ink cartridge of the present invention, any dye ink used in the ink jet recording apparatus can be used. Specifically, pure water / glycerin / food black Z (water-soluble black dye) / N-methylpyrrolidone (70/15/3/12 (mass ratio) black ink and the like can be exemplified. It is not limited.

  Hereinafter, the ink cartridge of the present invention will be described in detail, but the technical scope of the present invention is not limited thereto.

[Example 1]
[Resin molding]
100 parts by mass of isotactic polypropylene, 0.3 parts by mass of an organic phosphate ester compound, and 0.05 parts by mass of a neutralizing agent are mixed and injection molded by an extruder, and a test piece having a thickness of 2 mm and a prism part are included. An ink cartridge was prepared. As an organic phosphate ester compound, sodium-2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate (NA-11 represented by the formula (3): ADEKA Corporation Manufactured, particle size: 5 to 10 μm). As the neutralizing agent, DHT-4A (manufactured by Kyowa Chemical Co., Ltd.) described in JP-A No. 05-222250 (Asahi Denka Kogyo Co., Ltd.) or the like was used.

[Elution test to ink]
The obtained test piece was immersed in the test ink and heated at 100 ° C. for 10 hours using a PCT (pre-shear cooker tester). After air cooling to room temperature, the UV-visible absorption spectrum of the test ink was measured. The results are shown in Table 1.

[Transparency evaluation]
The obtained test piece having a thickness of 2 mm was subjected to haze measurement according to JIS K7105. The results are shown in Table 2. It can be evaluated that the lower the haze value, the higher the transparency.

[Bend elasticity measurement and stiffness evaluation]
The obtained test piece having a thickness of 2 mm was subjected to bending elastic modulus measurement according to JIS K7203. The results are shown in Table 3.

[Measurement of crystallization temperature]
A pellet of the resin composition was prepared, and DSC measurement was performed using a differential scanning calorimeter (DSC822: manufactured by METTLER TRADE). The results are shown in Table 4.

[Evaluation of reflected light quantity of prism]
The amount of reflected light of the ink cartridge having the prism portion was evaluated. The results are shown in Table 5.

[Example 2]
Instead of sodium-2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphate, hydroxyaluminum-bis [2,2'-methylene-bis (4,6-di-t- Butylphenyl) phosphate] (NA-21: manufactured by ADEKA Corporation) (Formula (2)) was used. Otherwise, a test piece was prepared in the same manner as in Example 1.

[Comparative Example 1]
Instead of sodium-2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate, bis (p-methylbenzylidene) sorbitol (Gelol DH: manufactured by Shin Nippon Rika Co., Ltd.) was used. Otherwise, a test piece was prepared in the same manner as in Example 1.

[Comparative Example 2]
Instead of sodium-2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate, 2,4-dibenzylidene sorbitol (Gelol D: manufactured by Shin Nippon Rika Co., Ltd.) was used. Otherwise, a test piece was prepared in the same manner as in Example 1.

[Comparative Example 3]
A test piece was prepared in the same manner as in Example 1 except that sodium-2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate was not used.

[Comparative Example 4]
A test piece was prepared in the same manner as in Example 1 except that an ethylene-propylene random copolymer was used instead of isotactic polypropylene.

[Comparative Example 5]
A test piece was prepared in the same manner as in Example 1 except that an ethylene-propylene random copolymer was used instead of isotactic polypropylene and no nucleating agent was used.

[Example 3]
Sodium-2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate (NA-11: manufactured by ADEKA Corporation) was used in the same manner as in Example 1 except that the particle diameter was 1 μm. Ink cartridges were prepared.

  In general, since organic eluate has an absorption band in the ultraviolet-visible region, it can be determined that the lower the absorbance, the less eluate. From the results, it is clear that the ink cartridge of the present invention has a smaller absorbance than Comparative Examples 1 and 2, shows almost the same value as Comparative Example 3 with no nucleating agent added, and very little elution.

  In general, it is known that when the haze value at a thickness of 2 mm is 70% or more, the optical detection device does not function normally due to the influence of ink or bubbles remaining on the optical reflecting surface. . From the results, it is clear that the ink cartridge of the present invention has high haze values of 53% and 50%, respectively, and high transparency.

  From the results, the ink cartridge of the present invention can obtain a high flexural modulus. The latch lever of the ink cartridge of the present invention has elasticity and can be attached and detached to and from an ink jet recording apparatus. It has rigidity compared to an ink cartridge of the same thickness and prevents ink leakage due to pressing. It is clear that it can be suppressed.

  From the results, the ink cartridge material of the present invention has a high crystallization temperature (Tc), and when the ink cartridge is molded, it can be solidified at a high temperature and the cooling time can be shortened, thereby improving the tact time.

  As a result, in the ink cartridge of the present invention, since the actual blending amount of the nucleating agent is stabilized, a decrease in the amount of light is suppressed, and the ink remaining amount in the ink cartridge can be detected with high accuracy. In addition, it is possible to suppress the elution of the nucleating agent from affecting printing, and it is possible to provide a high-quality ink cartridge.

It is a schematic front sectional view showing an example of the ink cartridge of the present invention. It is a schematic side view showing an example of the ink cartridge of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ink cartridge 2 Absorber 3 Prism 4 Ink storage chamber 5 Absorber storage chamber 6 Partition wall 6a Air introduction groove 7 Gas-liquid exchange passage 8 Ink supply port 9 Latch lever (elastic lever)

Claims (7)

The ink storage chamber for accommodating the dye ink, an ink cartridge for an ink jet recording apparatus provided with a part of the optical system detector for detecting the dye ink amount,
Some of the ink cartridge and the optical system detector, propylene homopolymer, a nucleating agent comprising an organic phosphate ester compound represented by formula (1), in that it is formed of a material containing A characteristic ink cartridge.

Wherein R ¹ represents a divalent hydrocarbon group having 1 to 10 carbon atoms, R ² to R ⁵ independently represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and M represents 1 to 3 A metal atom having any valence of valence or an atomic group containing the same is represented, and m represents an integer of 1 to 3.) The ink cartridge according to claim 1, wherein the organic phosphate ester compound is represented by Formula (2) or Formula (3).

3. The ink cartridge according to claim 1, wherein the material contains 0.01 to 1.0 part by mass of the nucleating agent with respect to 100 parts by mass of the propylene homopolymer . The ink cartridge according to any one of claims 1 to 3, wherein the material contains hydrotalcite as a neutralizing agent. The ink cartridge according to claim 4, wherein the material contains 0.005 parts by mass or more and 1.5 parts by mass or less of the neutralizing agent with respect to 100 parts by mass of the propylene homopolymer .   6. The ink cartridge according to claim 1, wherein a haze value of a molded body having a thickness of 2 mm formed of the material is 65% or less. 7. The ink cartridge according to claim 1, further comprising an elastic lever that protrudes from an outer wall and is positioned and attached to an ink jet recording apparatus so that it can be attached and detached .

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