Patent Application
20080021170
The ink cartridge of the present invention is an ink cartridge for an ink jet recording apparatus, which comprises being formed by a material including a propylene homopolymer and a nucleating agent containing an organic phosphoric acid ester compound represented by a formula (1):
wherein R1 represents a divalent hydrocarbon group having 1 to 10 carbon atoms; and R2 to R5 each independently represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms; M represents a metal atom of a valence from monovalent to trivalent or an atomic group containing such metal atom; and m represents an integer from 1 to 3.
The propylene homopolymer, to be employed in forming the ink cartridge of the present invention, is preferably polypropylene of an isotactic structure. Polypropylene of isotactic structure preferably has a high isotactic pentad ratio.
The nucleating agent to be employed in forming the ink cartridge of the present invention is to have a low interaction with the ink and to have a function of providing transparency. Such nucleating agent contains an organic phosphoric acid ester compound represented by the formula (1). In the formula, R1 represents a hydrocarbon group having 1 to 10 carbon atoms, and R2 to R5 each independently represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. The alkyl group may be linear, branched or cyclic. Also in the formula, M represents a metal atom of a valence from monovalent to trivalent or an atomic group containing such metal atom; and m represents an integer from 1 to 3. Examples of M include an alkali metal such as sodium, potassium or lithium, an alkali earth metal such as calcium or magnesium, an alkali earth metal having a hydroxyl group, a trivalent metal such as aluminum or indium, and such trivalent metal having a hydroxyl group. Specific examples of such organic phosphoric acid ester compound include:
sodium 2,2′-methylene-bis(4,6-di-t-butylphenyl)-phosphate,
sodium 2,2′-methylene-bis(4-t-butyl-6-methylphenyl)phosphate,
sodium 2,2′-methylene-bis(4-t-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-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-t-butyl-6-methylphenyl)-phosphate,
sodium 2,2′-ethylene-bis(4-t-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-i-propyl-6-ethylphenyl)phosphate,
sodium 2,2′-ethylene-bis(4,6-di-pentylphenyl)-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-t-butyl-6-methylphenyl)phosphate],
calcium bis[2,2′-methylene-bis(4-t-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-i-propyl-6-ethylphenyl)phosphate],
calcium bis[2,2′-methylene-bis(4,6-di-pentylphenyl)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-t-butyl-6-methylphenyl)phosphate],
calcium bis[2,2′-ethylene-bis(4-t-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-i-propyl-6-ethylphenyl)phosphate],
calcium bis[2,2′-ethylene-bis(4,6-di-pentylphenyl)-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], and
calcium bis[2,2′-t-octylmethylene-bis(4,6-di-t-butylphenyl)phosphate].
Further examples include:
aluminum tris[2,2′-methylene-bis(4,6-di-t-butylphenyl)phosphate],
aluminum tris[2,2′-methylene-bis(4-t-butyl-6-methylphenyl)phosphate],
aluminum tris[2,2′-methylene-bis(4-t-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-i-propyl-6-ethylphenyl)phosphate],
aluminum tris[2,2′-methylene-bis(4,6-di-pentylphenyl)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-t-butyl-6-methylphenyl)phosphate],
aluminum tris[2,2′-ethylene-bis(4-t-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-i-propyl-6-ethylphenyl)phosphate],
aluminum tris[2,2′-ethylene-bis(4,6-di-pentylphenyl)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], and
aluminum tris[2,2′-t-octylmethylene-bis(4,6-di-t-butylphenyl)phosphate].
Further examples include:
hydroxyaluminum bis[2,2′-methylene-bis(4,6-di-t-butylphenyl)phosphate],
hydroxyaluminum bis[2,2′-methylene-bis(4-t-butyl-6-methylphenyl)phosphate],
hydroxyaluminum bis[2,2′-methylene-bis(4-t-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-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-t-butyl-6-methylphenyl)phosphate],
hydroxyaluminum bis[2,2′-ethylene-bis(4-t-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-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], and
hydroxyaluminum bis[2,2′-t-octylmethylene-bis(4,6-di-t-butylphenyl)phosphate].
These compounds may be employed singly or in a combination of two or more kinds.
Among these, hydroxyaluminum bis[2,2′-methylene-bis(4,6-di-t-butylphenyl)phosphate] represented by a formula (2) (NA-21, manufactured by ADEKA Co.) may be mentioned as particularly advantageous:
Also sodium 2,2′-methylene-bis(4,6-di-t-butylphenyl)phosphate represented by a formula (3) may be mentioned as advantageous:
The nucleating agent containing such organic phosphoric acid ester compound is present in a content, in the cartridge forming material, preferably of from 0.01 to 1.0 part by mass, more preferably from 0.05 to 0.3 parts by mass, with respect to 100 parts by mass of the polypropylene. A content of the nucleating agent equal to or larger than 0.01 parts by mass allows to obtain a transparency and a mechanical strength in the obtained cartridge, and a content equal to or less than 1.0 part by mass allows to obtain a transparency and a mechanical strength sufficiently without unnecessary waste.
According to the invention, it is preferable that the nucleating agent has a particle diameter of from 1 μm to 10 μm. If the particle diameter of the nucleating agent is too small, the nucleating agent becomes easy to attach on a manufacturing machine so that deviation of an actual compounding amount becomes large. As a result of this, it is fear that a transparency of optical prism is deviated, an accuracy of detection of ink remaining amount is lowered, and detection is incorrectly made depending on the conditions. In contrast, it is not preferable that the particle diameter is too large, because dispersion property of nucleating agent is lowered and the effect of the nucleating agent is lowered.
In the cartridge forming material mentioned above, a neutralizing agent is contained advantageously. The neutralizing agent is employed for preventing the influence of residue of a catalyst, employed in the polymerization of the propylene homopolymer. As such neutralizing agent, a hydrotalcite type compound (basic aluminum magnesium carbonate) is employed advantageously. The hydrotalcite type compound shows little dissolution in the ink, thus capable of suppressing generation of deposits in the ink flow path connected to the ink jet head. A specific example is Mg4.3Al2(OH)12.6CO3.mH2O. A content of the hydrotalcite type compound in the cartridge forming material is preferably from 0.005 to 1.5 parts by mass, more preferably from 0.05 to 0.5 parts by mass, with respect to 100 parts by mass of the polypropylene. A content of the hydrotalcite type compound equal to or larger than 0.005 parts by mass can provide a neutralizing effect, and a content equal to or less than 1.5 parts by mass can provide a sufficient neutralizing effect without unnecessary waste.
In the cartridge forming material mentioned above, an antioxidant may be contained advantageously, within an extent not hindering the functions of the aforementioned substances. Also if necessary, additives employed in the polypropylene, such as an ultraviolet absorber, a filler and an antistatic may be contained within an extent not hindering the functions of the aforementioned substances.
An ink cartridge can be formed, with the aforementioned ink cartridge forming material, for example by a following method. Propylene homopolymer is added with prescribed amounts of the nucleating agent and if necessary various additives such as the neutralizing agent, then mixed for example with a Henschel mixer, and melt kneaded with an extruder, a kneader or a Bambury mixer to obtain a resin composition in which the components are uniformly dispersed and mixed. The resin composition may be once formed into pellets and then molded into an ink cartridge of a desired shape by an injection molding, an extrusion molding or a press molding. Otherwise, it may be molded without once being formed into pellets.
The ink cartridge molded with the aforementioned material can have a haze value of 65% or less for a 2 mm thickness. When an optical detecting apparatus is employed for detecting the decrease in the contained ink amount, such haze value enables a detection without an error.
As the haze value, a value measured according to JIS K7105-1981 may be adopted.
Also the ink cartridge molded with the aforementioned material can have a flexural modulus of 1000 MPa or higher for a 3 mm thickness. Such flexural modulus can suppress the ink leakage when the cartridge is depressed.
As the flexural modulus, a value measured according to JIS K7171-1994, under conditions of 2 mm/minute and 23° C.
The ink cartridge of the present invention may have any structure, but an example thereof is illustrated in
The ink supply from such ink cartridge to the ink jet recording head is executed in the following manner. When the ink is discharged from an ink discharge port of the head in response to a signal from the ink jet recording apparatus, an ink suction force is generated in the ink discharge port. Such suction force is transmitted through the absorbent member in the absorbent member containing chamber 5 and the gas-liquid exchange path 7 to the ink in the ink containing chamber 4, whereby the ink is supplied from the ink containing chamber 4 in an amount corresponding to the discharged amount. Along with the ink supply, the internal pressure of the ink containing chamber 4, which is closed except for the gas-liquid exchange path 7, is lowered to generate a pressure difference from the absorbent member containing chamber 5 in which the air is introduced from the atmosphere communication opening. While the ink discharge is executed continuously, the pressure difference continues to increase, but the air flowing into the absorbent member containing chamber 5 enters the ink containing chamber 4 through the absorbent member 2 and through the gas-liquid exchange path 7. At this point, the pressure difference between the ink containing chamber 4 and the absorbent member containing chamber 5 is resolved. This operation is repeated during the operation of the ink jet recording apparatus. In this operation, as the air flows into the air introducing groove 6a formed on the partition wall 6, an ink-air meniscus is stably formed in the gas-liquid exchange path 7 and the vicinity thereof, whereby the ink supply from the ink containing chamber 4 to the absorbent member containing chamber 5 is executed smoothly. Also the air introduction from the absorbent member containing chamber 5 to the ink containing chamber 4 is executed by constantly and promptly breaking the ink-air meniscus formed in the gas-liquid exchange path 7 and the vicinity thereof. In this manner, while the ink discharge operation is continued, the ink supply from the ink containing chamber 4 to the absorbent member containing chamber 5 and the air supply from the absorbent member containing chamber 5 to the ink containing chamber 4 can be executed smoothly while maintaining a prescribed negative pressure in the cartridge.
The ink cartridge also has a latch lever 9, which is an elastic lever having an engaging portion 9a and protrudes from an external wall of the ink cartridge. The engaging portion of the latch lever enables easy positioning and mounting for example on a carriage for the ink jet recording head, and also enables easy attaching and detaching. When the consumption of ink is detected by an ink amount detection apparatus to be described later, the latch lever can be operated to detach the ink cartridge from the carriage or the like for replacement with an ink cartridge filled with the ink.
In the ink cartridge of the invention, a detection apparatus is provided for detecting the ink amount contained in the ink containing chamber. The detection apparatus for example includes a prism 3 disposed in a bottom portion in the ink containing chamber, and a light emit/receiving apparatus (not illustrated) having a light emitting portion for irradiating the prism with a light and a light receiving portion for receiving the light transmitted by the prism, and can detect the remaining ink amount by the light received by the light receiving portion. The ink cartridge of the invention, having a high transparency, facilitates the optical detection of the remaining ink amount, thereby enabling detection of a high precision without an error.
The ink to be contained in the ink cartridge of the present invention may be any ink usable in the ink jet recording apparatus. A specific example is a black-color ink having a formulation of purified water/glycerin/Food Black Z (water-soluble black dye)/N-methylpyrrolidone (70/15/3/12 (parts by weight)), but the present invention is not limited to such example.
In the following, the ink cartridge of the present invention will be clarified in more details by examples, but the technical scope of the present invention-is not limited by such examples.
[Resin Molding]
100 parts by mass of an isotactic polypropylene, 0.3 parts by mass of an organic phosphoric acid ester compound, and 0.05 part by mass of neutralizing agent were mixed, and injection molded by an extruder to prepare a test piece of a thickness of 2 mm and an ink cartridge having a prism portion.
A sodium 2,2′-methylene-bis(4,6-di-t-butylphenyl)phosphate (NA-11: manufactured by ADEKA Co., particle diameter: 5-10 μ) represented by a formula (3) as an organic phosphoric acid ester compound and 0.05 part by mass of DHT-4A manufactured by Kyowa Chemical Co.) which is disclosed in Japanese Patent Application Laid-Open No. H05-222250 (Asahi dennka kogyo K.K.) and so on, as the neutralizing agent were mixed, and injected molded by an extruder to prepare a test piece of a thickness of 2 mm and an ink cartridge having a prism portion.
[Dissolution Test in Ink]
The obtained test piece was immersed in a test ink and heated at 100° C. for 10 hours in a PCT (pressure cooker tester). After cooling to the normal temperature, the test ink was subjected to a measurement of ultraviolet-visible absorption spectrum. Obtained result is shown in Table 1.
[Evaluation of Transparency]
The obtained test piece was subjected to a haze measurement according to JIS K7105-1981. Obtained result is shown in Table 2. A lower haze value indicates a higher transparency.
[Measurements of Flexural Modulus and Rigidity]
The obtained test piece was subjected to a measurement of flexural modulus according to JIS K7171-1994. Obtained result is shown in Table 3.
[Measurement of Crystallizing temperature]
Pellets of the resin composition were prepared and subjected to a DSC measurement by a differential scanning calorimeter (DSC822, manufactured by Mettler-Toledo Co.). Obtained result is shown in Table 4.
[Measurement of Reflective Light Amount of Prism]
An evaluation of reflective light amount of ink cartridge having a prism portion is performed. Obtained result is shown in Table 5.
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 (NA-11, manufactured by ADEKA Co.) was replaced by hydroxyaluminum bis[2,2′-methylene-bis(4,6-di-t-butylphenyl)phosphate] represented by the formula (2) (NA-11, manufactured by ADEKA Co.).
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 (NA-11, manufactured by ADEKA Co.) was replaced by bis(p-methylbenzylidene)sorbitol (Gelol DH, manufactured by New Japan Chemical Co.).
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 (NA-11, manufactured by ADEKA Co.) was replaced by 2,4-dibenzylidenesorbitol (Gelol D, manufactured by New Japan Chemical Co.).
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 (NA-11, manufactured by ADEKA Co.) was not used.
A test piece was prepared in the same manner as in Example 1 except that isotactic polypropylene was replaced by an ethylene-propylene random copolymer.
A test piece was prepared in the same manner as in Example 1 except that isotactic polypropylene was replaced by an ethylene-propylene random copolymer and no nucleating agent is added.
An ink cartridge was prepared in the same manner as in Example 1 except that a particle diameter of sodium 2,2′-methylene-bis(4,6-di-t-butylphenyl)phosphate (NA-11, manufactured by ADEKA Co.) represented by a formula (3) was 1 μm or less.
As organic dissolved substance generally has an absorption band in the ultraviolet region, a lower absorbance can be considered to indicate a smaller amount of the dissolved substance. Based on the results, the ink cartridge of the present invention has an absorbance smaller than in Comparative Examples 1 and 2, and comparable to that of Comparative Example 3 in which the nucleating agent was not added, thus clearly indicating a very small dissolution.
It is generally known that a haze value of 70% or higher for a 2 mm thickness may hinder, though very rarely, the normal function of the optical detection apparatus due to an influence of the ink or bubble remaining on the optical reflecting face. Based on the results, the ink cartridges of the present invention had haze values of 53% and 50%, thus clearly indicating a high transparency.
Based on the results, the ink cartridge of the present invention has a high flexural modulus. It is evident that the ink cartridge of the present invention has an elasticity in the latch lever, thus enabling satisfactory attaching to and detaching from the ink jet recording apparatus, and has a higher rigidity in comparison with the ink cartridge of a same thickness, thus evidently capable of suppressing the ink leakage under depression.
Based on the results, the ink cartridge material of the present invention has a high crystallizing temperature (Tc), and, in the molding of the ink cartridge, can solidify at a higher temperature and can reduce the cooling time, thereby reducing the tact time.
Based on the results, in the ink cartridge of the present invention, an actual compounding amount of nucleating agent is stabilized so that an amount of light is prevented from being lowered and a remaining amount of ink in the ink cartridge can be detected with high accuracy. Further, according to the invention, a high quality ink cartridge in which eluation matter of a nucleating agent rarely influences printing can be provided. In table 5, “o” of result means that light amount was not lowered and printing is not influenced by the eluation matter; and “x” means that either light amount was lowered or printing was influenced by the eluation matter.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2006-196758 filed Jul. 19, 2006, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-196758 | Jul 2006 | JP | national |
