JP5528887B2 - High gas barrier composition and liquid feeding member - Google Patents

Description

  The present invention relates to a high gas barrier composition suitably used for liquid transfer and a liquid feeding member comprising this composition, particularly a tube suitably used as an ink tube for ink supply of an ink jet printer. The present invention relates to a material having excellent gas barrier properties and excellent flexibility, kink resistance, moldability, and heat-fusibility.

  In an ink jet printer, ink is supplied from an ink tank to an ink jet head using an ink tube. Here, ink remains in the ink tube even when printing is stopped, and when the solvent or moisture evaporates from the remaining ink, the ink density becomes high and the viscosity becomes high. May occur. For this reason, the ink tube is required to have a gas barrier property that allows the solvent and moisture to hardly volatilize through the tube material.

  As materials satisfying such characteristics, for example, Patent Documents 1 and 2 describe thermoplastic elastomers in which a rubber component containing butyl rubber in an olefin-based thermoplastic resin is finely dispersed by dynamic crosslinking. Patent Document 3 describes a rubber composed of a butyl rubber polymer, an organic peroxide crosslinked rubber polymer, and an organic oxide. It is described that these materials are used as ink tubes for ink jet printers. Moreover, there exist patent documents 4-8 as a technique relevant to this invention, for example.

Japanese Patent No. 4160360: Sumitomo Rubber Industries JP 2009-95999 A: Sumitomo Rubber Industries JP 2007-45015 A: Brother Industries JP 2007-307875 A: Kureha Plastics Japanese Patent Application No. 2008-241168: Krabe Japanese Patent Application No. 2009-182874: Krabe JP 2005-307054 A: Bridgestone International Publication No. WO03 / 021309: Bridgestone

  In an ink jet printer, an ink tank is a fixed part, while an ink head is a part that operates during printing. For this reason, the ink tube connecting them needs to be flexible and difficult to kink so as not to hinder the operation of the ink head. Here, in the tubes according to Patent Documents 1 and 2, butyl rubber is dynamically cross-linked, that is, butyl rubber is cross-linked in a state where olefinic thermoplastic resin and butyl rubber are blended. Similarly, the tube according to Patent Document 3 is cross-linked after blending uncrosslinked butyl rubber with another rubber polymer. At this time, depending on the type of the olefin-based thermoplastic resin, performance may be affected by crosslinking. Specifically, the flexibility of the tube is lowered, and the bonding strength between the tubes is lowered when the tubes are connected by thermal fusion.

  The present invention has been made to solve such problems of the prior art, and the object of the present invention is, in particular, excellent gas barrier properties, flexibility, kink resistance, moldability. Another object of the present invention is to provide a composition and a liquid feeding member that are excellent in heat-fusibility.

In order to achieve the above object, the composition according to claim 1 of the present invention comprises 16 to 200 parts by weight of a polyolefin-based polymer material and 5 to 100 parts by weight of partially crosslinked butyl rubber with respect to 100 parts by weight of a styrene copolymer. Is blended.
The composition according to claim 2 is characterized in that the styrene copolymer is a styrene-isobutylene-styrene block copolymer.
Moreover, the liquid feeding member of Claim 3 consists of said composition.
Moreover, the tube of Claim 4 consists of said composition.
In the multiple tube according to claim 5, at least two or more of the above tubes are connected in parallel.
According to a sixth aspect of the present invention, there is provided a method for producing a multiple tube comprising 16 to 200 parts by weight of a polyolefin polymer material and 5 to 100 parts by weight of partially crosslinked butyl rubber with respect to 100 parts by weight of a styrene copolymer. The obtained composition is extruded to form a tube, and at least two tubes are arranged in parallel, and the tubes are heat-sealed.

In the present invention, while maintaining the excellent gas barrier property and flexibility of the styrene-based thermoplastic elastomer, the composition having the excellent gas barrier property of butyl rubber, kink resistance, and the excellent moldability of the polyolefin polymer material and It can be set as the liquid feeding member which consists of this composition.
Further, since uncrosslinked butyl rubber does not have rubber elasticity and needs to be crosslinked, in the present invention, butyl rubber partially crosslinked in advance is used as described above. Therefore, since it is not necessary to crosslink after blending the olefin polymer material, the olefin polymer material is not crosslinked, so that it does not affect the performance and retains excellent flexibility. Can do.
In addition, for example, a color inkjet printer includes an ink tank, an ink tube, and an inkjet head for each color. At this time, if each of the plurality of ink tubes operates independently, the ink tubes may be rubbed and worn or entangled. Therefore, there is a demand for a multiple tube in which a plurality of ink tubes are integrated. In the present invention, since the polyolefin-based polymer material is not cross-linked, the tubes can be easily heat-sealed to form a multiple tube.

It is a perspective view which shows the structure of the multiple tube by this invention. It is the schematic for demonstrating the minimum bending radius measurement. It is an end elevation which shows the structure of the multiple tube by the other form of this invention. It is an end elevation which shows the structure of the multiple tube by the other form of this invention. It is an end elevation which shows the structure of the multiple tube by the other form of this invention.

  The composition of the present invention comprises a styrene copolymer, a polyolefin polymer material, and a partially crosslinked butyl rubber.

  Examples of the styrene copolymer include styrene-ethylene-butylene-styrene copolymer (SEBS), styrene-ethylene-propylene-styrene copolymer (SEPS), and styrene-ethylene-ethylene-propylene-styrene copolymer. (SEEPS), styrene-isobutylene-styrene copolymer (SIBS), styrene-butadiene-styrene copolymer (SBS), styrene-isoprene-styrene copolymer (SIS), and the like. These are considered to have a block copolymer structure. Among these, a styrene-isobutylene-styrene block copolymer (SIBS) having particularly excellent gas barrier properties is preferable.

  By blending a polyolefin-based polymer material with this styrene-based thermoplastic elastomer, moldability can be improved and heat-fusibility can be imparted. Examples of polyolefin polymer materials include polyethylene resins, polypropylene resins, polybutene resins, ethylene-α-olefin copolymers, ethylene-vinyl acetate copolymers, ethylene- (meth) ethyl acrylate copolymers, ethylene- (meta ) Olefin resin such as methyl acrylate copolymer, ethylene-propylene copolymer, etc., Olefin rubber such as ethylene-propylene-diene copolymer, etc., and an olefin in which a rubber component is dispersed in an olefin resin such as polypropylene resin. A thermoplastic elastomer can be used. Further, a resin obtained by grafting or copolymerizing a polymer monomer having an unsaturated carboxylic acid such as maleic acid or maleic anhydride to an olefin resin may be used. Moreover, these may be used individually by 1 type, and may mix and use 2 or more types. The blending amount of the polyolefin polymer material is preferably 16 to 200 parts by weight with respect to 100 parts by weight of the styrene copolymer. If it is less than 16 parts by weight, the moldability is poor, and if it exceeds 200 parts by weight, the flexibility is lowered.

  The polyolefin polymer material preferably contains a crystalline part. Thereby, heat-fusibility improves further. “Contains a crystalline part” means a case where a crystalline resin is blended or a block copolymer having a block composed of a crystalline monomer component. Specific examples include those containing a crystalline resin such as polyethylene, polypropylene, polyamide, polyacetal, and polyethylene terephthalate, and those containing a block copolymer having a polyethylene block or a polypropylene block. For example, an olefin thermoplastic elastomer in which a rubber component is dispersed in the above-described polypropylene resin also corresponds to a polyolefin polymer material including a crystalline portion. One of these may be included alone, or two or more thereof may be included.

  Moreover, kink resistance can be improved by mix | blending partially crosslinked butyl rubber, maintaining gas barrier property at the high level. Butyl rubber is a copolymer composed of isobutylene groups and isoprene groups, and is usually abbreviated as IIR. Butyl rubber is a material having high gas barrier properties and excellent chemical resistance and oxidation resistance, and a partially cross-linked butyl rubber is a partially cross-linked butyl rubber used in the present invention. The Mooney viscosity at 127 ° C. of the partially crosslinked butyl rubber is preferably 30 to 90. If it is less than 30, permanent elongation characteristics may not be sufficient even if an olefin polymer material is blended, and the chemical resistance tends to decrease. If it exceeds 100, the moldability deteriorates. The compounding amount of the partially crosslinked butyl rubber is preferably 5 to 100 parts by weight with respect to 100 parts by weight of the styrene copolymer. If the amount is less than 5 parts by weight, the effect of improving kink resistance is not sufficient, and if it exceeds 100 parts by weight, the formability may be reduced and it may be difficult to form the shape intended by the design.

  Moreover, you may mix | blend various commonly used additives in the range which does not inhibit the objective of this invention. Examples of such additives include antioxidants, extenders, flame retardants, anti-aging agents, cross-linking agents, cross-linking aids, softeners, dispersants, colorants, and the like.

  The composition of the present invention is sufficiently kneaded using a known kneader such as a roll, a kneader, a banbury, a uniaxial kneader, a biaxial kneader, or the like by appropriately blending the above constituent materials. Can be obtained. The liquid feeding member of the present invention can be obtained by molding this composition into, for example, a tube shape by a molding method such as extrusion molding.

  It is also conceivable that the above composition is formed into a tube shape, and at least two or more of these tubes are connected in parallel to form a multiple tube as shown in FIG. For example, a color ink jet printer includes an ink tank, an ink tube, and an ink jet head for each color. At this time, if each of the plurality of ink tubes operates independently, the ink tubes may be rubbed and worn or entangled. Therefore, it is preferable to make the multiple tube 10 in which a plurality of tubes 1 are integrated. As a method of continuously connecting in parallel, for example, a method of passing the tubes 1 arranged in parallel in a heating furnace set to be equal to or higher than the softening point temperature of the composition constituting the tubes 1 and heat-sealing the tubes 1 to each other, A method of arranging the tubes 1 in parallel and blowing hot air to a place where the tubes 1 are in contact with each other and heat-sealing the tubes 1 can be considered. It is also conceivable to perform extrusion or the like so as to obtain the shape of the multiple tube 10 from the beginning.

  Moreover, as a form of a multiple tube, it is not limited to what is shown in FIG. 1, The form which laminated | stacked multiple rows is also considered. As an example, FIG. 3A shows a multiple tube 10 composed of a total of eight tubes 1 in which four tubes 1 are connected in parallel and stacked in two rows (hereinafter, the left-right direction in FIG. 3). Are shown as “rows” and up and down as “columns”). As a method for manufacturing such a multiple tube 10, for example, a method of arranging eight tubes 1 in the form of 4 rows × 2 columns from the beginning and thermally fusing the tubes 1 together, And then connecting them in 4 rows and stacking them in two rows, and then heat-sealing them, heat-sealing the tubes 1 in 2 rows in advance, connecting them in parallel, and arranging them in 4 rows to further heat them. A method of fusing can be considered. Among these, as shown in FIG. 3 (b), a method in which two rows of tubes 1 are heat-sealed in advance and connected in parallel, and these are arranged in four rows and further heat-sealed is the method of heat-sealing. This is preferable because the heat at the time can be applied uniformly. For example, eight tubes 1 are arranged in the form of 4 rows × 2 columns from the beginning and the tubes 1 are heat-sealed with each other, or the four tubes 1 are heat-sealed in advance and connected to the 4 rows. In the case of a method in which two rows are stacked and further heat-sealed, heat fusion between a tube of (2 rows, 1 column) and a tube of (2 rows, 2 columns) and (3 rows, 1 column) ) And the (3 rows, 2 columns) tube are heat-sealed, the portion to be contacted is surrounded by the tube, so that heat may not be efficiently applied. Of course, although there are difficulties in manufacturing, it is conceivable to perform extrusion or the like so as to form the multiple tube 10 from the beginning. Further, the present invention is not limited to the 4 rows × 2 columns multiple tube 10 as shown in FIG. 3. For example, the number of rows and the number of columns may be larger, as shown in FIGS. 4 and 5. Such a multiple tube 10 having another arrangement may be used. Even in these cases, when heat-sealing, it is preferable to configure the order of heat-sealing so that the locations where the tubes contact each other appear on the outer periphery.

  Embodiments of the present invention will be described below with reference to the drawings. The present embodiment is an example in which the composition of the present invention is molded to form a multiple tube as an example of a liquid feeding member, and FIG. 1 is a perspective view showing the multiple tube of the present invention.

First, the compounding materials shown in Table 2 were sufficiently kneaded by a kneader with the number of parts shown in Table 1, and the resulting composition was supplied to an extruder to produce a tube 1 having an inner diameter of 2 mmφ and an outer diameter of 4 mmφ. Using this tube 1 as a sample, gas barrier properties (water vapor transmission test), flexibility (Young's modulus measurement) and kink resistance (minimum bending radius measurement) were tested.
(Gas barrier property: water vapor transmission test)
Pure water is injected into the hollow portion of the sample, and both ends are sealed. This is left for a certain period of time in an atmosphere of a temperature of 40 ° C. and a humidity of 32% RH, and the weight before and after being left is measured. The amount of volatilization is calculated from the difference in weight before and after standing, and the transmission coefficient is obtained from the following equation.
Permeability coefficient (g · cm / cm ² · 24h) = [Volatilization amount (g) × Tube thickness (cm) × 24] / [Tube effective surface area (cm ² ) × Standing time (h)]
Effective tube surface area (cm ² ) = (Tube inner diameter + Tube wall thickness) x π x Tube length (Flexibility: Young's modulus)
A sample with a marked line distance of 40 mm is pulled at a rate of 100 mm / min by a constant speed tensile tester in an atmosphere of temperature 23 ± 5 ° C., and the stress at that time is measured. The Young's modulus is proportional to the initial slope of the stress-strain curve and is represented by the following equation. In the formula, σ is stress, L ₀ is the original length of the sample, and L is the sample length when the stress is applied.
Young's modulus (MPa) = σ / [(L−L ₀ ) / L ₀ ]
Considering the motor load when driving the ink head, those having a Young's modulus of 40 or less were accepted.
(Kink resistance: minimum bending radius measurement)
As shown in FIG. 2, the tube 1 is rounded to form a circle. Pull both ends of the tube so that the formed circle keeps a perfect circle, gradually reduce the diameter of the circle, and measure the diameter when the tube is buckled. The minimum bending radius is expressed by the following formula. In the formula, D represents the diameter when buckled.
Minimum bending radius (mm) = D / 2
In the standard A4 size inkjet printer, the tube is bent to a bending radius of about 15 mm by the reciprocating motion of the ink head. Therefore, those with a minimum bending radius of 15 mm or less were accepted.
(Formability)
Extrusions that were molded into the desired shape with a good surface condition were evaluated as ◯, those that were formed into the desired shape but with irregularities on the surface were evaluated as △, and the shape could not be molded into the desired shape. A thing is set as x.

(Thermal fusion property: adhesive strength measurement)
Moreover, 300 mm of the tubes 1 obtained as described above are taken, and in a state where five tubes 1 are arranged in parallel, hot air is blown to the portions where the tubes 1 are in contact with each other, and the outer surface portions of the respective tubes 1 are heat-sealed. A multiple tube 10 in which five tubes 1 were connected in parallel was used. Using this multiple tube 10 as a sample, the adhesive strength between the tubes 1 was measured. The adhesive strength was measured by grasping the adjacent tubes 1 of the multiple tube 10 and pulling them apart in the direction perpendicular to the adhesive surface and peeling them. Since there are 4 bonding surfaces for each sample, the value was the average of 4 locations. If the strength is low, the tubes peel off when the tubes are reciprocated. The results are also shown in Table 1.

  As described above, the tube according to the present invention was excellent in all of gas barrier properties, flexibility, kink resistance, and moldability. Moreover, it was excellent also in heat-sealability, and each tube 1 adhered with sufficient adhesive strength, and the multiple tube 10 was comprised. In contrast, Comparative Example 1 in which the amount of the polyolefin-based polymer material was less than 16 parts was not sufficiently moldable, and the heat fusion between the tubes 1 was insufficient. Moreover, it was confirmed that the comparative example 2 in which the polyolefin polymer material exceeds 200 parts has reduced flexibility. In Comparative Example 3 in which the partially crosslinked butyl rubber was less than 5 parts, the kink resistance value was not sufficient, and in Comparative Example 4 in which the partially crosslinked butyl rubber exceeded 100 parts, molding was performed by extrusion molding. I could not.

  As described above, the composition according to the present invention has an excellent gas barrier property, and also has excellent flexibility and kink resistance. Therefore, it can be suitably used particularly as an ink tube for ink supply of an ink jet printer. In addition, for example, it can be suitably used in a wide range of applications as a water-conducting / liquid-conducting / air-conducting pipe in, for example, the automobile field, pharmaceutical / medical field, food field, civil engineering / architectural field. Moreover, it is not limited to pipes, such as a tube and a hose, It can be used as various liquid feeding members, such as joints, such as an elbow, a nipple, and cheese, its components, a pump component, a valve, packing, a grommet. it can.

1 Tube 10 Multiple tubes

Claims (6)

16 to 200 parts by weight of polyolefin polymer material and 5 to 100 parts by weight of partially crosslinked butyl rubber are blended with 100 parts by weight of styrene copolymer, and the Mooney viscosity at 127 ° C. of the partially crosslinked butyl rubber is 30. A composition in which the polyolefin polymer material is polyethylene and the polyethylene is not crosslinked . The composition according to claim 1, wherein the styrene copolymer is a styrene-isobutylene-styrene block copolymer. A liquid-feeding member comprising the composition according to claim 1 or 2. A tube comprising the composition according to claim 1 or 2. The tube according to claim 4, wherein at least two or more tubes are arranged in parallel. A composition in which 16 to 200 parts by weight of polyethylene and 5 to 100 parts by weight of partially crosslinked butyl rubber are blended with 100 parts by weight of a styrene copolymer is extruded to form a tube, and at least two of the tubes are parallel. And a method of manufacturing a multiple tube in which the tubes are heat-sealed.

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