Ink fixing resin composition

Abstract

The object of the present invention is to provide a resin composition with improved ink fixation properties. [Solution] The present invention provides an ink fixing resin composition, wherein the resin composition comprises a resin and an oil or fat, and the oil or fat comprises an oil or fat having a melting point of 55°C or higher.

Description

Technical Field

[0001] The present invention relates to a resin composition for ink fixing.

Background Art

[0002] Regarding various pens, from the viewpoints that consumers value, there are characteristics such as the fixing property of ink on the surface of writing paper and the writing feeling by the pen. Since the components of ink and the like have a great influence on these characteristics, various ink compositions and the like have been proposed (for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] On the other hand, for resin compositions (such as sheets) containing olefin resins and the like, improvement in the fixing property of ink on their surfaces is also required.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a resin composition with improved ink fixing property.

Means for Solving the Problems

[0006] The present inventors have found that the above problems can be solved by a resin composition containing a predetermined oil and fat, and completed the present invention. Specifically, the present invention provides the following.

[0007] (1) A resin composition for ink fixing, wherein the resin composition contains a resin and an oil and fat, The oil and fat mentioned above consists of an oil and fat having a melting point of 55°C or higher. Resin composition.

[0008] (2) The resin composition according to (1), wherein the oil content is 0.005% by mass or more and 20% by mass or less with respect to the resin composition.

[0009] (3) The resin composition according to (1) or (2), wherein the oil and fat comprises a hardened oil derived from an animal oil or a vegetable oil.

[0010] (4) The resin composition according to any one of (1) to (3), wherein the oil and fat comprises oil and fat powder with an average particle size of 50 μm or less.

[0011] (5) The resin composition according to any one of (1) to (4), wherein the resin comprises an olefin resin.

[0012] (6) The resin composition according to any one of (1) to (5), wherein the resin composition is a resin sheet.

[0013] (7) A resin composition that provides improved writing comfort, The resin composition comprises a resin and an oil or fat. The oil and fat mentioned above consists of an oil and fat having a melting point of 55°C or higher. Resin composition.

[0014] (8) The resin composition according to (7), wherein the oil content is 0.005% by mass or more and 20% by mass or less with respect to the resin composition.

[0015] (9) The resin composition according to (7) or (8), wherein the oil and fat comprises a hardened oil derived from an animal oil or a vegetable oil.

[0016] (10) The resin composition according to any one of (7) to (9), wherein the oil and fat comprises oil and fat powder with an average particle size of 50 μm or less.

[0017] (11) The resin composition according to any one of (7) to (10), wherein the resin contains an olefin resin.

[0018] (12) The resin composition according to any one of (7) to (11), wherein the resin composition is a resin sheet.

Advantages of the Invention

[0019] According to the present invention, there is provided a resin composition with improved ink fixing property.

Embodiments for Carrying Out the Invention

[0020] Hereinafter, specific embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the object of the present invention. In addition, the preferred embodiments and more preferred embodiments exemplified below can be used in appropriate combinations with each other regardless of the expressions such as "preferred" and "more preferred". The description of the numerical range is illustrative, and the upper and lower limits of each range, as well as the ranges obtained by appropriately combining these values with the numerical values in the examples, can also be preferably used regardless of the expressions such as "preferred" and "more preferred". The terms such as "containing" or "including" may be appropriately read as "consisting essentially of" or "consisting only of". In the present invention, "A (numerical value) to B (numerical value)" means "A or more and B or less".

[0021] (1) Ink fixing resin composition In one aspect of the present invention, the ink fixing resin composition according to the present invention (hereinafter, also referred to as "the resin composition of the present invention") satisfies the following requirements. · It contains a resin and an oil. · The oil consists of an oil having a melting point of 55°C or higher.

[0022] In resin compositions where ink needs to be fixed, adjustments to the ink composition or the sheet composition can be considered to improve the fixation properties. The inventors of this invention focused on adjusting the sheet composition among these approaches.

[0023] Therefore, the inventors investigated and found that by incorporating an oil or fat with a melting point of 55°C or higher into the resin composition along with the resin, the ink's adhesion was significantly improved.

[0024] In the present invention, "ink fixability" encompasses the resistance to removal of ink applied to the surface of a resin composition by printing, writing, or the like. In the present invention, "improved ink adhesion" includes an increase in the degree of resistance to smudging. The ink's adhesion can be evaluated using the wiping jig method shown in the examples.

[0025] The composition of the resin composition of the present invention will be described in detail below.

[0026] (1-1) Resin In this invention, the resin is the base material of the resin composition, and the oils and fats described later are dispersed within the resin. The type of resin is not particularly limited; any resin used in molded sheets can be used. The resin may be used alone or in combination of two or more types.

[0027] From the viewpoint of easily improving ink adhesion, thermoplastic resins are preferred.

[0028] While the type of thermoplastic resin is not particularly limited, olefin resins are preferred from the viewpoint of easily achieving the effects of the present invention in a stable manner.

[0029] Olefin resins are resins whose main component is olefin units. Examples of such resins include polyethylene resins and polypropylene resins.

[0030] Examples of polyethylene resins include the following: • High-density polyethylene (HDPE): 0.942 g / cm³ 3 Polyethylene having the above density Medium-density polyethylene (MDPE): 0.930 g / cm³ 3 More than 0.942g / cm 3 Polyethylene with a density of less than [value missing] Low-density polyethylene (LDPE): 0.910 g / cm³ 3 More than 0.930g / cm 3 Polyethylene with a density of less than [value missing] • Ultra-low density polyethylene (ULDPE): 0.910 g / cm³ 3 Polyethylene with a density of less than [value missing] • Linear low-density polyethylene (LLDPE): 0.911 g / cm³ 3 More than 0.940g / cm 3 Polyethylene with a density of less than [value missing]

[0031] From the viewpoint of ensuring that the effects of the present invention are particularly stable, the resin preferably contains low-density polyethylene, and more preferably consists solely of low-density polyethylene.

[0032] (1-2)Oils and fats Any oil or fat with a melting point of 55°C or higher can be used. The oil or fat may be used alone or in combination of two or more types.

[0033] The melting point of the oil is 55°C or higher, preferably 58°C or higher, and more preferably 61°C or higher. The upper limit of the melting point of the oil is not particularly limited, but is preferably 90°C or lower, more preferably 80°C or lower, and even more preferably 75°C or lower.

[0034] The melting point of the oil powder used in this invention can be determined by measurement using a DSC (Differential scanning calorimetry). For example, using a DSC (DSC1, Mettler-Toledo), the sample is heated at a heating rate of 10°C / min, and the endothermic curve is measured. The melting point can be determined as the temperature at the intersection of the baseline before endothermic heating begins and the downward line of the endothermic peak.

[0035] The oils and fats may be either animal oils or vegetable oils, or processed oils of these (hardened oils, oil powders, etc.).

[0036] From the viewpoint of ensuring that the effects of the present invention are stably achieved, oil and fat powder and highly hydrogenated oil (for example, highly hydrogenated vegetable oil such as highly hydrogenated rapeseed oil) are preferred, and oil and fat powder is more preferred.

[0037] In the present invention, "oil powder" refers to oils and fats having a melting point of 55°C or higher, which are produced by grinding them using any grinding method (grinding with a grinder such as a cyclone mill or hammer mill, air-jet grinding with a fluidized bed jet mill or counter-jet mill, freeze grinding, extrusion granulation, spray cooling, etc.). Such oil powders are clearly distinguishable from powdered oils obtained by spray-drying an emulsion of oil and fat with excipients, emulsifiers, etc.

[0038] Examples of raw materials for oil and fat powder include oils and fats in which 80% or more by mass of the fatty acids constituting the oil or fat consist of saturated fatty acids with 16 or more carbon atoms (such as palm stearin, highly hydrogenated palm oil, highly hydrogenated rapeseed oil, highly hydrogenated erucic acid rapeseed oil, highly hydrogenated soybean oil, highly hydrogenated sunflower oil, highly hydrogenated safflower oil, highly hydrogenated beef tallow oil, etc.). These may be used individually or in combination of two or more types.

[0039] The average particle size of the oil and fat powder is preferably 50 μm or less, more preferably 0.5 to 50 μm, even more preferably 0.5 to 40 μm, even more preferably 1 to 30 μm, and most preferably 1 to 20 μm. Here, the average particle size (effective diameter) refers to the volume average diameter [MV]. The volume average diameter [MV] was determined by dry measurement using a particle size distribution analyzer (for example, Shimadzu Corporation, model name: SALD-2300) based on the laser diffraction scattering method (ISO13320, JIS Z 8825-1), and the obtained volume average diameter [MV] was taken as the average particle size. The volume average diameter [MV] can be calculated using the particle size, particle volume, and the sum of the particle volumes from the following formula. <Formula for calculating the average volume diameter> Volume-average diameter [MV] = (sum of particle size × volume of each particle) / total volume of particles The effective diameter refers to the spherical grain size of the crystal being measured, assuming that the measured diffraction pattern of the crystal matches the theoretical diffraction pattern obtained by assuming a spherical shape. Thus, in the laser diffraction scattering method, the effective diameter is calculated by matching the theoretical diffraction pattern obtained by assuming a spherical shape with the measured diffraction pattern, so the same principle can be used to measure whether the object being measured is plate-shaped or spherical.

[0040] The oil and fat powder used in the present invention contains oil and fat components. These oil and fat components include at least XXX-type triglycerides and optionally other triglycerides. The lipid component contains one or more XXX-type triglycerides having a fatty acid residue X with x carbon atoms at positions 1 to 3 of glycerol. The XXX-type triglyceride is a triglyceride having a fatty acid residue X with x carbon atoms at positions 1 to 3 of glycerol, and each fatty acid residue X is identical to the others. Here, the number of carbon atoms x is an integer selected from 16 to 20, preferably an integer selected from 16 to 18, and more preferably 18. The fatty acid residue X may be a saturated or unsaturated fatty acid residue. Specific examples of fatty acid residue X include, but are not limited to, palmitic acid, stearic acid, and arachidic acid. More preferably, the fatty acid is palmitic acid and stearic acid, and even more preferably stearic acid. The content of the XXX-type triglyceride is, for example, within a range of 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more, when the total mass of the oil powder or oil component is taken as 100% by mass, and within a range of 100% by mass or less, preferably 99% by mass or less, and more preferably 95% by mass or less. One or more types of XXX-type triglycerides can be used, preferably one or two types, and more preferably one type. If two or more types of XXX-type triglycerides are used, their sum equals the total content of XXX-type triglycerides. The composition of the oil powder (triglyceride composition) is determined by gas chromatography analysis as shown in the examples.

[0041] The oil and fat components contained in the oil and fat powder may or may not contain other triglycerides other than the XXX-type triglycerides mentioned above, as long as they do not impair the effects of the present invention. Other triglycerides may be multiple types of triglycerides and may be synthetic or natural oils. Examples of synthetic oils include glyceryl tricaprylate and glyceryl tricaprate. Examples of natural oils include cocoa butter, sunflower oil, rapeseed oil, soybean oil, and cottonseed oil. When the total triglycerides in the oil powder or oil component are considered to be 100% by mass, other triglycerides may be present in amounts of, for example, 1% or more by mass, or about 5-50% by mass, when the total mass of the oil powder or oil component is considered to be 100% by mass. The content of other triglycerides is, for example, 0-50% by mass, preferably 5-40% by mass, more preferably 10-30% by mass, and even more preferably 15-25% by mass, when the total mass of the oil powder or oil component is considered to be 100% by mass.

[0042] The oil and fat powder preferably consists substantially of the above-mentioned oil and fat components, and the oil and fat components preferably consist substantially of triglycerides. Furthermore, "substantially" means that the components other than the oil and fat components contained in the oil and fat powder, or the components other than triglycerides contained in the oil and fat components, constitute, for example, 0 to 15% by mass, preferably 1 to 10% by mass, and more preferably 2 to 5% by mass, when the oil and fat powder or oil and fat components are considered as 100% by mass.

[0043] Commercially available oil powders may be used. An example of a commercially available oil powder is "Konafat" (Nisshin Oillio Group Co., Ltd.).

[0044] The amount of oil and fat can be adjusted as appropriate depending on the desired effect. The lower limit of the oil and fat content is preferably 0.005% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, relative to the resin composition of the present invention. The upper limit of the oil and fat content is preferably 20% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less, relative to the resin composition of the present invention.

[0045] (1-3) Other ingredients The resin composition of the present invention may or may not contain any other components that are commonly incorporated into resin compositions, in addition to the above components. Examples of such components include pigments, inorganic substances (titanium dioxide, talc, calcium carbonate, etc.), organic substances (carbon black, etc.), antioxidants, plasticizers, light stabilizers, UV absorbers, and antibacterial agents. The content of such components can be appropriately set according to the desired effect, and the total amount is preferably 0.01 to 10% by mass, more preferably 0.05 to 5% by mass, relative to the resin composition of the present invention.

[0046] (1-4) Resin compositions and their uses The resin composition of the present invention is obtained by molding a resin containing oils and fats, and can be optionally used in applications requiring ink fixation on the resin surface. Therefore, the term "resin composition" in this invention can be used interchangeably with "resin molded product."

[0047] The form of the resin composition of the present invention is not particularly limited. Examples include pellets, sheets (including films), tableware (cups, trays, etc.), toys, and the like.

[0048] A preferred embodiment of the present invention is that the resin composition of the present invention is a sheet (resin sheet). In the present invention, the "sheet" can be any shape, but is preferably flat. Its thickness is not particularly limited, but is preferably 10 mm or less, more preferably 0.1 to 5 mm, and more preferably 0.2 to 3 mm. Such sheets can be suitably used as packaging materials, labels, and the like.

[0049] The resin composition of the present invention has good ink adhesion properties to its surface, and therefore can be used for writing, printing, and the like. In particular, if the resin composition of the present invention is a resin composition for writing, it can be referred to as a writing sheet, and if it is a resin composition for printing, it can be referred to as a printing sheet.

[0050] (1-5) Method for producing an ink fixing resin composition The ink-fixing resin composition of the present invention can be manufactured using the above-mentioned components by any molding method. Molding methods include hot press molding, extrusion molding, injection molding, blow molding, vacuum forming, and pressure forming.

[0051] Any writing ink, printing ink, etc., can be used as the ink. The ink may be either oil-based ink or water-based pigment ink, and oil-based ink is preferred.

[0052] (2) Resin composition with improved writing feel This invention includes a resin composition that provides improved writing comfort. The resin composition with improved writing feel according to the present invention can employ the same configuration as the ink-fixing resin composition described above.

[0053] In the present invention, "writing comfort" encompasses the ease of writing when writing on the resin composition using any marker (preferably an oil-based marker), etc. In this invention, "improved writing feel" encompasses an increase in the degree of ease of writing described above. The writing feel can be evaluated using the method shown in the examples. [Examples]

[0054] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0055] (1) Method for manufacturing resin sheets (resin compositions) In the mixing machine, predetermined amounts of high-density polyethylene (LDPE) and oils and fats were added in the proportions shown in Table 1, and the mixture was kneaded under the following mixing conditions. In Table 1, "amount of oil and fat" refers to the amount of oil and fat when the total amount of resin and oil and fat is considered to be 100% by mass.

[0056] [Mixing conditions] Mixing machine: Equipment name "Laboplastmill 4C150", stirring unit "Banbury mixer B75", manufactured by Toyo Seiki Seisakusho Co., Ltd. Mixing conditions: Shear mixing was performed at 165°C and 100 rpm for 5 minutes.

[0057] Next, the resulting mixture was cut into pieces with a maximum length of approximately 2 cm or less, and then heated, melted, and pressurized using a hot press under the following pressing conditions. This operation yielded a resin sheet (80mm long x 70mm wide x 1mm thick).

[0058] [Press Conditions] Hot press machine: Model name "AH-2003", manufactured by AS ONE. Pressing conditions: The mixture was melted at 175°C for 5 minutes, and then pressed at the same temperature with 5 tons of pressure for 1 minute.

[0059] [Table 1]

[0060] (1-1) Raw materials The raw materials used in this example are shown in Table 2.

[0061] [Table 2]

[0062] [Supplementary information regarding highly hardened rapeseed oil] The "highly hardened rapeseed oil" used in this example has the following physical properties. • Melting point: 67℃

[0063] [Supplementary information regarding oil and fat powders] The "oil powder" (product name "Konafat #2") used in this example is a white oil powder made from plant-derived edible oils and fats, possessing the following physical properties. ·Average particle size: 10.0μm Melting point: 68.2℃ • Content of XXX-type triglycerides, which have 18-carbon fatty acid residues X (stearic acid residues) at positions 1-3 of glycerin, when the total mass of the oil and fat powder is considered as 100% by mass: 79.6% by mass

[0064] (1-2) Analysis method The various properties and physical characteristics of the oil and fat powder were determined using the following analytical methods.

[0065] [Average particle size of oil and fat powder] The average particle size was determined by dry measurement of the volume-based particle size distribution using a particle size distribution analyzer (Shimadzu Corporation, model name: SALD-2300) based on the laser diffraction scattering method (ISO13320, JIS Z 8825-1) to obtain the volume-average diameter [MV], which was then used as the average particle size. The volume-average diameter [MV] was calculated using the following formula, with respect to the particle size, particle volume, and the sum of the particle volumes. Volume-average diameter [MV] = (sum of particle size × volume of each particle) / total volume of particles

[0066] [Melting point of fats and oils] Using a DSC (DSC1, Mettler-Toledo), the sample was heated at a heating rate of 10°C / min, and the endothermic curve was measured. The melting point was determined as the temperature at the intersection of the baseline before endothermic heating began and the downward line of the endothermic peak.

[0067] [Triglyceride composition] The triglyceride composition was determined by gas chromatography analysis. The gas chromatography analysis conditions are shown below. ·DB1-ht (0.32mm x 0.1μm x 5m) Agilent Technologies (123-1131) ·Injection volume: 1.0μL ·Inlet: 370℃ Detector: 370℃ • Split ratio: 50 / 1 35.1kPa constant pressure Column CT: 200℃ (0 min hold) ~ (15℃ / min) ~ 370℃ (4 min hold)

[0068] (2) Evaluation of the ink fixation properties of the resin sheet The following method was used to draw lines on the surface of each resin sheet using a commercially available oil-based marker, and the adhesion of the lines was evaluated. The following tests were all conducted at room temperature (approximately 25°C).

[0069] Each resin sheet and an oil-based marker (manufactured by Zebra Co., Ltd., product name: Maki) were attached to a static / dynamic friction measuring instrument (manufactured by Trinity Lab Co., Ltd., product name: TL-201Ts), and a line was drawn on the surface of the resin sheet with the oil-based marker under the following conditions.

[0070] [Demarcation Criteria] Load: 50g Speed: 20.0mm / s Line length: 30mm

[0071] After drawing the lines, each resin sheet was left to stand at room temperature (approximately 25°C) for 24 hours to allow the ink to dry.

[0072] After drying, each resin sheet and wiping jig were attached to a static and dynamic friction measuring machine, and the surface of the resin sheet was wiped with the wiping jig along the drawn lines under the following conditions. In this example, a wiping jig was used, which consisted of a dried paper wiper (manufactured by Nippon Paper Crecia Co., Ltd., product name: Kimwipe S-200) attached to the surface of a friction evaluation surface contactor.

[0073] [Wiping conditions] Load: 50g or 100g Speed: 20.0mm / s Number of wipes: 10 back and forth

[0074] After wiping, the lines on the surface of each resin sheet were visually observed and evaluated according to the following criteria. The results are shown in Table 3 under "Ink Fixation".

[0075] [Evaluation Criteria for Ink Fixation] A: The line was clearly visible, and no ink was present on the wiping jig. B: The line was clearly visible, but ink was present on the wiping jig. C: The line was visible, but the overall appearance was faint. D: The line was difficult to see or was broken. E: The ink did not adhere to the resin sheet, causing the line to spread and bleed in the direction of wiping. F: The line was barely visible.

[0076] (3) Writing feel of resin sheet Using each resin sheet, four monitors were asked to write on the surface with the same oil-based marker used in the above-mentioned test, "Evaluation of Ink Fixation of Resin Sheets." The writing feel was evaluated by a group of people based on the following criteria. The results are shown in Table 3 under "Writing Feel".

[0077] [Evaluation Criteria for Writing Comfort] A: It was smooth and had a good writing feel. B: The writing experience felt slightly like there was a brake. C: The strong braking effect made it difficult to write.

[0078] [Table 3]

[0079] As shown in the evaluation results above, all resin sheets that met the requirements of the present invention exhibited excellent ink adhesion. In particular, when the oil or fat was in the form of an oil or fat powder, stable ink fixation was observed across a wide range of formulations.

[0080] Furthermore, resin sheets that met the requirements of the present invention tended to have superior writing comfort. This effect tended to be observed when the amount of oil and fat blended was 2.0% by mass or less.

Claims

1. A resin composition for fixing ink, The resin composition comprises a resin and an oil or fat. The oil and fat mentioned above consists of an oil and fat having a melting point of 55°C or higher. Resin composition.

2. The resin composition according to claim 1, wherein the content of the oil and fat is 0.005% by mass or more and 20% by mass or less relative to the resin composition.

3. The resin composition according to claim 1, wherein the oil and fat comprises a hardened oil derived from animal oil or vegetable oil.

4. The resin composition according to claim 1, wherein the oil and fat comprises oil and fat powder with an average particle size of 50 μm or less.

5. The resin composition according to claim 1, wherein the resin comprises an olefin-based resin.

6. The resin composition according to any one of claims 1 to 5, wherein the resin composition is a resin sheet.

7. A resin composition that improves writing comfort, The resin composition comprises a resin and an oil or fat. The oil and fat mentioned above consists of an oil and fat having a melting point of 55°C or higher. Resin composition.

8. The resin composition according to claim 7, wherein the content of the oil and fat is 0.005% by mass or more and 20% by mass or less with respect to the resin composition.

9. The resin composition according to claim 7, wherein the oil and fat comprises a hardened oil derived from an animal oil or a vegetable oil.

10. The resin composition according to claim 7, wherein the oil and fat comprises oil and fat powder with an average particle size of 50 μm or less.

11. The resin composition according to claim 7, wherein the resin comprises an olefin-based resin.

12. The resin composition according to any one of claims 7 to 11, wherein the resin composition is a resin sheet.

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