JP2006306975A - Ink follower composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink follower composition excellent in temporal stability, without causing a separation phenomenon (oil separation) of base materials, even when stored at a high temperature or for a long period. <P>SOLUTION: This ink follower composition at least comprises one kind, or a mixture of two or more kinds, selected from slightly-volatile organic liquids, a thickening agent, and a sucrose fatty acid ester. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is accommodated in a state of being directly filled in an ink accommodating portion of an ink cartridge used in a recording instrument such as a water-based ballpoint pen, a fountain pen, or a water-based marking pen using water as a main solvent or an ink jet printer. The ink is stored in the ink storage part together with the ink to seal the boundary part that can be in contact with the outside air of the ink, to suppress ink drying and ink leakage, or to reduce ink adhesion to the inner wall of the ink storage part The present invention relates to an ink follower composition.

When ink in a free state is accommodated in the ink tank without using an ink occlusion body such as a fiber bundling body, and the viscosity of the ink is very high, thousands to 20,000 mPa · s, If the inner diameter is as small as 2.8 mm or less, the ink layer in the ink tank is difficult to move under its own weight, and the end of the ink tank opposite to the pen tip is open. Even in this case, there is very little risk of ink leakage from the part, but the ink tank has a large diameter such that the inner diameter of the ink tank exceeds 2.8 mm or the viscosity of the ink is as low as 50 to several thousand mPa · s. In some cases, when an impact is applied, a force exceeding the weight of the ink is applied to the ink, and when the ink is placed in a high temperature environment, the fluidity of the ink itself may decrease. Therefore, there is concern about ink leakage That. Therefore, petrolatum, silicone grease, silicone oil, or a mixture of liquid paraffin and petrolatum is arranged in layers at the interface position on the side opposite to the ink pen tip, and an attempt to prevent backflow of the ink is made by the difficulty of movement of this layer. What is done is known. This layer follows the movement of the ink interface accompanying a decrease in ink capacity due to writing, and is basically obtained as a layer that is always in contact with the ink interface. It is called an ink follower composition. Also, in the case of water-based inks using water as the main solvent, it is known that ink follower compositions are used for the purpose of preventing ink from drying out and preventing ink from adhering to the inner surface of the ink storage cylinder during use. ing. Ink follower compositions in water-based inks include petrolatum (see Patent Document 1), silicone oil (see Patent Document 2), polybutene (see Patent Documents 3 and 4), α-olefin oligomer (see Patent Document 4), ethylene- Those obtained by imparting viscosity to a hardly volatile organic liquid such as α-olefin oligomer (see Patent Document 5) and dibenzylidene sorbitol (see Patent Document 6) are known.
JP-A-57-200472 JP 2000-96033 A Japanese Patent Laid-Open No. 6-264048 JP-A-9-220896 JP-A-7-266780 JP-A-57-153070

However, the ink follower imparted with a viscosity to the above-mentioned hardly volatile organic liquid has a drawback that a separation phenomenon (oil separation) of a base material easily occurs when stored at a high temperature or for a long time. there were.
For ink followers, if the viscosity-imparting agent used is inorganic fine particles such as silicon dioxide, titanium oxide and clay minerals, the particles themselves, if they are metal soap, fibrous soap particles, dextrin fatty acid esters, etc. In the case of the dissolution type thickener, the thickener molecules are in a viscous state by forming a network having a network structure in the substrate. At this time, the base material is present in the network of the network structure formed by the viscosity-imparting agent. However, when the ink follower is stored at a high temperature or for a long time, the viscosity is imparted by van der Waals force or intermolecular force. It is thought that the oil separation phenomenon occurs when the particles and molecules of the agent attract each other, and the network interval of the network structure becomes close, and the base material that cannot be held is pushed out of the network structure. When oil separation occurs in the ink follower of the writing instrument, the separated base material moves into the ink or leaks out from the opening of the ink container, and the layer volume of the ink follower is reduced. The function to prevent backflow will be reduced. In addition, when the base material is separated, the amount of the base material decreases compared with that contained in the ink follower, so that the viscosity of the ink follower increases, and resistance to movement of the ink follower accompanying ink ejection of the writing instrument is increased. The quality of the ink follower cannot be maintained, and in many cases, the quality of the writing instrument itself may be deteriorated.

  As an improvement measure for this problem, the present invention provides an ink follower composition comprising at least one or a mixture selected from a hardly volatile organic liquid, a viscosity imparting agent, and a sucrose fatty acid ester. Is the gist.

  The ink follower composition fulfills its function by the viscosity imparting agent particles and molecules contained therein forming a network with a network structure and holding the substrate. Stability over time of the entanglement is an important factor because of the structure in which the substrate is held by the entanglement of the network structure of the viscosity imparting agent. Sucrose fatty acid ester attracts the viscosity-imparting agent of the ink follower and attracts the viscosity-imparting agents such as van der Waals force and intermolecular force that work between the particles and molecules of the viscosity-imparting agent. The oil-releasing phenomenon can be prevented because it acts to relieve the force and suppress the mesh of the network structure from becoming dense over time. Furthermore, the sucrose fatty acid ester has an action of lowering the surface tension of the base material, making it easy for the base material to penetrate into the network structure of the thickening agent entangled by capillary action, Since the compatibility with the material is improved, the base material is stably held in a network structure. Therefore, it is presumed that the separation phenomenon of the base material when stored at a high temperature or for a long time can be suppressed.

Hereinafter, the present invention will be described in detail.
The hardly volatile organic liquid is used as a base material for the ink follower composition. Since the ink follower composition of the present invention is used so as to be in direct contact with the ink, it does not chemically react with the ink, and it is necessary that dissolution or mixing suspension hardly occur. Also, in order to prevent the position of the ink and the ink follower composition from reversing due to the buoyancy due to the specific gravity difference between the ink and the ink follower composition, it is preferable that the specific gravity difference between the ink and the ink follower composition is small. . Therefore, it is preferable to select the hardly volatile organic liquid serving as the base material of the ink follower composition used in the product using the water-based ink from the water-insoluble organic liquid having a specific gravity in the range of 0.8 to 1.2. . Specifically, phthalate esters such as di-2-ethylhexyl phthalate (specific gravity 0.99) and dibutyl phthalate (specific gravity 1.05), phosphate esters such as tricresyl phosphate (specific gravity 1.175), adipine Adipic acid esters such as di-2-ethylhexyl acid (specific gravity 0.93) and isodecyl adipate (specific gravity 0.92), sebacic acid esters such as di-2-ethylhexyl sebacate (specific gravity 0.92), trimellitic acid Trimellitic acid esters such as tri-2-ethylhexyl (specific gravity 0.99), citric acid esters such as triethyl citrate (specific gravity 1.14) and tributyl acetylcitrate (specific gravity 1.04), epoxidized soybean oil (specific gravity) 0.99) and epoxidized linseed oil (specific gravity 1.04) Carboxymethyl fatty acid ester (specific gravity from 0.92 to 0.97), and a plasticizer such as a polyester-based plasticizer (specific gravity 1.02 to 1.12). Polybutene LV-7, LV-10, LV-25, LV-50, LV-100, HV-15, HV-35, HV-35, HV-50, HV- 100, HV-300 (manufactured by Shin Nippon Petrochemical Co., Ltd.), Polybutene 0H, 5H, 10H-T, 15H, 300H, 15R, 35R, 100R, 100R, 300R Liquid polybutenes (specific gravity 0.82 to 0.90), polybutadiene (specific gravity 0.90), IP solvent 2835 (Idemitsu Petrochemical Co., Ltd.), NAS- Liquid paraffins (specific gravity 0.85 to 0.90) such as 5H (manufactured by NOF Corporation), Cosmo SP10, SP15, SP32, SP32, SP52, SP83 (above, manufactured by Cosmo Oil Lubricants), α- Olefi Liquid oligomers such as oligomers (specific gravity 0.82 to 0.85) and liquid rubbers, silicones such as polydimethyl silicone (specific gravity 0.75 to 1.00), polyether-modified silicone (specific gravity 1.00 to 1.10) Oils, mineral oils such as paraffinic / naphthenic / aromatic process oils (specific gravity 0.85 to 1.05), petroleum jelly and extender oil, and oils and fats such as vegetable oil and polyoxyethylene hydrogenated castor oil. These hardly volatile organic liquids can be used alone or in combination.

  The consistency-imparting agent in the present invention increases the viscosity of the ink follower composition and imparts viscosity, so that the ink follower composition is less likely to move due to impact applied to the ballpoint pen body, etc. It makes the layer difficult to break. For example, for increasing the viscosity and imparting consistency, in addition to fine-particle silica such as Aerosil R972, R974, and 200 (manufactured by Nippon Aerosil Co., Ltd.), Disparon 305 (hydrogenated castor oil, Enomoto Kasei) Made from hydrogenated castor oil type, such as soroid (quaternary ammonium salt of cellulose sulfate ester, made by Sanki Co., Ltd.), leopard KE, same TL, same KL (modified dextrin, Dextrin series such as Chiba Flour Milling Co., Ltd., metal soaps such as aluminum soap, calcium soap, sodium soap, lithium soap and barium soap, and clay series such as bentonite and montmorillonite. These gelling agents may be used alone or in combination of two or more. Further, the blending ratio of the viscosity imparting agent is preferably 1 to 10% by weight with respect to the total amount of the ink follower composition. If it is 1% by weight or less, the gelation strength as an ink follower composition becomes weak and the ink tends to flow backward, and if it is 10% by weight or more, the gelation strength is too strong to follow the ink. It tends to be worse.

  Sucrose fatty acid ester is used in order to prevent the oil-release phenomenon of the base material of an ink follower composition. Sucrose fatty acid esters are those in which a fatty acid is ester-bonded to the eight hydroxyl groups of sucrose, and generally have a wide HLB value from a high level of new oil to a high level of hydrophilicity depending on the type and degree of esterification of the fatty acid. Although it is known, when it uses for the ink follower which uses a hardly volatile organic liquid for a base material like this invention, that whose HLB value is 10 or less is used. Typical examples thereof include DK ester F-90 (HLB value 9.5), F-70 (HLB value 8), F-50 (HLB value 6), F-20W (HLB value 2). F-10 (HLB value 1), Cosmelike B-30 (HLB value 3), S-70 (HLB value 8), S-50 (HLB value 6), S-10 (HLB value 1) ), P-10 (HLB value 1), L-50 (HLB value 5), L-10 (HLB value 1), R-20 (HLB value 2), R-10 (HLB value 1). ), O-10 (HLB value 1) (above, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Surf Hope SE COSME C-1701 (HLB value 1), C-2102 (HLB value 2), 2101 ( HLB value 1), C-1205 (HLB value 5), C-1201 (HLB value 1), c-1601 (HLB) 1), C-1809 (HLB value 9), C-1807 (HLB value 7), C-1805 (HLB value 5), C-1803 (HLB value 3), C-1802 (HLB value 2) ), C-1801 (HLB value 1), C-1800 (HLB value 1), C-2203 (HLB value 3) (above, manufactured by Mitsubishi Chemical Foods Co., Ltd.). The content of the ink follower composition is preferably 0.02 wt% or more and 5 wt% or less. If the amount used is less than 0.02% by weight, it is sufficient to relieve the attractiveness of the viscosity-imparting agents such as van der Waals force and intermolecular force acting between the particles and molecules of the viscosity-imparting agent. The amount of sucrose fatty acid ester adsorbed on the viscosity imparting agent cannot be obtained, and the effect of lowering the surface tension of the ink follower is insufficient, so that the base material cannot be prevented from oil separation. On the other hand, if the content exceeds 5% by weight, the viscosity-imparting agent will inhibit the network structure from forming and the ink follower will not easily form a viscous state, or the affinity of the ink with the solvent will increase and An emulsification phenomenon occurs at the interface of the ink follower and the ink follower mixes, causing problems such as failure to function as an ink follower.

  In addition to the essential components described above, the ink follower composition of the present invention may be used by appropriately selecting conventionally known fat and oil additives such as a pour point depressant, a viscosity index improver, and an antioxidant as necessary. can do.

  In order to produce the ink follower composition of the present invention, various conventionally known methods can be applied. For example, when a dextrin-based viscosity imparting agent is used, it is mixed with other components by heating (130 ° C to 140 ° C) with an agitator, and Aerosil is used as the viscosity imparting agent. In such a case, it can be easily obtained by dispersing and kneading together with other components using a dispersing machine such as a kneader or a roll mill.

Hereinafter, the present invention will be described in more detail with reference to examples.
Example 1
Spectracin 100 (base material, poly α-olefin, specific gravity 0.86, manufactured by ExxonMobil)
50.0 parts by weight Lucant HC-100 (base material, ethylene-α-olefin copolymer, specific gravity 0.85, manufactured by Mitsui Petrochemical Co., Ltd.) 43.3 parts by weight Aerosil R972 (viscosity imparting agent, silica, Japan) Aerosil Co., Ltd.) 5.0 parts by weight Leopard KL (gelator, dextrin palmitate ester, manufactured by Chiba Flour Milling Co., Ltd.)
1.2 parts by weight DK ester F-50 (sucrose fatty acid ester, HLB value 6, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
0.5 parts by weight Among the above components, Spectracin 100 and Lucant HC-100 are stirred while heating to 140 ° C., and after reaching 140 ° C., Aerosil R972, Leopearl KL, and DK Ester F-50 are added. After stirring for 3 hours, the ink follower composition was obtained by gradually cooling to room temperature.

(Example 2)
Polybutene 15R (base material, polybutene, specific gravity 0.87, manufactured by Idemitsu Petrochemical Co., Ltd.)
70.0 parts by weight Lucant HC-40 (base material, ethylene-α-olefin copolymer, specific gravity 0.84, manufactured by Mitsui Petrochemical Co., Ltd.) 24.1 parts by weight Aerosil R972 (previously described) 4.0 parts by weight Leopard KE (Viscosity imparting agent, dextrin palmitate ester, manufactured by Chiba Flour Milling Co., Ltd.)
0.9 parts by weight of cosmetic S-70 (sucrose fatty acid ester, HLB value 8, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
1.0 part by weight Among the above components, polybutene 15R and Lucant HC-40 are stirred while being heated to 130 ° C, and when the temperature reaches 100 ° C, Aerosil R972, Leopearl KE and Cosmelike S-70 are added. Stirring was continued, and after reaching 130 ° C. for 3 hours, the mixture was gradually cooled to room temperature to obtain an ink follower composition.

(Example 3)
Spectracin 100 (described above) 60.0 parts by weight polybutene HV-15 (base material, polybutene, specific gravity 0.87, manufactured by Nippon Petrochemical Co., Ltd.)
25.0 parts by weight Lucant HC-40 (previously described) 10.3 parts by weight Aerosil R972 (previously described) 3.0 parts by weight Leopard KL (previously described) 1.3 parts by weight DK ester F-90 (sucrose fatty acid ester, HLB value 9.5, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
0.4 parts by weight Among the above components, Spectracin 100, Polybutene 15R and Lucant HC-40 are stirred while being heated to 130 ° C., and after reaching 130 ° C., Aerosil R972, Leopard KL and DK Ester F-90 are added. In addition, the mixture was further stirred for 3 hours, and then slowly cooled to room temperature to obtain an ink follower composition.

Example 4
Lucant HC-100 (previously described) 58.0 parts by weight Lucant HC-40 (previously described) 33.0 parts by weight Aerosil R974 (viscosity imparting agent, silica, manufactured by Nippon Aerosil Co., Ltd.) 9.0 parts by weight Cosmelike R -10 (sucrose fatty acid ester, HLB value 1, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
3.0 parts by weight The above components were placed in a kneader and stirred for 2 to 3 hours, and then kneaded twice with a three-roll mill to obtain an ink follower composition.

(Example 5)
Cosmo SP-83 (base material, liquid paraffin, specific gravity 0.88, manufactured by Cosmo Oil Lubricants)
55.0 parts by weight Lucant HC-100 (previously described) 39.0 parts by weight Aerosil R972 (previously described) 3.2 parts by weight aluminum stearate # 600 (gelling agent, aluminum soap, manufactured by NOF Corporation)
0.8 parts by weight Surf Hope SE COSME C-1205 (sucrose fatty acid ester, HLB value 5, manufactured by Mitsubishi Chemical Foods Co., Ltd.) 2.0 parts by weight Cosmo SP-83 and Lucant HC-100 among the above components Stir while heating to 130 ° C., and after reaching 130 ° C., add Aerosil R972, Aluminum Stearate # 600 and Surf Hope SE COSME C-1205 and stir for another 3 hours, then slowly cool to room temperature. An ink follower composition was obtained.

(Comparative Example 1)
Ink follower composition for ballpoint pen as in Example 1, except that 0.5 part by weight of base material Spectracin 100 was added instead of adding DK ester F-50 (sucrose fatty acid ester). Got.

(Comparative Example 2)
An ink follower composition for ballpoint pens was obtained in the same manner as in Example 2, except that 1.0 part by weight of the base polybutene 15R was added in place of Cosmelike S-70 (sucrose fatty acid ester) in Example 2. It was.

(Comparative Example 3)
Ink follower composition for ballpoint pens as in Example 3, except that 0.4 parts by weight of base polybutene HV-15 was added in place of DK ester F-90 (sucrose fatty acid ester) in Example 3. I got a thing.

(Comparative Example 4)
Ink follower composition for ballpoint pen as in Example 4, except that 3.0 parts by weight of base Lucant HC-100 was added in place of Cosmelike R-10 (sucrose fatty acid ester) in Example 4. I got a thing.

(Comparative Example 5)
The composition of the ink following pair of Example 5 was the same as Example 5 except that 2.0 parts by weight of the base Lucant HC-100 was added instead of Surf Hope SE COSME C-1205 (sucrose fatty acid ester). Thus, an ink follower composition for a ballpoint pen was obtained.

  The ink follower compositions described in Examples 1 to 5 and Comparative Examples 1 to 6 were filled into a commercially available ballpoint pen (Hybrid K105, manufactured by Pentel Co., Ltd.) together with the following test sample ink. The hybrid K105 is a ballpoint pen using a ballpoint pen refill having a structure in which a semitransparent synthetic resin pipe is used as an ink storage cylinder and a penpoint holder equipped with a ballpoint penpoint is attached to the tip. The ink container is filled directly with water-based ink on the pen tip side and ink follower composition on the rear end side in contact with each other. Fill this ballpoint pen with 0.75 g of the following ink for test sample, and after filling 0.1 g of each ink follower composition on the top of the ink, place it so that centrifugal force works in the direction of the pen tip. The centrifuge (produced by Japan Centrifuge Co., Ltd .: tabletop centrifuge H-103N) is centrifuged to remove the gas present in the writing instrument to make a ballpoint pen sample. The state of the ink follower when left for 3 weeks was visually confirmed from the appearance. The results are shown in Table 1.

  In addition, the aqueous ink adjusted with the following compositions and methods was used for the test sample.

(Test ink composition and adjustment method)
Carbon black # 850 (colorant, carbon black, manufactured by Mitsubishi Chemical Industries)
11.5 parts by weight Emulgen A-60 (dispersant, surfactant, manufactured by Kao Corporation) 1.0 parts by weight ethylene glycol (humidity retention solvent) 12.0 parts by weight diethylene glycol (humidity retention solvent) 7.0 parts by weight John Krill 450 (fixing improver, acrylic resin emulsion, manufactured by Johnson Co., Ltd.)
12.0 parts by weight TBZ · FL25 (preservative, 25% dispersion of 2- (4-thiazolyl) benzimidazole, manufactured by Sanai Oil Co., Ltd.) 0.2 parts by weight Kelzan (thickener, xanthan gum, tricrystal ( Co., Ltd.) 0.3 parts by weight monoethanolamine (pH adjuster) 1.0 parts by weight ion-exchanged water 55.0 parts by weight The above components except for Kelzan and Jonkrill 450 were mixed together and stirred. After stirring for 2 hours with a ball mill and further dispersing for 6 hours with a ball mill, Joncrill 450 and Kelzan were added and stirred for 2 hours. Finally, the particles were passed through a 480 mesh nylon mesh to remove coarse particles and water for ballpoint pens. A black ink was obtained.

Claims (7)

An ink follower composition comprising at least one or a mixture selected from a hardly volatile organic liquid, a consistency imparting agent, and a sucrose fatty acid ester. The ink follower composition according to claim 1, wherein the hardly volatile liquid contains one or a mixture of two or more selected from α-olefin oligomers, ethylene-α-olefin copolymers, polybutenes, and mineral oils. The ink follower composition according to claim 1, wherein the viscosity imparting agent is one type or two or more types selected from fine particle silica, modified dextrin, metal soap, and clay mineral. The ink follower composition according to any one of claims 1 to 3, wherein a total amount of the viscosity imparting agent is 1.0 wt% or more and 10.0 wt% or less with respect to the total amount of the ink follower. The ink follower composition according to claim 1, wherein the sucrose ester has an HLB value of 1 or more and 10 or less. The ink follower composition according to any one of claims 1 to 5, wherein a content of the sucrose ester is 0.02 wt% or more and 5 wt% or less with respect to a total amount of the ink follower. The ink follower composition according to any one of claims 1 to 6, wherein the ink follower composition is for a ballpoint pen that uses water-based ink.