JP3399588B2 - Ink for writing implements - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a writing instrument, and more particularly to an ink for a writing instrument. [0002] Fountain pens, ballpoint pens, felt-tip pens and the like are widely used as writing implements using ink. The ink used includes a water-soluble substance and an oil-based substance, and includes a water-soluble or oil-based substance in which a dye or a pigment is dispersed. [0003] The above-mentioned ink has the following disadvantages. In the case of the water-soluble ink, since the dye used is water-soluble , the recorded characters and pictures are blurred by water even after recording. Further, when low-quality paper having poor paper quality is used as recording paper, ink penetrates the paper more than necessary, and bleeding occurs more than the pen tip. Also, in the case of oil-based ink, when low-quality paper of poor paper quality is used as the recording paper, as in the case of the water-soluble ink, the ink penetrates the paper more than necessary and bleeds more than the pen tip. . Furthermore, in the case of oiliness, an organic solvent is used as a solvent, and in some cases, a substance that may have a bad influence on the human body is contained. In addition, the use of organic solvents has not been welcomed in recent years when global environmental issues have been widely taken up. SUMMARY OF THE INVENTION [0004] The present invention provides an ink for writing implements that can eliminate ink bleeding on recording paper and can obtain an extremely good image density. That is, the present invention is a writing implement characterized in that it is an aqueous dispersion containing a polyester particle containing an ionic group in the range of 20 to 500 eq / ton, which is colored with a dye that is insoluble in water at normal temperature. It is ink for use. The present invention has solved the problem of obtaining a high image density by using polyester, which can be easily dyed, as colored particles. Further, since the polyester is an emulsion, when it adheres to recording paper, it also has the effect of reducing bleeding. [0005] The polyester colored particles used in the present invention are preferably in the form of an emulsion, and more preferably the particle size is 1 micron or less. Further, the polyester resin used for the polyester colored particles of the present invention comprises a polyvalent carboxylic acid and a polyvalent alcohol. Examples of the polycarboxylic acids used in the polyester resin include, for example, terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, diphenic acid, sulfoterephthalic acid, Sulfoisophthalic acid, 4-sulfophthalic acid, 4
-Sulfonaphthalene-2,7 dicarboxylic acid, 5 [4-sulfophenoxy] isophthalic acid, sulfoterephthalic acid,
And / or their metal salts, aromatic dicarboxylic acids such as ammonium salts, aromatic oxycarboxylic acids such as p-oxybenzoic acid, p- (hydroxyethoxy) benzoic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, Aliphatic polycarboxylic acids such as dodecane dicarboxylic acid, unsaturated fatty acids such as fumaric acid, maleic acid, itaconic acid, hexahydrophthalic acid, tetrahydrophthalic acid, etc., and alicyclic dicarboxylic acids; Other examples of the carboxylic acids include trivalent or higher polyvalent carboxylic acids such as trimellitic acid, trimesic acid, and pyromellitic acid. Examples of the polyhydric alcohols used for the polyester resin include aliphatic polyhydric alcohols, alicyclic polyhydric alcohols, and aromatic polyhydric alcohols.
Aliphatic polyhydric alcohols include ethylene glycol
, Propylene glycol, 1,3-propanediol-
2,3-butanediol, 1,4-butanediol
1,5-pentaneddiol, 1,6-hexanediol, neopentyl glycol, diethylene glycol
, Dipropylene glycol, 2,2,4-trimethyl-1,3-pentaneddiol, polyethylene glycol
Examples include aliphatic diols such as toluene, polypropylene glycol and polytetramethylene glycol, and triols and tetraols such as trimethylolethane, trimethylolpropane, glycerin and pentaerthritol. it can. [0007] Alicyclic polyvalent alcohols include 1,4-
Cyclohexanediol, 1,4-cyclohexanedimethanol, spiroglycol, hydrogenated bisphenol A, ethylene oxide adducts and hydrogenated bisphenol A adducts of propylene oxide, tricyclodecanediol, Tricyclodecane dimethanol and the like can be exemplified. Examples of aromatic polyhydric alcohols include para-xylene glycol, meta-xylene glycol, ortho-xylene glycol, 1,4-phenylene glycol, and ethylene oxide adduct of 1,4-phenylene glycol. , Bisphenol A, and ethylene oxide adducts and propylene oxide adducts of bisphenol A. Further, as a polyester polyol, ε
-Lactone-based polyester polyols obtained by ring-opening polymerization of lactones such as caprolactone. In addition, a monofunctional monomer may be introduced into the polyester for the purpose of blocking the polar group at the terminal of the polyester polymer. Monofunctional monomers include benzoic acid, chlorobenzoic acid, bromobenzoic acid, parahydroxybenzoic acid, monoammonium sulfobenzoate, monosodium sulfobenzoate, cyclohexylaminocarbonylbenzoic acid, n-dodecylaminocarbonylbenzoate Acid, tert-butylbenzoic acid, naphthalenecarboxylic acid, 4-methylbenzoic acid, 3-methylbenzoic acid, salicylic acid, thiosalicylic acid, phenylacetic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, octanecarboxylic acid, lauric acid, stearyl acid And monocarboxylic acids such as lower alkyl esters thereof, or aliphatic alcohols.
Monoalcohols such as alcohols, aromatic alcohols and alicyclic alcohols can be used. In the present invention, it is preferable to use unsaturated monomers among these. Other components are appropriately selected depending on the glass transition temperature of the polyester resin, compatibility with the monomer, and the like. As the ionic group to be introduced into the polyester, a mono- or dicarboxylic acid having an alkali metal sulfonate or ammonium sulfonate can be preferably used. , A sulfate group, a phosphate group, a phosphonate group, a phosphinate group or an anionic group such as an ammonium salt or a metal salt thereof, or a cationic group such as a primary to tertiary amine group. You can use a monomer or the like. When an alkali metal carboxylate or ammonium carboxylate is introduced, a carboxyl group is added to the polymer terminal by introducing a polyvalent carboxylic acid such as trimellitic acid into the system at the end of polymerization of the polyester. Then, a method of neutralizing this with ammonia, sodium hydroxide, or the like to exchange the group with a carboxylate group can be used. Further, by containing a mono- or dicarboxylic acid having a sulfonic acid alkali metal base or a sulfonic acid ammonium base, these ionic groups can be introduced into the polyester resin. As salts, ammonium ions, Li, Na,
Salts such as K, Mg, Ca, Cu, Fe and the like are mentioned, and particularly preferred are K salts and Na salts. In the present invention, 5-
It is preferable to use sodium sulfoisophthalic acid or metasodium sulfobenzoic acid. More specific examples of the polyester resin in the present invention are shown below as component examples other than the ionic group-containing monomer. a) a polyvalent carboxylic acid containing at least 80 mol% of an aromatic monomer, and b) a polyester resin obtained from 0 to 90 mol% of ethylene glycol and 100 to 10 mol% of propylene glycol, or a) A polyvalent carboxylic acid containing at least 80 mol% of an aromatic monomer, and b) a polyester resin obtained from 5 to 80 mol% of 2,3-butanediol and 20 to 95 mol% of ethylene glycol, or a A) polyhydric carboxylic acids containing at least 80 mol% of an aromatic monomer, b) 70-95 mol% of C2-C4 aliphatic glycols, c) mono and / or mono- and / or having a tricyclodecane skeleton Polyester resin obtained from 5 to 30 mol% of polyhydric alcohols,
Or a) a polycarboxylic acid containing at least 80 mol% of an aromatic monomer, b) 70 to 95 mol% of a C2 to C4 aliphatic glycol, c) 5 to 30 mol of hydroxymethyltricyclodecane A) a polyhydric carboxylic acid containing at least 80 mol% of an aromatic monomer, and b) 70 to 95 mol% of a C2 to C4 aliphatic glycol. C) a polyester resin obtained from 5 to 30 mol% of tricyclodecanedimethanol, or a) a polycarboxylic acid containing at least 80 mol% of an aromatic monomer, and b) a C2 to C4 fat. Group-based glycols 70 to 95 mol%, c) mono-and / or polyvalent alcohol having cyclohexane skeleton
A) a polyvalent carboxylic acid containing at least 80 mol% of an aromatic monomer, and b) a C2 to C4 aliphatic glycol 70 to 70 mol%. 95 mol%, c) 5-30 mol% of cyclohexanediol, or a) a polycarboxylic acid containing at least 80 mol% of an aromatic monomer, and b) a C2 -C4 aliphatic. A polyester resin obtained from 70 to 95 mol% of a systemic glycol, c) 5 to 30 mol% of a hydrogenated biphenol, or a) a polycarboxylic acid containing an aromatic monomer in a proportion of 80 mol% or more. And b) 70 to 95 mol% of C2 to C4 aliphatic glycols, c) 5 to 30 mol% of hydrogenated bisphenol A, or a) mono and / or having a naphthalene skeleton Aromatic system containing 1 to 20 mol% of divalent or higher carboxylic acid Polyhydric carboxylic acids containing at least 80 mol% of monomers; and b) 70-100 mol of C2 -C4 aliphatic glycols.
%, C) a polyvalent alcohol containing 0 to 30 mol% of an alicyclic monomer.
And polyester resins obtained from them. Further, the “a) aromatic monomer” shown here is preferably terephthalic acid or isophthalic acid.
The ratio of terephthalic acid to isophthalic acid is as follows: terephthalic acid content / isophthalic acid content = 90 to 40/10 to 60
[Mol%] is preferable, and furthermore, terephthalic acid content / isophthalic acid content = 80 to 50/20 to 50 [mol%],
Further, terephthalic acid content / isophthalic acid content =
85-60 / 15-40 [mol%] is preferable. When an ionic group-containing monomer is introduced into a polyester resin to give an ionic group to the polyester resin, the polyester resin exhibits water dispersibility. As the ionic group-containing monomer, a mono- or dicarboxylic acid having an alkali metal sulfonic acid group or an ammonium sulfonic acid salt described above can be preferably used. Monomer, a sulfate group, a phosphate group, a phosphonate group, a phosphinate group or an anionic group such as an ammonium salt or a metal salt thereof;
A cationic group monomer such as a tertiary or tertiary amine group can be used. When an alkali metal carboxylate or ammonium carboxylate is introduced, a carboxyl group is added to the polymer terminal by introducing a polyvalent carboxylic acid such as trimellitic acid into the system at the end of the polymerization of the polyester, and A method can be used in which this is neutralized with ammonia, sodium hydroxide, or the like, and exchanged with a carboxylate group. These alkali metal carboxylate bases or ammonium carboxylate bases are not included in the above "acid value" (the acid value is the carboxyl group value and does not include the carboxylate) . The content of these ionic groups including sulfonic acid groups and or groups of a salt thereof, the polyester resin to, 20 to 500 m in equivalent / 1000 g
And preferably 50 to 200 meq / 1000 g. When the content of the ionic group is less than a predetermined amount, sufficient water dispersibility cannot be obtained. As the dye, "a dye insoluble in water at normal temperature"
Is used. These are generally classified as disperse dyes or oil-soluble dyes. More specifically, C.I. I. Disperse Yellow 198 C.I. I. Disperse Yellow 42 C.I. I. Disperse Red 92 C.I. I. Disperse Violet 26 C.I. I. Disperse Violet 35 C.I. I. Disperse Blue 60 C.I. I. At least one dye selected from Disperse Blue 87 is preferably used. These are particularly excellent in light fastness, sublimation fastness, hue and saturation, and are preferable as three primary colors for process colors. In addition, known dyes and pigments may be used in combination for fine adjustment of hue. As a method for incorporating the dye into the polyester resin, a high-temperature dispersion dyeing method can be used. The method of directly kneading the dye precursor into the resin is not a preferable method in consideration of the damage of the dye by heating. Since the polyester resin of the present invention shows good stable dispersibility in water due to the action of the ionic group, high-density dyeing is possible while maintaining the particle shape. The ink for writing implements of the present invention comprises colored polyester particles dispersed in water,
It is contained at 0 wt%. Further, the writing instrument ink of the present invention,
In addition to the colored polyester particles, if necessary, a dispersant,
A surfactant or a polymer dispersion stabilizer, which is a dispersion stabilizing aid, may be added. Also, to increase the wettability of the particles,
Ethylene glycol, glycerin and various polyhydric alcohols may be added. Further, various chelating agents may be added to block metal ions mixed in the ink. Further, in order to improve the storage stability of the ink, various germicides, fungicides, ultraviolet absorbers, antioxidants and the like may be added. Example 1 (Synthesis of polyester resin) In an autoclave equipped with a thermometer and a stirrer, 130 parts by weight of dimethyl terephthalate, 56 parts by weight of dimethyl isophthalate, 8 parts by weight of melitic acid, 159 parts by weight of ethylene glycol, 30 parts by weight of tricyclodecane dimethanol, and 0.1 part by weight of tetrabutoxy titanate were charged and heated at 180 to 230 ° C. for 120 minutes to effect a transesterification reaction. Was done. Then, the temperature of the reaction system was raised to 240 ° C., and the reaction was continued at a system pressure of 1 to 10 mmHg for 60 minutes, thereby obtaining a copolymerized polyester resin. Next, 340 parts by weight of the obtained polyester resin, 150 parts by weight of methyl ethyl ketone, 140 parts by weight of tetrahydrofuran, dye C.I. I. Dissolve 30 parts by weight of the cake of Disperse Blue 87 at 80 ° C.
Was added to obtain an aqueous microdispersion of a copolymerized polyester resin having a particle diameter of about 0.15 μm. Further, the obtained aqueous microdispersion was placed in a distillation flask and distilled until the fraction temperature reached 100 ° C. After cooling, water was added to adjust the solid concentration to 30%. Hereinafter, the dye is represented by: C.I. I. Disperse Yellow 198 C.I. I. Dyeing was carried out in the same manner as in the case of Disperse Red 92 to obtain an aqueous microdispersion. The aqueous microdispersion thus obtained was used as a fountain pen ink. The paper used was medium quality paper. As a result, when the ink according to the present invention was used, there was no bleeding of the ink. After drying, the water droplets were observed, but did not soak in the water again. In addition, the produced aqueous microdispersion showed extremely good stability without generation of a precipitate or precipitation of a dye even when left at room temperature for 3 months or more. On the other hand, a dispersion that is prepared by emulsion polymerization of a styrene polymer and then dyed has a low coloring concentration,
Further, when the dispersion was poor in stability and left at room temperature for 3 months or longer, precipitation of dye was observed. According to the present invention, there is no bleeding of the ink on the recording paper and an extremely good image density can be obtained.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-340835 (JP, A) JP-A-1-234479 (JP, A) JP-A-63-182384 (JP, A) JP-A-60-1985 26070 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C09D 11/00-11/20

Claims (1)

(57) Claims 1. An aqueous dispersion containing polyester particles containing an ionic group in the range of 20 to 500 eq / ton and colored with a dye insoluble in water at normal temperature. An ink for writing implements, which is a body.