JPS62256882A - Water-based ink - Google Patents

Abstract

PURPOSE:To obtain a water-based ink capable of providing a water-resisting writing on the surface of paper and plastics, by dissolving an acid dye, a direct dye or an epoxy-added water soluble dye in an aqueous vehicle contg. a partially sulfonated polyester resin. CONSTITUTION:A partially sulfonated polyester resin, which is a linear polyester having a skeleton comprising a dicarboxylic acid component and a diol component (e.g., polyethylene glycol) and has an arom. ring in part of any one of the two components to which a sulfonic acid group has been bonded, is added to hot water to dissolve and disperse the resin therein. The dispersion is then allowed to cool. A dye selected from among an acid dye, a direct dye and an epoxy-added dye obtd. by reacting a water-soluble dye having an active hydrogen atom with a compd. having an epoxy group is added and dissolved in the dispersion, thereby obtaining an intended water-based ink. This water- based ink fits with the surface of various materials and is suitable for use in a pen for recorders.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a water-based ink applied to writing instruments and recorder pens, and in particular, it is water-resistant not only to paper surfaces but also to plastic surfaces penetrated by the ink. Relating to water-based inks that give handwriting or records.

BACKGROUND OF THE INVENTION Many water-based inks for writing instruments or recording pens that provide water-resistant handwriting or records on paper surfaces, or water-based inks for writing instruments or recording pens that are applied to ink-permeable plastic surfaces, have been proposed. These are various resin emulsions, water-soluble resins, specific water-soluble organic solvents, surfactants, or combinations thereof for the purpose of imparting water resistance to handwriting and making it possible to write on hydrophobic surfaces such as plastics. teaches a water-based ink containing . However, with water-based inks that provide this type of water-resistant handwriting, when the nib of a writing instrument or recording pen is left open, insoluble products are deposited on the surface of the nib due to evaporation of water, and the next time the pen is This hinders the flow of ink from the inside of the body to the surface of the pen tip, which tends to cause a smudge phenomenon.

Furthermore, there are few disclosures of water-based inks that provide water-resistant handwriting on both paper and plastic surfaces, and although there are inks that have pigments dispersed in a slightly higher viscosity water-based vehicle, this type of particle-dispersed type High-viscosity ink has only been put to practical use in marking pens (so-called paint markers) that have an extremely thick porous pen body and send ink from the container to the pen body via a valve mechanism. . Such colored liquids for paint markers contain particles and have a high viscosity, so it is difficult to apply them to fine-point fountain pens, sign pens, and recorder pens.

Problems to be Solved by the Present Invention The present invention can be applied to writing instruments such as fountain pens, sign pens, and ballpoint pens that have a fine nib for fine print, and recorder pens for recorders, and can be applied not only to paper but also to ink pens. a
The present invention aims to provide a water-based ink that provides water-resistant handwriting even on the surface of S plastics.

Means for Solving the Problems The aqueous ink of the present invention is produced by the reaction of an acid dye, a direct dye and a water-soluble dye containing active hydrogen with a compound having an epoxy group in an aqueous vehicle containing a partially sulfonated polyester resin. One or two selected from the group consisting of products (hereinafter abbreviated as epoxy addition dyes)
It is a composition made by dissolving more than one type of dye.

The acidic dye is selected from dyes classified as acidic dyes in the Co1or Index, and in terms of chemical structure, belongs to the azo type, metal complex salts thereof, anthraquinone type, triphenylmethane type, and xanthine type.

The direct dye is selected from dyes classified as direct dyes in the Co1or Index, and in terms of chemical structure, belongs to the Ab type, metal complex salts thereof, stilhen type, thiazole type, dioxazine type, and phthalocyanine type.

The epoxy addition dye is obtained by reacting a water-soluble dye having active hydrogen with a compound having an epoxy group and has the structure shown by the following formula.

(D) II-(CIl□-CIl (011)-R)
, 1 Here, D is a dye residue, R is a C6-C4 alkyl group, or -CIl□OR'(R' is) (, an optionally branched C, -C, alkyl group, C3- C3 represents an alkenyl group, (meth)acrylic acid group, propyltrimethoxysilane, or a polyhydric alcohol residue having a molecular weight of 300 or less), m represents 1 or 2, and n represents a number from 1 to 4.

Regarding this type of epoxy addition dye, JP-A-61-14
The compound is described in detail in Japanese Patent No. 270, and the compounds described therein are preferably used.

These dyes are contained in an amount of 0.1 to 30% of the total amount in the ink composition.
It is used in a range of 1 to 15% by weight, preferably 1 to 15% by weight.

The partially sulfonated polyester resin is a linear polyester whose skeleton is composed of a dicarboxylic acid and a diol, a portion of both components has an aromatic ring to which a sulfonic acid group is bonded, and at least one of the diol components part is polyethylene glycol having a repeating unit number of 2 to 10. Dicarboxylic acid components include malonic acid, succinic acid, adipic acid, sebacic acid, maleic acid, fumaric acid,
Examples include cyclohexane dicarboxylic acid, phthalic acid, naphthalene dicarboxylic acid, and derivatives thereof, and diol components include ethylene glycol, propylene glycol, 1,3-propanediol, diethylene glycol, triethylene glycol, polyethylene glycol, cyclohexane diol, and dihydroxybenzene. , methylene diphenol, thiodiphenol, biphenol, and their R'A'J components, and the components having an aromatic ring to which the sulfonic acid is bonded include sulfoisofucuric acid, sulfoterefucuric acid, and sulfophenylic acid. , 4-sulfonaphthalene-2,7-dicarboxylic acid, sulfodimethylisophthalic acid, 4'-sulfophenyl-
3,5-dicarbomethoxybenzenesulfonate, 6°
~Sulfo-2°-naphthyl-3,5-dicarboxyhenzenesulfomethyl, 5-(4'-(sulfo)-phenoxy)isophthalic acid, 5-(4°-(sulfo)-phenoxy) The resin is In the ink composition, it is used in an amount of 0.1 to 30% by weight, preferably 5 to 20% by weight based on the total amount.

The vehicle for the aqueous ink of the present invention is obtained by dispersing or dissolving the partially sulfonated polyester resin in water, and if necessary, glycols such as ethylene glycol, propylene glycol, diethylene glycol, and polyethylene glycol, ethylene glycol monomethyl ether, etc. , glycol ethers such as propylene glycol monomethyl ether, diethylene glycol monobutyl ether, glycerin, 2-pyrrolidone, N-methylpyrrolidone, dimethylimidazurinone, etc., a plasticizer for the resin such as phthalate ester, and handwriting. Volatile organic solvents such as ethanol and propatool to speed up the drying of ink, surfactants to modify the ink's wettability to hydrophobic surfaces and permeability into capillary channels, pH adjusters, rust preventives, and preservatives. etc. may be added.

Function As mentioned above, partially sulfonated polyester resin has various hydrophilic and hydrophobic parts in its structure, so water-based ink containing it stains various surfaces, and the dye in the ink becomes friendly to the resin. It exists in a state where the parts are assembled, and the resulting handwriting is considered to be water resistant.

Example Example inks were prepared as follows.

(1) Preparation of partially sulfonated polyester resin aqueous dispersion A predetermined amount of resin was added to hot water at about 90°C under stirring, and 2
After continuing stirring for 0 to 40 minutes to dissolve and disperse the resin, the mixture is allowed to cool.

An aqueous resin dispersion having the following composition was obtained.

Resin A aqueous dispersion Partially sulfonated polyester resin A 28 parts by weight Dimethyl phthalate (plasticizer) 3 parts by weight Water
69 parts by weight Resin B Aqueous dispersion Partially sulfonated polyester resin 3 25 parts by weight Water
75 parts by weight Resin C aqueous dispersion Partially sulfonated polyester resin C 30 parts by weight Water
The properties of the partially sulfonated polyester resin used in an amount of 70 parts by weight are as follows.

Resin A Resin B Resin C Molecular weight Approx. 18,000 Approx. 18,000
Approximately 14,000 water fIJ, base price 5.3 5
．． 0 6.0 acid value <2 <2 <
2 Glass transition point 55℃ 38℃29℃ (2)
Preparation of ink A predetermined amount of dye, the above partially sulfonated polyester resin aqueous dispersion, other additives and the remaining water are mixed,
Stir for 2 hours while heating to 0℃, and after cooling, filter paper! ! I finished it after a while.

Next, a comparative ink was prepared as follows.

Predetermined amounts of dye, additives, and water were mixed, stirred for 2 hours while heating to 40 to 50°C, cooled, and filtered with a filter paper to obtain a finished ink.

The contents of the raw materials (note numbers) in Table 1 are as follows.

(1) Direct dye (C, 1, Direct Black
154) 15% water) 8 liquids (2) Direct dye (C, 1, Direct Black
19) (3) Direct dye (C, 1, Direct Bla
ck 154) 1 mole of butyl glycidyl ether
15% water volume/min of molar adduct (4) Acid dye (C,1,8cid Red 92
) 15% aqueous solution of adduct of 1 mole of ethylene glycol diglycidyl ether to 2 moles (5) Acid dye (C,1, Ac1d Blue 83)
(6) Basic dye (C, 1, Ba5ic Violet
1) Partially sulfonated polyester resin aqueous dispersion (lO) described on pages 1)(7) to f918.9 Polyacrylic acid ester emulsion, solid content 44% Oυ Polyvinyl alcohol, average degree of polymerization approximately 500,
Degree of saponification: 97oA 75% aqueous solution of sodium salt of sulfosuccinic acid dialkyl ester Polyoxyethylene sorbitan monolaurate (b) 30% aqueous solution of sodium salt of sulfosuccinic acid dialkyl ester Next, for each of the above inks, Tests (1) to (4)
I did it.

Each ink was filled in a predetermined amount into a marking pen equipped with a nib made of a synthetic resin molded body having an axial capillary ink passage, and used as a sample pen for testing.

(1) Water resistance of handwriting on paper Each sample pen was used on writing paper A (jls P3201
) with a specified group of characters written on it (about 10 minutes after writing)
After soaking in running water for 1 hour, it was dried and changes in handwriting were examined visually and on a gray scale.

(2) Handwriting on polyester film A predetermined group of characters was written on the polyester film using each sample pen, and the condition of the handwriting was observed.

(3) Water resistance of handwriting on polyester film The film obtained in (2) (after approximately 30 minutes of writing) was immersed in running water for 1 hour, dried, and changes in handwriting were examined visually and on a gray scale. Ta.

(4) Writing performance of the sample pen after being left open After opening the sample pen and leaving it for 2 hours, writing was performed on writing paper A to examine the writing performance.

The test results are shown in Table 2.

Table 2 Test results The judgment symbols in the table are as follows.

Items (1) and (3) ◎ Gray scale grade 5 ○ Gray scale grade 3 to 4 △ Gray scale grade 1 to 2 Slightly observed △ Repelling and shrinkage observed Item (4) ◎ Immediately writable 05 characters or less △ 6 to 10 characters writable As shown in Effect Table 2 of the invention, the present invention Water-based inks provide water-resistant handwriting not only on paper but also on ink-penetrated plastic surfaces, yet do not form precipitates that impede ink flow at the open nib.

Claims (1)

[Claims] 1. An epoxy addition dye selected from acid dyes, direct dyes, and epoxy addition dyes obtained by the reaction of a water-soluble dye containing active hydrogen with a compound having an epoxy group in an aqueous vehicle containing a partially sulfonated polyester resin. A water-based ink made by dissolving dyes. 2. Partially sulfonated polyester resin is a linear polyester whose skeleton is a dicarboxylic acid and a diol, and a part of both of the above components has an aromatic ring to which a sulfonic acid group is bonded, and the diol component has an aromatic ring. 2. The water-based ink according to claim 1, wherein at least a portion thereof is polyethylene glycol having 2 to 10 repeating units.