JPS59168079A - Water-based ink composition for writing utensil - Google Patents

Abstract

PURPOSE:To provide the titled ink composition which contains hydroquinone or derivative thereof and N,N,N',N'-tetrakis-(2-hydroxyalkyl)ethylenediamine, causes no blurring in writing and is especially suitable for a ball-point pen. CONSTITUTION:The ink composition contains hydroquinone of formula I (where R1,2 are 1-4C alkyl or formula II: n is 1-3; both R1 and R2 can not be H) or derivative thereof and N,N,N',N'-tetrakis-(2-hydroxyalkyl)ethylenediamine of formula III(where R3,4,5,6 are groups shown by formula IV. They may be identical or at least one of them may be different; n is 0.1-3). Inorganic and organic pigments which are used for water-based coating and water color are all applicable to the ink composition and they should preferably be in fine particles and have a low specific gravity and hydrophilicity.

Description

[Detailed description of the invention] The present invention relates to an aqueous writing instrument ink composition.

More specifically, the present invention relates to an ink composition for an aqueous marking device that is particularly suitable for ballpoint pens.

Water-based writing instrument ink compositions conventionally used for writing instruments such as marking pens and ballpoint pens are susceptible to problems such as when the writing instrument is left vertically for a long time with the pen tip facing upward, or when the writing instrument is shaken or dropped. When an impact is applied, or due to inertial force, the ink in the pen tip moves in the distal direction I\, reducing the amount of ink in the pen tip, resulting in ink smearing when writing. Particularly in the case of Paul Ben, when ink moves and air bubbles enter the narrow ink passage that connects the ball and ink cylinder, not only does it cause ink smearing, but in some cases, the flow of ink from the ink cylinder toward the pen tip is blocked, causing the casing. In some cases, it became impossible to write, causing a so-called ink drop phenomenon, which became a fatal defect that could not be recovered.

As a result of various studies, the present inventor has discovered that hydroquinone, hydroquinone derivatives (hereinafter referred to as hydroquinones) represented by the general formula (I), and the general formula (II ) denoted by N
, N, N', N'-tetrakis-(2-hydroxyalkyl)ethylenediamine (hereinafter referred to as ethylenediamines), the above-mentioned difficulties can be solved to a satisfactory degree by adding an aqueous ink composition for ink compositions. It was discovered that this could be obtained, and the present invention was finally completed.

Pigments used in the present invention include inorganic pigments such as carbon black, titanium oxide, Bengara 1 ultramarine blue, navy blue, and chromium oxide, and quinacridone red (C, I).

Pigment Red + 22), Quinacridone Violet (C, 1, Pigment Violet I9), Phthaloshanine Green (C, 1, Pigment Green 7), Phthaloshanine Pull = (C, 1, Pigment Blue 16), etc. All organic pigments such as copper phthalocyanine pigments, Hansa Yellow (C, 1, Pigment Yellow 1), Hansa Yellowett RB (CHl, Pigment Red 3), and monoazo pigments that can be used in normal water-based paints and water-based paints. However, from the viewpoint of dispersion stability, it is naturally desirable to use fine particles, low specific gravity, and hydrophilic properties.

Hydroquinones used in the present invention include, in addition to hydroquinone, alkylhydroquinones such as ethylnohehydroquinone and butylhydroquinone, hydroquinone monoalkyl ethers such as hydroquinone monomethyl ether and hydroquinone monoglobyl ether,
Methyl/1-hydroquinone mono(-butyl ether, propyl/h-alkyl such as hydroquinone monomethyl ether)/-hydroquinone monoalkyl ether, hydroxyalkylhydroquinone such as hydroxyethyl hydroquinone, hydroquinone monohydroxyalkyl such as hydroquinone monohydroxyethyl ether Examples include ether, hydroxyalkylhydroquinone monohydroxyalkyl ether such as hydroxyethylhydroquinone monohydroxyethyl ether.

Ethylenediamines used in the present invention include N, N
, N',N'-tetrakis-(2-hydroxypropyl)ethylenediamine, N,N,N',N'-tetrakis-(2-hydroxybutyl)ethylenediamine, etc., but the former is advantageously used in terms of cost. .

- One or more known additives may be added to the ink composition of the present invention, if necessary. Examples of such additives include water-soluble organic solvents such as glycols, glycol ethers, and glycol ether esters to suppress ink evaporation, preservatives such as sodium benzoate, potassium sorbate, sodium pentachlorophenol, and phenol. Rust inhibitors such as benzotriazole and the like are exemplified.

Furthermore, surfactants are effective in stabilizing the dispersion of pigments and smoothing out the ink, so it is desirable to add them. Depending on the type of pigment, nonionic, cationic, anionic, and amphoteric surfactants can be used. However, nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, and polyoxyethylene sorbitan fatty acid ester are conveniently used.

In the present invention, it is preferable to use a water-soluble resin because it improves the dispersion stability of the pigment and its fixation on the writing surface, such as polyvinyl alcohol, polyvinylpyrrolidone, hydroxyethyl cellulose, ammonium polycarboxylate, or polyacrylic acid oligomer. I'll give it to you.

In the ink composition for aqueous writing instruments of the present invention, 100 parts by weight of the ink composition (hereinafter "parts by weight" is simply referred to as "parts") contains 8 to 30%, preferably 5 to 15%, of the pigment, the hydroquinones and ethylene diamide, preferably 0.02~1O%,
water! 5 to 75q6, preferably 40 to 60%, are dissolved and mixed. If the pigment is less than 396, the coloring density will be insufficient, and the pigment will be less than 80.
If it exceeds 0.01% of hydroquinones and ethylenediamines, the ink will not flow well and cause a blurring phenomenon.
If it is less than 20%, the ink drop phenomenon cannot be prevented, and if it is 20% or more, storage stability and pigment dispersibility will deteriorate.

When using water-soluble resin, 80% or less, preferably 0
．． 5 to 1596 is used, and if it is 80% or more, the viscosity becomes high and the writing aptitude is impaired.

Water is used as a solvent, but in addition to the above three components, it may be added in an amount corresponding to the writing aptitude of 5 to 40%, preferably 5 to 40%.
~80% is used. 50% or less of water, preferably 1
It is desirable that 5 to 45% of the ink be replaced with a water-soluble organic solvent such as glycol or a known moisture absorbent such as glycerin to suppress evaporation of the ink.

In addition, appropriate amounts of preservatives, rust preventives, and surfactants are added as additives.

The functions played by hydroquinones and ethylenediamines in the present invention are theoretically estimated as follows.

First, the molecules of hydroquinones and ethylenediamines are composed of a hydrophilic hydroxyl group and a lipophilic residue, and the hydrophilic group interacts with water in the ink or organic solvent molecules such as glycol, glycol ether, or glycol ether ester. Since the lipophilic group binds in some way to the pigment and the precipitate forming the nib of the writing instrument and parts, no ink drops are produced, the evaporation of water and solvent is suppressed, and precipitation of the pigment is prevented. Next, when turned into an aqueous solution, the fiber bundles of felt and chemical fibers develop an affinity for fibrous plastics or metals without reducing their surface tension. It penetrates the interior of plastic nib, plastic or metal ballpoint pen sockets, and ink cylinders at a moderate speed, so it does not create bubbles and does not smear when written on paper. (Excessive penetration rate leaves air bubbles in sparse portions of the fiber bundle.) Hydroquinones also have the secondary effect of preventing ink discoloration as antioxidants, of course.

vCll-1 for preparing the ink of the present invention: Normally, all the components except the pigment are mixed and dissolved to form a homogeneous solution, that is, a vehicle.The pigment is added to this, and the mixture is processed using a known dispersion device such as a ball mill, a colloid mill, or an 8-roll mill. What is necessary is just to disperse|distribute uniformly using it.

If the pigment is a pigment paste that is dispersed in a liquid component, all the components may be mixed, dissolved, and dispersed at once.

Next, examples will be shown to further clarify the present invention.

Example 1 Ethylene glycol 23.0 parts Diglycerin 5.0 parts Hydroquinone monoethyl ether 0.1 part Sodium benzoate
1.0 part Neugen EAI
0.1 part (polyoxyethylene alkyl phenyl ether manufactured by Dai-Kogyo Seiyaku) Water 68
．． 8 parts of the above was placed in a stirring tank, heated to 50°C, stirred for 2 hours, and then VAGC7127 Yellow (C, 1, Bigmenoto Yellow)
7 parts (pigment manufactured by Dainichiseika Chemical Industry Co., Ltd.) was added and stirred for an additional hour to obtain a solid ink.

Example 2 Ethylene glycol 20.0 parts Urea 10. Ofη dihydroquinone monoethyl ether O,a S sodium benzoate 1.0 parts Nonibol 1'
60 0.1 part (Sanyo Chemical Polyoxyethylene Nonyl Phenyl Microlith Sprue 4GA
A blue ink was obtained according to Example 1 from 7.0 parts (resin-processed pigment manufactured by Ciba Geigy).

Example 3 Ethylene glycol 25.0 parts Diglycerin 2.0 parts Hydroquinone hydroxyethyl ether 0.5 parts Sodium benzoate
1.0 part water
68.5 parts Quinacridone Red 8.0 parts (C, 1, Pigment Red I22) A blue ink was obtained in accordance with Example IK.

Example 4 Ethylene glycol 20.0 parts Thiodiethylene glycol IO, 0 parts Hydroquinone monomethyl ether 0.1 part Sodium benzoate
1.0 part Evan
0.1 part (polypropylene oxide polyethylene glycol block copolymer manufactured by Dai-Kogyo Seiyaku Co., Ltd.) Water 61.
8 parts Microlith Brown 2RA 7.0 parts (resin-processed pigment manufactured by Ciba Geigy) According to Example 1, a high-quality ink was obtained.

Example 5 Diethylene glycol 15.0 parts Thiodiethylene glycol 5.0 parts Urea
10.0 parts hydroquinone
0.5 part Noni ball
0.1 part (Polyoxyethylene nonylphenyl ether manufactured by Sanyo Chemical Co., Ltd.) = Iku Lis Black CA 70 fls
(Resin-processed pigment manufactured by Ciba Geigy) According to Example 1, a Kururu ink was obtained.

Example 6 Ethylene glycol 100 parts N, N,
N', N'-tetrakis-(2-human 18o part roxyprovir)-ethylenediamine C-flavored oil containing 'L M 匈v4 examples! Obtain red ink according to.

Example 7 Ethylene glycol IO9θ part N,
N,N',N'-Tetrakis-(2-18,0 parts hydroxypropyl)-ethylenediamine sodium benzoate 1.0 parts Polyoxyethylene alkylny 0.1 parts Chill (Trademark Score Rollna 400° Manufactured by Kao Atlas ■ ) Water 6S,
Part 9 Microlith Plue 4 G A 5
．． 0 parts (resin-processed pigment manufactured by Ciba Geigy) A blue ink is obtained according to Example 1.

Example 8 Thiodiglycol 5.0 parts Ethylene glycol 4.0 parts N, N, N'
, N'-tetrakis-(2-17,0 parts hydroxypropyl)-ethylenediamine Potassium rubic acid 0.5 parts Score Roll 400 0.1 part (manufactured by Kao Atlas, polyoxyethylene alkyl ether) Water 66.
4 parts Carbon black 7.0 parts Black ink was obtained according to Example 1.

Comparative Examples 1 to 8 Ink compositions of Examples 1 to 8 except for the hydroquinones or ethylenediamines and replacing the components with water were prepared by the same means, and comparative tests were conducted on ink drops.

Ink Drop Test The inks of Examples 1 to 8 and Comparative Examples 1 to 8 were mixed with a diameter of 0.
A polyacetal socket equipped with a 44 m-long steel ball, diameter 1.1 wφ, length 28 aaw (7) A water-based ballpoint pen was filled into the polyester ink absorbing material of a pole pen using a polyester ink extractor.

This ballpoint pen (with a cap) was vertically dropped from a height of 8 Octn onto a concrete floor Vc 8 times with the pen tip facing upward. All of the ballpoint pens filled with the Example ink and the Comparative Example ink had ink drop and were unable to write at the same time. However, the example ink was kept at room temperature of 25℃! After leaving the pen for a week in a vertical position with the nib pointing upwards, most of the pens recovered to a writable state. The number of books that were able to be written out of the 100 test subjects is listed in the attached table.

Separate table 56

Claims (1)

[Claims] Pigment. Hydroquinone or hydroquinone derivatives of general formula tI) [wherein R1 and R2 represent hydrogen, an alkyl group having 1 to 4 carbon atoms, or a -(CH2CH20)nH group, and n represents an integer of 1 to 8. Except when both R1 and R2 are hydrogen] and N , N , N' represented by the general formula (sha)
, N'-tetrakis-(2-hydroxyalkyl)ethylenediami/ [([1) In the formula, R3, R4, R5 and R6 are groups represented by H -CH2CH(CH2)nH, and between - or At least one ink composition may be different, and n is an integer of 0 or 1 to 8.] An aqueous ink composition for a writing instrument characterized by containing at least one selected from: