JPS58147471A - Water-based ink for writing utensil - Google Patents

Abstract

PURPOSE:To provide the titled ink having excellent water-resistance and age stability and low offsetting tendency, by compounding an oil-based dye prepared by the salt-forming reaction of an acidic dye with a basic dye, with gamma-butyrolacetone and water. CONSTITUTION:An oil-soluble dye obtained by the salt-forming reaction of an acidic dye with a basic dye is dissolved completely in gamma-butyrolactone. The solution is mixed with water (preferably >=40% of the solution), and if necessary, with a water-soluble organic solvent such as lower alcohol, etc. and a surface active agent, etc. to obtain the objective ink. The amount of the oil-soluble dye and that of the gamma-butyrolactone are preferably 0.3-15wt% and 20-40wt% based on the whole ink composition, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION In particular, the present invention relates to a water-based ink for writing instruments that has excellent water resistance, stability over time, and little set-off.

Traditionally, water-based inks using water-based dyes such as direct dyes, acid dyes, and basic dyes have been applied to paper with a brush. Although it has excellent properties such as less bleeding and set-off when printed once, it has the problem of inferior water resistance compared to oil-based inks using oil-based dyes.

Also, although oil-based inks that use oil-based dyes have extremely good water resistance compared to water-based inks that use water-based dyes, they have the problem of bleeding and set-off when written on paper, etc. Aromatic solvents were used to dissolve the dyes, which caused problems with toxicity and odor.

Therefore, the inventors of the present invention have attempted to solve the problems of the water resistance of water-based inks and the bleeding and set-off of oil-based inks in Japanese Patent Application No. 135558/1982. This solution also solves the issue of stability over time, which is particularly important for water-based inks. That is, if the aqueous ink for writing instruments has poor stability over time, ink discharge may be poor, the density of the mark may decrease, or ink smearing may occur.

The present inventors conducted a detailed investigation of oil-based dyes and dye solubilizers used to improve the above-mentioned stability over time.

The oil-based dyes currently on the market are classified by chemical structure as follows.

Namely, they are monoazo type, disazo type, red metal complex type monobuzo type, a/traquinone type, phthalocyanine type, triarylmethane type, and salt-forming type of acid dye and basic dye.

The present inventors have found that, in various combinations of the above-mentioned oil-based dyes and dye solubilizing agents, water-based inks created by the combination of oil-based dyes obtained by salt formation of acidic dyes and basic dyes, and -butyrolactone are extremely effective. The present invention has finally been completed based on the knowledge that the ink has excellent stability over time. The gist of this invention is a water ink for writing instruments which is composed of at least butyrolactone and water.

It is not clear why the following common water-based ink of the 16 invention has excellent stability over time, but among oil-based inks, the oil-based ink obtained by salt formation of acidic dye and basic dye has an ionic bonding group in two molecules. Butyrolactone has high polarity and has excellent affinity with water even though it is insoluble in water.-Butyrolactone has high polarity and excellent compatibility with water.
It is presumed that these factors work together to provide excellent stability over time.

Hereinafter, one aspect of the present invention will be explained in detail.

Alcohol Yellow 2105 is an oil dye obtained by salt formation of an acidic dye and a basic dye.
゜Same Red2305. Same BIue2503. Same Biue
2505 (manufactured by Central Synthesis ■), Vali fas
tBlue 1603. SP Green i8
, 22. 25 (hereinafter referred to as Orient Chemical Industry)
AIy, en8pilon fiery
Red BH, Aizen 8pilon Pink
Bll.

Same Violet BH, Aizen 5pilon R
ed CBH (that's all.

(manufactured by Hodogaya Chemical Co., Ltd.), etc., and can be used alone or in combination, and the amount used is preferably 03 to 15% by weight based on the aqueous Inoki total strength.

When it comes to the solubilizing agent for the oil-based dye, monobutyrolactone is used, and is more preferably 20-40% by weight than 1-45MN% based on the total amount of the water-based ink.

The amount of water used is 40, t'j based on the total amount of water-based ink.
'L'A% or more is good, and if it is less than 40% -
This is not preferable because the influence of the lactone becomes greater and problems of bleeding and transfer may occur.

In addition to the above composition, alcohol, methyl alcohol, and ethyl alcohol may be used to adjust physical properties such as viscosity.

Lower alcohols such as n-furobyl alcohol and in-propyl alcohol; acetone.

Ketones such as diacetone alcohol, ketone ar+ −
yl: f) Cyclic ether alcohols such as lahydrofurfuryl alcohol; alkanolamines such as monoethanolamine and jetanolamine; amides such as dimethylformamide and dimethylacetamide; ethers such as tetrahydrofuran and dioxane; Ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol.

Polyhydric alcohols and derivatives thereof such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and glycerin; Water-soluble nitrogen-containing 5-membered ring ketos/groups such as 2-pyrrolidone and N-methyl-2-pyrrolidone An organic solvent can also be added as appropriate.

2. Glass in the water-based ink for writing instruments of the present invention.

In order to impart fixing properties to non-absorbing surfaces such as metals and resins, a mixed solvent of butyrolactone and water that is soluble in butyrolactone but not in water is used as disclosed in Japanese Patent Application No. 121288/1986. Compatible resins can be added to.

Furthermore, various known surfactants are added to adjust the surface tension, etc., urea is added to prevent the nib of writing instruments from drying out, and all known anti-fungal and anti-fungal agents are used as appropriate. It is also possible.

Next, 1-About the method for producing the water-based ink of the invention: 1 ml
Specifically, an oil dye obtained by salt formation of an acidic dye and a basic dye is added to monobutyrolactone, completely dissolved, and then water and other ingredients are added to form an ink.

In addition, when adding 屹・I fat, after dissolving the resin in the butyrolactone, an oil dye is added, and then a water-soluble organic solvent, water, and other components are added in this order to form an ink.

Hereinafter, the present invention will be explained in more detail based on Examples.
In the examples, "parts" indicate "parts by weight."

Example 1 \i c h l) l 13 l u e 25
05 2. O part A 1chol It
ed 2'305 2.0 part A 1rh
ol Yclow 2103 2.0
Part A+zt:n SpHon) Two LEDs
OHHD, 5 parts and -butyrolactone
40.0 parts propylene glycol
55 parts water
400 parts urea (moisturizer)
Add 100 parts of the above dyestuff to butyrolact/.

After stirring and dissolving, add propylene glycol while stirring.
Water and urea were added in this order to obtain the desired black water-based ink.

Comparative Example 1 A black water-based ink was obtained in the same manner as in Example 1 except that monovalerolactone was used in place of the butyrolactone in Example 1.

Example 2 Al chol Red 2305
4.0 parts butyrolactone 4
'0.0 part ethyl alcohol 10.
0 parts water
42.9 parts Denka Butyral 2000
-L 3.0 parts (butyral resin,
Manufactured by Denki Kagaku Kogyo ■) Nt, +C silicone L-76
000.1 part (silico/based surfactant 1 Nippon Unicar 11 manufactured by Shu) Add the above ingredients Denka Butyral 2000-L to a mixed solution of butyrolactone and ethyl alcohol, dissolve completely, and add Alc h o 1
Comparative Example 2 Instead of Aachol Red 2305 in Example 2, (lra sol, tied 2BL A red water-based ink was obtained in the same manner as in Example 2, except that a metal-containing complex monoazo oil dye (manufactured by Ciba Geigy ■) was used.

Big Example Lovali r;+s+ Biue 1603
4.0 parts Butyrolact 7 3
50 parts ethylene glycol 10.0 parts water
47.5 parts urea
10.0 parts Pentachlorophenol f) 'J'7mu 0.5 part (
Preservative, anti-mold agent) Vali fast Blue 160 with the above ingredients
After adding 3 to δ-butyrolactone and completely dissolving it, other components were added and mixed with stirring to obtain the desired red water-based ink.

Comparative Example 3 Vali fast Blue 160 of Example 6
Victoria Blue F4R (B
ASF SeIL triarylmethane type oil dye),
? A blue water-based ink was obtained in the same manner as in Example 3, except that N-methyl-2-pyrrolidone was used instead of -butyrolactone.

Example 4 SP Green 18 4i
1i Do-butyrolactone 40 parts Propylene glycol 6 parts Water
4
33 parts urea
10 parts SP Green of the above ingredients
Add 1B to Zaichi Petit Clactone and after completely dissolving it,
Other ingredients were added and mixed thoroughly to obtain the desired green water-based ink.

0ri instead of SP Green 18 of Tsuchigami-Yuji Murder Case 4
entOil (,1reen BG (manufactured by Orient Chemical Industry ■).

A green water-based ink was obtained in the same manner as in Example 4, except that anotraquinone-based oil dye) was used.

Example 5 Alzen 5pilon violet BH5
, 0 parts and -butyrolactone 35.0 parts water
599 part Neugen P
091 parts (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., nonionic surfactant) - Aizen 5pilon vi; o with the ingredients listed in
Add let B1-1 to and-butyrolactone and dissolve completely, then add other ingredients and mix thoroughly with stirring,
The desired purple water-based ink was obtained.

Nikodan-2 A purple water-based ink was obtained in the same manner as in Example 5, except that 25 parts of the 599 parts of water in Example 5 was replaced with butyrolactone.

The water-based inks obtained in Examples 1 to 5 and Comparative Examples 1 to 5 were filled into commercially available felt-tip pens, and a stability test over time, a water resistance test, and a set-off test were conducted.

The results are shown in Table-1.

Table-1 *1 Stability test over time The felt-tip pens filled with the inks obtained in Examples 1 to 5 and Comparative Examples 1 to 5 were left horizontally indoors for 6 months and 9 months, and were printed on JISP3201 writing paper A. The state of the handwriting was observed when it was written.

*2 Water resistance test using a felt-tip pen filled with the ink obtained in Examples 1 to 5 and Comparative Examples 1 to 5.

JI! i P32 [+1 Write on writing paper A, 3
After 0 seconds, the writing paper is soaked in water for 1 hour and the handwriting is blurred.
× indicates that the density of handwriting has decreased.

Those that do not are marked as ○.

*3 Set-off test *2 Using a felt-tip pen, write on two sheets of straw paper, and the ink penetrates into the second sheet of straw paper, causing the straw paper to get dirty.

W) If the handwriting on the paper is blurred, mark it as ×.

As described above, the water-based ink for writing instruments of the present invention is good, has little set-off, and is suitable as a water-based ink for writing instruments.

14- Procedural amendment (voluntary) 1. Display of the case Patent Application No. 51272, filed in 1982, 2, Title of the invention: Water-based ink for writing instruments 5, Person making the amendment Relationship to the case Patent applicant address: 7-2-6, Kokinumachi, Nihonbashi, Chuo-ku, Tokyo, Amendment Corrections will be made based on the errata below.

Claims (1)

[Scope of Claims] 1) A water-based ink for writing instruments comprising at least an oil-based dye obtained by salt formation of an acidic dye and a basic dye, r-butyrolactone, and water. 2) The amount of water used is 40% of the total amount of water-based ink for writing instruments.
Claim 1 characterized in that the overlap is more than
Water-based ink for writing instruments as described in section.