JPH02185577A - Liquid eraser - Google Patents

Abstract

PURPOSE:To prepare a liquid eraser which has an improved dispersion stability which improves the drying properties and affinity therewith of a water-base ink rewritten on an erased letter by compounding a hiding agent, a specific dispersant, a resin, and a solvent. CONSTITUTION:A hiding agent (e.g. rutile type titanium dioxide), 1-2wt.% dispersant comprising a cationic surfactant, an alkyltrimethylammonium chloride and/or dialkyldimethylammonium chloride (e.g. stearyltrimethylammonium chloride), 6-10wt.% resin (e.g. lauryl methacrylate resin), and a solvent (e.g. methylcyclohexane) are compounded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention is a method for correcting all kinds of handwriting. ! This invention relates to a so-called all-purpose correction fluid that can be used to cover the screen.

(Prior Art) The so-called universal correction fluid refers to a correction fluid that can correct and conceal any written line, regardless of whether it is an oil-based ink or a water-based ink. These correction fluids form a solvate with a solvent that does not dissolve or diffuse the components contained in the ink used in writing instruments, a resin that is soluble in this solvent, a solvent, and a strong solvate with a masking agent. Dispersants that exhibit interaction, and I! such as titanium dioxide that has hiding power! ! i
It consists of a drug.

Resin monomers and dispersants to enhance the dispersion effect.

A correction liquid made by mixing a solvent and a masking agent and polymerizing the resin monomer in the mixed solution (JP-A-59-59754) A correction liquid using polyvinyl alkyl ether as the resin and a naphthenic or paraffinic solvent as the solvent (equity: 6 liters) -42952) are known.

(Problem to be Solved by the Invention) When these all-purpose correction fluids are rewritten on the correction surface with water-based ink, the ink is difficult to get on the correction surface, and in some cases, the ink may be completely applied and no writing possible. there were. This phenomenon is particularly noticeable when fountain pen ink is used.

Furthermore, water-based ink rewritten on the corrected surface dries extremely slowly (if rewritten at 20°C and 60% humidity,
The re-writing ink does not dry even after several minutes have elapsed, and when you trace it with your hand, the re-writing ink sticks to your hand and the correction surface becomes dirty again.

(Means for Solving the Problem) As a result of repeated research in order to solve these drawbacks, the present inventor found that the problem can be solved by using alkyl 1-dimethylammonium chloride and/or dialkyldimethylammonium chloride as a dispersant. I found out. That is, the above-mentioned dispersant is added in an amount of 1 to 2% by weight based on the correction liquid composition consisting of a masking agent, a resin, a solvent, and a dispersant. The amount of dispersant added varies depending on the specific surface area and amount of the hiding agent added to the correction fluid, but when 50% by weight of titanium dioxide is added to the hiding agent, 1% by weight is appropriate. Even if the amount added is less than this, the masking agent is well dispersed, but no dispersant micelles are formed in the liquid. On the other hand, addition of 2% by weight or more not only increases the cost of the correction fluid, but also may generate excessive micelles of dispersant in the correction fluid, causing ink rewritten on the correction surface to bleed. Yes, it's not good.

(Function) When the dispersant is added to the correction fluid formulation, the dispersant dissociates to produce a cation containing an alkyl group. This cation bonds with the anion (-0-) generated by dissociation of the hydroxyl group on the surface of the masking agent through strong ionic interaction, and forms an electric double layer with the alkyl group portion facing the solvent portion. A solvent that strongly interacts with the alkyl group portion of the dispersant forms a solvate, and an amount of resin that interacts with the solvent becomes entangled between the solvated molecules. The resin forms a solvate with the solvent, but if the amount of the resin added is less than the solvation number, aggregation will occur, so a slightly excessive amount is appropriate. When a methacrylic acid lauryl ester resin is used, the amount of added resin is preferably 6% by weight or more, but an excessive amount of resin added causes an increase in the viscosity of the liquid, so 10% by weight or less is appropriate.

In this way, the system becomes dispersion stabilized. This correction fluid
When applied to the object to be repaired, the solvent in the solution begins to scatter, while the dispersant micelles present in the solution are attracted to water molecules in the atmosphere and form an adhesive at the interface between the surface to be repaired and the atmosphere. Arrange. At this time, part of the solvent and resin solvated by the dispersant hydrophobic group ionically bonded to the masking agent is absorbed by the dispersant molecules that are trying to align at the interface between the correction surface and the atmosphere and is desorbed from the surface of the masking agent. As a result, during the solvent scattering process, stress occurs at various locations on the repaired surface due to the solidification of the resin.

This stress causes water molecules in the atmosphere to enter the repair surface due to the extremely high polarity of the dispersant used, creating a large number of pores on the repair surface, solidifying and stabilizing the repair surface. to become

Therefore, while a large number of pores are formed on the dry and solidified repair surface, the surface is extremely polar, and water molecules in the atmosphere are oriented to the dispersant's polar group.
The surface tension of the correction surface is comparable to that of water, so even if you write with highly polar fountain pen ink, the writing line will not touch the correction surface or become thin, and furthermore,
Since the water molecules or other polar molecules contained in the water-based writing ink quickly enter the pores formed on the correction surface, the writing lines dry extremely quickly.

(Example) Table 1 shows formulation examples of Examples of the present invention and Comparative Examples.

Examples and ■ Exposure row Note that (1) to (9) in the table are as follows.

(1) Polymerization from 1,000 ml. Molecular weight approximately 6.5X10'(2
) Methacrylic acid ester resin (Mitsubishi Rayon) (3
) Rutile titanium dioxide (Tohoku Chemical) (4) Stearyltrimethylammonium chloride (active ingredient 50%2)
Nikko Chemical) (5) Dioctyldimethylammonium chloride (80% active ingredient 1 Nikko Chemical) (6) Methylcyclohexane (Maruzen Petrochemical) (7
) Isooctane (Maruzen Petrochemical) (8) Dispersant (I
(Company C1) (9) Dispersant (Special Reagent Grade) The formulations in Table 1 were mixed with 1) EI stirring using a ball mill. The obtained correction fluid was applied to the paper surface, and after the correction surface had dried, writing was performed using a fountain pen in the atmosphere at 20° C. and 360% humidity. Table 2 shows the writing condition at that time and the staining of the baryta paper when it was compressed with a force of 1 kg/cJ 30 seconds after writing.

According to FIGS. 1 and 2, Example 1. and a scanning electron micrograph (SEM photograph) of the corrected surface of Comparative Example 1.

The magnification is 1000 times.

As can be seen from the figure, a large number of pores were present in the example, but no pores were found to be generated in the comparative example.

(Effect of the invention) As described above, by using alkyltrimethylammonium chloride and/or dialkyldimethylammonium chloride as a dispersant used in the correction liquid, the polarity of the correction surface is increased, and when a conventional correction liquid is used. The writing performance of water-based writing ink, which could not be written satisfactorily, can be improved to the same level as when writing on paper, and furthermore,
By successfully creating many pores on the correction surface, we were able to significantly shorten the drying time of water-based ink written on the correction surface, such as water-based ballpoint pen ink and fountain pen ink.

[Brief explanation of the drawing]

Figure 1 is a scanning electron micrograph (S
EM photograph), and Figure 2 is a scanning electron micrograph of a comparative example (
SEM photo).

Claims (2)

[Claims] (1) A correction fluid consisting of a hiding agent, a dispersant, a resin, and a solvent. (2) The correction fluid according to claim 1, which uses alkyltrimethylammonium chloride and/or dialkyldimethylammonium chloride as a dispersant.