JPH03153779A - Core material of water color pencil - Google Patents

Abstract

PURPOSE:To obtain an excellent writability and resistance to moisture absorption as well as a sufficient breaking strength and improve the solubility of written characters in water by compounding a polyoxyethylene-polyoxypropylene condensate as at least a part of a surfactant. CONSTITUTION:The title core material mainly comprises a water-sol. binder, a lubricant, a body, a pigment, and a surfactant, and the surfactant contains a polyoxyethylene-polyoxypropylene condensate of formula 1 as at least a part of it. The polyoxyethylene-polyoxypropylene condensate, pref. having hydrophobic groups (polypropylene glycol) with a mol.wt. of 1200-2300 and an ethylene oxide content in total molecules of 30-70%, is compounded pref. in an amt. of 5-15%.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a water-soluble binder, a lubricant, and a pigment.

A surfactant is used as the main material, and a small amount of the surfactant (
By using a polyoxyethylene-polyoxypropylene condensate as a part of the product, it has particularly excellent moisture absorption resistance and sufficient breakage strength, and furthermore, the drawing marks are similar to paints that are well soluble in water. Watercolor pencil lead.

(Prior Art) Conventional watercolor pencil leads of this type are either dye-type pencils containing a water-soluble binder and water-soluble dye, or a surfactant is used in the composition to maintain water-solubility. Pigment types with characteristics such as moisture absorption resistance and breakage strength are common.

It has not yet reached the point where it has sufficient qualities such as water solubility of drawing traces, light resistance, appearance shape, and writing quality and colorability.

(Problems to be Solved by the Invention) The conventional watercolor pencil lead obtained in this way uses a solid lubricant that is insoluble in water in the dye type, and only the water-soluble dye reduces the solubility of the drawing traces in water. Since it is controlled, good products have a high content of water-soluble dyes, which causes moisture absorption of the lead and decrease in breakage strength due to aging, fading of drawing traces,
Furthermore, there were various problems such as poor appearance and shape due to the occurrence of vertical cracks during core drying. Regarding pigment types, the effect of the type or amount of surfactant added, in other words, those that exhibit excellent efficacy due to the solubility of the drawn trace in water originally have a weak core breakage strength, and moisture absorption progresses over time, making it even more difficult. There were drawbacks such as a decline in

(Means for Solving the Problems) The present invention aims to solve the problems existing in conventional watercolor pencil leads and to effectively maintain all physical properties.

To solve these problems, we developed water-soluble binders such as polyvinyl alcohol, polyacecool, methyl cellulose, and ethyl cellulose, lubricants such as oils, waxes, and higher fatty acids, and talc and titanium oxide.

A dielectric material such as calcium carbonate, a pigment, and a surfactant are used as main materials, and at least a portion of the surfactant contains a hydrophobic group, tl! A polyoxyethylene-polyoxypropylene condensate whose water chain length can be freely changed was added.

Polyoxyethylene-polyoxypropylene condensate is
The hydrophobic group molecular weight is preferably 1.200 to 2,300,
1400 to 2100 is optimal, and the ethylene oxide content in the total molecule is preferably 30 to 70%, and 40 to 60%.
% is optimal, and polyoxyethylene outside this specified range
When a polyoxypropylene condensate is used, there are disadvantages in that the solubility of the drawing marks decreases due to water and/or the breakage strength decreases as the core absorbs moisture due to oral changes.

In addition, the content ratio of the polyoxyethylene-polyoxypropylene condensate in the composition is preferably 5 to 15%, and 5%
If it is less than 15%, the solubility of the drawing mark with water will decrease, the writing touch will be hard and the coloring will be poor, and if it exceeds 15%, the solubility of the drawing mark with water will improve, but the quality of the lead will change or breakage due to moisture absorption. A decrease in strength was observed.

Silica powder material: Benzidine Yellow Surfactant: Polyoxyethylene-polyoxypropylene condensate 15 parts 15 parts 8 parts (Example) The present invention will be explained in more detail based on the following Examples.

[Example 1] Water-soluble binder: Polyvinyl alcohol Lubricant: Carnauba wax myristic acid P, E, G, "4000" Constitution material: Litopon talc 15 parts 5 parts 15 parts 10 parts 8 parts 22 parts Water-soluble binder: Carboxy Methylulose sodium salt polyacecool lubricant Nirice wax stearic acid P, E, G, 4000 Constitution Materials: Precipitated calcium carbonate talc diatomaceous earth Materials: Miloli blue 15 parts 3 parts 4 parts 15 parts 12 parts 7 parts 20 parts 4 parts 10 parts Surfactant: 10 parts of polyoxyethylene-polyoxybrobylene condensate Pigment: 10 parts of Permanent Red 2B Surfactant: 10 parts of alkylaryl sulfonate [Comparative Example 1] Water-soluble binder: Ethyl cellulose lubricant : Montan wax stearic acid 135Σ paraffin Materials: Talc titanium oxide Water-soluble dye; Malachite green [Comparative example 2] Water-soluble binder: Tracanth gum Lubricant: Palmitic acid stearyl alcohol Cetyl alcohol Body material: White clay Talc 18 parts 10 parts 14 Parts 8 parts 20 parts 10 parts 20 parts The above blended composition was mixed in a Nigoo mixer, then subjected to a roll treatment, molded and dried to form a shape with a diameter of 3 and a length of 1.
A core of 85 cranes was made. Table 1 compares the physical properties of these leads, including writing feel, coloring, light resistance, moisture absorption, breakage strength, solubility of drawing marks in water, and presence or absence of vertical core cracking.
It is as shown in Table 1-2.

15 parts, 16 parts, 8 parts, 8 parts, 10 parts, 23 parts. #Kenjitei 4 Karanishi A sample was prepared by repeatedly coloring paper No. A2 so that the paper surface was filled in horizontally and vertically evenly.

03→The core state was stored at room temperature and relative humidity of 80% for 5 days, and the weight increase rate was shown.

$4 → Span 30W1 Measured at room temperature 20℃.

1 → Create colored paper in the same way as light-fast color testing paper, and rub the colored surface arbitrarily with a water-soaked paintbrush to judge the degree of dissolution.

Using a carbon arc lamp type light fastness tester for 1-O dye fastness test, the horizontal and vertical colors were exposed simultaneously for a certain period of time, and the color was visually observed using the colored paper in the previous section as a reference (Effect of the invention) The present invention has an excellent writing quality. In addition, a watercolor pencil lead has been obtained which is rich in coloring power, does not fade due to light, has very little moisture absorption by the lead due to environmental changes, has sufficient breakage strength, and has excellent solubility of drawing traces in water.

Claims (3)

[Claims] (1) A water-soluble binder, a lubricant, an extender, a pigment, and a surfactant are used as main materials, and at least a part of the surfactant is a polyoxyethylene-polyoxypropylene condensate having the following chemical structure. A watercolor pencil lead that is characterized by: ▲Contains mathematical formulas, chemical formulas, tables, etc.▼ (2) The polyoxyethylene-polyoxypolypyrene condensate has a hydrophobic group (polypropylene glycol) molecular weight of 1
, 200 to 2,300, and the ethylene oxide content in the total molecule is 30 to 70%. (3) The watercolor colored pencil lead according to claims 1 and 2, wherein the content ratio of the polyoxyethylene-polyoxypropylene condensate in the blend composition is 5 to 15%.