JPH09193589A - Method for finishing water-based paint of pencil barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the fast-drying properties, blocking resistance and scuff resistance without containing nitrocellulose or organic solvent to be a problem of flammability and the other by painting and finishing a pencil barrel made of timber or synthetic timber by sequentially painting specific water-based sealer, water-based enamel paint and water-based clear. SOLUTION: Water-based sealer formed by using acryl or vinyl emulsion resin, water dissolving type acrylic resin vehicles, dispersing and mixing pigment so that the pigment volume concentration becomes 50 to 70% to provide 5000 to 40000cPs (23 deg.C) of viscosity is painted. Then, water-base enamel paint formed by using, as vehicle, acrylic emulsion resin or water dissolving type acrylic resin having 45 deg.C or higher of Tg, dispersing and mixing pigment so that the pigment volume concentration becomes 5 to 40% to provided 5000 to 40000cPs (23 deg.C) is painted. Further, water-based clear paint formed by mixing 1 to 5wt.% of clear with clear paint solid content is painted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for finishing a water-based paint on a pencil shaft, and more specifically, on a pencil shaft surface made of wood or synthetic wood, three kinds of water-based fillers, water-based enamel paint and water-based clear paint are used. The present invention relates to a method for finishing a water-based paint on a pencil shaft, which paints are repeatedly applied.

[0002]

2. Description of the Related Art A typical paint finishing method for conventional pencil shafts made of wood or synthetic wood is that each pencil shaft supplied to a hopper passes through a paint container containing paint and then a rubber tie for ironing. Then, the excess paint is removed (called ironing paint), and the painted pencil shaft is dried to complete one cycle of paint. Usually, the pencil shaft after the coating is dried is supplied to the hopper again, and the coating cycle is repeated 5 to 8 times for coating.

Therefore, it is necessary that the paint used is quick-drying and blocking-resistant. In addition, the painted pencil shaft must have excellent scratch resistance in order to prevent it from being scratched by rubbing against the machine during the painting finish or the printing and foil stamping process after the painting finishing process. Is. Further, since pencils are stored in a boxed state every dozen even after being made into a product, the clear top coating must have blocking resistance during high temperature storage. Nitrocellulose-based paint (N
C) The lacquer satisfies these points.

However, the nitrocellulose-based lacquer paint used as an enamel or a clear has a risk of fire, and therefore, there is a problem that great care must be taken in safety control of the manufacturing process. Further, since the conventional paint is a paint containing an organic solvent, there is a problem that there is a risk of environmental pollution and ignition. Furthermore, conventional nitrocellulose-based lacquer paints are brushed under humid conditions (that is, the solvent evaporates too quickly, so the surface of the applied lacquer is rapidly cooled and the atmospheric temperature of the part in contact with the lacquer surface falls below the dew point. The water vapor in the atmosphere is condensed on the surface of the undried coating film, and this water content is dissolved in a solvent (alcohols) that is miscible with water and is contained in the coating film. Of the nitrocellulose lacquer coating film, and it is redissolved in the nitrocellulose-based lacquer coating film due to migration of the plasticizer from the eraser.

[0005]

Therefore, the present invention overcomes the above-mentioned problems of the prior art, and does not contain nitrocellulose or an organic solvent, which has flammability or other problems, and is a nitrocellulose-based lacquer coating film. It is an object of the present invention to provide a method for coating and finishing a pencil shaft with a coating film having a quick-drying property, blocking resistance, scratch resistance (high hardness) and blocking resistance at high temperature which are comparable to those of the above.

[0006]

According to the present invention, at least one of an acrylic resin, a vinyl emulsion resin, and a water-soluble acrylic resin is used as a vehicle on the surface of a pencil shaft made of wood or synthetic wood. The extender pigment and / or the coloring pigment are dispersed and mixed at a pigment volume concentration (PVC) of 50 to 70% to obtain a viscosity of 5000 to 400.
00cps (23 ° C) water-based sealing agent is applied, and then at least one of acrylic emulsion resin or water-soluble acrylic resin having a glass transition temperature (Tg) of 45 ° C or more as a vehicle is used as a vehicle. A coloring pigment and / or an extender pigment having a pigment volume concentration (PVC) of 5 to 40
%, The viscosity is 5000 when dispersed and mixed.
-40,000 cps (23 ° C) water-based enamel paint, and glass transition temperature (Tg) as a vehicle
Is at least 45 ° C., at least one of acrylic emulsion resin or water-soluble acrylic resin as a main vehicle, and a wax emulsion containing microcrystalline wax as a main component, or a silicone emulsion containing dimethylpolysiloxane as a main component, or 1 to 5% by weight of the water-soluble silicon compound as a solid component in the clear coating, either alone or in the form of a mixture, based on the solid content of the clear coating.
The mixed viscosity is 5000 to 40,000 cps (23
C.) water-based clear paint is applied.

[0007]

According to the present invention, as described above, a pencil shaft made of wood or synthetic wood is sequentially coated with an aqueous filling agent, an aqueous enamel paint and an aqueous clear to finish the pencil shaft. We have succeeded in achieving the above objectives.

The water-based filler for coating a pencil shaft according to the present invention is an acrylic or vinyl emulsion resin such as acrylic emulsion resin, styrene-acrylic emulsion resin, vinyl acetate-acrylic emulsion resin, vinyl acetate emulsion resin, or the like. One or more of water-soluble acrylic resin is used as a vehicle, calcium carbonate,
Extending pigments such as talc, clay and barium sulfate and / or coloring pigments such as titanium oxide, red iron oxide, yellow iron oxide, phthalocyanine green, and azo yellow are used for pigment volume concentration (P
VC) 50 to 80%, preferably 60 to 70% dispersed and mixed to have a viscosity of 5000 to 4000
0 cps (23 ° C.), preferably 15000 to 2500
It is a paint of 0 cps (23 ° C.) (viscosity is adjusted with an associative thickener such as polyoxyethylene type), which can be applied to a pencil shaft by a conventional method.

According to the present invention, a water-based enamel paint is applied onto the coating film for the sealing agent. This pencil shaft coating water-based enamel has a glass transition temperature (Tg) of 45 as a vehicle.
Acrylic emulsion resin, styrene-acrylic emulsion resin, vinyl acetate at a temperature of ℃ or more, preferably 55 to 75 ℃
One or more of acrylic emulsion resin such as acrylic emulsion resin or water-soluble acrylic resin is used as a vehicle, and organic system such as titanium oxide, yellow iron oxide, phthalocyanine blue, azo yellow, carbon black, etc. And an inorganic color pigment or an extender pigment such as calcium carbonate or silica is dispersed and mixed so that the PVC value becomes 5 to 40%, and the viscosity is 5,000 to 40,000.
cps (23 ° C.), preferably 15000-25000
cps (23 ° C.) (viscosity adjusted with a polyoxyethylene-based associative thickener) is applied by the ironing coating method as in the conventional method, for example, on a drying conveyor under the conditions of 80 to 100 ° C. dry.

According to the present invention, an aqueous clear paint is further applied onto the aqueous enamel coating film. This water based clear paint for pencil axis has a vehicle Tg of 45 ° C or higher,
Acrylic emulsion resin preferably at 55 to 75 ° C,
One or more of acrylic emulsion resin such as styrene-acrylic emulsion resin, vinyl acetate-acrylic emulsion resin or the like, or water-soluble acrylic resin as a main vehicle, and a wax emulsion containing microcrystalline wax as a main component Silicone emulsion containing dimethylpolysiloxane as a main component or water-soluble silicone compound as a solid component is mixed in clear coating in an amount of 1 to 5% by weight alone or in the form of a mixture, and has a viscosity of 5000 to 30000 cps (23 ° C.), Preferably 8
000 to 17,000 cps (23 ° C.) (viscosity adjusted with a polyoxyethylene-based associative thickener) is applied by an ironing coating method, for example, dried on a drying conveyor under the conditions of 80 to 100 ° C. A desired finish coating film can be obtained by.

According to the present invention, as described above, the water-based sealing agent, the water-based enamel paint and the water-based clear paint are applied in this order to the pencil shaft. The coating method can be performed in the same manner as the conventional method, and the preferable film thickness of each coating and the number of coatings are as follows.

───────────────────────────── Coating film Thickness coating times ────────────── ─────────────── Aqueous filling agent 35-40 (μm) 1-2 times ────────────────────── ─────── Water-based enamel paint 25-30 (μm) 2-3 times ──────────────────────────── Water-based clear Paint 5-10 (μm) 1-2 times ─────────────────────────────

[0013] Example Hereinafter, examples will be described the present invention in more detail,
It goes without saying that the content of the present invention is not limited to these examples.

The coating method in the following examples was carried out as follows using an apparatus as shown in FIG. That is, the pencil shafts 2 supplied to the hopper 1 are extruded one by one by the ejection rod 3, and the extruded pencil shafts 2 are fed to the feed roll 4
To the tank 6 containing the paint 5
The paint 5 is attached to the peripheral side surface of the pencil shaft 2, the paint 5 is made uniform by a rubber die 7 and the pencil shaft 2 is ejected from the tank 6, and both corners of the extruded pencil shaft 2 are inclined. It is carried while being supported by the belt conveyor 8 and the pencil shaft 2 is put in a drying device in the middle of the carrying to dry the paint 5 so that one coating is completed. It is a painting method.

As the paint 5, an eye-stopping agent paint for smoothing the unevenness of the wood shaft surface and hiding the wood skin surface, an intermediate coating (water-based enamel) paint for producing a color and smoothing the coating film, and a luster And a gloss (water-based clear) paint for protecting the coating film was used.

The tests and evaluation methods in the following examples are as follows. 1) Sealability, smoothness ... Observe the surface condition after coating twice. ◯: The surface is sufficiently concealed and the surface has no roughness. Δ: The edge part has insufficient concealing property and there is almost no surface roughness. Lack

2) Adhesion: The axis of the sample (end axis of all steps)
Make a cut in the coating film with a cutter and attach a cellophane tape to the part to evaluate the presence or absence of peeling. ○: No peeling ×: Peeling

3) Film thickness: The thickness of the coating film cross section is evaluated by the axis of each coating.

4) Concealment property ... Observe the surface condition after coating. ○: The underlying surface is sufficiently concealed ×: There is insufficient concealment at the edge part

5) Blocking in hopper: After coating and drying, the sample loaded in the hopper is left at room temperature for 60 minutes and then observed. ○: Easy to unravel without blocking ×: With blocking

6) Glossiness: A sample (end axis of all steps) is used in a range of about 3 cm at the center of the axis, and 60 ° specular reflection is used to measure three points within the range. ○: more than 75 △: 75 to 65 ×: less than 65

7) Scratchability in the printing process ... Observe the sample after printing the mark characters (enlarged 10 times). ○: No scratch marks ×: There is scratch marks

Example 1 A main vehicle having the composition shown in Table I (the numbers in the table are% by weight, and the amount of the resin is the varnish) was added together with the pigments having the concentrations shown in Table I. Using a device shown in Fig. 1, a stop agent (viscosity is shown in Table I) was used for pencil wood (dimension: shaft length 1
It was applied twice on the surface of 74 mm, shaft diameter 7.2 mm) (drying condition: 90 ° C. × 40 seconds). The results of the resulting coatings are shown in Table I.

[0024]

[Table 1]

Example 2 Main vehicle having the constitution shown in Table II (the numbers in the table are% by weight,
Water-based enamel paint (viscosity is shown in Table II)
No. of Example 1 is shown using the apparatus shown in FIG. The pencil shaft obtained in 2 was coated twice (drying condition: 90 ° C. × 40
Seconds). The results of the coating films obtained are shown in Table II.

[0026]

[Table 2]

Example 3 Main vehicle having the composition shown in Table III (the numbers in the table are% by weight,
Water-based clear paint (viscosity is shown in Table 3).
(Shown in FIG. III) using the apparatus shown in FIG.
The pencil shaft obtained in 12 was painted twice (drying condition: 90
C x 40 seconds). The results of the coating films obtained are shown in Table III.

[0028]

[Table 3]

[0029]

As shown in the results of Tables I to III, according to the method for finishing the water-based paint on the pencil shaft according to the present invention, it is possible to eliminate the conventional paint which may cause fire or environmental pollution. A pencil shaft that has excellent gloss, does not cause blocking under high humidity conditions, and has no problem of scratches in a printing process or the like can provide a coating film.

[Brief description of the drawings]

FIG. 1 is a drawing showing a coating apparatus used in Examples and Comparative Examples of the present specification.

[Explanation of symbols]

 1 ... Pencil stock hopper 2 ... Pencil 3 ... Push rod 4 ... Feed roll 5 ... Paint 6 ... Paint tank 7 ... Shigoki rubber die 8 ... Conveyor belt

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yasushi Nita 4-1-115 Minamishinagawa, Shinagawa-ku, Tokyo Japan Paint Co., Ltd. Tokyo office

Claims (1)

[Claims] 1. A surface of a pencil shaft made of wood or synthetic wood,
At least one of acrylic, vinyl-based emulsion resin, and water-soluble acrylic resin is used as a vehicle, and an extender pigment and / or a coloring pigment is added to this as a pigment volume concentration (PVC).
Of 50 to 70% is dispersed and mixed, and an aqueous filler having a viscosity of 5000 to 40,000 cps (23 ° C.) is applied, and then a glass transition temperature (T
g) At least one type of acrylic emulsion resin or water-soluble acrylic resin having a temperature of 45 ° C. or higher is used as a vehicle, and a coloring pigment and / or an extender pigment is added thereto so that the pigment volume concentration (PVC) is 5 to 40%. A water-based enamel paint with a viscosity of 5,000 to 40,000 cps (23 ° C), which is dispersed and mixed in, is applied, and an acrylic emulsion resin or water-soluble acrylic resin having a glass transition temperature (Tg) of 45 ° C or more as a vehicle. At least one type of resin is used as a main vehicle, and a wax emulsion containing microcrystalline wax as a main component, a silicone emulsion containing dimethylpolysiloxane as a main component, or a water-soluble silicon compound as a solid component in a clear coating is used alone or 1 to 5 weight of clear paint solid matter in the form of mixture Mixing viscosity comprising the 5000-40
A method for finishing an aqueous paint on a pencil shaft, which comprises applying an aqueous clear paint of 000 cps (23 ° C).