JP2022018343A - Pressure-sensitive transfer correction tape - Google Patents

Abstract

To provide a pressure-sensitive transfer correction tape that is thin but has excellent concealing power and excellent appearance, and to provide a pressure-sensitive transfer correction tape with improved ink absorption of writing instruments equipped with oil-based ink and water-based ink such as ballpoint pens.MEANS FOR SOLVING THE PROBLEM: There is provided a pressure-sensitive transfer correction tape in which a concealing layer and an adhesive layer are sequentially laminated on a substrate made of paper or a plastic film, either directly or via a release layer. By containing at least a titanium dioxide/calcium carbonate composite pigment as a pigment used for the concealing layer, the tape has excellent concealing power, excellent ink absorption, and a small difference in color between the front and back of the tape, resulting in an excellent appearance.SELECTED DRAWING: None

Description

The present invention relates to a pressure-sensitive transfer correction tape used for concealing and correcting characters and the like erroneously recorded on paper or the like.

When erasing things that cannot be erased with an eraser, such as writing with a writing tool such as a ballpoint pen, pen, sign pen, marker pen, printed matter with a laser printer, inkjet printer, thermal printer, copy drawing with PPC copy, pressure-sensitive copy, etc. Is provided with a handheld pressure sensitive transfer correction tape with an automatic take-up mechanism.

The pressure-sensitive transfer correction tape generally has a multilayer structure in which a concealing layer containing a white pigment and a pressure-sensitive adhesive layer are laminated in this order on one side of a base material. Such a pressure-sensitive transfer correction tape is usually used in a state where it is wound in a roll shape and loaded in a transfer tool that also serves as a holder.

In such a pressure-sensitive transfer correction tape, when the characters and drawn lines are covered and concealed, the concealing power that the characters and the like cannot be seen through is important. In order to improve the hiding power of the pressure-sensitive transfer correction tape, there are methods such as increasing the amount of the white pigment added to the hiding layer or increasing the film thickness of the hiding layer. However, from the viewpoint of handleability of the pressure-sensitive transfer correction tape, it is desired to make the film thickness thinner.

As a method of improving the hiding power while reducing the film thickness of the hiding layer, it has been proposed to include a non-white pigment such as carbon black in the hiding layer. However, although the hiding power increases as the content of the non-white pigment increases, if the content of the non-white pigment is too large, the appearance of the tape appears to be colored in the color of the non-white pigment. There was a problem that it was mistakenly recognized.

Further, in pressure-sensitive transfer correction tape, the ink forming the concealing layer is generally solvent-based, that is, an oil-based base, and the polymer contained in the concealing layer is often lipophilic. Therefore, when rewriting on the modified coating layer with a writing instrument using a water-based ink or a water-based gel ink containing water as a main component and having high polarity and high surface tension, the affinity between the highly polar ink and the modified coating layer becomes high. The ink is scarce and the ink is difficult to penetrate into the modified coating layer, so that the ink dries slowly. As a result, there is also a problem that the rewritten characters or the like are blurred when they are scratched by the paper surface or a finger or the like.

As a method of increasing the hiding power without affecting the "whiteness" of the tape, in Patent Document 1, the total content of the white pigment and the white extender pigment contained in the hiding layer and the weight per 1 m ² of the hiding layer are determined. By keeping the content within a certain range and the content of carbon black contained in the pressure-sensitive adhesive layer and the weight per 1 m ² of the pressure-sensitive adhesive layer within a certain range, the hiding power is excellent and the tape can be used. A pressure-sensitive transfer correction tape with a small difference in color between the front and back and an excellent appearance has been proposed. However, the amount of carbon black added must be extremely small, and the problem that the quality of the product tends to be unstable due to the large change in color due to the variation in the amount of carbon black added cannot be solved.

On the other hand, Patent Document 2 covers a modified coating with a water-based ink or a water-based gel ink by containing 0.5 to 35% by mass of an amphipathic polymer having a hydroxyl group as a hydrophilic portion and a hydrophobic portion in a concealing layer. The purpose of the present invention is to provide a pressure-sensitive transfer correction tape having excellent drying properties of ink when rewritten on a layer. However, although the amphipathic polymers of this document are soluble in alcohols, they are not well soluble in water, so the absorbency of water-based inks or water-based gel inks is at a level that is not yet sufficient to solve the problem. It can not be said.

Japanese Unexamined Patent Publication No. 2018-0086408 JP-A-2017-170743

In view of the above situation, it is an object of the present invention to provide a pressure-sensitive transfer correction tape which is thin but has excellent hiding power and excellent appearance. Another object of the present invention is to provide a pressure-sensitive transfer correction tape having improved ink absorbency of a writing instrument equipped with oil-based ink or water-based ink such as a ballpoint pen.

As a result of diligent research to solve the above problems, the present inventors have sequentially laminated a concealing layer and an adhesive layer on a substrate made of paper or a plastic film, either directly or via a release layer. A pressure-sensitive transfer correction tape that has excellent concealing power, excellent ink absorbency, and excellent appearance by containing at least a titanium dioxide / calcium carbonate composite pigment as a pigment used for the concealing layer. I found that it could be.

According to the present invention, there is provided a pressure-sensitive transfer correction tape having excellent hiding power even if it is thin, excellent in appearance, and excellent in absorption of writing lines written with a writing instrument equipped with oil-based ink or water-based ink such as a ballpoint pen. can do.

Hereinafter, the present invention will be described in detail.
The pressure-sensitive transfer correction tape of the present invention is a pressure-sensitive transfer correction tape in which a concealing layer and an adhesive layer are sequentially laminated on a substrate made of paper or a plastic film, either directly or via a release layer. The pigment used for the concealing layer is characterized by containing at least a titanium dioxide / calcium carbonate composite pigment.

In the titanium dioxide / calcium carbonate composite pigment used in the present invention, for example, calcium carbonate particles having an average particle size of about 30 to 60 nm adhere around titanium dioxide particles having an average particle size of about 50 to 200 nm by van der Waals force. This refers to a pigment composed of particles having a core-shell structure with titanium dioxide particles as the core and calcium carbonate particles as the shell. The titanium dioxide / calcium carbonate composite pigment can be made by adding titanium dioxide powder or the like while vigorously mixing a suspension of calcium carbonate fine particles with something like a shock mixer that causes turbulence.

One of the differences between a simple titanium dioxide / calcium carbonate mixture and a titanium dioxide / calcium carbonate composite pigment is its whiteness. In the titanium dioxide / calcium carbonate composite pigment, the primary particles of titanium dioxide are coated with a large number of calcium carbonates, so that the calcium carbonate acts like a kind of spacer and has the effect of keeping the distance between the titanium dioxide particles constant. be. In reality, a plurality of composite particle units in which a large number of calcium carbonates are coated around the primary particles of titanium dioxide are gathered to form a state like so-called secondary particles having an average particle diameter of about 1 μm. Titanium dioxide is a white pigment having a large light scattering power, but usually, the primary particles of titanium dioxide aggregate to form secondary particles, so that the originally possessed light scattering power is not exhibited. On the other hand, in the titanium dioxide / calcium carbonate composite pigment, since the primary particles of titanium dioxide can maintain an appropriate distance by the calcium carbonate spacer, the degree of white concealment is significantly improved as compared with the amount of titanium dioxide added. Further, since the titanium dioxide / calcium carbonate composite pigment is bulky particles, when a binder is added to form a coating film, voids are likely to occur in the coating film, and ink absorbability is improved. Further, since the surface unevenness is appropriately generated on the coating film, the coating film tends to be matte. If the concealing layer of the pressure-sensitive correction transfer tape is glossy, there is a problem that only the corrected part shines and the corrected part becomes conspicuous. Even for such a problem, a certain effect can be obtained by using the titanium dioxide / calcium carbonate composite pigment.
The preferable composition ratio of the titanium dioxide / calcium carbonate composite pigment is 10/90 to 40/60 in terms of the weight ratio of titanium dioxide and calcium carbonate. When the composition ratio of titanium dioxide is less than 10% or more than 40%, the degree of white concealment tends to decrease, and the effect of compounding the pigment tends to decrease.

In addition to the titanium dioxide / calcium carbonate composite pigment, general titanium dioxide that is not composited with calcium carbonate may be used in combination with the concealing layer of the present invention as a white pigment. Since the titanium dioxide / calcium carbonate composite pigment has a bulky particle structure, if a large amount is added to the concealing layer ink, the ink viscosity tends to increase and the coating suitability tends to decrease. Therefore, when used in combination with general titanium dioxide, it is possible to improve ink absorbency while achieving both white concealment and coatability. The preferable mixing ratio of the titanium dioxide / calcium carbonate composite pigment and general titanium dioxide is 2/8 to 9/1, more preferably 4/6 to 7/3. In addition to that, extender pigments such as calcium carbonate, magnesium carbonate, aluminum silicate, aluminosilicate, magnesium carbonate, barium sulfate, aluminum oxide, talc, celite, clay, etc. may be mixed alone or two or more kinds separately. It can also be used.

Since the object of modification is usually white paper, it is common to use a white pigment as shown above as the pigment, but for example, when colored paper or the like is the object of modification, the said Along with the white pigment, a colorant of any color other than white depending on the color of the colored paper may be used in combination.

Colorants other than white include, for example, titanium yellow, iron oxide pigments, ultramarine, cobalt blue, chromium oxide green, chrome yellow, chrome vermillion, cadmium yellow, cadmium red and other inorganic pigments, azolakes, Hansa, etc. Examples thereof include one or more organic pigments such as benzimidazolone-based, monoazo-based, pyrazolone-based, condensed azo-based, phthalocyanine-based, quinacridone-based, perylene-based, dioxazine-based, anthraquinone-based, and isoindolinone-based.

The dispersant (pigment dispersant) improves the dispersibility of the pigment, and a known polymer compound, surfactant, or the like can be selected and used according to the type of pigment or extender pigment to be used. .. The surfactant used as the dispersant may be nonionic, anionic or cationic. For example, sorbitan fatty acid ester, glycerin fatty acid ester, decaglycerin fatty acid ester, polyglycerin fatty acid ester, propylene glycol fatty acid ester, pentaerythritol fatty acid ester, polyoxyethylene sorbit fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyethylene glycol fatty acid ester, poly. Nonionic surfactants such as oxyethylene alkyl ether and polyoxyethylene alkyl nonylphenol; Anionic surfactants such as alkyl sulfates, polyoxyalkyl ether acetates and polyoxyalkyl ether phosphates; alkylammonium salts and alkylbenzyls. Examples thereof include cationic surfactants such as ammonium salts.

Examples of the binder component of the concealing layer of the present invention include styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-butadiene rubber, and styrene-isoprene-styrene. Block copolymer (SIS), styrene-ethylene / propylene block copolymer (SEP), polyurethane resin, urethane rubber, fluororubber, acrylonitrile-butadiene rubber, ethylene-vinyl acetate copolymer, ethylene-ethylacryllate copolymer One or more flexible rubber-like resins such as ordinary synthetic rubbers or rubber-like resins such as coalesced, chlorosulfonated polyethylenes and cyclized rubbers, and saturated or unsaturated alicyclic hydrocarbon-based resins. One or more of styrene-acrylic copolymer resin, ketone resin, vinyl chloride-vinyl acetate copolymer resin, polyolefin resin such as polyethylene and polypropylene, etc. have a small elongation rate and a melting point or softening point of 100. It is preferable to use both components of a glassy resin having a temperature of ℃ or higher and a high hardness in combination.

It is preferable to mix 2 to 30 parts, preferably 5 to 15 parts of the glass-like resin with 10 parts of the rubber-like resin (weight part, the same applies hereinafter).

The binder obtained in such a blending ratio has appropriate elasticity and forms a concealing layer having excellent writeability on the concealing layer after transfer. If the composition of the glass-like resin exceeds the above range or only the glass-like resin is used, the flexibility of the concealing layer is lost and cracks are likely to occur during transfer. If the amount of the glassy resin is less than the above range, the writing property is deteriorated and the cutting property of the concealing layer is deteriorated. If the binder is composed of only a rubber-like resin, the cutability is further lowered.

The thickness of the concealing layer (meaning the thickness after drying, the same applies hereinafter) is preferably in the range of 10 to 40 μm, more preferably 12 to 30 μm. If the thickness is less than the above range, the hiding power is insufficient, while if the thickness exceeds the above range, the cutability at the time of transfer is deteriorated, the writeability after transfer is deteriorated, or the modified paper is used. When copying, the boundary between the corrected part and the uncorrected part tends to be a shadow and become unsightly.

The pressure-sensitive adhesive layer in the present invention is not particularly limited, and any conventional one can be used. For example, as the pressure-sensitive adhesive used for the pressure-sensitive adhesive layer, acrylic resin-based, rosin-based, rubber-based, vinyl ether resin-based, polyisobutylene-based, and other pressure-sensitive adhesives can be used. The pressure-sensitive adhesive layer can be formed by applying an organic solvent solution, an organic solvent dispersion, an aqueous solution or an aqueous dispersion (including an emulsion) of the pressure-sensitive adhesive on a concealing layer and drying it. The thickness of the pressure-sensitive adhesive layer is preferably about 0.8 to 5 μm.

As the base material constituting the pressure-sensitive transfer correction tape of the present invention, a plastic film or paper having bending rigidity suitable for a transfer tool having an automatic winding mechanism is preferable. Examples of the plastic film include a polyester film such as polyethylene terephthalate and a polyolefin film such as polyethylene and polypropylene. The thickness of the base material is preferably 3 to 30 μm, and a release layer such as a silicon resin, a silicon resin in which an inorganic pigment or an organic pigment is dispersed is formed on one side or both sides of the base material, if necessary.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

<Release processing of base tape>
A mold release agent made of a silicon-based resin was applied to both sides of a PET film having a thickness of 12 μm so that the film thickness after drying was 0.5 μm, and the film was dried to form a mold release layer.

(1) Adjustment of Titanium Dioxide / Calcium Carbonate Composite Pigment Anatase-type titanium dioxide having an average particle size of 180 nm and cubic-shaped precipitated calcium carbonate having an average particle size of 50 nm are mixed at a weight ratio of 20/80 and then water. Was added to prepare a 20% by weight slurry. The pH of the mixed slurry was adjusted to 7.8 by blowing carbon dioxide into it. The pH-stabilized slurry was passed through a colloidal mill. The gap between the rotor and the stator of the colloidal mill was set to 100 μm. The residence time in the colloidal mill was less than 0.1 seconds. The temperature of the mixture was 20 ° C. The generated 50 nm precipitated calcium carbonate particles adhered to the surface of titanium dioxide by Van der Waals force. The obtained composite particles had a titanium dioxide: calcium carbonate weight ratio of 20:80 and a specific surface area of 10 m ² / g. The obtained slurry was dried and then mesh-passed to obtain a mixed powder.

<Making pressure-sensitive transfer correction tape>
(Example 1)
The concealing layer ink of the following formulation was applied to one side of the release layer so that the weight per 1 m ² after drying was 20 g / m ² , and dried to form a concealing layer.
Tough Tech H1221 (SEBS) 14 parts by weight Super ester A-100 (special rosin ester) 14 parts by weight Titanium dioxide / calcium carbonate composite pigment 70 parts by weight Homogenol L-18 (dispersant) 2 parts by weight With 100 parts by weight of the above materials 50 parts by weight of toluene and 50 parts by weight of MEK were mixed and dispersed in a disperser for 60 minutes to prepare a coating liquid. This was applied to one side of the support with a coater and dried to form a concealing layer. Next, a water-based acrylic pressure-sensitive adhesive (Boncoat W-26 manufactured by DIC) was applied onto the concealing layer so that the thickness after drying was 1.5 μm, and dried to prepare a pressure-sensitive transfer correction sheet 1.

(Example 2)
The concealing layer ink of the following formulation was applied to one side of the release layer so that the weight per 1 m ² after drying was 20 g / m ² , and dried to form a concealing layer.
Tough Tech H1221 (SEBS) 14 parts by weight Superester A-100 (special rosin ester) 14 parts by weight Titanium dioxide / calcium carbonate composite pigment 40 parts by weight JR-806 (rutyl type titanium dioxide) 30 parts by weight Homogenol L-18 (dispersant) ) 2 parts by weight A total amount of 100 parts by weight of the above material, 50 parts by weight of toluene and 50 parts by weight of MEK were mixed and dispersed by a disperser for 60 minutes to adjust the coating liquid. This was applied to one side of the support with a coater and dried to form a concealing layer. Next, a water-based acrylic pressure-sensitive adhesive (Boncoat W-26 manufactured by DIC) was applied onto the concealing layer so that the thickness after drying was 1.5 μm, and dried to prepare a pressure-sensitive transfer correction sheet 2.

(Comparative Example 1)
The concealing layer ink of the following formulation was applied to one side of the release layer so that the weight per 1 m ² after drying was 20 g / m ² , and dried to form a concealing layer.
Tough Tech H1221 (SEBS) 14 parts by weight Super Ester A-100 (special rosin ester) 14 parts by weight JR-806 (rutyl type titanium dioxide) 62 parts by weight White luster 0 (magnesium carbonate) 8 parts by weight Homogenol L-18 (dispersant) 2 parts by weight A total amount of 100 parts by weight of the above material, 50 parts by weight of toluene and 50 parts by weight of MEK were mixed and dispersed by a disperser for 60 minutes to adjust the coating liquid. This was applied to one side of the support with a coater and dried to form a concealing layer. Next, a water-based acrylic pressure-sensitive adhesive (Boncoat W-26 manufactured by DIC) was applied onto the concealing layer so that the thickness after drying was 1.5 μm, and dried to prepare a pressure-sensitive transfer correction sheet 3.

The obtained pressure-sensitive transfer correction sheet was cut into small rolls, wound into a roll having a width of 5 mm and a length of 10 m, and loaded into a commercially available pressure-sensitive transfer correction tape cassette.

<Evaluation method>
(1) Coating stability The obtained concealing layer ink was allowed to stand for 120 minutes, and the state was visually observed and evaluated according to the following criteria.
◯: Ink components did not separate or settle.
X: Ink components were separated or settled.

(2) Ink absorbency (water resistant ink)
Transfer the pressure-sensitive transfer correction tape to PPC paper, write on the concealing layer using a water-based gel ink ballpoint pen (G-2, ball diameter 0.7 mm, ink color / black, manufactured by Pilot Corporation), and after 5 seconds, The surface of the writing line was rubbed with a finger, the length of the writing line was measured, and the dryness was evaluated according to the following criteria.
⊚: Elongation length of writing line is less than 2 mm ○: Elongation length of writing line is 2 mm or more and less than 5 mm.
Δ: The elongation length of the writing line is 5 mm or more and less than 10 mm.
X: The elongation length of the writing line is 10 mm or more.
(Note) ◎ and ○ are areas suitable for practical use.

(3) Concealment The transparency of the characters corrected by the pressure-sensitive transfer correction tape was evaluated according to the following criteria.
〇: Characters are not transparent at all △: Characters are slightly transparent but unreadable ×: Characters can be seen through and can be read (Note) ○ and △ are areas suitable for practical use.

Claims (1)

A pressure-sensitive transfer correction tape in which a concealing layer and an adhesive layer are sequentially laminated on a base material made of paper or a plastic film, either directly or via a release layer, and at least as a pigment used for the concealing layer, calcium dioxide. A pressure-sensitive transfer correction tape characterized by containing a titanium / calcium carbonate composite pigment.