JPH1029660A - Packaging material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve an adhesive strength for a support member made of plastic by incorporating a phenolic compound in an ink-absorbing layer in a packaging material wherein an ink-absorbing layer is formed on one of faces of a support member made of plastic and heat-sealing properties are provided on the other face thereof. SOLUTION: A packaging material wherein an ink-absorbing layer is formed on one of faces of a support member made of plastic and heat-sealing properties are provided on the other face thereof has a phenolic compound contained in the ink-absorbing layer. A phenolic compound which is one of color forming components for a heat-sensitive recording paper is used as the phenolic compound to be employed for the ink-absorbing layer. It is preferable that an effective content of the phenolic compound is made to be 10-30 pts.wt. to the amount of 100 pts.wt. of an organic or an inorganic pigment in the ink-absorbing layer. Further, a heat-seal layer is formed from an extruded laminate layer formed on one of faces of a base material made of a plastic film, or from a non- oriented film, etc., stuck on one of faces of a base material made of a plastic film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic packaging material of a type in which a sealing portion can be formed by heat sealing. The present invention provides a packaging material that can be printed on an ink absorbing layer existing on the surface of a plastic packaging material even after the printing.

[0002]

2. Description of the Related Art Various recording materials having an ink-absorbing layer provided on a support have been proposed. However, the present inventors have proposed an ink-absorbing layer in a packaging material in which a sealed portion is formed by heat sealing. Proposed what was provided.

In this case, in order to improve the adhesive strength of the ink absorbing layer to a plastic support, an anchor resin layer made of a water-dispersible thermoplastic resin, specifically, an ionomer resin or a core-shell type emulsion is used. A method has been proposed in which an anchor coat layer is formed and an ink absorbing layer is provided on the anchor coat layer. However, although the method is excellent in characteristics, there is a problem in that the number of processing steps is increased, the process is complicated, and the cost is inferior.

[0004]

SUMMARY OF THE INVENTION A packaging material having an ink-absorbing layer capable of obtaining a sufficient adhesive strength even when directly applied to a plastic support is proposed.

[0005]

Means for Solving the Problems As a result of diligent studies, the present inventors have found that the inclusion of a phenol compound in the ink absorbing layer improves the adhesive strength to a plastic support. Is completed.

As the phenol compound that can be used here, a phenol compound that is generally known as a color developer, which is one of the coloring components of thermosensitive recording paper, can be used. The particularly effective content of the phenol compound is preferably 10 to 30 parts by weight based on 100 parts by weight of the organic or inorganic pigment in the ink absorbing layer. If it exceeds 30 parts by weight, yellowing may be conspicuous when exposed to sunlight or the like. The lower limit is about 5 parts by weight, depending on the phenol compound used.

The packaging material of the present invention comprises a plastic support and an ink absorbing layer formed on one surface of the support, and the other surface of the support has heat sealing properties. Things.

[0008] In the packaging material of the present invention, the plastic support may be formed of a plastic film having heat welding property at a low temperature, or a base material formed of a plastic film and one side of the base material. And a heat seal layer.

The heat seal layer may be an extruded laminate layer formed on one side of a plastic film substrate, a non-stretched film adhered to one side of a plastic film substrate, or a stretched oriented film having a small orientation effect. Consists of

When the plastic film support comprises a plastic film substrate and a heat-sealing layer formed on one side of the substrate, the plastic film substrate is heat-treated. A seal layer may be partially provided.

Further, the ink absorbing layer formed on the plastic support may be partially formed, for example, in a stripe shape or a lattice shape.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In the packaging material of the present invention having the above-described structure, the support may be, for example, HDPE, LDPE,
It is possible to use a plastic film having a low-temperature heat-adhesive property consisting of a non-stretched single film made of L-LDPE, PP, polyvinyl chloride resin or the like.

A support comprising a plastic film such as polyethylene terephthalate, polycarbonate, polyphenylene sulfide, polyetherimide, polysulfone, polystyrene, nylon, cellulose diacetate, cellulose triacetate and the like on which a heat-sealing layer is provided on one side is used as a support. Can be used as

The heat seal layer is made of, for example, HDP
E, LDPE, L-LDPE, ionomer, ethylene-propylene copolymer, ethylene-butene copolymer, propylene-butene copolymer, ethylene-propylene-butene copolymer, unstretched PE film, unstretched EVA film, etc. May be laminated by dry lamination, extrusion lamination, or the like. Further, the heat seal layer is made of EV.
A, such as A, syndiotactic-1,2-polybutadiene, ethylene-propylene-random copolymer, copolyester, and the like, may be laminated with a stretched oriented film having little orientation effect and good heat sealability at low temperature.

As a method of forming a heat seal layer by extrusion lamination, an anchor agent such as an organic titanate-based, polyethylene-imine, urethane-based, or polyester-based anchor is applied to a plastic base material serving as a support. Extrusion lamination method in which a heat seal layer of PP, EVA, ionomer, etc. is melt-extruded and formed into a film on the application surface of the resin, or a resin which becomes a base material and a resin which becomes a heat seal layer using two or more extruders. And a co-extrusion laminating method or the like in which the two are joined in a molten state inside the die or at the opening of the die.

A support on which a heat-sealing layer composed of a stretched film having a low orientation effect and good heat-sealing properties at a low temperature is laminated is preferably formed by stretching a laminated film of an unstretched plastic film as a base material and an unstretched heat-sealing layer. It can also be manufactured by performing an orientation treatment.

In addition, a general additive, such as an antioxidant, an antistatic agent, a slip agent, or the like, which is mixed in an ordinary resin molded product, is appropriately added to a plastic film serving as a plastic support as needed. May be.

Prior to forming the ink-absorbing layer on one surface of the support, the surface on which the ink-absorbing layer is to be formed is preferably subjected to an easy-adhesion treatment.

An example of the easy adhesion treatment is that the surface of the support on which the ink absorbing layer is to be formed is subjected to a corona discharge treatment in air, nitrogen, carbon dioxide or the like.

The ink-absorbing layer contains a resin as a binder component and an inorganic pigment and / or an organic pigment for improving ink absorbability, and further contains a stabilizer, a dispersant,
Thickener, defoamer, antioxidant, wetting agent, ultraviolet absorber,
It is preferably formed as a coating layer of a coating solution composed of an aqueous solution or a water-based emulsion of a resin constituting a binder component containing various auxiliaries such as a waterproofing agent.

Further, in the ink absorbing layer, a dye fixing agent having an ink fixing action, for example, a dicyan or amine polycondensate, a polycationic polymer, an addition polymer or a copolymer is preferably used. It is preferable to form an ink absorbing layer in which the effect of preventing the outflow of ink is effectively exerted by containing.

The resin used as the binder component in the ink absorbing layer preferably has good adhesiveness to the pigment to be mixed into the ink absorbing layer and also has affinity, permeability or swelling property to the ink. , Starch and starch derivatives, water-soluble polymers such as polyvinyl acetate, water-based polymer latex such as acrylic resin and styrene-butadiene copolymer, etc. are used, and 20 to 80% by weight of the solid components constituting the ink absorbing layer It is good to use in the range.

Examples of the pigment used in the ink absorbing layer include inorganic pigments such as synthetic silica, calcium carbonate, barium sulfate, titanium oxide, zinc oxide, zinc carbonate, satin white, aluminum silicate, magnesium silicate, and alumina.
Organic pigments such as plastic pigments, urea resin pigments, melamine resin pigments, and organic / inorganic composite pigments;
Two or more pigments may be used in combination. The pigment used in the ink absorbing layer is 20 to 300 ml / 1.
Those having an oil absorption of 00 g are preferable, and 100 to 30 g
Those having an oil absorption of 0 ml / 100 g are more preferred. When two or more pigments are used in combination, it is preferable that a mixed system of these pigments has an oil absorption within the above range.

The thickness of the ink absorbing layer is about 1 to 20 μm, preferably about 2 to 15 μm, so that the ink absorbing action of the ink absorbing layer is sufficient and the formation of the ink absorbing layer can be performed well. is there.

Specific examples of the phenol compound which is an essential component of the present invention include 4,4'-isopropylidenebisphenol, 4,4'-isopropylidenebis (o-methylphenol), and 4,4'-secondarybutylidene Bisphenol, 4,4'-isopropylidenebis (2-tert-butylphenol), 4,4'-cyclohexylidenediphenol, 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,2 ' -Methylenebis (4-ethyl-6-tert-butylphenol),

4,4'-butylidenebis (6-tert-butyl-2-methylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,1 , 3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl)
Butane, 4,4'-thiobis (6-tert-butyl-2-methylphenol), 4,4'-diphenolsulfone, 4-isopropoxy-4'-hydroxyphenylsulfone, 4-benzyloxy-4'-hydroxy Diphenyl sulfone, 4,4′-diphenol sulfoxide,

Isopropyl p-hydroxybenzoate,
Benzyl p-hydroxybenzoate, Benzyl protocaquitenate, Stearyl gallate, Lauryl gallate, Octyl gallate, 1,7-bis (4-hydroxyphenylthio) -3,5-dioxaheptane,
1,5-bis (4-hydroxyphenylthio) -3-oxapentane, 1,3-bis (4-hydroxyphenylthio) -propane, 1,3-bis (4-hydroxyphenylthio) -2-hydroxypropane ,

Bis (4-hydroxyphenyl) acetic acid methyl ester, bis (4-hydroxyphenyl) acetic acid benzyl ester, bis (4-hydroxyphenyl) acetic acid butyl ester,

1,3-bis (4-hydroxycumyl) benzene, 1,4-bis (4-hydroxycumyl) benzene, 2,4'-diphenolsulfone, 3,3 '
-Diallyl-4, 4'-diphenol sulfone, and the like.

In the packaging material of the present invention having the above-mentioned laminated structure, an ink absorbing layer is formed on a plastic support, and an aqueous solution of a water-soluble polymer, which is a binder component of the ink absorbing layer, or an acrylic resin or the like is used. A phenol compound is pulverized to an average particle size of about 2 to 10 μm using a wet disperser such as a sand grinder to a coating agent of an aqueous emulsion solution such as a styrene / butadiene copolymer, and the mixture is coated. If it is formed as a layer, there is no adverse effect on the operation such as environmental pollution or contamination of the operating machine when using an organic solvent-based coating agent, and it can be manufactured at a low cost.

The above-mentioned packaging material of the present invention can form a sealed portion of a package by heat sealing means utilizing the heat sealing property of the surface opposite to the ink absorbing layer. An impulse eel method, a hot fusing sealing method, an impulse fusing sealing method, a melting sealing method, a high frequency sealing method, an ultrasonic sealing method, and the like can be applied, including a heat sealing method in which a plate is pressed against a surface to be sealed. In addition, it is a matter of course that the package made of this packaging material can be formed with an adhesive bonded portion together with the seal portion formed by the heat seal as described above.

[0032]

EXAMPLES Hereinafter, the specific structure of the packaging material of the present invention will be described with reference to production examples, and the characteristics of the packaging material will be described.

Example 1 One side of a support made of a polypropylene resin film having a thickness of 20 μm extruded from a T-die was subjected to corona discharge treatment, and then the corona discharge-treated surface was provided with the following composition [A]
And a coating material for an ink jet recording layer according to [B] was applied at 6 g (dry) / m ² to form an ink absorbing layer, thereby obtaining a packaging material according to one embodiment of the present invention.

Composition [A] Silica (Nip Seal HD: manufactured by Nippon Silysia Ltd.)
00 parts by weight ethylene-vinyl acetate copolymer (Sumikaflex
471: manufactured by Sumitomo Chemical Co., Ltd .... 40 parts by weight diallyldimethylammonium chloride polymer (PA
S-H-1L: manufactured by Nitto Boseki Co., Ltd. 15 parts by weight Water 300 parts by weight These were dispersed with a homogenizer for 1 hour.

Composition [B] 2,2-Bis (4-hydroxyphenyl) p
ropane (BPA: Nippon Steel Chemical Co., Ltd.) 20 parts by weight polyvinyl alcohol (PVA105: Kuraray Co., Ltd.)
1 part by weight Water 40 parts by weight These were dispersed in a ball mill for 10 hours. [A] and [B] were converted to silica: phenol compound = 100: 20.
(Weight ratio) to obtain a coating agent for ink jet recording.

Example 2 Example 1 was repeated except that the BPA of the composition [B] in Example 1 was changed to bis- (3-allyl-4-hydrophenyloxysulfone) (TGSA: manufactured by Nippon Kayaku Co., Ltd.). Similarly, a packaging material of the present invention was obtained.

Comparative Example 1, Examples 3 and 4 Comparative Example 1 was prepared by adding BPA having the composition [B] of Example 1 and Example 3 was prepared by adding 5 parts of BPA to silica, and Example 40 was prepared. This was designated as Example 4, and respective packaging materials were obtained.

[Experiment] Using the packaging materials of the above Examples and Comparative Examples, using a wrapping machine manufactured by Zandam,
When an A4-size book having a thickness of about 1 cm was wrapped by the impulse fusing and sealing method at a fusing temperature of 400 ° C. and a line speed of 8,000 books / hour, no trouble occurred and normal lapping was performed.

Further, a Scitex 6240 printing system (ink jet printer, Scitex Digital Printi) was applied to the surface of the ink absorbing layer which is the surface of the package obtained by the above wrapping test.
ng inc. Line speed of 100 to 15
When address printing was performed at 0 m / min, normal high-resolution printing could be performed. Further, even if the printed portion was rubbed with a fingertip immediately after printing the address, the printed did not bleed.

Further, the package on which the above address printing was performed was immersed in tap water at room temperature for 1 hour, and almost no bleeding of the print was recognized. When the drop test and the rubbing test of the package on which the address printing was performed were performed, no heat-sealed portion was broken.

However, the adhesive strength of the ink-absorbing layer was measured by using a commercially available mending tape (manufactured by Sumitomo 3M Co., Ltd.) by reciprocating 10 times at a speed of 300 mm / min with a rubber-coated steel roller. When a peel test was conducted at a speed of 30 cm / sec, the following differences were observed. Examples 1-4: O, peeling of the ink absorbing layer was hardly observed. Comparative Example 1: ×, the ink absorbing layer was peeled on almost the entire surface, and the portion became transparent.

[0042]

The packaging material of the present invention comprises a plastic support, and an ink absorbing layer formed on one surface of the support, and the other surface of the plastic support is provided on the other side. It has heat-sealing properties, whereby a sealed portion can be formed by heat-sealing when used as a packaging material for a package when shipped by mail or home delivery.

For this reason, the sender's address, name, PR matters, and the like can be recorded in advance on the packaging material by printing, and when the packaging material is not flat, after the packaging material is formed. Is a non-contact type recording method using an ink jet, and when the package is flat, not only the above-mentioned non-contact type recording method but also a contact type recording method such as a dot printer or thermal transfer recording. Thus, the destination such as the address and name can be recorded.

Conventional direct mailing is performed by preparing a series of labels separately recording the address and name of the destination, and attaching a label for each destination to the surface of the package. However, according to this method, if there is an error in attaching the label, it is necessary to re-create only the label of the address where the error occurred, and the address and name of the address for direct mail. Since it is almost impossible to extract only a specific item from among all recorded files and re-create the label, direct mail will be left out to the address where the label sticking error occurred The fact is that it is.

On the other hand, if a method of recording a destination such as an address and a name on the ink absorbing layer on the surface of the package after preparing the package with the packaging material of the present invention is adopted, Since there is no sticking error, leakage of direct mail due to label sticking error can be eliminated.

In the packaging material of the present invention, an ink-absorbing layer formed on a plastic support can be formed as a coating layer of a water-based coating agent. There is no adverse effect on the operation that occurs when doing so. Further, the packaging material of the present invention is a packaging material in which the phenol compound contained in the ink-absorbing layer is less likely to peel off the printed portion due to handling during delivery.

Claims (1)

[Claims] 1. A packaging material comprising a plastic support and an ink absorbing layer formed on one surface of the support, the other surface of the support having heat sealing properties. 3. The packaging material according to claim 1, wherein the ink absorbing layer contains a phenol compound.