JPH07219436A - Insert mold label - Google Patents

Abstract

(57) [Abstract] [Purpose] Recently, in connection with the problem of waste treatment related to the global environment, there is an increasing movement to recycle plastic molded products by peeling labels from molded products. It is required to have an insert mold label that can be easily peeled off from a plastic molded product in a normal bottle washing process using warm water or steam without peeling off during handling at distribution or sale or immersion in normal temperature water. is there. [Structure] The present invention is an insert-molded label which is preliminarily mounted in a plastic molding die and attached to a molded product at the same time as plastic molding. An insert mold label provided with a delayed tack type heat-sensitive adhesive layer (20) to which an expanding agent (21) and a crosslinking reaction type curing agent are added.

Description

Detailed Description of the Invention

[0001]

[Field of Industrial Application] The present invention is easy to peel from a plastic molded product in a normal bottle washing process with warm water or steam, without peeling it during handling at the time of distribution or sale or immersion in normal temperature water. The present invention relates to an insert mold label.

[0002]

2. Description of the Related Art Conventionally, a label is previously mounted in a plastic molding die, and a label is attached to a molded article at the same time as plastic molding such as a blow molding method or an injection molding method (simultaneous molding attachment). ) Method is widely used, the insert mold label (conventional molding simultaneous sticking label) pasted by this insert molding method can be used as It was firmly adhered, and it was usually difficult to peel it from a plastic molded product.

[0003]

In connection with the recent problem of waste disposal related to the global environment, there is an increasing movement to separate the label from the molded product and reuse the plastic molded product. Insert label that can be easily peeled off from a plastic molded product by a normal bottle washing process using hot water or steam without being peeled off during handling at distribution, sale, immersion in normal temperature water, etc. Is what has been requested.

[0004]

Means for Solving the Problems In response to the above demands, the present invention provides an insert mold label which is preliminarily mounted in a plastic molding die and attached to a molded article simultaneously with plastic molding. As shown in FIG. 1, a microcapsule-shaped thermal expansion agent (21) and a crosslinking reaction type curing agent were added to the back surface (lower surface in FIG. 1) of the label substrate (10),
By providing a heat-sensitive adhesive layer (20) of delayed tack type (adhesiveness is generated by heating and the adhesiveness continues even after cooling, industry term), handling at distribution, sales and normal temperature water The present invention provides an insert mold label that can be easily peeled from a plastic molded product by a normal bottle washing process using warm water, steam, etc. without being peeled off by immersion in water.

Further, according to the present invention, as shown in FIG. 2, an adhesive reinforcing layer (30) for improving interlayer adhesive strength is provided between the label substrate (10) and the heat-sensitive adhesive layer (20). Inserts that can be easily peeled off from plastic molded products by a normal bottle washing process with hot water or steam, which has improved peeling resistance during distribution, handling at the time of sale, immersion in normal temperature water, etc. A mold label is provided.

The label substrate (10) in the insert mold label of the present invention is the same as the conventional one,
The surface is provided with an appropriate printed pattern layer (11), etc.
A paper base material, a resin film base material, a synthetic paper base material, a metal foil base material, or a laminated base material thereof having a thickness of about 200 μm can be used without particular limitation.

There is no particular limitation on the microcapsule-shaped heat-expanding agent (21) in the insert mold label of the present invention. For example, a vinylidene chloride copolymer is used as a shell wall to enclose a low boiling point hydrocarbon. , Average particle size is 5
Ordinary microcapsule-like thermal expansion agent of about 30 μm
(21) is a delayed tack type heat-sensitive adhesive layer described later
It is used by adding 0.1 to 10% by weight to (20).

Regarding the cross-linking type curing agent in the insert mold label of the present invention, an appropriate cross-linking type curing agent having two or more epoxy groups or two or more isocyanate groups can be used as a delayed tack type described later. In order to improve the water resistance of the heat-sensitive adhesive layer (20), 0.05 to 10% by weight is added to the heat-sensitive adhesive layer (20). That is, when the heat-sensitive adhesive layer (20) is activated by heating the insert mold label, the crosslinking reaction type curing agent reacts with a hydroxyl group or a carboxyl group in the heat-sensitive adhesive layer (20) and becomes water resistant. As a result, the adhesiveness with the label base material (10) is improved.

In the insert mold label of the present invention, regarding the delayed tack type heat-sensitive adhesive layer (20) to which the above-mentioned microcapsule-shaped thermal expansion agent (21) and a crosslinking reaction type curing agent are added, It is basically composed of a polymeric material, a tackifier, and a solid plasticizer.It does not have tackiness at room temperature, but when it is heated, tackiness occurs, and the tackiness can be maintained for a considerable time after cooling. Persistent (commonly called delayed tack type, the same applies below) Thermosensitive adhesive layer (20)
Is appropriately provided on the back surface of the label substrate (10).

Here, the polymer material is a component which gives an adhesive force to the heat-sensitive adhesive layer (20), and is a polyvinyl acetate type, copolyethylene-vinyl acetate type, polyacrylic acid ester type, polychlorinated type. Vinyl type, natural rubber type, synthetic rubber type,
Polymer materials such as copolyvinyl acetate-acrylic acid ester-based, polyester-based, polyurethane-based, etc. can be preferably used.

The tackifier is a component which is activated by heating to enhance the tackiness of the heat-sensitive adhesive layer (20), and is a rosin derivative resin type, terpene resin type, phenol resin type, A tackifier such as a xylene resin can be preferably used.

Further, the solid plasticizer is heated to a temperature not lower than the melting point and melted to swell and dissolve the above-mentioned polymer material and tackifier to give the heat-sensitive adhesive layer (20) an adhesive property. It is a component that gives adhesive strength, and since the molten solid plasticizer does not crystallize easily even after cooling, the tackiness and adhesive strength of the heat-sensitive adhesive layer (20) are maintained for a considerable time. Ingredients are diphenyl phthalate, dihexyl phthalate, dicyclohexyl phthalate, dihydroabietyl phthalate, dimethyl isophthalate, sucrose benzoate, ethylene glycol dibenzoate, trimethylolethane tribenzoate, tribenzoic acid glyceride, tetra Suitable solid plasticizers such as pentaeryt benzoate, sucrose octaacetate, tricyclohexyl citrate, N-cyclohexyl-P-toluenesulfonamide It is intended that can be used.

In addition, a preservative, a dispersant, a defoaming agent, etc. can be added to the delayed tack type heat-sensitive adhesive layer (20), if necessary.

Further, in the insert mold label of the present invention, the adhesive reinforcing layer (30) for improving the interlaminar adhesive strength is a cellulose derivative resin, a styrene copolymer resin,
Acrylic acid resin, methacrylic acid resin, rosin ester resin, polyvinyl acetate resin, polyvinyl chloride resin,
Adhesion reinforcement layer consisting of one or more resins such as vinyl chloride-vinyl acetate copolymer resin, polyester resin, polyurethane resin, butyral resin, polyamide resin, styrene-vinyl acetate copolymer resin (30), so that the interlayer adhesive strength between the label substrate (10) and the heat-sensitive adhesive layer (20) is stronger than the interlayer adhesive strength between the heat-sensitive adhesive layer (20) and the plastic molded article. The label base material (10) and the heat-sensitive adhesive layer are selected according to the type of the label base material (10)
It is provided appropriately between (20).

[0015]

In the insert mold label of the present invention, the label is mounted in advance in the plastic molding die,
At the same time as plastic molding such as blow molding method and injection molding method, the heat of the plastic molding heats and pressurizes the insert mold label so that the heat-sensitive adhesive layer (2
When (0) is activated, the above-mentioned crosslinking reaction type curing agent and polymer material, tackifier, and solid plasticizer act on the delayed tack type heat-sensitive adhesive layer (20) to provide adhesiveness and strong adhesive force. In addition, since the molten solid plasticizer does not crystallize easily even after cooling, the adhesiveness of the heat-sensitive adhesive layer (20) and the strong adhesive force are maintained for a considerable time. That is, it can be firmly adhered to a molded product in a state of being bitten into a plastic molded product more than or equal to that of a conventional label for simultaneous molding.

The above-mentioned heat during plastic molding is used.
(90 to 150 ° C.), when the insert mold label of the present invention is heated and pressed, the heat-sensitive adhesive layer (20) is softened and the microcapsule-shaped thermal expansion agent (21) is thermally expanded. However, because the heating time during plastic molding is short (about 20 seconds) and the plastic molding die is cooled (below 60 ° C),
Furthermore, it is strongly pressed during plastic molding (7 kg / cm ²
Therefore, the thermal expansion agent (21) in the form of microcapsules has a small degree of thermal expansion, and can be firmly adhered to the molded product in a state where it is likewise eaten into the plastic molded product. .

Further, in the insert mold label of the present invention, as shown in FIG. 3, a plastic molded product is subjected to a normal bottle washing process with hot water or steam of about 80 ° C.
When the insert-molded label attached to (40) at the same time as molding is heated, the delayed tack type heat-sensitive adhesive layer (20) is softened by heating to cause tackiness.
In (see FIG. 3 (A)), the thermal expansion agent (21) in the form of microcapsules added to the heat-sensitive adhesive layer (20) undergoes thermal expansion (see FIG. 3 (B)), resulting in heat sensitivity. Concavo-convex (22
(See (C)), and the adhesive force (contact area) of the molding simultaneous adhesion surface (22) is reduced, and the heat-sensitive adhesive layer
By thermal expansion of the microcapsule-shaped thermal expansion agent (21) added to (20), due to the difference in thermal expansion between the label substrate (10) and the heat-sensitive adhesive layer (20), the insert mold label is The insert mold label is curled (see FIG. 3D), and the insert mold label that is simultaneously attached to the plastic molded product (40) during molding is easily peeled off from the plastic molded product (40).

That is, in the insert mold label of the present invention, a delayed tack type in which a microcapsule-shaped thermal expansion agent (21) and a crosslinking reaction type curing agent are added to the back surface of the label substrate (10). By providing the heat-sensitive adhesive layer (20), it does not peel off during handling at the time of distribution, sale, immersion in normal temperature water, etc., and peeling from plastic molded products by a normal bottle washing process with warm water or steam Thus, an insert mold label that is easy to obtain can be obtained.

[0019]

EXAMPLE FIG. 1 is a partial sectional view of an insert mold label in Example 1, Comparative Example 1, and Comparative Example 2 of the present invention. That is, on the back surface of the label substrate (10) provided with an appropriate printed pattern layer (11) on the surface, a microcapsule-shaped thermal expansion agent (21) and a crosslinking reaction type curing agent are added, a delayed tack type FIG. 3 shows the state of an insert mold label provided with the heat-sensitive adhesive layer (20). Also, in FIG.
It is a fragmentary sectional view of an insert mold label in Example 2 of the present invention. That is, the label base material (10) and the heat-sensitive adhesive layer (2
(0), the adhesive reinforcing layer (30) to improve the interlayer adhesive strength
3 shows the state of the insert mold label provided with.

<Example 1> As the polymer material, ethylene was used.
100 parts by weight of an aqueous emulsion of vinyl acetate copolymer and a rosin derivative ester as a tackifier
100 parts by weight of an aqueous emulsion having a softening point of 120 ° C. and dicyclohexyl phthalate as a solid plasticizer.
100 parts by weight of an aqueous emulsion (melting point 64 ° C.) and 3 of a delayed tack type heat-sensitive adhesive composed of
00 solid parts by weight, vinylidene chloride-acrylonitrile copolymer as a shell wall and isobutane encapsulated therein, having an average particle size of 10 to 20 μm and an expansion starting temperature of 80 ° C., a microcapsule-shaped thermal expansion agent (21) 10 parts by weight and 5 parts by weight of a liquid crosslinking reaction type curing agent of a bisphenol A type epoxy compound having two epoxy groups are added to prepare an aqueous resin dispersion (aqueous emulsion). A delayed tack type heat-sensitive adhesive layer composition was prepared.

Subsequently, as shown in FIG. 1, the back surface of a polypropylene synthetic paper base material (10) having a thickness of 80 μm and provided with an appropriate printed pattern layer (11) on the front surface was subjected to a roll coating method.
This heat-sensitive adhesive layer composition is applied and dried at room temperature to obtain a delayed tack type heat-sensitive adhesive layer (20) having a layer thickness of 25 μm.
The insert mold label of Example 1 provided with is prepared.

Comparative Example 1 The delayed tack type heat-sensitive adhesive layer composition of Example 1, in which the microcapsule thermal expansion agent (21) and the crosslinking reaction type curing agent were not added, that is, As a polymer material, 100 solid parts by weight of an aqueous emulsion of ethylene-vinyl acetate copolymer, as a tackifier, 100 solid parts by weight of an aqueous emulsion of rosin derivative ester, and as a solid plasticizer, an aqueous solution of dicyclohexyl phthalate. An aqueous resin dispersion (aqueous emulsion) in the form of a delayed tack type heat-sensitive adhesive composed of 100 solid parts by weight of the emulsion was prepared.

Subsequently, as shown in FIG. 1, the same polypropylene synthetic paper base material (10) as in Example 1 having an appropriate printed pattern layer (11) on the surface was roll-coated by a roll coating method. This heat-sensitive adhesive is applied and dried at room temperature to give a layer thickness of 2
The insert-molded label of Comparative Example 1 was prepared in which a delayed tack type heat-sensitive adhesive layer (20) of 5 μm was provided.

<Example 2> The same delayed tack type heat-sensitive adhesive layer composition as in Example 1, that is, 100 solid parts by weight of an aqueous emulsion of ethylene-vinyl acetate copolymer as a polymer material, As a tackifier, 100 solid parts by weight of an aqueous emulsion of rosin derivative ester, and as a solid plasticizer, 100 solid parts by weight of an aqueous emulsion of dicyclohexyl phthalate, 300 solids of a delayed tack type heat-sensitive adhesive. 10 parts by weight of a microcapsule-shaped thermal expansion agent (21) encapsulating isobutane with vinylidene chloride-acrylonitrile copolymer as a shell wall, and a crosslinking reaction type curing agent of a bisphenol A epoxy compound And 5 parts by weight of a delayed tack type thermosensitive adhesive in the form of an aqueous resin dispersion (aqueous emulsion). Adhesive layer composition was prepared.

Subsequently, as shown in FIG. 2, a polyester having an appropriate printed pattern layer (11) provided on the surface and having a thickness of 80 μm.
(PET) On the back surface of the film substrate (10), an adhesive reinforcing layer (30) comprising a vinyl chloride-vinyl acetate copolymer resin and a polyurethane resin is interposed, and this heat-sensitive adhesive layer is formed by a roll coating method. The insert mold label of Example 2 was prepared in which the composition was applied and dried at room temperature to provide a delayed tack type heat-sensitive adhesive layer (20) having the same layer thickness of 25 μm as in Example 1. .

Comparative Example 2 The same delayed resin type thermosensitive adhesive layer composition as in the above-mentioned aqueous resin dispersion (aqueous emulsion) was prepared in the same manner as in Examples 1 and 2.

Subsequently, as shown in FIG. 1, the same polyester film base material (10) as in Example 2 having an appropriate printed pattern layer (11) on the surface was adhered to the back surface of Example 2 for reinforcement. Layer (3
This heat-sensitive pressure-sensitive adhesive layer composition was applied by a roll coating method without passing through (0) and dried at room temperature to obtain a delayed tack type heat-sensitive adhesive having the same layer thickness of 25 μm as in Examples 1 and 2. The insert mold label of Comparative Example 2 provided with the agent layer (20) was produced.

<Bottle Washing Test> The insert mold labels of Example 1, Comparative Example 1, Example 2 and Comparative Example 2 were 50 × 1.
After cutting into 00 mm and heating at 120 ° C. for 20 seconds to give adhesiveness and adhesiveness to the heat-sensitive adhesive layer (20), a usual insert mold is applied to the surface of the polyester sheet having a thickness of 1.0 mm. -Similar to blow molding method, 7kg / cm ²
Then, 50 pieces of the test pieces for the bottle washability test were prepared.

Then, tap water heated to 60 ° C. and 80
10 pieces of each test piece are immersed in tap water heated to ℃ and 3% caustic soda water heated to 80 ℃, and insert without leaving external force such as rubbing. The time (minutes) until the mold label peels itself is measured. Considering the conditions of the normal bottle washing process with hot water or steam, the self-peeling time is 10 minutes or less, and passes (○). It is what Table 1 shows the results of the bottle washing test of Example 1, Comparative Example 1, Example 2, and Comparative Example 2.

[0030]

[Table 1]

Regarding the bottle-washing contamination in the table, in consideration of the situation of a normal bottle-washing process with hot water or steam,
Without applying external force such as rubbing, when the insert mold label was allowed to stand and was self-peeling, the case where no residual heat-sensitive adhesive layer (20) was observed on the surface of the polyester sheet was regarded as pass (○). It is a thing. Regarding the peeling resistance in the table, 5 pieces of each test piece were immersed in normal temperature water at the time of sale or at home for handling, and allowed to stand for 48 hours to peel off the insert mold label or The case where no floating or the like was observed was judged as pass (○). further,
Regarding the measurement of the adhesive strength in the table, in terms of handling at the time of distribution and sales, the heat-sensitive adhesive layer (5 sheets) of each test piece that was pressed and adhered for 24 hours as described above ( 2
0) and the polyester sheet adhesive strength JIS-Z-023
Adhesive force of 800g / 25mm or more measured according to 7.
It is a pass (○).

[0032]

As described above, in the insert mold label of the present invention, the back surface of the label substrate (10) has a microcapsule-shaped thermal expansion agent (21) and a crosslinking reaction type curing agent. Delayed tack type with added agent
By providing the heat-sensitive adhesive layer (20) (which becomes sticky when heated and remains sticky even after cooling), it can be peeled off by handling at the time of distribution, sale or immersion in normal temperature water. Instead, it is possible to provide an insert mold label (molding simultaneous sticking label) that can be easily peeled from a plastic molded product in a normal bottle washing process using warm water, steam, or the like.

That is, in the insert mold label of the present invention, the label is preliminarily mounted in the plastic molding die, and at the same time as the plastic molding such as the blow molding method or the injection molding method, the insert molding label is heated by the heat during the plastic molding. When the label is heated and pressed to activate the heat-sensitive adhesive layer (20), by the action of the crosslinking reaction type curing agent and polymer material, the tackifier, and the solid plasticizer,
It gives adhesiveness and strong adhesion to the delayed tack type heat-sensitive adhesive layer (20), and it can be molded into a plastic molded product more than equivalent to the conventional co-sticking label. It can be firmly attached to products.

Further, in the insert mold label of the present invention, as shown in FIG. 3, a plastic molded product is subjected to a normal bottle washing process with hot water or steam of about 80 ° C.
The insert-molded label that is simultaneously attached to the molding (40) is heated, and in a state where the delayed tack type heat-sensitive adhesive layer (20) that is tacky when heated is softened, the heat-sensitive adhesive layer ( By heat-expanding the microcapsule-shaped heat-expanding agent (21) added to (20), the surface of the heat-sensitive adhesive layer (20) that is simultaneously attached to the plastic molding (40)
(22) has unevenness, which reduces the adhesive force (contact area) of the simultaneous molding attachment surface (22), and also the heat-sensitive adhesive layer.
By thermal expansion of the microcapsule-shaped thermal expansion agent (21) added to (20), due to the difference in thermal expansion between the label substrate (10) and the heat-sensitive adhesive layer (20), the insert mold label is The insert-molded label is curled so as to be rolled up, and the insert-molded label that is attached to the plastic molded product (40) at the same time as the molding is easily peeled off from the plastic molded product (40).

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of an insert mold label in Example 1, Comparative Example 1, and Comparative Example 2 of the present invention.

FIG. 2 is a partial cross-sectional view of an insert mold label according to a second embodiment of the present invention.

FIG. 3 shows the insert mold label of the present invention,
FIG. 6 is a partial cross-sectional view showing a state where the insert mold label attached to the plastic molded product (40) at the same time as the molding is easily separated from the plastic molded product (40).

[Explanation of symbols]

10 ... Label base material, polypropylene synthetic paper base material, polyester film base material 11 ... Printed pattern layer 20 ... Heat-sensitive adhesive layer 21 ... Microcapsule-shaped thermal expansion agent 22 ... Simultaneous molding affixing surface 30 ... Adhesion reinforcing layer 40 … Plastic molded products

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuka Imai 1-5-1, Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd.

Claims (2)

[Claims] 1. Mounting in advance in a plastic molding die,
An insert-molded label that is attached to a molded product at the same time as plastic molding, in which a microcapsule-shaped thermal expansion agent (21) and a crosslinking reaction type curing agent are added to the back surface of the label substrate (10). Tack type heat-sensitive adhesive layer (2
The insert mold label is characterized in that (0) is provided. 2. The label substrate (10) and the heat-sensitive adhesive layer (2)
(0), the adhesive reinforcing layer (30) to improve the interlayer adhesive strength
The insert mold label according to claim 1, wherein the insert mold label is provided.