JPH02282050A - Packing container - Google Patents

Abstract

PURPOSE:To prevent the trade mark portion of a cover paper from peeling off by a method wherein water-soluble delayed tacky adhesive, in which crystalline plasticizer is dispersed in resin polymer, is applied on the upper and lower faces of a packing container and dried, and an adhesive layer is formed, which becomes sticky by heat over 60 deg.C. CONSTITUTION:Delayed tacky adhesive is painted on the edges of the upper and lower faces 1A and 1B and dried naturally to form an adhesive layer 2 which becomes sticky by heat over 60 deg.C. Forming the adhesive layer 2 can be carried out in such a manner that the adhesive is applied after the container 1 is assembled or painted with a roller at the step of printing a trade mark, etc., on the portions 1A and 1B which become the upper and lower faces respectively when the container is assembled after a sheet of corrugated paper is cut into the developing shape of the container. Thereby, an adhering strength endualable for a long distance transportation can be achieved without tacky of the adhesive layer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a packaging container, and more particularly to a packaging container that is less likely to cause back strain during transportation.

[Conventional technology]

Conventionally, for example, can beer is packed in cardboard boxes, and when shipped from a factory, more than 80 cans are stacked in parallel on pallets, and each pallet is loaded onto a trailer for transport. Unload the cargo. However, during transportation, the cardboard boxes on the pallet bounce or move sideways due to vibrations caused by braking, stopping, starting, curves, slopes, etc. of the trailer. After lining up the trucks, unloading work begins. Even if a forklift truck is used, it takes a lot of time and effort to organize the cardboard boxes on the pallet, so in some cases, the cardboard boxes are glued together using adhesive (hot melt). Measures are taken to stack them on pallets.

[Problem to be solved by the invention]

The above method of using hot melt adhesive has excellent adhesion between boxes, but when unloading cardboard boxes individually from a pallet, the adhesive layer adheres to the bottom of the box above. When separated, the surface paper of the lower box may be peeled off while still being adhered to the adhesive layer, and vice versa. When such boxes are delivered to stores, they give a very bad image.

That is, there were problems such as the surface paper of the trademark part peeling off, the adhesive layer being too bulky, or part of the box tearing.

In view of these circumstances, this invention has been developed to ensure that packaging containers such as stacked cardboard boxes are glued together during transportation so that the cargo does not collapse, and when sorting from a pallet, it is easy to separate containers by simply lifting them. It was developed with the aim of providing a packaging container that can be used without causing any damage to the surface of the container.

[Means to solve the problem]

In order to solve the above-mentioned problems, this invention (1) applies an aqueous delayed tack adhesive in which a crystalline plasticizer is dispersed in a resin polymer to the upper and lower surfaces of a packaging container and dries it for 60 minutes.
A packaging container characterized by forming an adhesive layer that becomes sticky when exposed to heat of ℃ or more.

(2) The main ingredients are a crystalline plasticizer, an acrylic resin emulsion, and a rosin resin emulsion, and one or more of a dispersant, an antifoaming agent, a thickener, and an antiblocking agent are added as necessary. Apply the mixed delayed tack adhesive to the top and bottom of the cardboard box and let it dry.
A packaging container characterized by forming an adhesive layer that becomes sticky when exposed to heat of ℃ or more.

We took technical measures.

[Effect]

The present invention configured as described above has the following effects.

First, even if the adhesive layer, which becomes sticky when exposed to heat of 60°C or higher, is formed on the top and bottom surfaces of cardboard boxes (when laminated), the normal temperature is 55°C or lower even in summer. , it is not sticky in its original state.

Therefore, at a factory, when products are packed into containers such as cardboard boxes and the adhesive layer is heated to 60°C or higher just before being loaded onto a pallet, the crystalline plasticizer in the adhesive layer melts and the resin polymer is heated. Activated lick tackiness occurs. Therefore, when a plurality of cardboard boxes are stacked on top of each other with the adhesive layer becoming sticky, the boxes are connected together in a vertical relationship.

When the temperature of the adhesive layer drops to the ambient temperature range, the adhesive layer hardens and firmly fixes the boxes together, so boxes placed on pallets may collapse during transportation by truck, etc. do not have.

After transportation, when separating each section from the pallet, simply lift the upper box to remove the hardened adhesive layer (the bottom of the upper box and the top of the lower box are joined). It is separated vertically (because the adhesive strength in the horizontal direction is strong, but the adhesive strength in the vertical direction is weak).

〔Example〕

Next, embodiments of the invention will be described with reference to the drawings. 1st
The figure is a perspective view of a packaging container 1 made of a cardboard box.

A delayed tack adhesive is applied to the edges of the upper surface 1^ and lower surface 1B of the packaging container 1, and an adhesive layer 2 that becomes sticky when heated at 60° C. or higher is formed by air drying. .

The adhesive layer 2 may be formed after the container 1 is completed, or at the stage of cutting the cardboard for the cardboard box and printing the trademark etc., as shown in FIG. The coating thickness of the adhesive layer 2 may be 4.51 r/rrf to 10 r/r/cm in solid coating.
rrf (dry), which changes depending on the size of the box and the area to be coated. That is, in this embodiment, as shown in the figure, the width of the edge of the upper and lower surfaces of the box is approximately 3a11 to 3a11.
Although it is shown that it is formed with a width of 5 mm, it is also possible to apply a solid coating to the upper and lower surfaces IA and 1B, as shown in a perspective view in Fig. 3 and a developed view in Fig. 4, or in a diagonal pattern, a grid pattern, or trademark,
It can also be formed into a shape such as a flower pattern.

Furthermore, the packaging container 1 is not limited to a cardboard box.

Next, the composition of the delayed tack adhesive used in this invention will be explained in detail.

- An example of a delayed tack type adhesive inside the shell is a mixture of 50% polyvinyl acetate emulsion, 100 parts of dicyclohexyl phthalate, and 50 parts of dicyclohexyl phthalate, which is placed in a box for 24 hours. After applying and drying at a low temperature, when heated at 75°C to 100°C, dicyclohexyl phthalate (plasticizer) melts and softens the polyvinyl acetate resin, causing it to become sticky. In other words, after application, the painted surface remains hardened at normal temperatures.
It is not sticky, but only becomes sticky when heated.

Therefore, if this adhesive layer 2 is formed on the packaging container 1, the adhesive layer 2 of the packaging container 1 can be
Since it does not become sticky, it is easy to handle. After accommodating the product and packaging it, the adhesive layer 2 is
If heated above 0℃, the adhesive layer becomes sticky and the adhesiveness lasts for several hours, so if multiple cardboard boxes are stacked side by side on a pallet as described above, the boxes will stick to each other. The upper and lower parts are connected via an adhesive layer. The sticky adhesive layer hardens over time and loses its stickiness, but
The upper and lower adhesive layers that are adhered to each other will not peel off unless strong force is applied.

An example of a typical delayed tack adhesive is diphenyl phthalate: 45 parts by weight Indene resin: 45 parts by weight Ethyl cellulose: 10 parts by weight Amine dispersant: 6 parts by weight Polybutyl methacrylate emulsion (50% concentration) 10 parts by weight Water: 160 parts by weight The composition of the amine dispersant is 1 part of stearic acid, 1 part of polymerized rosin containing abietic acid dimer 40X, 1 part of 2-ethyl 2-aminopropanol, and 3 parts of water.

This adhesive layer is fully activated at 67°C.

When the above components are changed to 50 parts of ethyl cellulose, 50 parts of diphenyl phthalate, and 20 parts of emulsion, the temperature at which the adhesive layer is activated increases to 75°C. As the emulsion, a vinyl chloride/vinylidene chloride copolymer emulsion or a synthetic rubber latex can be used. Petroleum resins, terpene resins, and rosin derivatives can be used in place of ethylcellulose.

As for the dispersion method of solid plasticizer, dicyclohexyl phthalate 40% polyoxyethylene (5 mol) alkylphenol
10% aqueous solution of 2x polyvinyl alcohol (saponification degree 88%) 38% water
20
% in a ball mill for 16 hours.

The delayed tack pressure-sensitive adhesive using the solid plasticizer dispersion thus obtained is as follows: Crystalline plasticizer dispersion 100 to 160 parts by weight Hydrocarbon resin emulsion (50%) 10 to 20 parts by weight Vinyl acetate-acrylic There are formulations such as 1 part of 2-ethylhexyl acid (75 copolymer emulsion (55%)) 25-50If (45-50% solids).

There is also a delayed tack type adhesive in which a crystalline plasticizer is melted, emulsified in water, and mixed with an emulsion. Examples of emulsified adhesives with rosin derivatives are as follows.

Dicyclohexyl phthalate 5 parts by weight Melt polymerized rosin at 95°C 5.3 parts by weight 3.3% aqueous solution of ethanolamine 28 parts by weight Cellulose ether 0.18 parts by weight are mixed and emulsified Next, dicyclohexyl phthalate 25 parts by weight A delayed tack pressure-sensitive adhesive activated at 75° C. is obtained by melting and emulsifying the above-mentioned emulsion and adding 10 parts of polybutyl methacrylate emulsion ('a degree 50%).

The following formulation is also available as a method of dispersing an emulsion in a molten crystalline plasticizer.

Dicyclohexyl phthalate 50 parts by weight Pentaerythritol tetrabenzoate 8i! ! After heating a quantity of tribenzoic acid glyceride to 135°C and melting it,
43 parts by weight vinylpyrrolidone-ethyl acrylate (60:40) copolymer emulsion (
10 parts by weight (concentration 40X) are heated to 49° C. and slowly added to the melt.

Other emulsions that can be used include copolymer emulsions such as vinyl acetate and ethylene, vinyl and lolidone and styrene, and styrene and butadiene.

The adhesive layer 2 in this invention must meet the following objectives.

(1) Normal temperature (
It should not become sticky even when exposed to direct sunlight in summer, radiant heat, etc.).

(2) It easily becomes sticky when heated at 60'C to 120C (temperature reached at layer surface).

(3) When the packaging container and the container are connected together, the containers do not separate from each other during transportation.

(4) When the packaging containers are unloaded from the pallet, they can be easily separated from each container.

(5) The surface of the packaging container, especially the surface paper, should not be torn or damaged during the above sorting.

(6) The surface to which the adhesive is applied should not lose its beauty due to cloudiness, etc.

The following conditions are necessary.

As a result of repeated experiments to satisfy the above conditions, the following combination sequence is presented in this invention.

A Crystalline plasticizer 35 parts by weight Acrylic resin emulsion (solid content 50%) 40 parts by weight Rosin resin emulsion (solid content 50%) 25 parts by weight Dispersant (amine) 20 parts by weight Antifoaming agent (silicone oil) 5 parts by weight Part thickener (
Polyvinyl alcohol) 5 parts by weight B Crystalline plasticizer 16 parts by weight Acrylic resin emulsion (solid content 50x) 37 parts by weight Rosin resin emulsion (solid content 50%) 25f! 22 parts by weight of silicic acid fine powder (anti-blocking) 5 parts by weight of dispersant (amine) 5 parts by weight of antifoaming agent (silicone oil) 5 parts by weight of thickener (casein)
5 parts by weight C crystalline plasticizer
40 parts by weight acrylic resin emulsion (50%) 35
Part by weight Rosin resin emulsion (50%) 25i
l! Parts: Dispersant: 20 parts by weight Defoaming agent: 7 parts by weight Thickener
10 parts by weight D crystalline plasticizer
45 parts by weight Acrylic resin emulsion (50K) 45 parts by weight Rosin resin emulsion (50%) 10 parts by weight Dispersant
7i 1 part thickener 15 parts by weight or more is one example of blending, and is not limited to this.

Examples of the crystalline plasticizer include diphenyl phthalate, dihexyl phthalate, and dicyclohexyl phthalate.

Dihydroabiethyl phthalate Dimethyl isophthalate, Sufurose benzoate Dibenzoic acid ethylene glycol Tribenzoic acid Trimethylolethane Tribenzoic acid glyceride Tetrabenzoic acid Pentaerythritol Octaacetic acid Sucrose Tricyclohexyl citric acid Tocyclohexyl-P-toluenesulfonamide, etc. In addition, dehydroabiethylamine carbonate and methoxyethyl stearate can be used as latent plasticizers.

Among these crystalline plasticizers, dicyclohexyl phthalate (
Melting point: 63 to 65°C) is generally used in delayed tack adhesives, but if a plasticizer with a low melting point is used, produkking tends to occur, so plasticizers with a high melting point, such as sucrose benzoate (melting point: 98°C) ) etc., that is, a plasticizer with a melting point of 65°C begins to melt at 65°C or higher and is fully activated at 75°C. The delayed tack pressure-sensitive adhesive which has become sticky due to this will melt at 52°C when reheated after curing. Therefore, it is preferable to use a crystalline plasticizer with a melting point of 73 to 75°C or higher to prevent blocking in the summer.

Next, as the acrylic resin emulsion, for example, vinyl acetate 2-ethylhexyl acrylate (45:55) copolymer emulsion (solid content 50%) is used, but the resin emulsion is not limited thereto.

Rosin-based resin emulsions are used to provide curability at low temperatures and tackiness when heated. For example, polymerized rosin is melted at 95°C and added to a 3.3% aqueous solution of ethanolamine at a ratio of 6:30 (polymerization percentage). ) is used.

The crystalline plasticizer and acrylic resin (solid content 50%)
The mixing ratio of the king mixture of rosin resin (solid content 50x) is crystalline plasticizer 15-45f! Parts by weight Acrylic resin 35 to 55 parts by weight Rosin resin 15 to 35 parts by weight are preferred.

If the amount of crystalline plasticizer exceeds the amount of resin content (solid content), the adhesive layer tends to whiten after activation, so to prevent this, it is necessary to keep the amount within the above-mentioned appropriate amount. Good.

Further, when the amount of crystalline plasticizer relative to the resin solid content is 702 or less, the degree of occurrence of blocking becomes stronger after activation. In order to prevent this, fine silicic acid powder was added as in Formulation B above. Further, as the anti-blocking agent, carnauba wax, stearic acid, unsaturated dicarboxylic acid, etc. can be used.

The antifoaming agents include propyl, butyl, cetyl, fatty acid alcohol, glycol derivatives, sorbitol derivatives,
Soybean oil, silicone oil, nitrogen compounds, etc. are used.

As the adhesive, carboxymethyl cellulose, methyl cellulose, casein, polyvinyl alcohol, sodium polyacrylate, starch, etc. are used.

[Experiment example]

Next, experimental examples of the pressure-sensitive adhesives A to D will be shown.

For each of Adhesives A to D, the coating amount was approximately 4.5 mm per IM using a roller printing method on sample base paper (corrugated paperboard).
5. , eg, 8g, 10,
After 1 hour of air drying, it was heated with hot air at 200°C for 30 seconds (surface temperature reached 100-105°C).

Immediately adhere this to each type with the adhesive layer facing each other,
The lower corrugated paper was fixed to the base plate, a load of 1 kg/10 rrr was applied to the upper corrugated paper, and the white board was tilted to determine the slip angle of the upper corrugated paper.
It was found to withstand angles from 1.5° to 57.5°.

Next, after 10 minutes of adhesion in the above process, the lower paper of the two upper and lower cardboard sheets was fixed to a vibrator, and the upper paper
/- load, amplitude 50 am, 250 cycles/
When horizontal vibration was applied for 10 minutes, the number of times it took for the upper and lower sheets to separate was 106 to 261 times.

Regarding surface adhesion, a 50μ semi-rigid PVC film was attached to the adhesive layer of each sample after heating, and
After 4 hours, the vinyl chloride film was peeled off at a peeling angle of 180° and a speed of 10,100 O/min after nitering at 23° C. and 65XRH to determine the peel strength, which was 5 to 15 g/40 w width.

As a result of the above test, the overall quality was determined in the order of A, B, C, and D. In addition, when the adhesive layers (number 2 in the drawing) using these adhesives A, B, C, and D are formed on the upper and lower surfaces of a cardboard box, multiple cardboard boxes are stacked on a pallet and tracked in parallel. It has become clear that the load will not collapse at all even if it is loaded on a truck or the like and transported using the conventional method.

It was also discovered that the upper and lower cardboard boxes could be easily separated by the weight of the lower cardboard box by simply lifting the upper box.

On the other hand, when the adhesive layer 2 is formed on the packaging container 1 and dried, it has a milky white color due to the non-transparent properties of the crystalline plasticizer and the like contained therein.

However, the milky white color disappears by heating and melting the crystalline plasticizer.

However, after the two boxes are adhered and separated, the adhesive layer 2 may whiten over time.

To prevent this whitening, (1) reduce the amount of crystalline plasticizer (formulation B), and (2) select a plasticizer that melts at high temperatures and ~12
0 °C) melting (in the case of formulation A) is preferred,
However, if the amount of crystalline plasticizer is too small, blocking tends to occur, so in formulation B, a large amount of antiblocking agent (fine silicic acid powder) is mixed.

In this way, when comparing Formulation A and Formulation B, Formulation B has a lower degree of whitening in the unheated state, but whitening was observed in both at room temperature (26-27°C) 30 days after heat activation. I can't do it.

In this way, if you are concerned about whitening of the adhesive layer 2, you can select formulation A or formulation B, and if you are concerned about whitening, you can use other formulation examples. To avoid this, it is possible to take measures such as putting a coloring agent into the adhesive or applying it in a pattern so that the whitening does not become noticeable.

The amount of the adhesive layer 2 applied and the amount of the thickener may be changed as needed depending on the size, weight, number of layers, etc. of the packaging container to which it is applied.

〔Effect of the invention〕

This invention has the following excellent effects.

(1) Since the delayed tack type adhesive layer is pre-formed on the packaging container, the adhesive layer does not become sticky at normal temperatures, and has an excellent texture and aesthetic appearance. Just by heating the adhesive layer to 60°C or higher just before accommodating the products and stacking them on a pallet, it is possible to obtain adhesive strength that can withstand long-distance transportation, and it is also extremely easy to separate the container sides. It has the effect of being able to do so without damaging the container.

(2) Since a water-based adhesive is applied, the amount of application can be small and uniform, and the cost can be lower than that of hot melt adhesives.

[Brief explanation of drawings]

The drawings relate to embodiments of the invention, with FIG. 1 being a perspective view of a packaging container, and FIG. 2 being a developed view of a cardboard box. FIG. 3 is a perspective view of packaging containers having different box shapes, and FIG. 4 is a developed view of the box shown in FIG. 3. 1...Packaging container, 1A...Top surface, 1B...
・Bottom surface, 2... Delayed tack adhesive layer.

Claims (2)

[Claims] (1) A water-based delayed tack adhesive containing a crystalline plasticizer dispersed in a resin polymer is applied to the top and bottom surfaces of a packaging container and dried to form an adhesive layer that becomes sticky when heated at 60°C or higher. A packaging container characterized by: (2) The main ingredients are a crystalline plasticizer, an acrylic resin emulsion, and a rosin resin emulsion, and if necessary, a dispersant, an antifoaming agent, a thickener, and an antiblocking agent.
Apply a delayed tack adhesive containing one or more of them to the top and bottom of the cardboard box and dry it for 60 minutes.
A packaging container characterized by forming an adhesive layer that becomes sticky when exposed to heat of ℃ or more.