JPH06122152A - Thermally shrinkable label - Google Patents

Abstract

PURPOSE:To obtain a thermally shrinkable label at a low temperature and prevent a vessel from being deformed in a heat shrinking step by using a mixture of at least two polymers selected from polyethylene terephthalate, special copolyester and copolymer. CONSTITUTION:A label sent by a conveyor 1 and covered in close contact with a glass bottle 8' loosely covered with the label is transferred to a rotary table 4, and thermally shrinked in a steam tunnel 5. The thus treated label is formed by using a mixture of at least two polymers selected from (1) polyethylene terephthalate synthesized from telephthalic acid or its derivatives, telephthalic acid or its derivatives, (2) copolyester synthesized from ethylene glycol introduced with 1,4-cyclohexane methanol, and (3) copolymer synthesized from telephthalic acid or its derivatives and isophthalic acid or its derivatives, etc.

Description

Detailed Description of the Invention

[0001]

The present invention is made of a specific material,
The present invention relates to a heat-shrinkable label exhibiting a specific heat-shrinkable property, and by providing a label from the outside, the label is provided for industrial use.

[0002]

2. Description of the Related Art Conventionally, for example, a label in the form of a heat-shrinkable plastic sleeve which is loosely covered on containers is heat-shrinked by passing through a shrink tunnel or the like in which hot air flows, so that the container is closely covered. However, since the heat shrinkage temperature is in a high temperature range, if it is applied to, for example, plastic containers having a low softening point, problems such as deformation of the containers during the heat shrinking process will occur. Was pointed out.

[0003]

The present invention has been made to solve these conventional problems and to provide a heat-shrinkable label that can be applied to containers having a low softening point.
Its characteristic is that in heat-shrinkable labels, it was synthesized from polyethylene terephthalate or teretaful acid or its derivative synthesized from terephthalic acid or its derivative and glycol component, and ethylene glycol into which 1.4 cyclohexanedimethanol was introduced. It comprises a mixture of at least two polymers selected from copolyester and a copolymer synthesized from terephthalic acid or its derivative, isophthalic acid or its derivative and a glycol component, and in a heat shrinkage-temperature graph, 60 ° C to 95 ° C. It is at the point of drawing a curve showing a sharp rise between ° C.

Means for solving the problems will be specifically described below. The heat-shrinkable label of the present invention is preferably used for containers, and such containers include glass bottles, plastic bottles such as polyester bottles, metal cans and the like, but are not particularly limited, but particularly have a low softening point and a low melting point. A preferable example is a plastic bottle made of the above material. Further, the heat-shrinkable label, at least one of them, preferably, the circumferential direction in the sleeve state,
In the heat shrinkage-temperature graph, a gradient of "35% / 10 ° C" or more that shrinks 35% or more during an increase of 10 ° C between arbitrary temperatures of 60 to 95 ° C is drawn.
It is made of the above-mentioned material showing a sharp rise. Examples of such a label include a label formed in a sleeve shape by stacking both ends of appropriately cut flat films, which are stretched in uniaxially, biaxially, etc., and center-sealed. Further, it is usually formed in a sleeve shape with the center seal or the like slightly larger than the diameter of the containers, so that the containers can be loosely covered and then heat-shrinked. There is no particular limitation as long as the label is cut and used as a sleeve-like label. The graph shown in FIG. 1 is the heat shrinkage rate at each temperature of the hot blood shrinkable labels made of different plastic materials, and shows the heat shrinkage rate in the weft direction of the film prepared by uniaxially stretching the weft. The heat shrinkage ratio is a value after 30 seconds of immersion in the Gunserin bath.

FIG. 1 shows polyvinyl chloride (1), polyethylene (2), polystyrene polymer (3), and a mixture (4) of polyester polymers according to the present invention exemplified in Example (1) described later. In the graph showing the relationship between temperature and heat shrinkage when used as a material, for example, in the case of the polyester polymer shown in (4), the graph rises sharply at 75 to 85 ° C.

As described above, according to the present invention, as shown in FIG. 1, in the heat shrinkage-temperature graph in the weft direction of the film formed by weft uniaxial stretching, the temperature rises sharply, for example, 60-9.
The present invention relates to a heat-shrinkable label made of a material that shows a curve that heat shrinks by 35% or more, preferably 40% or more with respect to a temperature increase of 10 ° C at any temperature between 5 ° C. It also has low temperature shrinkability, which is particularly effective.

As described above, according to the present invention, in the heat shrinkage-temperature graph as shown in FIG.
The present invention relates to a heat-shrinkable label made of the following material which draws a curve showing a sharp rise as exemplified above, wherein the material is polyethylene terephthalate synthesized from terephthalic acid or its derivative and a glycol component, Terephthalic acid or its derivatives,
1.4 cyclohexanedimethanol (preferably 10
40 mol%)-incorporated ethylene glycol, and at least two polymers selected from terpolymers synthesized from terephthalic acid or a derivative thereof, inphthalic acid or a derivative thereof and a glycol component. Can be a mixture of.

The means for covering the containers with the heat-shrinkable label of the present invention to cause the heat-shrinkage is not particularly limited, but, for example, a wet heat atmosphere can be mentioned. Such a moist heat atmosphere is not particularly limited, and its temperature and humidity may be appropriately determined depending on the degree of orientation of the material of the label and the like, but is not particularly limited, but usually, for example, a relative humidity of 90% or more An atmosphere of preferably 99% or more and a temperature of 70 ° C. or more, preferably about 80 to 95 ° C. can be exemplified, and more preferably, a substantially related temperature of 100% using live steam and a temperature of 80 to 9 are used.
The atmosphere in the tunnel type box of about 5% can be illustrated.

An atmosphere in a tunnel type box of about 0 to 95% can be exemplified.

The moist heat atmosphere also includes hot water in its range. At this time, the temperature of the hot water may be appropriately determined depending on the properties of the mixture, but usually 8 for example.
Hot water of 0 ° C. or higher, preferably 90 to 100 ° C. can be exemplified, and a method of dipping in the hot water and causing heat shrinkage can be mentioned, but it is needless to say that the hot water may be showered. There is no limit. The processing time is not particularly limited, but it is needless to say that a short time is preferable in the case of an automatic machine or the like, and it may be appropriately determined in consideration of the effect.

In order to cover the containers with the heat-shrinkable label of the present invention so that the heat-shrinkable label can be more effectively heat-shrinked, the ordinary heat-shrinking method using dry heat and the heat-shrinking method under a humid heat atmosphere can be used in combination. desirable. Examples of the dry heat shrink method in this method include a method using a shrink tunnel in which normal dry heat air circulates and jets, a hot air blowing method, and the like.
There is no particular limitation, if preliminary shrinkage is performed by dry heat in advance, and then complete heat shrinkage is performed in a moist heat atmosphere, shrinkage plaque does not occur, and the label can be coated in a preferable state,
Of course, it goes without saying that heat shrinkage is possible only by the dry heat shrink method.

[0011]

【Example】

Example 1 Thermoplastic polyester 20 obtained from dimethyl isoflerate and dimethyl terephthalate and ethylene glycol
A mixture consisting of 80% by weight of a diester of terephthalate and 80% by weight of a copolyester obtained from ethylene glycol into which 1.4 cyclohexanedimethanol was introduced was formed into a flat film by extrusion, and then at 75 ° C. in the latitudinal direction. Tenter stretching was performed about 3.3 times to obtain a film having a large heat shrinkability in the weft direction. This film shows a heat shrinkage-temperature graph as shown in FIG. 1 (4), which shows a heat shrinkage of about 50% between 10 ° C. and 75 to 85 ° C., and a sharp rise between 60 and 95 ° C. It was made of a material that draws a curve.

After printing such a film, center-sealing it in a tubular shape, and then cutting it into an appropriate length, the main heat-shrinking direction coincides with the circumferential direction of the sleeve, and the sleeve-type heat-shrinkable label is formed. Got

Then, the label is coated on a glass bottle in a loose state, and in this state, the relative humidity by live steam is about 100%,
The tunnel-shaped box was placed in a hot and humid atmosphere at a temperature of 85 ° C for about 12 seconds to cause it to heat-shrink, and when it came out of the box, the heat-shrinkable label was adhered to the glass bottle and the print pattern was distorted at the top and bottom edges. It was a beautiful piece with no distortion.

Example 2 The glass bottle coated with the label obtained in Example (1) in a loose state was heat-shrinked by the rotary shrink device shown in FIG. 2 to obtain the same beautiful appearance as in Example (1). A glass bottle (8) was obtained which had the label coated tightly.

The rotary shrink device referred to here is, for example, a glass bottle (8 ') loosely covered with a label sent to a conveyor (1), a timing screw (2) and a supply star wheel (3). It is a system that is placed on a rotary table (4) via a steam tunnel (5) through which steam is spouted and then directed to an exit by a conveyor (1) via a discharge star wheel (6). . At this time, the steam tunnel (5) from which the live steam is jetted is provided with pipes (9) each having four steam jet outlets (7) inside and outside, respectively. Is related humidity about 100%, humidity 90
C., time 10 seconds.

Example 3 Similar to Example (1), a glass bottle covered loosely so that the label was covered up to the outer peripheral portion of the bottom surface,
First, in the shrink tunnel, it was partially pre-contracted by dry heat, and then it was heat-contracted in the same moist heat atmosphere as in Example (1). As a result, such a label was adhered to the outer periphery of the bottom surface of the glass bottle. It was beautiful with no distortion of the printed pattern and no distortion of the upper edge.

[0017]

Since the heat-shrinkable label of the present invention can be heat-shrinked at a low temperature, it does not cause deformation of the container in the heat-shrinking step even when applied to low softening point containers. It has a special effect.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the heat shrinkage ratio on the vertical axis and the temperature when the horizontal axis indicates temperature.

FIG. 2 is a plan view showing an example of a rotary shrink device.

[Explanation of symbols]

 1 Conveyor 2 Timing screw 3 Supply star wheel 4 Rotary table 5 Steam tunnel 6 Discharge star wheel

Claims (1)

[Claims] 1. A copolyester and terephthalic acid synthesized from polyethylene terephthalate or teretaful acid or its derivative synthesized from terephthalic acid or its derivative and a glycol component and 1.4 cyclohexanedimethanol-introduced ethylene glycol or terephthalic acid or It is composed of a mixture of at least two polymers selected from a copolymer synthesized from its derivative and isophthalic acid or its derivative and a glycol component, and has a rapid thermal shrinkage-temperature graph between 60 ° C and 95 ° C. A heat-shrinkable label featuring a rising curve.