KR100824577B1 - Pressure-sensitive adhesive tape and method for producing the same - Google Patents

Abstract

It provides a technique for improving the adhesion between the biodegradable gas film and the rubber-based adhesive layer.

After rubbing the surface of the biodegradable film 9 by the friction means 7, an adhesion layer raw material liquid is applied to form an adhesion layer to obtain an adhesive tape. By the friction treatment, the adhesion between the base film and the adhesive layer is improved. In the case where the pressure-sensitive adhesive layer raw material liquid is rubber-based, the pressure-sensitive adhesive layer may be formed after the primer raw material liquid containing the organic compound is applied to the friction treatment surface and the primer layer is formed. A filler, a coloring agent, an antioxidant, etc. can be added to an adhesion layer in the range which does not impair biodegradability. What is necessary is just to use the biodegradable thing also the peeling film bonded to the adhesion layer surface.

Description

PRESSURE-SENSITIVE ADHESIVE TAPE AND METHOD FOR PRODUCING THE SAME

The present invention relates to the technical field of adhesive tapes, and more particularly, to adhesive tapes using a biodegradable resin film.

Conventionally, the base film and the adhesive tape in which the adhesive layer is formed on the surface thereof are widely used, but in the case of adhering the release film on the adhesive layer, the adhesive force between the base film and the adhesive layer is stronger than the adhesive force between the release film and the adhesive layer. Since the surface of the base film is subjected to surface treatment such as sandblasting or corona treatment, or to form a primer layer on the base film, an adhesive layer is formed on the surface of the primer layer. Various techniques for improving the adhesive force between the base film and the adhesive layer, such as forming, have been developed.

Various kinds of materials such as paper, plastic film, and metal foil are used for the gas film, but when the adhesive tape is burned and disposed of, if the gas film is plastic, toxic gas may be generated or environmental pollution may occur. In addition, when the gas film is plastic, there is a risk of destroying the ecosystem since the gas film is not decomposed when disposed in the soil.

Therefore, in recent years, adhesive tapes that are naturally decomposed by microorganisms have been actively developed by using a film made of a biodegradable material in a gas or a peeling film, and among them, polylactic acid film in terms of adhesiveness and strength is used as a gas film. The adhesive tape used for this is attracting attention.

However, when the surface treatment is performed to increase the adhesive strength to the polylactic acid film, the corona treatment is less effective than the investment of the equipment, and there is a concern that the biodegradability may be impaired when the base layer such as primer coating is formed.

In addition, in the case of cellophane tape, the cellophane serving as a gas film lacks moisture resistance. Thus, by coating the saran resin on both sides to improve moisture resistance, and after forming a primer layer on one side, an adhesive layer is formed on the surface thereof. At the same time, the other side was peeled off, and the single-sided adhesive tape was wound in a roll shape.

As described above, in the prior art, a complicated process was required to produce a single sided tape.

The present invention has been made to solve the problems of the prior art, the object of which is to obtain a biodegradable adhesive tape. It is also to provide a technique for opaque, colored, and long-lived without compromising biodegradability.

The present invention provides a pressure-sensitive adhesive tape having a biodegradable base film and a pressure-sensitive adhesive layer formed on the base film. After the base film surface is rubbed by friction means, the pressure-sensitive adhesive layer is formed on the friction-treated surface. have.

The present invention provides a biodegradable base film, a primer layer formed on the base film, and a pressure-sensitive adhesive tape having an adhesive force formed on the base layer. The primer layer was formed on the surface.

In these adhesive tapes of the present invention, the base film has a polylactic acid film, and the polylactic acid film surface can be subjected to the friction treatment.

In this case, a biaxially oriented polylactic acid film can be used for the polylactic acid film.

In addition, in the adhesive tape of the present invention, by forming a biore film on the base film, the surface of the biore film can be subjected to the friction treatment.

In the pressure-sensitive adhesive tape of the present invention described above, the pressure-sensitive adhesive which does not inhibit the biodegradability of the base film as a pressure-sensitive adhesive component contained in the pressure-sensitive adhesive layer may be a main component.

In this case, the pressure-sensitive adhesive may use natural rubber.

Moreover, in the adhesive tape of this invention demonstrated above, an opaque filler can be contained in the said adhesion layer, without impairing the biodegradability of the said gas film.

This filler can be used insoluble in water.

Moreover, in the adhesive tape of this invention demonstrated above, the said adhesive layer can contain the coloring agent which does not inhibit the biodegradability of the said gas film.

An oil-soluble thing can be used for this coloring agent.

When the adhesive layer of the adhesive tape demonstrated above contains a polyisoprene rubber, this adhesive layer can be made to contain a phenol-type antioxidant.

Moreover, in the adhesive tape demonstrated above, a peeling film can be adhere | attached on the said adhesion layer.

The release film in this case can use what has biodegradability.

This release film can be comprised with a polyvinyl alcohol film.

On the other hand, even in the case of a biodegradable resin or a non-biodegradable resin, in the case of an adhesive tape having a rubber-based adhesive layer formed on a gas film surface made of a resin, after friction treatment of the gas film surface by friction means, the friction The rubber-based adhesive layer can be formed on the treated surface.

As a base film which does not have biodegradability, a polyester film or a polyimide film can be used.

In addition, in the present invention, in the case of the pressure-sensitive adhesive tape manufacturing method of sending the base film formed in the shape of a tape in the longitudinal direction and applying the pressure-sensitive adhesive layer raw material solution to the surface of the base film to form an adhesive layer, The gas film surface is rubbed with friction means before applying the liquid.

In this case, an organic compound can be used as a solvent for the said adhesion layer raw material liquid.

In addition, the base film is formed in a tape-like shape, and the base film is sent in the longitudinal direction, and the primer layer raw material solution is applied to the surface of the base film to form a primer layer. In the adhesive tape preparation method of forming the adhesive layer, in the present invention, the surface of the base film is rubbed with a friction means before applying the primer layer.

In this case, the primer layer raw material liquid may be an organic compound, and the adhesive layer raw material liquid may be water.

This invention is comprised as mentioned above, and is an adhesive tape in which the adhesion layer was formed on the base film using biodegradable films, such as a polylactic acid film and a bioreno film, as a base film. The pressure-sensitive adhesive layer is formed on the surface of the primer layer after rubbing the surface of the gas film by a desired number of friction means, followed by direct application and drying, or after forming a primer layer on the friction surface.

In the prior art, although the adhesive force between the biodegradable film and the adhesive layer is weak, when the surface of the gas film is subjected to friction treatment, the adhesive force between the substrate film and the adhesive layer is increased, thereby obtaining a biodegradable adhesive tape.

By using a biodegradable adhesive component such as natural rubber as the adhesive layer and using a biodegradable film such as polyvinyl alcohol film as the release film, the whole adhesive tape having biodegradability can be obtained.

What is necessary is just to use the thing which does not inhibit the biodegradability of an adhesion layer, when adding the filler and coloring agent for opacity to an adhesion layer.

In the case where the adhesive layer raw material liquid is water, the adhesive strength is not increased even if the surface of the gas film is rubbed, but the primer layer raw material liquid containing the organic compound is applied to the friction treated surface of the gas film to form a primer layer. In this case, since the adhesive force between the base film and the primer layer is increased, an adhesive tape may be obtained by forming an adhesive layer on the surface of the primer layer. Since the thickness of a primer layer may be thin compared with an adhesion layer, the usage-amount of the organic solvent at the time of manufacturing an adhesive tape is minimal.

1 is a view for explaining the manufacturing process of the adhesive tape of the present invention.

2 is a graph showing the relationship between friction recovery and peel strength.

3 is a cross-sectional view showing an example of the adhesive tape of the present invention.

4 is a cross-sectional view showing another example of the adhesive tape of the present invention.

First, the manufacturing method of the adhesive tape of one Embodiment of this invention is demonstrated.

Referring to Fig. 1, a release roll 3 wound around a polylactic acid film (a film biaxially stretched by Shimatsu Seisakusho Co., Ltd.) and a friction means 7 having a flexible friction cloth such as a cotton cloth formed on the surface of a roll body are formed. The polylactic acid film 9 is taken out from the release roll 3, and is wound up by the winding roll 4 via the friction means 7.

At this time, the friction means 7 is rotated in the direction opposite to the traveling direction of the polylactic acid film 9, so that the surface of the polylactic acid film 9 is rubbed in a dry atmosphere (at room temperature, atmospheric pressure, air).

Subsequently, the polylactic acid film 9 wound on the winding roll 4 was released to move the inside of the general adhesive layer forming apparatus, and the adhesive layer raw material solution in which the isoprene rubber-based adhesive was dissolved in the organic solvent as a main component was applied and dried on the friction treated surface. After forming a layer, the peeling film which consists of a polyvinyl alcohol film (PVA film) was crimped | bonded to this adhesive layer surface, and the adhesive tape was obtained.

Reference numeral 10 in Fig. 3 denotes the adhesive tape, and the adhesive layer 13 is formed on the base film 11 made of the frictionally treated polylactic acid film, and the release film 14 is adhered on the adhesive layer 13. When using the adhesive tape 10, the peeling tape 14 is peeled off and the adhesive layer 13 is crimped | bonded to a to-be-adhered body.

The adhesive force (peel strength) of the adhesive tape 10 was measured. As a result, the adhesive force was 6 g / 2 cm between the adhesive layer 13 and the peeling film 14 (the load required to peel off the peeling film when the width of the adhesive tape was 2 cm), and the base film 11 (polylactic acid film) and the adhesion. Between layers 13 was 800 g / 2 cm. It was 50 g / 2cm when the peeling film 14 was peeled off and the adhesion layer 13 was bonded to the stainless plate.

Thus, the adhesive strength between the surface of the base film 11 subjected to the friction treatment and the adhesive layer 13 is sufficiently high.

For comparison, the same polylactic acid film surface was formed as a gas film without rubbing with the friction means 7, and the adhesive layer was only 30 g / 2 cm between the gas film and the adhesive layer.

In addition, the release film 14 which can be used for the adhesive tape 10 of this invention is not limited to a PVA film, The biodegradable film which consists of polycaprolactone, polyester, polybutyric acid, etc. can be used widely.

As the friction means 7, a cloth made of Japanese traditional paper, carbon fiber, nylon, rayon, or the like can be used. Even if the friction means is composed of a hard material, the adhesive force is improved, but since the flaw is caused in the gas film 11, it is preferable to have a velvet having flexibility when transparency is required.

Moreover, in addition to natural isoprene rubber, various rubber adhesives, such as synthetic isoprene rubber, nitrile rubber, and SBR rubber, can be used for the adhesive which can be used for forming the said adhesion layer 13. However, from the viewpoint of biodegradability, it is preferable to use natural isoprene rubber or synthetic isoprene rubber.

Next, the present invention will be described in more detail with reference to the following examples.

(Example 1)

First, synthetic isoprene rubber (IR-10 manufactured by Kuraray Co., Ltd.) is dissolved in toluene, a pressure-sensitive adhesive layer raw material solution having a solid content of 10% is produced, and a friction means comprising a surface film of a gas film made of polylactic acid film. Rub 10 times to prevent scratches (friction treatment), and the adhesive layer raw material liquid was flowed to the surface of the friction-treated gas film, toluene was evaporated by drying at 80 ° C. for 5 minutes, and the adhesive layer (isoprene rubber layer) having a thickness of 10 μm. )

Next, the base film in which the adhesion layer was formed was cut in half, and the adhesion layers were adhere | attached, and the test film was obtained.

When the self-adhesive force of this test film was measured, the measurement result of 800 g / 2cm was obtained. The fracture surface was caused by the cohesive failure of isoprene rubber.

Next, a test sheet was prepared under the same conditions as described above except that the number of rubs by rubbing means was changed, and the self-adhesive force was measured. The results are shown in Table 1 below.

Relationship between Friction Recovery and Self Adhesive Force collection Self adhesive force (g / 2cm) One 250 2 350 3 400 4 500 5 800 6 800 7 800 9 800

In order to improve the adhesive force from the said table, it turns out that it is effective to rub 5 times or more in a cotton cloth.

(Comparative Example 1)

Except not rubbing with a friction means, a test film was prepared in the same manner as in Example 1, and the value of the self-adhesive force was 30 g / 2 cm. The peeling surface was an interface of a base film and an adhesion layer.

(Comparative Example 2)

Instead of rubbing with friction means, the surface of the gas film was corona treated, and other conditions were used to prepare a test film in the same manner as in Example 1. The self-adhesive force was measured and found to be 50 g / 2 cm. Although the self-adhesive force was larger than the case of the comparative example 1, the peeling surface was an interface of a base film and an adhesion layer.

In addition, instead of rubbing with a friction means, the surface of the base film was subjected to surface treatment by UV irradiation, and the test film was prepared in the same manner as in Example 1 above. The value which measured the self-adhesive force was 30g / 2cm, and was the same intensity as the comparative example 1 of no treatment. The peeling surface was also the interface between a base film and an adhesion layer.

(Example 2)

(Example 2a)

Nitrile rubber (Nibol 1042: manufactured by Nihon Xeon) was kneaded without mixing anything, and then dissolved in MEK (methyl ethyl ketone) to prepare a pressure-sensitive adhesive layer raw material solution.

After rubbing this surface 10 times with a steel swab using a biaxially stretched polyester film having a thickness of 50 µm as a base film, the pressure-sensitive adhesive layer raw material solution was applied and dried to form a pressure-sensitive adhesive layer. This adhesive tape was bonded to each other in the same manner as in Example 1 to prepare a test film to measure the self-adhesive force. The adhesive strength was 3000g / 2cm.

(Example 2b)

Natural rubber was dissolved in toluene to prepare an adhesive layer raw material solution. The surface was rubbed ten times with Ben curtain using a biaxially stretched polylactic acid film having a thickness of 50 μm as a gas film, and then the adhesive layer raw material solution was applied and dried on the friction treated surface, and the self-adhesive force was measured in the same manner as in Example 1. . The adhesive strength was 1000 g / 2 cm.

(Example 2c)

Block SIS rubber (TR1107: manufactured by Shell Co., Ltd.) was dissolved in toluene to prepare a pressure-sensitive adhesive layer raw material solution. After rubbing this surface 10 times with a nylon brush using a polyimide film having a thickness of 50 µm as a base film, the adhesive layer raw material solution was applied and dried on the friction treated surface, and the self-adhesive force was measured in the same manner as in Example 1. The adhesive strength was 600g / 2cm.

(Comparative Example 3)

In Examples 2a to 2c, a self-adhesive force was measured under the same conditions except that the surface of the base film was not subjected to friction treatment. The adhesive strengths of the adhesive tapes corresponding to Examples 2a to 2c were 900 g / 2 cm, 30 g / 2 cm and 10 g / 2 cm, respectively. The release surface is between the adhesive layer and the base film.

In this way, the film surface is oriented by rubbing the gas film surface, and the adhesive applied to the surface is also oriented, thereby obtaining three times or more of adhesive strength as compared with the case where the rubbing treatment is not performed.

In particular, as can be seen from Comparative Example 3, when forming the rubber-based adhesive layer and the base film, since the adhesive strength between the base film is low, the primer layer was formed in the prior art, but in the present invention The adhesive strength can be improved only by performing the friction treatment.

(Comparative Example 4)

Instead of the polylactic acid film, a gaseous film was composed of a polyester film, and a test film was prepared in the same manner as in Example 1 by rubbing the surface with a friction means made of Ben curtain to measure the self-adhesive force. It shows in the graph of FIG. 2 with the case of a polylactic acid film.                 

In the case where the base film is a polyester film, there is no effect of improving the adhesion by the friction treatment of the surface, but in the case where the base film is a polylactic acid film, a remarkable effect appears.

(Example 3)

The surface of the base film made of a polylactic acid film is rubbed with a friction means made of a buff (nylon brush) (buff polishing). Other than that, the test film was produced on the same conditions as Example 1, and the self-adhesive force was measured. The conditions for buff polishing were 1 kg / cm in pressure and 4 m / min in speed. No abrasive is used. The adhesive force of the test piece was 1000g / 2cm. The buff side has a greater effect of improving adhesion due to friction than cotton cloth.

Next, a description will be given of an adhesive tape having a small amount of organic solvent using the base film subjected to the friction treatment.

(Example 4)

The surface of the gas film made of polylactic acid film is rubbed 10 times so as not to be scratched by using a friction means made of cotton cloth, and the primer layer raw material solution made of 5% toluene solution of natural rubber (RSSI) is applied and dried on this surface. To obtain a primer layer having a thickness of 1 μm.

Natural rubber latex ("latex" refers to a suspension of natural rubber, synthetic rubber or plastics in water) was used as an adhesive layer raw material solution, and applied and dried on a primer layer to form an adhesive layer having a thickness of 10 µm. This adhesive tape is shown by the code | symbol 20 of FIG. The primer layer 22 and the adhesion layer 23 are laminated | stacked on the base film 21.

Next, the adhesive tape 20 was cut in half, and the adhesive layers 23 were adhered to each other to prepare a test film, and the self-adhesive force was measured. Moreover, it adhered to stainless steel (SUS) and measured the adhesive force with respect to stainless steel.

(Comparative Example 5)

The adhesive film having a film thickness of 10 μm was formed by directly applying and drying the same natural rubber latex as used in Example 4 without forming a primer layer on the friction-treated gas film 21 used in Example 4 to obtain an adhesive tape. . Also about this adhesive tape, the self adhesive force and the adhesive force with respect to stainless steel were measured by the method similar to Example 4.

(Comparative Example 6)

On the friction-treated gas film 21 used in Example 4, in Example 3, a 5% toluene solution of natural rubber (RSSI) consisting of a primer layer was applied and dried, and an adhesive layer having a thickness of 10 μm was formed and adhered. The tape was produced. The self-adhesive force and the adhesive force to stainless steel were also measured for this adhesive tape.

(Comparative Example 7)

The self-adhesive force and the adhesion to stainless steel were measured by laminating the same primer layer and the adhesive layer as in Example 4 on the polylactic acid film without friction treatment.

<Measurement result>

The measurement result of Example 4, the comparative example 5, and the comparative example 6 is shown in the following table.                 

Adhesive tape using natural rubber latex Self adhesion Adhesion to SUS Peeling point Example 4 500 20 Adhesive cotton Comparative Example 5 40 20 Polylactic acid film cotton Comparative Example 6 1000 30 Adhesive cotton Comparative Example 7 30 20 Polylactic acid film cotton

Although the peeling place was peeling from the adhesive surface in Example 4, in the comparative example 5, it was peeling between a base film and an adhesion layer, and in the comparative example 7, it was between a base film and a primer layer.

As can be seen from the measurement results of Comparative Example 7 in Table 2 above, the adhesion to the base film does not improve when the friction treatment is not carried out. Even if rubber latex is applied to the surface of the substrate film subjected to the friction treatment, the adhesive strength does not improve.

In addition, as can be seen from Example 4 and Comparative Example 6, in the case of natural rubber (RSSI), the effect of the friction treatment of the base film is large.

However, when comparing Example 4 and Comparative Example 6, since toluene was used when forming the adhesion layer of 10 micrometers in the comparative example 6, the toluene content was 190 g / m <2>, but the primer of 1 micrometer in Example 4 was used. Since toluene was used when the layer 22 was formed, the toluene amount was 19 g / m 2, and the use amount of 1/10 was sufficient compared to Comparative Example 6.

Air emissions of organic solvents tend to be regulated globally, so it is desirable to reduce their use as much as possible. As in Comparative Example 5, when the adhesive layer is formed by directly applying a natural rubber latex without using an organic solvent, the effect of the friction treatment is small, but as in Example 4, between the adhesive layer and the gas film Forming a thin primer layer on the substrate can be seen that the use of a little organic solvent is sufficient.

Next, the adhesive tape using the biaxially stretched polylactic acid film is demonstrated.

(Example 5)

A biaxially oriented polylactic acid film surface having a thickness of 40 µm was used for the gas film, and the surface was rubbed in the same manner as in Example 1. On the surface subjected to the friction treatment, a solution of 6 parts by weight of natural rubber, 4 parts by weight of natural resin and 90 parts by weight of toluene was applied and dried, and an adhesive layer having a thickness of 30 µm was formed to prepare an adhesive tape.

The adhesive force between the pressure-sensitive adhesive layer and the base film, the adhesive force to stainless steel when the adhesive tape was attached to the stainless steel, the film tensile strength and the film elongation rate of the adhesive tape were measured.

(Comparative Example 8)

Except not performing friction treatment, the adhesive tape was produced on the same conditions as Example 5, and the same measurement as Example 5 was performed.

Measurement result

The measurement results of Example 5 and Comparative Example 8 are shown in Table 3 below. The measurement result of the commercial item 1 (PP packing tape manufactured by Nitto Denko Co., Ltd.) is shown together.

Adhesive tape using biaxially oriented polylactic acid film Example 5 Comparative Example 8 Commercial item 1 Adhesion to SUS (g / 2㎝) 500 500 500 Adhesion between gas film (g / 2㎝) 1000 500 Not measurable Film Tension Force (㎏) 5 5 11.5 Film Elongation (%) 260 260 300 Commercial item 1: PP packing tape made by Nitto Denko Co., Ltd.

In the case of Comparative Example 8, since the adhesive force to the substrate film of the adhesive layer is the same size as the adhesive strength to the stainless steel to be the adherend, when the adhesive tape of Comparative Example 8 is stuck to the adherend, the adhesive is deposited when the adhesive tape is peeled off. There is a risk of electrodeposition on the ash side.

delete

On the other hand, in Example 5, since the adhesive force with respect to the friction process surface of a base film is large, there is no possibility that an adhesive may be electrodeposited to the adherend side.

As described above, according to the present invention, the biaxially stretched polylactic acid film is subjected to friction treatment to produce an adhesive tape having a biodegradable whole material. This adhesive tape can be wound in a roll shape and used for packaging tape or the like.

Next, the color of the adhesive tape will be described.

Since the adhesive tape using the uniaxially stretched polylactic acid film has a thickness of 50 μm or less, the adhesive tape is assimilated with the background color when the adhesive layer is transparent and adhered, so that the adhesive place is unclear.

(Example 6)

6 parts by weight of natural rubber and 0.6 parts by weight of calcium carbonate were dissolved in 93.4 parts by weight of toluene and applied and dried on the surface of a biaxially stretched polylactic acid film (40 µm thick) subjected to the same rubbing treatment as in Example 1 to have a thickness of 10 µm. An adhesive layer was formed to prepare an adhesive tape.

Natural rubber is an adhesive and calcium carbonate is an opaque filler.

(Comparative Example 9)

Except not subjected to the friction treatment, the adhesive tape was produced in the same manner as in Example 1 to measure the adhesive force.

(Comparative Example 10)

Except not containing calcium carbonate, a pressure-sensitive adhesive tape was prepared in the same manner as in Example 6 to measure the adhesive force.

Measurement result

The adhesive force between the base film and the adhesive layer of this adhesive tape and the adhesive force, the transmittance | permeability, and the biodegradability at the time of sticking the adhesive tape on stainless steel were measured.

The measurement results are shown in Table 4 below.

Adhesive Tape Containing Calcium Carbonate Example 6 Comparative Example 9 Comparative Example 10 Adhesion to SUS (g / 2㎝) 30 30 30 Adhesive force between base film (g / 2cm) 1000 30 1000 Transmittance (%) 0 0 90 Biodegradable U U U

As can be seen from Example 6, even if the adhesive layer contains an opaque filler (calcium carbonate), there is an effect of improving adhesion by friction. Since the transmittance is zero, the background color is completely hidden, and the place where it is attached can be easily confirmed. Moreover, biodegradability is not impaired even if an opaque filler (calcium carbonate) is added.

On the other hand, in the case of the comparative example 9, since there is no friction treatment and adhesive force is low, there exists a possibility of electrodeposition. In the comparative example 10, since the transmittance | permeability is high, recognition at the time of adhesion is difficult.

In addition, calcium carbonate is preferable as an opaque filler because it can be produced in shells and is derived from living organisms, but the present invention is not limited to calcium carbonate.

For example, an opaque material which is neutral in pH such as aluminum oxide and insoluble in water may be used.

In the said Example 6, it can also distinguish from a ground by adding an additive to an adhesion layer, making it opaque and coloring. In that case, it is necessary to add a biodegradable pigment | dye so as not to impair the biodegradability of a lactic acid film.

(Example 7)

A pressure-sensitive adhesive tape was prepared by dissolving 5 parts by weight of natural rubber and 0.05 parts by weight of chlorophyll in 94.95 parts by weight of toluene, applying and drying the surface of the polylactic acid film subjected to the same rubbing treatment as in Example 1 to form an adhesive layer having a thickness of 10 μm. It was.

The adhesive force was the same as the case where no pigment was added. Biodegradability was not inhibited either.

Moreover, since chlorophyll is useful, even if this adhesive tape was put in water, a pigment | dye did not spill but it was suitable for practical use.                 

(Example 8)

The adhesive tape was produced on the conditions same as Example 7 except having changed chlorophyll into carotene (soluble). With the same adhesive strength as in Example 7, biodegradability was not impaired and there was no elution of the pigment in water.

(Comparative Example 11)

An adhesive tape was prepared under the same conditions as in Example 7, except that chlorophyll was changed to food additive blue No. 1. Edible blue No. 1 is water-soluble, so when the adhesive tape is placed in water, the dye has leaked out. The same was true when the food blue No. 1 was changed to food blue No. 2.

(Comparative Example 12)

An adhesive tape was prepared under the same conditions as in Example 7 except that chlorophyll was changed to Eisenspiron Green GNH (soluble pigment of non-food additive). The dye did not elute even if placed in water, but the biodegradability of the coated surface did not proceed.

Next, the calcium carbonate used in Example 6 was used as an opaque filler and added to the adhesion layer with a pigment | dye.

(Example 9)

5 parts by weight of natural rubber, 0.05 parts by weight of copper chlorophyll and 0.5 parts of calcium carbonate were dissolved in toluene and applied and dried on the surface of the polylactic acid film subjected to the same rubbing treatment as in Example 1 to form a pressure-sensitive adhesive layer having a thickness of 20 µm. Was produced.

(Comparative Example 13)                 

An adhesive tape was produced under the same conditions as in Example 9 except that the friction treatment was not performed.

(Comparative Example 14)

An adhesive tape was prepared under the same conditions as in Example 9 except that Eisenpyron Green GNH (non-food additive oil-soluble dye) was used instead of the food additive copper chlorophyll compound.

(Comparative Example 15)

An adhesive tape was prepared under the same conditions as in Example 9 except that the water-soluble edible additive blue No. 1 was used instead of the copper chlorophyll compound.

Evaluation results

The adhesive force between the adhesive tape and the base film and the adhesive force when the adhesive tape was attached to the back side of the base film were measured. Moreover, the solubility and biodegradability of the pigment | dye to water were evaluated. The evaluation results are shown in Table 5 below.

Adhesive tape containing calcium carbonate and colorant Example 10 Comparative Example 16 Comparative Example 17 Comparative Example 18 Adhesion to Friction Surface (g / 2㎝) 1000 30 1000 1000 Adhesion to the back of gas film (g / 2㎝) 30 30 30 30 Elution to water radish radish radish Coloring water Biodegradable U U * U     * Marking does not proceed only to the coated part

As can be seen from Table 5, although the adhesive force to the back surface of the base film not subjected to the friction treatment is weak, even if a colorant and an opaque filler are contained in the adhesive layer, the adhesion to the surface of the substrate film subjected to the friction treatment is strong.

delete

When making a biodegradable adhesive tape, polyisoprene rubber (a kind of natural rubber) can be used as an adhesive.

However, a disadvantage is that polyisoprene rubber becomes poor when absorbing oxygen. For example, if the adhesive surface is exposed in the air, the surface becomes sticky at first, but later hardens and impairs the adhesiveness. Neither sticky state nor hardened surface is preferable as the adhesive tape.

Therefore, an anti-aging agent (antioxidant, heat aging inhibitor, vulcanization accelerator, etc.) for improving the surface stability of polyisoprene rubber is required.

(Examples 11-18)

The adhesive tape was produced by the same method as Example 1 except having added 1 type or 2 types of antioxidants of FDA application to the polyisoprene rubber solution.

The addition ratio was 1 part by weight of the phenolic antioxidant A and zero or 0.5 parts by weight of the antioxidant B other than the phenolic based on 100 parts by weight of the polyisoprene rubber.

Phenolic antioxidant A is nocrack NS30 (4,4'-butylidenebis- (3-methyl-6-third-butylphenol): 4,4'-butylidene-bis (3-methyl-6 -ter-butylphenol)) or a nocrack PBK, and as an anti-aging agent B other than a phenolic, phosphorus nocrack TNP (tris (nonylphenyl) phosphite), imidazole-based furnace Clark MBZ (Zinc salt of 2-mercaptobenzimidazole), or Knock Cera BZ of dithiocarbamic acid (Di-n-butyldithiocarbamate zinc: zinc di-n -butyl dithiocarbamate) were used (all manufactured by Daiuchi Shinko Chemical Co., Ltd.). Table 6 shows the kinds of the antioxidants A and B of Examples 11 to 18.

Type of added antioxidant Antioxidant A Antioxidant B Example 11 Nocrack30 radish Example 12 Nocrack30 NocrackMBZ Example 13 Nocrack30 Nocrack TNP Example 14 Nocrack30 Knock Cera-BZ Example 15 Nocrack PBK Example 16 Nocrack PBK NocrackMBZ Example 17 Nocrack PBK Nocrack TNP Example 18 Nocrack PBK Knock Cera-BZ Comparative Example 19 Not added In comparison to 20 No-crack CD (amine type) Comparative Example 21 Nocrack 630F (amine type)

(Comparative Examples 19-21)

As a comparative example, an adhesive tape without adding an antioxidant (Comparative Example 19) an adhesive tape using Nocrack CD which is an amine antioxidant or Nocrack 630F (all manufactured by Daiuchi Shinko Chemical Co., Ltd.) (Example 20 , 21). The kind of antioxidant is shown together in Table 6 above.

Measurement result

The adhesive face of the adhesive tape was faced up and stored in a 60 degreeC thermostat, and the adhesive force was confirmed by the touch.

Six days later, the strength of the self-adhesive force (adhesion between the friction surface of the gas film and the adhesive layer) and the biodegradability were measured.                 

Evaluation of the storage days and surface conditions, the measurement results of the adhesive force between the adhesive layer of the pressure-sensitive adhesive tape and the gas film after storage and the results of evaluation of biodegradability are shown in Table 7 below.

Evaluation and Measurement Results 1 day 2 days 3 days 4 days 5 days 6 days Adhesive force between base film (g / 2cm) Biodegradable Example 11 ○ ○ ○ ○ ○ ○ 1000 U Example 12 ○ ○ ○ ○ ○ ○ 1000 U Example 13 ○ ○ ○ ○ ○ ○ 1000 U Example 14 ○ ○ ○ ○ ○ ○ 1000 U Example 15 ○ ○ ○ ○ ○ ○ 1000 U Example 16 ○ ○ ○ ○ ○ ○ 1000 U Example 17 ○ ○ ○ ○ ○ ○ 1000 U Example 18 ○ ○ ○ ○ ○ ○ 1000 U Comparative Example 19 × × * × × * 1000 U Comparative Example 20 ○ × × × × * 1000 radish Comparative Example 21 ○ ○ ○ × × × 1000 radish ○: Indicates that it has not changed before storage. X: It shows the sticky state. *: Indicates no stickiness.

As can be seen from Table 7, the adhesion to the gas film surface subjected to the friction treatment is high even when the anti-aging agent is added to the polyisoprene rubber.

When the phenolic anti-aging agent was used, aging of the adhesion layer was prevented and the surface was stable. On the other hand, the amine-based antioxidants had an anti-aging effect for only 3 days.

In addition, the antioxidants of phenol, phosphorus, imidazole and dithiocarbamic acid did not inhibit the biodegradability, but the biodegradability of the amine antioxidant was inhibited.

In addition to the polylactic acid film, the gas film of the adhesive tape of the present invention can be widely used a film having biodegradability and frictionally treated surfaces. The adhesive tape which uses a bionore film as a biodegradable film other than a polylactic acid film is demonstrated.

Bionore is a high molecular weight aliphatic polyester obtained by the polycondensation reaction of a glycol such as 1,4-butanediol and an aliphatic dicarboxylic acid such as succinic acid or adipic acid, and has biodegradability.

The molecular structure is represented by the following formula (1).

Biorefilms are classified into two types, polybutylene succinate (PBS) and polybutylene succinate adipate (PBSA), by a combination of m and n in the above formula.

The physical properties of the biorefilms (PBS and PBSA) are shown in the following table in comparison with general-purpose resins.

Properties of Biorefilm manufactured by Showa Kobunshi Co., Ltd. Compound name PBS PBSA General purpose resin (comparative example) Grade name # 1001 # 1020 # 3001 # 3020 PP HDPE HDPE Density (g / cm 3) 1.26 1.26 1.23 1.23 0.90 0.95 0.92 Melting Point (℃) Glass Transition Point (℃) Crystallization Temperature (℃) 114 -32 75 115 -32 75 94 -45 50 95 -45 50 165 -5 120 130 -120 104 108 -120 80 Molecular weight of mass mean (* 10,000) 22 15 22 15 - - - Tensile Strength [MPa┃kgf / ㎠┃] Tensile Elongation (%) 56.8 ┃580┃ 600 20.6 ┃ 210 ┃ 320 44.1 ┃ 450 ┃ 800 35.3 ┃ 360 ┃ 450 49.0 ┃ 500 ┃ 800 39.2 ┃ 400 ┃ 700 29.4 ┃ 300 ┃ 800 Flexural Modulus [MPa┃kgf / ㎠┃] 657 ┃6700┃ 686 ┃7000┃ 323 ┃ 3300 ┃ 343 ┃ 3500 ┃ 1370 ┃ 14000 ┃ 1080 ┃ 11000 ┃ 196 ┃ 2000 ┃ Heat of combustion [KJ / g ┃㎈ / g┃] 23.6 ┃ 5640 ┃ 23.9 ┃ 5720 ┃ 44.0 ┃10500┃ 46.0 ┃11000┃ Crystallinity (mass%) 30 to 45 20-30 50 75 30-40 PBS: polybutylene succinate PBSA: polybutylene succinate adipate

As is clear from Table 8, Bionorre has a high tensile elongation, strong viscosity, and flexibility. Therefore, it is suitable for the use of the film, sheet | seat, nonwoven fabric, etc. which require flexibility.

delete

delete

(Example 19)

Using a bioreole film having a thickness of 40 µm for the gas film, the surface was rubbed in the same manner as in Example 1, and 5 parts by weight of natural rubber and 1 part by weight of natural resin were dissolved in 94 parts by weight of toluene. It dried, the adhesive layer of thickness 20micrometer was formed, and the adhesive tape was obtained.

The adhesive force between the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape and the base film and the adhesive force when the pressure-sensitive adhesive tape was attached to the stainless steel were measured.

(Comparative Example 22)

The adhesive tape was produced on the same conditions and the measurement similar to Example 19 except having carried out the friction process to the bioreno film of Example 19.

Measurement result

The measurement results are shown in Table 9 below.

Adhesive Tape Using Bionorre Film Example 19 Comparative Example 22 Commercial item 2 Adhesion to SUS (g / 2㎝) 70 70 70 Adhesive force between base film (g / 2cm) 200 70 Not measurable Film Tension Force (㎏) 2.7 2.7 2.8 Film Elongation (%) 700 700 500 Commercially available product 2: Salt to protect tape made by Nitto Denko Co., Ltd.

In the case of the comparative example 22, since the adhesive force between a base film and an adhesion layer is weak, there exists a possibility that an adhesive may adhere to an adherend side when peeling an adhesive tape from an adherend. The adhesive tape of Example 19 is not the same.

delete

Thus, according to this invention, the biodegradable adhesive tape which has flexibility can be obtained. Since natural rubber and resin are biodegradable, a whole adhesive tape having biodegradability can be obtained.

Flexible adhesive tapes are suitable for protective tapes for drawing processing. In the case of the protective tape, a soft vinyl chloride film is conventionally used, but by using a biodegradable adhesive tape, there is no problem of disposal or dioxin generation during incineration.

In addition, in the above embodiment, a polylactic acid film or a bionore film was used as the base film, but the present invention also includes two or more kinds of films having biodegradability.

Since the adhesive force between the base film and the pressure-sensitive adhesive layer can be strengthened, the pressure-sensitive adhesive layer does not peel off from the base film surface.

Disposal is simple because the gas film is biodegradable.

In the case of a flexible adhesive tape, for example, when used in a tape for binding food such as vegetables, the adhesive tape can be treated together with vegetable waste at a fruit and vegetable shop. Since the adhesive tape of this invention which used a biore film for a base film is excellent in flexibility and extensibility, it is suitable for the protection tape for drawing processing. Can be used for packing tape.

Claims (27)

An adhesive tape having a biodegradable base film and an adhesive layer formed on the base film, And the base film surface is subjected to friction treatment by friction means, and then the adhesive layer is formed on the friction treated surface. An adhesive tape having a biodegradable gas film, a primer layer formed on the gas film, and an adhesive layer formed on the primer layer, And the base film surface is rubbed by friction means, and then the primer layer is formed on the rubbed surface. The adhesive tape according to claim 1 or 2, wherein the base film has a polylactic acid film, and the surface of the polylactic acid film is subjected to the friction treatment. The adhesive tape according to claim 3, wherein the polylactic acid film is a biaxially stretched polylactic acid film. 3. The adhesive film according to claim 1 or 2, wherein the base film has a film made of aliphatic polyester obtained by polycondensation of glycol and aliphatic dicarboxylic acid, and the surface of the base film is subjected to the friction treatment. tape. The pressure-sensitive adhesive tape of claim 1, wherein the pressure-sensitive adhesive component included in the pressure-sensitive adhesive layer is selected from the group consisting of natural isoprene rubber, synthetic isoprene rubber, nitrile rubber, and SBR rubber. The pressure-sensitive adhesive tape of claim 6, wherein the pressure-sensitive adhesive is natural isoprene rubber. The pressure-sensitive adhesive tape of claim 1, wherein the pressure-sensitive adhesive layer contains calcium carbonate or aluminum oxide as a filler. The adhesive tape according to claim 8, wherein the filler is one which is insoluble in water. The pressure-sensitive adhesive tape of claim 1, wherein the pressure-sensitive adhesive layer contains an oil-soluble colorant. The adhesive tape according to claim 10, wherein the colorant is chlorophyll or carotene. The pressure-sensitive adhesive tape of claim 1, wherein the pressure-sensitive adhesive layer contains polyisoprene rubber and a phenol-based anti-aging agent. The adhesive tape according to claim 1, wherein a release film is adhered on the adhesive layer. The pressure-sensitive adhesive tape of claim 13, wherein the release film has biodegradability. 15. The pressure-sensitive adhesive tape of claim 14, wherein the release film is made of a polyvinyl alcohol film. delete delete A pressure-sensitive adhesive tape manufacturing method of forming a pressure-sensitive adhesive layer by sending a base film formed in a tape shape in a base film in a long side direction and applying a pressure-sensitive adhesive layer raw material solution to the surface of the base film, A method for producing a pressure-sensitive adhesive tape, wherein the surface of the gas film is rubbed with a friction means before the pressure-sensitive adhesive layer is applied. 19. The method of claim 18, wherein the pressure-sensitive adhesive layer raw material liquid contains an organic compound as a solvent. After the base film is formed into a tape-shaped base film in a long direction, a primer layer raw material liquid is applied to the surface of the base film to form a primer layer, and then a pressure-sensitive adhesive layer is coated on the surface of the primer layer. As a pressure-sensitive adhesive tape manufacturing method to form, A method of manufacturing an adhesive tape, wherein the surface of the base film is rubbed with a friction means before applying the primer layer. 21. The method of claim 20, wherein the primer layer raw material liquid is an organic compound, and the adhesive layer raw material liquid is water. The pressure-sensitive adhesive tape of claim 2, wherein the pressure-sensitive adhesive component included in the pressure-sensitive adhesive layer is selected from the group consisting of natural isoprene rubber, synthetic isoprene rubber, nitrile rubber, and SBR rubber. 3. The pressure-sensitive adhesive tape of claim 2, wherein the pressure-sensitive adhesive layer contains calcium carbonate or aluminum oxide as a filler. The pressure-sensitive adhesive tape of claim 2, wherein the pressure-sensitive adhesive layer contains an oil-soluble colorant. The pressure-sensitive adhesive tape of claim 2, wherein the pressure-sensitive adhesive layer contains polyisoprene rubber and a phenol-based anti-aging agent. The adhesive tape according to claim 2, wherein a release film is adhered on the adhesive layer. 25. The pressure-sensitive adhesive tape of claim 24, wherein the colorant is chlorophyll or carotene.

Images