JPH0776329B2 - Adhesive tape or sheet manufacturing method - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a method for manufacturing an adhesive tape or sheet. More specifically, it relates to a method for producing an adhesive tape or sheet in which a photopolymerizable composition layer provided on one surface of a substrate is irradiated with light to polymerize the photopolymerizable composition.

[Prior art]

BACKGROUND ART Conventionally, a method for producing a pressure-sensitive adhesive tape or sheet in which a photopolymerizable composition layer is provided on a substrate and light is irradiated to polymerize the photopolymerizable composition is known. For example, JP-A-58-118873 discloses a method for producing an adhesive film, which comprises coating a photopolymerizable composition on a substrate,
A method of irradiating light to polymerize the photopolymerizable composition is described.

[Problems to be Solved by the Invention]

The above-mentioned production method, when the concentration of oxygen dissolved in the photopolymerizable composition is high, polymerization is inhibited, so conventionally, the dissolved oxygen concentration is lowered to 1 ppm or less before entering the photopolymerization chamber, or atmospheric oxygen. The photopolymerizable composition layer was polymerized by irradiating it with light in a photopolymerization chamber whose concentration was maintained at 1000 ppm or less. And the atmospheric oxygen concentration in this photopolymerization chamber is 1000 ppm.
In the following, usually, nitrogen gas is flowed into the photopolymerization chamber and the air in the photopolymerization chamber is replaced with nitrogen gas. A large amount of nitrogen gas is necessary to keep the oxygen concentration below 1000 ppm. To improve this, a nitrogen gas circulating photopolymerization chamber is adopted to save nitrogen gas. But,
In any case, there is a problem that a considerable amount of nitrogen gas is required and the cost becomes high. Further, when nitrogen gas is blown into the photopolymerization chamber, the nitrogen gas stream promotes evaporation of the monomers in the photopolymerization composition, resulting in a change in composition and a decrease in performance of the pressure-sensitive adhesive. Further, before introducing into the photopolymerization chamber, a method of reducing the amount of oxygen dissolved in the photopolymerizable composition is to blow nitrogen gas into the photopolymerizable composition to expel dissolved oxygen, Although a method such as adding an oxygen scavenger such as phenyldiisodecyl phosphite to the composition or lowering the oxygen concentration in the atmosphere of the coating chamber for coating the photopolymerizable composition on the substrate has been carried out. , This is not enough,
Furthermore, it was necessary to reduce the atmospheric oxygen concentration in the photopolymerization chamber. In addition, both methods require large-scale equipment,
There is a problem that it is complicated, and when the photopolymerizable composition becomes thick, the heat of polymerization becomes difficult to dissipate, the temperature becomes high, and the monomer evaporates. Therefore, there is a problem that the composition is changed and the performance of the pressure-sensitive adhesive is lowered, or the base material heated to a high temperature after the product is wound up is contracted and deformed. Therefore, an object of the present invention is to provide a method for producing a pressure-sensitive adhesive tape or sheet that does not use nitrogen gas or can suppress the amount used as much as possible and does not require a large-scale device.

[Means for Solving the Problems]

The present invention has been made to solve the above problems and achieve the above objects, and in a water tank, a belt hung on a plurality of rolls is provided in a state of being partially submerged in water. The base material provided with the photopolymerizable composition layer in the above, the photopolymerizable composition layer so that the photopolymerizable composition layer is on the outside, run along the outer periphery of the belt submerged in water, the photopolymerizable composition The photopolymerizable composition layer is irradiated with light while the material layer is submerged in water to polymerize the photopolymerizable composition. In the present invention, the base material includes all the base materials conventionally used for adhesive tapes or sheets. For example, a synthetic resin film such as a polyvinyl chloride film, a polyethylene terephthalate film, a polyethylene film, a polypropylene film, a paper product such as kraft paper, or cellophane is suitable. The substrate used in the present invention includes, in addition to the above-mentioned film, those obtained by subjecting the surface of the above-mentioned film to release treatment. In the present invention, a photopolymerizable composition layer is provided on the surface of the base material which has not been subjected to a release treatment, and polymerization with light makes it possible to produce a pressure-sensitive adhesive tape or sheet in which the pressure-sensitive adhesive layer is adhered to the base material. Further, when a photopolymerizable composition layer is provided on the release-treated surface of a substrate and polymerization is performed, a double-sided pressure-sensitive adhesive tape or sheet can be produced in which the pressure-sensitive adhesive layer is peeled from the substrate and used. in this case,
A nonwoven fabric may be provided in the pressure-sensitive adhesive layer to serve as a core material for the double-sided pressure-sensitive adhesive tape or sheet. In the present invention, the photopolymerizable composition means a composition which, when irradiated with light, is polymerized into a pressure-sensitive adhesive. Such a photopolymerizable composition is composed of a monomer or a partially polymerized product of this monomer and a photopolymerization initiator. Many photopolymerizable compositions have been known so far. For example, acrylic, polyester,
There are many photopolymerizable compositions such as epoxy-based. The present invention includes all of these known photopolymerizable compositions. In particular, an acrylic photopolymerizable composition is suitable. Since the photopolymerizable composition provided on one surface of the substrate used in the present invention runs along the outer circumference of the belt immersed in water, a water-insoluble photopolymerizable composition is preferable. However, since the photopolymerization reaction is extremely fast, the dissolution rate is slow,
Those that dissolve in a small amount can be used. Further, the viscosity of the photopolymerizable composition of the present invention is not particularly limited, but when the substrate provided with the photopolymerizable composition layer is run in water along the outer peripheral surface of the belt, the photopolymerizable composition is It is better that the object sticks to the surface of the substrate and is difficult to separate. From this viewpoint, it is preferable that the photopolymerizable composition has a high viscosity. Therefore, it is preferable to pre-polymerize the polymerizable composition to some extent before it is submerged in water. In the present invention, light is a general term for electromagnetic waves such as visible light rays, ultraviolet rays, and electron beams. Generally, light containing a large number of wavelengths suitable for the photopolymerizable composition is used. Most of the conventionally used photopolymerizable compositions are polymerized by ultraviolet rays, and thus ultraviolet rays are most often used as light. In the present invention, the light source for irradiating the photopolymerizable composition layer with light may be provided at an appropriate position. For example, the photopolymerizable composition is provided outside the side wall or bottom wall of the aquarium, and the side wall or bottom wall is made of a light-transmissive material, and the light emitted from this light source is transmitted through the side wall or bottom wall. The layer may be irradiated, or a light source may be installed in the water tank and irradiation may be performed from here. Also, a light source is installed inside the roll or belt, and the roll or belt and the base material are made of a light-transmissive material, and the light emitted from the light source is transmitted through the roll or belt and the base material. The polymerizable composition layer may be irradiated. Here, the light-transmitting material used is a generic term for materials having a property of transmitting light used in the present invention. For example, when the light is ultraviolet rays, Pyrex glass, quartz glass, etc. are preferable. It is a good material. In the present invention, the belt hung on a plurality of rolls means that the belt is hung on two or more rolls. In the present invention, a part of the rolls is submerged in the water in the water tank. It will be operated as it is. Therefore, a part of the at least one roll is submerged in the water. The belt used in the present invention is wound on a plurality of rolls. At this time, there are various arrangements of rolls. For example, the first
As shown in the figure, a device in which two rolls are arranged side by side, as shown in FIG. 3, a device in which two rolls are arranged side by side, as shown in FIG. 5, (a) A device in which three rolls of the same size are arranged, (b) a device in which three large and small rolls are arranged, (c) another device in which three large and small rolls are arranged, (d) the same size There are various devices such as a device in which four rolls are arranged, (e) a device in which four large and small rolls are arranged, and (f) another device in which four large and small rolls are arranged. These rolls are belted. And
This belt runs partly underwater. The greater the distance traveled in water, the greater the distance traveled in water of the substrate provided with the photopolymerizable composition layer that runs along the outer circumference, and the longer the distance that light is irradiated. Therefore, the speed of the base material can be increased. In the present invention, the photopolymerizable composition layer is provided on one surface of the substrate, and as a method for providing the photopolymerizable composition layer, all methods conventionally used for producing an adhesive tape or sheet can be used. For example, a method of coating or casting a photopolymerizable composition on a base material, a method of laminating a nonwoven fabric or paper having a photopolymerizable composition absorbed on the base material, or a method of providing on the base material. There is a method of coating or casting the photopolymerizable composition on the material such as the nonwoven fabric.

[Work]

In the present invention, the base material provided with the photopolymerizable composition on one surface is run along the outer peripheral surface of the belt submerged in water. Does not come into direct contact with air. Therefore, the amount of oxygen dissolved in the photopolymerizable composition is extremely small. Since the photopolymerizable composition is polymerized by irradiating the photopolymerizable composition layer with light in such a situation, there is no problem in photopolymerization. Further, since the photopolymerizable composition is run outside along the outer circumference of the belt wound on the roll, the photopolymerizable composition does not adhere to the roll and the belt. Further, in this way, when the photopolymerizable composition submerged in water is irradiated with light, water deprives the heat of polymerization, and therefore the temperature of the photopolymerizable composition layer does not rise, so that the monomer does not evaporate. ,
Therefore, the composition does not change, a pressure-sensitive adhesive with good performance can be manufactured, and the base material does not deform. Further, since the photopolymerizable composition is generally lighter than water, when it is run in water along the outer circumference of the belt, the water pressure and the force of floating the photopolymerizable composition upward causes the photopolymerizable composition layer to become a base. Stick to the material. Further, when the base material provided with the photopolymerizable composition layer is operated along the outer periphery of the belt as described above, it is easier to increase the operation distance than to operate the roll surface. , The operating speed can be increased and the productivity is increased.

【Example】

Next, examples will be described. FIG. 1 is an explanatory view showing one embodiment of the present invention, FIG. 2 is an explanatory view showing another embodiment of the present invention, FIG. 3 is an explanatory view showing another embodiment, and FIG. FIG. 5 is an explanatory view showing another embodiment, and FIG. 5 shows another embodiment of the present invention and is an explanatory view showing only the arrangement of rolls and belts. First, the embodiment shown in FIG. 1 will be described. In FIG. 1, 1 is a base material. 2 is a coating device. 4 is a water tank, and water 41 is put in this water tank 4. 3 is a roll partly immersed in water, and 31 is a roll provided in water. A belt 35 is hung between the roll 3 and the roll 31. When the belt 35 is hung in this manner, the belt 35 is attached so that the belt 35 is partially submerged in the water 41 for operation. Then, as shown by the arrow, the image is rotated clockwise in the figure. Reference numeral 5 is a wall made of Pyrex glass attached from the bottom wall to the side wall of the water tank 4. 6 is an ultraviolet lamp, and the ultraviolet rays emitted from this ultraviolet lamp 6 pass through the wall 5 of Pyrex glass,
The surface of the rotary drum 3 is irradiated. Reference numeral 7 is a draining device. Reference numeral 8 is a moisture adjustment box. Next, a method for producing an adhesive tape using this device will be described. The base material 1 is supplied from a supply device (not shown) (from the right in the figure), runs along the outer peripheral surface of the belt 35, and is introduced into the coating device 2 provided on the outer peripheral surface. The photopolymerizable composition is applied to one surface of the substrate 1 by the coating device 2 to form a photopolymerizable composition layer. Thus, the substrate 1 provided with the photopolymerizable composition layer,
Further, when it is run along the outer peripheral surface of the belt 35, it is submerged in the water 41 in the water tank 4. Then, due to the water pressure and the force of floating the photopolymerizable composition layer lighter than water, the photopolymerizable composition layer comes into close contact with the substrate 1. In this state, while traveling along the outer circumference 32 of the belt 35 in the water 41, the ultraviolet rays emitted from the ultraviolet lamp 6 pass through the wall 5 and are applied to the photopolymerizable composition. The photopolymerizable composition is polymerized to form an adhesive. At this time, since the photopolymerizable composition is in the water 41, there is no supply of oxygen, therefore, the amount of oxygen dissolved in the photopolymerizable composition is small, polymerization is not blocked, and polymerization is smoothly performed. Advances. Also, since it is in water 41, the heat of polymerization generated during polymerization is water.
By 41, cooling prevents the photopolymerizable composition from reaching a high temperature. In this way, when the photopolymerizable composition is polymerized and becomes a pressure-sensitive adhesive, the base material emerges from the water tank 4. Water adhering to the adhesive is taken out by the water draining nozzle 7 and further dried in the moisture adjusting box 8 to produce an adhesive film. This adhesive film is wound into a roll and cut into a certain width to produce an adhesive tape. Next, the embodiment shown in FIG. 2 will be described. In FIG. 2, the prepolymerization chamber 9 is provided between the coating device 2 and the surface of the water 41, and the ultraviolet rays emitted from the ultraviolet lamp 61 pass through the wall 51 of the Pyrex glass to form the photopolymerizable composition. Of the material layer and this prepolymerization chamber 9
The apparatus is the same as the apparatus shown in FIG. 1 except that the inside is filled with nitrogen gas. A method for producing an adhesive tape using this apparatus is such that after the photopolymerizable composition is applied to the base material 1 by the application apparatus 2, the UV rays emitted from the ultraviolet lamp 61 in the prepolymerization chamber 9 are used. ,
A part of the photopolymerizable composition is polymerized. As described above, the substrate 1 provided with the partially polymerized photopolymerizable composition layer is a belt.
It can be manufactured in the same manner as in FIG. 1 except that it is submerged in water 41 along the outer periphery of 35. When the photopolymerizable composition is prepolymerized in this manner, the viscosity of the photopolymerizable composition becomes large and it becomes difficult to separate from the substrate 1, which is convenient. In the embodiment shown in FIG. 3, the two rolls 33, 33 are attached so as to be partially submerged in water.
A belt 35 is provided between 33, the rolls 33, 33 are rotated counterclockwise, and the substrate 1 is supplied from the left. Others are the same as the embodiment shown in FIG. In the embodiment shown in FIG. 4, the prepolymerization chamber 9 is provided between the coating device 2 and the surface of water 41, and the ultraviolet rays emitted from the ultraviolet lamp 61 pass through the wall 51 of Pyrex glass, Except that the photopolymerization composition layer is irradiated and that the inside of the prepolymerization chamber 9 is filled with nitrogen gas,
This is the same as the embodiment shown in FIG. FIG. 5 shows another embodiment, only the arrangement of rolls and belts. Here, (a) a device in which three rolls are arranged in a triangle,
(B) A device in which three large and small rolls are arranged, (c) Another device in which three large and small rolls are arranged, (d) 4 of the same size
It shows an apparatus in which four rolls are arranged, (e) an apparatus in which four large and small rolls are arranged, and (f) another apparatus in which four large and small rolls are arranged. In this way, if the number of rolls is increased, it is easy to increase the length of the belt that runs underwater, which is convenient.

【The invention's effect】

In the present invention, while the photopolymerizable composition is submerged in water,
Because it is polymerized by light, there is no polymerization inhibition by oxygen,
Therefore, in order to eliminate the effect of this oxygen, conventionally, it is almost unnecessary or almost not necessary to replace the inside of the photopolymerization chamber or the coating device with nitrogen gas, and the oxygen scavenger is added to the photopolymerizable composition It is extremely convenient because it is not added. Further, in the present invention, most of the photopolymerizable portion is sealed with water, so that the photopolymerizable composition does not evaporate,
Therefore, the composition does not change and the performance of the pressure-sensitive adhesive does not deteriorate. Further, since the polymerization is carried out in water, the heat of polymerization generated at the time of polymerization is also cooled by water and does not reach a high temperature. Therefore, the monomer does not evaporate, and as a result, the composition does not change and the performance of the pressure-sensitive adhesive decreases. There is no. Further, if the base material provided with the photopolymerizable composition layer is operated along the outer periphery of the belt, it is easier to increase the operation distance than to operate the base material on the roll surface. Can be increased, productivity can be increased, and cost can be reduced.

[Brief description of drawings]

FIG. 1 is an explanatory view showing one embodiment of the present invention, FIG. 2 is an explanatory view showing another embodiment, FIG. 3 is an explanatory view showing another embodiment, and FIG. 4 is another other embodiment. FIG. 5 shows another embodiment of the present invention, and is an explanatory view showing only the arrangement of rolls and belts. 1 ... Substrate 2 ... Coating device 3, 31, 32, 33 ... Roll 35 ... Belt 4 ... Water tank 5 ... Light transmissive window (Pyrex glass window) 6 ... UV lamp

Claims (1)

[Claims] 1. A base material provided with a belt wound on a plurality of rolls partially immersed in water in a water tank and having a photopolymerizable composition layer on one surface thereof, While the photopolymerizable composition layer is on the outer side, the belt is moved along the outer periphery of the belt submerged in water, and while the photopolymerizable composition layer is submerged in water, the photopolymerizable composition layer A method for producing an adhesive tape or sheet, which comprises irradiating a material layer with light to polymerize the photopolymerizable composition.