JPH0441577A - Preparation of pressure-sensitive adhesive tape or sheet - Google Patents

Abstract

PURPOSE:To prepare a pressure-sensitive adhesive tape or sheet by using a minimum amount of inactive gas by introducing a base having on its one side a photopolymerizable composition layer into a photopolymerization chamber whose inlet and outlet are water-sealed, followed by irradiation with light in an inactive gas atmosphere for polymerization. CONSTITUTION:A base 1 is introduced into a coating apparatus 2 along with the outer periphery of a rotating drum 3, where a photopolymerizable composition is applied on its one side to provide a photopolymerizable composition layer. Then, the base 1 is introduced into a photopolymerization chamber 5 filled with an inactive gas from the water-sealed inlet thereof, and irradiated, through a wall 51, with a UV ray emitted from a UV lamp 6, whereby the photopolymerizable composition is polymerized. Thereafter, the base 1 leaves the chamber 5 and passes through water for water sealing stored in a water tank 4. After removing excessive water by a draining nozzle 7, the base is dried in a water content adjusting box 8.

Description

[Detailed description of the invention] [Industrial application field]

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

[Conventional technology]

BACKGROUND ART Conventionally, a method for producing an adhesive tape or sheet is known in which a photopolymerizable composition layer is provided on a base material and the photopolymerizable composition is polymerized by irradiation with light. For example, in JP-A No. 58-118873, a photopolymerizable composition is applied onto a base material, irradiated with light, and the photopolymerizable composition is polymerized. It describes how to do so.

[Problem to be solved by the invention]

In the above production method, if the concentration of oxygen dissolved in the photopolymerizable composition is high, polymerization will be inhibited, so conventionally, the dissolved oxygen concentration is reduced to 1 ppm or less before entering the photopolymerization chamber, or
The photopolymerizable composition layer was irradiated with light and polymerized in a photopolymerization chamber in which the atmospheric oxygen concentration was maintained at 11,000 pp or less. Then, the atmospheric oxygen concentration in this photopolymerization chamber was set to 1100.
In order to reduce the amount to 0 pp or less, nitrogen gas is normally introduced into the photopolymerization chamber and the air in the photopolymerization chamber is replaced with nitrogen gas. A large amount of nitrogen gas is required to maintain the atmospheric oxygen concentration below 11,000 pp. To improve this, a nitrogen gas circulation type photopolymerization chamber is used to save nitrogen gas. However, in any case, there is a problem that a considerable amount of nitrogen gas is required and the cost is high. Furthermore, when nitrogen gas is blown into the photopolymerization chamber, there is a problem that the flow of nitrogen gas accelerates the evaporation of monomers in the photopolymerization composition, changes the composition, and deteriorates the performance of the adhesive. In addition, there are methods to reduce the amount of oxygen dissolved in the photopolymerizable composition before introducing it into the photopolymerization chamber, such as blowing nitrogen gas into the photopolymerizable composition to drive out dissolved oxygen, or Methods used include adding oxygen scavengers such as phenyl diisodecyl phosphite to the composition, or lowering the atmospheric oxygen concentration in the coating chamber where the photopolymerizable composition is applied to the substrate. However, this alone is not enough,
Furthermore, it was necessary to reduce the atmospheric oxygen concentration in the photopolymerization chamber.Furthermore, both methods require large-scale equipment;
There is a problem with being boring. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for producing an adhesive tape or sheet with good performance, which can minimize the amount of nitrogen gas used and does not require large-scale equipment.

[Means for Solving the Problems 1] The present invention has been made in order to solve the above problems and achieve the above objects.After providing a photopolymerizable composition layer on one surface of a base material, irradiation with light is performed. In the method for producing an adhesive tape or sheet in which the photopolymerizable composition is polymerized on the substrate by passing through a photopolymerization chamber, the photopolymerization chamber is located at the entrance of the substrate provided with the photopolymerizable composition layer. and the outlet is sealed with water to form a closed photopolymerization chamber, and the photopolymerization chamber is filled with an inert gas, and the photopolymerizable composition layer is While the substrate provided with is passing through the photopolymerization chamber, the photopolymerizable composition layer is irradiated with light to polymerize the photopolymerizable composition on the substrate. be. In the present invention, the base material refers to the conventional 1. Includes all base materials used in adhesive tapes or sheets. for example,
Suitable materials include synthetic resin films such as polyvinyl chloride film, polyethylene terephthalate film, polyethylene film, and polypropylene film, paper products such as kraft paper, and cellophane. In addition to the above-mentioned films, the substrate used in the present invention also includes the above-mentioned films whose surfaces have been subjected to mold release treatment. In the present invention, a photopolymerizable composition layer is provided on the surface of the base material that has not been subjected to mold release treatment, and by polymerizing it with light, it is possible to produce an adhesive tape or sheet in which the adhesive layer is in close contact with the base material. Furthermore, by providing a photopolymerizable composition layer on the release-treated surface of a base material and polymerizing it, a double-sided adhesive tape or sheet can be produced by peeling the adhesive layer from the base material. in this case,
A nonwoven fabric can also be provided in the adhesive layer to serve as the core material of a double-sided adhesive tape or sheet. In the present invention, the photopolymerizable composition refers to a composition that polymerizes to become an adhesive when irradiated with light. Such a photopolymerizable composition consists of a monomer or a partially polymerized product of this monomer and a photopolymerization initiator, and there are conventionally known types of photopolymerizable compositions. For example, acrylic, polyester,
There are many photopolymerizable compositions such as epoxy type. The present invention includes all of these known photopolymerizable compositions. In particular, acrylic photopolymerizable compositions are suitable. In the present invention, the entrance of the photopolymerization chamber is sealed with water, and the substrate provided with the photopolymerizable composition layer enters the photopolymerization chamber by diving through the water. Therefore, the photopolymerizable composition provided on one surface of the substrate is preferably a water-insoluble photopolymerizable composition. However, since it passes through water at a fast rate, it is possible to use a substance that has a slow dissolution rate and dissolves in a small amount. Although the viscosity of the photopolymerizable composition of the present invention is not particularly limited, it is preferable that the photopolymerizable composition sticks to the surface of the substrate and is difficult to separate from it. From this point of view, it is preferable that the viscosity of the photopolymerizable composition is high. Therefore, it is preferable to prepolymerize the polymerizable composition to some extent before entering the photopolymerization chamber. In the present invention, light generally refers to electromagnetic waves such as visible light, ultraviolet rays, and electron beams. - For boat fishing, light containing many wavelengths suitable for photopolymerizable compositions is used. Since many conventionally used photopolymerizable compositions are polymerized by ultraviolet light, ultraviolet light is most often used as the light. In the present invention, a light source for irradiating the photopolymerizable composition layer with light may be provided at an appropriate position. For example, the photopolymerizable composition is provided on the outside of the side wall or bottom wall of the aquarium, the side wall or the bottom wall is made of a light-transmitting material, and the light emitted from this light source is transmitted through the side wall or bottom wall. The layer may be irradiated with the light, or a light source may be installed in the aquarium and the light may be irradiated from there. Alternatively, the roll or belt and the base material may be made of a light-transmitting material, and the light emitted from the light source may be transmitted through the roll or belt and the base material to irradiate the photopolymerizable composition layer. Here, the light-transmitting material used is a general term for materials used in the present invention that have the property of transmitting light.
For example, if the light is ultraviolet rays, Pyrex glass, quartz glass, etc. are suitable materials. The photopolymerization chamber in the present invention has an inlet and an outlet sealed with water, and is completely closed. Therefore, when an inert gas such as nitrogen gas is introduced into the photopolymerization chamber, the structure is such that no or almost no leakage occurs. To explain the preferred structure of this photopolymerization chamber, the photopolymerization chamber is sealed, and a rotating drum or a plurality of rotating drums with belts are installed in the chamber so that the center of the drum is exposed. The drum or belt and the wall of the photopolymerization chamber are sealed with water from a water tank. Then, the substrate is moved along a rotating drum or belt, and the water-sealed area is used as an inlet and an outlet, from which the substrate passes through the water of the water-sealing tank and enters and exits. To explain the method of photopolymerization using a device with this structure,
The substrate provided with the photopolymerizable composition layer is moved along the outer periphery of a rotating drum or belt with the photopolymerizable composition layer on the outside. The sequence of this operation is to first pass through the water-sealed water tank and enter the photopolymerization chamber. This photopolymerization chamber is filled with an inert gas such as nitrogen gas. Once inside the photopolymerization chamber, the photopolymerizable composition layer of the substrate running along the rotating drum or sheet is irradiated with light, and the photopolymerizable composition polymerizes to form an adhesive. Once the polymerization is complete,
Exit from the water-sealed exit of the photopolymerization chamber. When exiting the photopolymerization chamber, the animal crawls through the water in the water-sealed aquarium in the same way as when entering the photopolymerization chamber. In the present invention, a photopolymerizable composition layer is provided on one side of the substrate, and any method conventionally used for producing adhesive tapes or sheets can be used for this method. For example, methods include applying or casting a photopolymerizable composition onto a base material, overlaying a nonwoven fabric or paper, etc. that has absorbed the photopolymerizable composition on the base material, and applying the photopolymerizable composition onto the base material. There is a method of applying or casting a photopolymerizable composition onto a material such as a nonwoven fabric. [Function 1] The photopolymerization chamber used in the present invention is a closed chamber whose inlet and outlet are sealed with water. Inert gas does not leak from this photopolymerization chamber, and even if it does leak, it is in a very small amount1, so the amount of inert gas used is significantly reduced. Furthermore, since the inert gas does not leak, or even if it does leak, it is only in a very small amount, there is no need to introduce inert gas to the extent that the air current is present, and evaporation of the photopolymerized product due to the air current is almost eliminated. Therefore, there is no change in composition and no deterioration in adhesive performance. In addition, since the photopolymerizable composition layer is polymerized by irradiating the photopolymerizable composition layer with light in the photopolymerization chamber that is filled with inert gas and has almost no leakage, dissolved oxygen is removed. Photopolymerization occurs smoothly without any hindrance. [Example] Next, an example will be described. FIG. 1 is an explanatory diagram showing one embodiment of the present invention, and FIG. 2 is an explanatory diagram showing another embodiment of the present invention. 3 to 8 are explanatory diagrams showing different embodiments, respectively. In FIG. 1, l is the base material. 2 is a coating device. 4 is a water tank for water sealing, and water 41 is placed in this water tank 4. 3 is a rotating drum, and this rotating shaft is parallel to the water surface of the water tank 4 for water sealing. Then, as shown by the arrow, it is rotated clockwise in the figure. 5 is a photopolymerization chamber filled with nitrogen gas. 51
is a Pyrex glass wall that runs from the bottom wall to the side wall. To explain the structure of the water seal in the photopolymerization chamber 5, the tip of the wall 52 provided at the boundary between the water tank 4 and the photopolymerization chamber 3 is provided in contact with the outer periphery of the rotating drum 3, and the photopolymerizable material is The base material 1 provided with the material layer runs along the outer periphery of this rotating drum 3.
When the vehicle is operated, water is dammed up at the contact point between the base material 1 and the wall 52, and this portion is water-sealed. The water seal at the exit is also the same. Reference numeral 6 denotes an ultraviolet lamp, and light emitted from the ultraviolet lamp 6 passes through a Pyrex glass wall 51 and irradiates the surface of the rotating drum 3 in the photopolymerization chamber 5. 7 is a draining device. 8 is a moisture adjustment box. Next, a method for manufacturing an adhesive tape using this apparatus will be described. The base material 1 is supplied from a supply device (not shown) (from the right in the figure), travels along the outer peripheral surface 32 of the rotating drum 3, and is introduced into the coating device 2 provided on the outer peripheral surface. The coating device 2 coats the photopolymerizable composition onto one surface of the substrate 1 to provide a photopolymerizable composition layer. In this way, the base material 1 provided with the photopolymerizable composition layer is
Furthermore, it is caused to travel along the outer circumferential surface 32 of the rotating drum 3,
From the water-sealed entrance, go into the water 41 and enter the photopolymerization chamber 5.
Go inside. While the substrate 1 is moving in the photopolymerization chamber 5, ultraviolet light emitted from the ultraviolet lamp 6 passes through the wall 51 and is irradiated onto the photopolymerizable composition, causing the photopolymerizable composition to polymerize. and becomes an adhesive. At this time, since the photopolymerizable composition is polymerized in a photopolymerization chamber filled with inert gas, there is less oxygen dissolved in the photopolymerizable composition, and polymerization is inhibited. Polymerization proceeds smoothly without any problems. In this way, when the photopolymerizable composition polymerizes and becomes an adhesive, the base material 1 passes through the water 41 in the water sealing water tank 4,
It comes out from the photopolymerization chamber 5. Water adhering to the adhesive is removed by a draining nozzle 7 and further dried in a moisture adjustment box 8 to produce an adhesive film. This adhesive film is wound up into a roll and cut into chambers to produce an adhesive tape. Next, the embodiment shown in FIG. 2 will be described. In FIG. 2, a prepolymerization device 9 is provided between the coating device 2 and the surface of the water 41, and the ultraviolet rays emitted from the ultraviolet lamp 6I are transmitted through the Pyrex glass wall 53.
This apparatus is the same as the apparatus shown in FIG. 1, except that the photopolymerizable composition layer is irradiated and the prepolymerization chamber 9 is filled with nitrogen gas. The method for producing an adhesive tape using this apparatus is to apply ultraviolet rays from an ultraviolet lamp in a prepolymerization apparatus 9 after a photopolymerizable composition is applied to a substrate 1 in a coating apparatus 2.
A portion of the photopolymerizable composition is polymerized. In this way, the substrate provided with the partially polymerized photopolymerizable composition layer enters the photopolymerization chamber 5 along the outer periphery 32 of the rotating drum 3 through the water-sealed entrance. Thereafter, an adhesive tape is manufactured in the same manner as in FIG. Prepolymerizing the photopolymerizable composition in this way increases the viscosity of the photopolymerizable composition, making it difficult to separate from the substrate 1, which is convenient. FIG. 3 has the same structure as FIG. 1, except that an ultraviolet irradiation lamp 6 is provided on the rotating drum 3 and the substrate 1 is supplied from below. The method for manufacturing an adhesive tape using this device is to manufacture the adhesive tape in the same manner as in FIG. 1, except that the base material 1 is supplied from a not-shown supply device (from the left in the figure). . In FIG. 4, as in FIG. 3, an ultraviolet irradiation lamp 6 is provided on the rotating drum 3, and the base material 1 is supplied from below. The difference from FIG. 3 is that a preliminary polymerization device 9 is provided between the coating device 2 and the water tank 4, and the ultraviolet rays emitted from the ultraviolet lamp 61 are transmitted through the Pyrex glass wall 53, resulting in photopolymerization. irradiating the composition layer; and
This prepolymerization chamber 9 is filled with nitrogen gas. A method for producing an adhesive tape using this device is that after a photopolymerizable composition is coated on a substrate 1 in a coating device 2, a prepolymerization device 9 is used to apply ultraviolet rays emitted from an ultraviolet lamp 6. , polymerize a portion of the photopolymerizable composition. In this way, the base material 1 provided with a partially polymerized photopolymerizable composition layer
enters the photopolymerization chamber 5 along the outer periphery 32 of the rotating drum 3 through a water-sealed entrance. Thereafter, an adhesive tape is manufactured in the same manner as in FIG. The apparatus shown in FIG. 5 includes the rotating drum 3 in FIG.
This is a device in which a belt 33 is hung between rolls 3L32. The method for producing an adhesive tape using this device is as shown in FIG. Adhesive tape is manufactured in the same way. In this way, the belt 33 hung on the rolls 31, 32
If the base material 1 provided with the photopolymerizable composition layer is moved along the route, it is easy to increase the distance traveled, and therefore, the speed of travel can be increased, and productivity increases. In the apparatus shown in FIG. 6, a prepolymerization device 9 is provided between the coating device 2 and the water tank 4 of the device shown in FIG. The apparatus is the same as that shown in FIG. 5, except that the photopolymerizable composition layer is irradiated through the wall 53 of the prepolymerization apparatus 9, and that the interior of the prepolymerization apparatus 9 is filled with nitrogen gas. It is. A method for producing an adhesive tape using this device is that after a photopolymerizable composition is coated on a substrate 1 in a coating device 2, a prepolymerization device 9 is used to apply ultraviolet rays emitted from an ultraviolet lamp 61. , polymerize a portion of the photopolymerizable composition. in this way,
The substrate 1 provided with the partially polymerized photopolymerizable composition layer enters the photopolymerization chamber 5 along the outer periphery of the belt 33 through a water-sealed entrance, as shown in FIG. Manufactured in the same manner as the method. The device shown in the seventh circle is the rotating drum 3 in FIG.
Instead, a belt 33 is placed between the rolls 31, 32. In the method of manufacturing an adhesive tape using this device, the base material 1 is fed from a feeding device (not shown) (from the right in the drawing) and runs along the outer periphery of the belt 33. Thereafter, the adhesive tape is manufactured in the same manner as shown in FIG. In this way, when the substrate 1 provided with the photopolymerizable composition layer is moved along the heddles hung on the rolls 31, 32, it is easy to increase the distance traveled and therefore the speed of travel can be increased. It can be done faster and productivity will increase. In the apparatus shown in FIG. 8, a preliminary polymerization chamber 9 is provided between the coating device 2 and the water tank 4 of the apparatus shown in FIG. The apparatus is the same as that shown in FIG. 7, except that the photopolymerizable composition layer is irradiated through the wall 53 and that the interior of the prepolymerization chamber 9 is filled with nitrogen gas. It is. A method of manufacturing an adhesive tape using this apparatus is to apply ultraviolet rays emitted from an ultraviolet lamp 61 in a prepolymerization chamber 9 after a photopolymerizable composition is applied to a substrate 1 in a coating apparatus 2. Then, a part of the photopolymerizable composition is polymerized. in this way,
The substrate 1 provided with the partially polymerized photopolymerizable composition layer enters the photopolymerization chamber 5 along the outer periphery of the belt 33 through an entrance sealed with water. Thereafter, the adhesive tape is manufactured in the same manner as shown in FIG.

【Effect of the invention】

In the present invention, the photopolymerization chamber has an inlet and an outlet sealed with water,
The rest of the rooms are almost completely sealed and closed, so
Even if inert gas is put in this, it will not leak at all, or even if it leaks, it will only be in a very small amount, so the amount of inert gas consumed is extremely small (and the cost can be greatly reduced. Also, in this way, Since the inert gas is not replenished into the photopolymerization chamber or is replenished only in a very small amount, no air current is generated due to the introduction of the inert gas. performance will not deteriorate.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention, and FIG. 2 is an explanatory diagram showing another embodiment. 3 to 8 are explanatory diagrams each showing another embodiment of the present invention. 1----------1 base material 2--11-111--Coating device 3-------1 rotating drum 4-- ---
−−−−−−・−・Water seal tank 5−・−−−−−1−−
---・Light-transmitting window (Pyrex glass window)

Claims (1)

[Claims] (1) Manufacture of an adhesive tape or sheet in which a photopolymerizable composition layer is provided on one side of a base material, and then passed through a photopolymerization chamber while irradiating light to polymerize the photopolymerizable composition on the base material. In the method, the photopolymerization chamber is a closed chamber in which the inlet and outlet of the substrate provided with the photopolymerizable composition layer are sealed with water, and the entire photopolymerization chamber is closed. The inside is filled with an inert gas, and while the substrate provided with the photopolymerizable composition layer passes through the photopolymerization chamber, the photopolymerizable composition is A method for producing an adhesive tape or sheet, which comprises irradiating a material layer with light to polymerize a photopolymerizable composition on a substrate.