JPH0776330B2 - 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, the composition changes, and the performance of the pressure-sensitive adhesive decreases. 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 of being annoying. Therefore, it is an object of the present invention to provide a method for producing a pressure-sensitive adhesive tape or sheet that can suppress the amount of nitrogen gas used as much as possible and that does not require a large-scale device.

[Means for Solving the Problems]

The present invention has been made to solve the above problems and to achieve the above objects, and after providing a photopolymerizable composition layer on one surface of a substrate, while irradiating light, pass through the photopolymerization chamber, In the method for producing a pressure-sensitive adhesive tape or sheet in which a photopolymerizable composition is polymerized on a substrate, the photopolymerization chamber is water-sealed at the inlet and outlet of the substrate provided with the photopolymerizable composition layer, The entire polymerization chamber is a closed chamber, the photopolymerization chamber is filled with an inert gas, the substrate provided with the photopolymerizable composition layer, While passing through the photopolymerization chamber, the photopolymerizable composition layer is irradiated with light to polymerize the photopolymerizable composition on the substrate. 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 non-woven fabric may be provided in the pressure-sensitive adhesive layer to form the core material of 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 an adhesive material. 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. In the present invention, the inlet of the photopolymerization chamber is sealed with water, and the base material provided with the photopolymerizable composition layer dives into the water and enters the photopolymerization chamber. Therefore, the photopolymerizable composition provided on one surface of the substrate is preferably a water-insoluble photopolymerizable composition.
However, since the rate of passage through water is high, it is possible to use one that has a low dissolution rate and dissolves in a small amount. Further, the viscosity of the photopolymerizable composition of the present invention is not particularly limited, but it is preferable that the photopolymerizable composition adheres 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 entering the photopolymerization chamber. 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. Alternatively, the roll or belt and the substrate may be made of a light transmissive material, and the light emitted from the light source may be transmitted through the roll or the belt and the substrate to irradiate the photopolymerizable composition layer. 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 suitable. It is a good material. The photopolymerization chamber in the present invention is watertight at the inlet and the outlet, and is entirely closed. Therefore, when an inert gas such as nitrogen gas is introduced into this photopolymerization chamber, the structure is such that no leak or almost no leak occurs. Explaining the preferred structure of this photopolymerization chamber, the photopolymerization chamber is closed, in which a rotating drum or a plurality of rotating drums with belts is provided so as to partially expose the head, The rotating drum or belt and the wall of the photopolymerization chamber are water-sealed with water in a water tank for water sealing. Then, the base material runs along a rotating drum or belt, and the place where it is water-sealed serves as an inlet and an outlet, from which the base material passes through the water in the water-sealing water tank to enter and exit. Explaining the method of photopolymerization in an apparatus having such a structure,
The substrate provided with the photopolymerizable composition layer is run along the outer periphery of the rotating drum or belt so that the photopolymerizable composition layer is on the outside. The order of this operation is
Go through the water tank that is a water seal and enter the photopolymerization chamber. The photopolymerization chamber is filled with an inert gas such as nitrogen gas. When entering the photopolymerization chamber, the photopolymerizable composition layer of the substrate running along the rotating drum or the sheet is irradiated with light, and the photopolymerizable composition is polymerized to form an adhesive. When the polymerization is completed, it exits from the water-sealed outlet of the photopolymerization chamber. When exiting from the photopolymerization chamber, as in the case of entering, it goes through the water in the water-sealed water tank and exits from the photopolymerization chamber. 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]

Since the photopolymerization chamber used in the present invention is a closed chamber in which the inlet and the outlet are sealed with water, once it is filled with an inert gas such as nitrogen gas, this inert gas is It does not leak from the photopolymerization chamber, and even if it leaks, it is extremely small. Therefore, the amount of inert gas used is greatly reduced. In addition, since the inert gas does not leak, or even if it leaks, the amount thereof is extremely small, it is not necessary to introduce the inert gas to the extent that an air flow is generated, and the evaporation of the photopolymerization product by the air flow is almost eliminated. Therefore, there is no change in composition and there is no deterioration in the performance of the pressure-sensitive adhesive. Further, since the photopolymerizable composition layer is irradiated with light in the photopolymerization chamber which is filled with the inert gas and hardly leaks to polymerize the photopolymerizable composition, the dissolved oxygen is dissolved. Photopolymerization is smooth without any hindrance.

【Example】

Next, examples will be described. FIG. 1 is an explanatory view showing one embodiment of the present invention, and FIG. 2 is an explanatory view showing another embodiment of the present invention. 3 to 8 are explanatory views showing different embodiments. In FIG. 1, 1 is a base material. 2 is a coating device. Reference numeral 4 is a water tank for sealing water, and water 41 is put in the water tank 4. 3 is a rotary drum, the axis of rotation of which is parallel to the water surface of a water tank 4 for water sealing. Then, as shown by the arrow, the image is rotated clockwise in the figure. 5 is a photopolymerization chamber, which is filled with nitrogen gas. 51 is a Pyrex glass wall attached from the bottom wall to the side wall. The structure of the water sealing of the photopolymerization chamber 5 will be described. The tip of the wall 52 provided at the boundary between the water tank 4 and the photopolymerization chamber 3 is the rotary drum 3
When the base material 1 provided in contact with the outer periphery of the base material 1 and provided with the photopolymerizable composition layer is operated along the outer periphery of the rotary drum 3, water is generated at the contact point between the base material 1 and the wall 52. Is blocked, and this part is sealed with water. The water seal at the exit is similar. Reference numeral 6 denotes an ultraviolet lamp, and the light emitted from the ultraviolet lamp 6 passes through the wall 51 of Pyrex glass and irradiates the surface of the rotary drum 3 in the photopolymerization chamber 5. 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 drawing), runs along the outer peripheral surface 32 of the rotary drum 3, 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, it is operated along the outer peripheral surface 32 of the rotary drum 3 and enters the photopolymerization chamber 5 through the water-sealed inlet, submersing in the water 41. While the base material 1 is operating in the photopolymerization chamber 5, the ultraviolet light emitted from the ultraviolet lamp 6 passes through the wall 51 and is applied to the photopolymerizable composition, so that the photopolymerizable composition is It polymerizes and becomes an adhesive. At this time, since the photopolymerizable composition is polymerized in the photopolymerization chamber filled with an inert gas, the amount of oxygen dissolved in the photopolymerizable composition is small, and the polymerization is blocked. Polymerization proceeds smoothly without In this way, when the photopolymerizable composition is polymerized and becomes an adhesive, the base material 1 penetrates the water 41 in the water tank 4 for water sealing,
Exit from photopolymerization chamber 5. 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 device 9 is provided between the coating device 2 and the surface of the water 41, and the ultraviolet light emitted from the ultraviolet lamp 61 passes through the wall 53 of the Pyrex glass to form the photopolymerizable composition. Except that the material layer is irradiated and the prepolymerization chamber 9 is filled with nitrogen gas.
It is the same as the device shown in the figure. A method for producing an adhesive tape using this apparatus is as follows. After the photopolymerizable composition is applied to the base material 1 by the coating apparatus 2, it is irradiated with ultraviolet rays from an ultraviolet lamp in the prepolymerization apparatus 9,
A part of the photopolymerizable composition is polymerized. Thus, the base material 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 inlet. After that, an adhesive tape is manufactured by the same method as in FIG. Thus, prepolymerization of the photopolymerizable composition is convenient because the viscosity of the photopolymerizable composition increases and it becomes difficult to separate from the substrate 1. FIG. 3 has the same structure as that of FIG. 1 except that the ultraviolet irradiation lamp 6 is provided on the rotary drum 3 and the substrate 1 is supplied from below. A method of manufacturing an adhesive tape using this apparatus is the same as that of FIG. 1 except that the substrate 1 is supplied from a supply device (not shown) (from the left in the drawing). . In FIG. 4, as in FIG. 3, the ultraviolet irradiation lamp 6 is provided on the rotary drum 3 and the base material 1 is supplied from below. 3 is different from FIG. 3 in that a pre-polymerization device 9 is provided between the coating device 2 and the water tank 4, and the ultraviolet light emitted from the ultraviolet lamp 61 passes through the wall 53 of Pyrex glass to cause photopolymerization. The composition layer is irradiated, and the inside of the prepolymerization chamber 9 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 substrate 1 by the coating apparatus 2, the ultraviolet rays emitted from the ultraviolet lamp 6 in the prepolymerization apparatus 9 are used. A part of the photopolymerizable composition is polymerized. in this way,
The base material 1 provided with the partially polymerized photopolymerizable composition layer enters the photopolymerization chamber 5 along the outer periphery 32 of the rotary drum 3 through the water-sealed inlet. After that, an adhesive tape is manufactured by the same method as in FIG. The apparatus shown in FIG. 5 is equivalent to the rotary drum 3 in FIG.
Is a device in which the belt 33 is hung between the rolls 31 and 32. The method for producing an adhesive tape using this apparatus is the first one except that the substrate 1 supplied from a supply device (not shown) (from the right in the figure) is run along the outer circumference of the belt 33.
The adhesive tape is manufactured in the same manner as the figure. As described above, when the base material 1 provided with the photopolymerizable composition layer is operated along the belt 33 wound around the rolls 31 and 32, it is easy to increase the operation distance, and therefore the operation speed Can be faster and productivity will increase. The apparatus shown in FIG. 6 is provided with a prepolymerization apparatus 9 between the coating apparatus 2 and the water tank 4 of the apparatus shown in FIG. 5, and the ultraviolet rays emitted from the ultraviolet lamp 61 are Pyrex glass. Irradiating the photopolymerizable composition layer through the wall 53,
And, except that the inside of this prepolymerization apparatus 9 is filled with nitrogen gas, it is the same as the apparatus shown in FIG. 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 coating apparatus 2, the ultraviolet rays emitted from the ultraviolet lamp 61 in the prepolymerization apparatus 9 are used. A part of the photopolymerizable composition is polymerized. in this way,
It is shown in FIG. 5 except that the substrate 1 provided with the partially polymerized photopolymerizable composition layer enters the photopolymerization chamber 5 along the outer periphery of the belt 33 from the water-sealed inlet. It is manufactured by the same method. The device shown in FIG. 7 corresponds to the rotary drum 3 in FIG.
Instead of this, the belt 33 is placed between the rolls 31 and 32. In the method of manufacturing an adhesive tape using this apparatus, the base material 1 supplied from a supply device (not shown) (from the right in the drawing) runs along the outer circumference of the belt 33. After that, the adhesive tape is manufactured by the same method as in FIG. In this way, when the base material 1 provided with the photopolymerizable composition layer is operated along the belt wound around the rolls 31 and 32, it is easy to increase the operation distance, and thus the operation speed is increased. It can be faster and more productive. The apparatus shown in FIG. 8 is provided with a prepolymerization chamber 9 between the coating apparatus 2 and the water tank 4 of the apparatus shown in FIG. 7, and the ultraviolet rays emitted from the ultraviolet lamp 61 are Pyrex glass. Irradiating the photopolymerizable composition layer through the wall 53,
And, except that the inside of this prepolymerization chamber 9 is filled with nitrogen gas, it is the same as the device shown in FIG. A method for producing an adhesive tape using this apparatus is as follows: UV light emitted from an ultraviolet lamp 61 in the prepolymerization chamber 9 after the photopolymerizable composition is applied to the substrate 1 by the application apparatus 2. Then, a part of the photopolymerizable composition is polymerized. in this way,
The base material 1 provided with the partially polymerized photopolymerizable composition layer enters the photopolymerization chamber 5 along the outer periphery of the belt 33 from the water-sealed inlet. After that, the adhesive tape is manufactured by the same method as shown in FIG.

【The invention's effect】

In the present invention, the photopolymerization chamber is sealed with water at the inlet and outlet,
Others are almost completely sealed and closed rooms,
Even if an inert gas is put into this, it does not leak at all, or even if it leaks, the amount is very small, the consumption of the inert gas is extremely small, and the cost can be greatly saved. Further, as described above, since the inert gas is not replenished into the photopolymerization chamber or only a very small amount thereof is replenished, an air flow due to the introduction of the inert gas is not generated, and therefore the evaporation of the monomer in the photopolymerizable composition is prevented. In addition, the performance of the adhesive does not deteriorate.

[Brief description of drawings]

FIG. 1 is an explanatory view showing one embodiment of the present invention, and FIG. 2 is an explanatory view showing another embodiment. 3 to 8 are explanatory views showing other embodiments of the present invention. 1 ... Substrate 2 ... Coating device 3 ... Rotating drum 4 ... Water tank 5 ... Light-transmissive window (Pyrex glass window) 6 ... UV lamp

Claims (1)

[Claims] 1. A pressure-sensitive adhesive tape or sheet comprising a photopolymerizable composition layer provided on one surface of a substrate, which is passed through a photopolymerization chamber while being irradiated with light to polymerize the photopolymerizable composition on the substrate. In the production method of, the photopolymerization chamber is a chamber in which the inlet and the outlet of the substrate provided with the photopolymerizable composition layer are water-sealed, and the entire photopolymerization chamber is closed. The chamber is filled with an inert gas, and the substrate on which the photopolymerizable composition layer is provided is the photopolymerization chamber while passing through the photopolymerization chamber. A method for producing an adhesive tape or sheet, which comprises irradiating a functional composition layer with light to polymerize the photopolymerizable composition on a substrate.