JPH05269880A - Production of releasable material - Google Patents

Abstract

PURPOSE:To obtain a releasable material having excellent releasability and not lowering the self-adhesiveness of a self-adhesive without requiring a large- scale apparatus by kneading a releasable compd. with a thermoplastic resin and crosslinking and curing the resulting kneaded mixture by the irradiation with radiation. CONSTITUTION:A thermoplastic resin compsn. 4 containing a releasable compd. is charged in a hopper 2 and heated and melted in an extruder 1 to be extruded from a T-die 3 to form an extrusion film 5. A base material 7 is delivered from a base material supply roll 6 and the film extruded from the T-die 3 is bonded to the base material 7 by a press bonding roll 10 to form a laminate 11. A radiation permeable film 9 is supplied to the upper surface of the T-die film of the laminate from a radiation permeable film supply roll 8 to be bonded thereto by a separate press bonding roll 12 to obtain a laminate 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a container for food and drink or an adhesive container for paints, a release paper for an adhesive label, a base surface of office supplies, or an adhesive tape for packaging. The present invention relates to a method for producing a releasable base material used for an adhesive material that can be used when imparting releasability to the back surface of the.

[0002]

2. Description of the Related Art With the development of adhesive materials in recent years, adhesive labels and sheets, which have been mainly used in the field of office supplies, have expanded their fields of use, and are used in electric equipment, automobiles, building materials,
Products that use adhesive properties in a wide range of areas such as packaging and transportation have made a major advance. These adhesives, adhesive labels, adhesive sheets, adhesive tapes, etc. cannot be handled by themselves such as storage and transportation, and should be handled together with release paper or release base material to prevent adhesion to other things. Is required. This release paper or release substrate must be an emulsion or solvent solution of a condensation-type or addition-type silicone release agent directly on a substrate such as a plastic film or paper or a substrate laminated with polyolefin in order to develop release properties. Is applied by a roll coater or the like, and is dried and crosslinked in a hot air oven to produce.

However, in the step of applying the above silicone-based release agent to the substrate and further heat-treating, not only the heat treatment apparatus becomes large-scale, but also the temperature required for curing the silicone-based release agent is increased. It was relatively expensive and therefore the substrates used were also limited to those that were heat resistant. In addition, since a solvent such as toluene is used when applying the above silicone-based release agent, a large amount of equipment cost and energy are required to recover the solvent.

In this case, it is conceivable to omit the large-scale heat treatment step of the release agent by mixing the silicone release agent with the thermoplastic resin, but these methods are required as release paper or release sheet. In addition to not exhibiting sufficient releasability, the release agent bleeds to the surface of the base material simply by mixing with a thermoplastic resin and migrates to the adhesive layer of labels, sheets, tapes, etc. There is a fatal defect that causes it.

As a means for solving such a problem, a radiation-curable reactive organopolysiloxane is mixed with a resin and molded by a melt (extrusion) lamination and inflation method, followed by irradiation with radiation to fix a release agent. There is a proposal of a method of converting to the same (JP-A-57-187221).
JP-A-62-85930).

Further, the inventors of the present invention first molded a composition obtained by mixing a olefin-based thermoplastic resin with dimethylpolysiloxane, a polyfunctional compound and an antioxidant, and then subjected it to electron beam irradiation to release the peelable material. Have been proposed.

However, the radiation-curable reactive organopolysiloxanes, dimethylpolysiloxanes and other compounds used in the above-mentioned methods, which exhibit releasability by being cross-linked and cured by irradiation with radiation, are not suitable for irradiation with electron beams. However, in order to increase the molding speed, a very large amount of nitrogen is required, which not only greatly affects the manufacturing cost, but also significantly deteriorates the working environment at the manufacturing site.

[0008]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention The present inventors have found the problems of the above-mentioned conventional methods and a thermoplastic resin composition containing a compound having a composition capable of exhibiting releasability upon irradiation with radiation and a thermoplastic resin. Taking into consideration the problems in the method of manufacturing peelable materials by molding and irradiating with radiation, we have earnestly studied to obtain an inexpensive peelable material that does not require complicated steps and eliminates the conventional problems. As a result, we succeeded in developing a peelable material that does not require a large-scale device, has excellent peeling performance, and does not reduce the tackiness of the pressure-sensitive adhesive.

[0009]

The present invention comprises a compound having a composition capable of exhibiting releasability by being crosslinked / cured by irradiation with radiation (referred to as a releasable compound in the present invention) and a thermoplastic resin (Resin A). A thermoplastic resin composition containing (composition A) is extruded into a film, and one side of the thermoplastic resin composition is laminated with a base material by a pressure bonding roll to form a base material / composition A laminate. A radiation-transmissive film is laminated on the composition A layer side of the laminate using a pressure roll of (1) to form a laminate of substrate / composition A / radiation transparent film, and then the radiation transmission of the laminate is performed. The method for producing a peelable material, which comprises radiating radiation from the side of the transparent film to crosslink and cure the peelable compound contained in the composition A layer, and peeling the radiation transparent film from the laminate. Eye We were able to achieve.

In the present invention, the composition A mainly comprises a peelable compound and a thermoplastic resin (resin A). The releasable compound may be one that exhibits releasability as a result of indirect interaction with the pressure-sensitive adhesive. For example, a polymerizable organopolymer having a mercapto group, a vinyl group, an acryloyl group, a methacryloyl group, or the like. A polysiloxane or a composition obtained by adding a polyfunctional compound to the polysiloxane as necessary,
Alternatively, there is a composition of dimethylpolysiloxane and a polyfunctional compound, and a composition in which an antioxidant is added to and mixed with a thermoplastic resin can be used.

The thermoplastic resin (resin A) mixed with this peelable compound may vary depending on the conditions of use, but in general, low density polyethylene, medium density polyethylene, high density polyethylene, and a small amount of ethylene. Copolymers with other α-olefins, polypropylene, random or block copolymers of propylene with small amounts of other α-olefins, ethylene and vinyl acetate, vinyl chloride, (meth) acrylic acid, (meth) acrylic Copolymer with acid ester, etc., α, β-unsaturated carboxylic acid ester, copolymer with α, β-unsaturated carboxylic acid anhydride, etc.,
Examples thereof include polyvinyl chloride, polyamide, polyester, and mixtures thereof. In particular, copolymers with low density polyethylene, ethylene-vinyl acetate copolymer, ethylene / α, β-unsaturated carboxylic acid ester / α, β-unsaturated carboxylic acid anhydride, etc. are relatively expensive in terms of cost and performance. It is highly effective.

As the other thermoplastic resin (resin B) sandwiched between the composition A and the base material, a thermoplastic resin to which the above-mentioned organopolysiloxane, dimethylpolysiloxane or the like is not added is used. it can.

For example, as resin B, low density polyethylene, medium density polyethylene, high density polyethylene, copolymer of ethylene and a small amount of other α-olefin, polypropylene, random of propylene and a small amount of other α-olefin. Alternatively, a block copolymer, a copolymer of ethylene and a vinyl ester, an α, β-unsaturated carboxylic acid ester, an α, β-unsaturated carboxylic acid anhydride, or the like, or a mixture thereof can be used, but particularly low density Polyethylene and ethylene-vinyl acetate copolymer are preferred.

The thermoplastic resin (resin A) and the other thermoplastic resin (resin B) used in the composition A may contain an antioxidant, a coloring inhibitor or the like which are usually used. Although the thickness varies depending on the use, it is usually about 5 to 20 μm.

As a film which transmits radiation, a film made of an aromatic polyester resin such as poly (ethylene terephthalate) or poly (butylene terephthalate) has a high resistance to deterioration by radiation and can be repeatedly used. In particular, a film made of polyethylene terephthalate is transparent. It is preferable because it is easy to use because of its rigidity. The thickness is not particularly limited, but a readily available material having a thickness of about 20 to 50 μm can be used.

The base material to be laminated with the thermoplastic resin composition (composition A) or another thermoplastic resin (resin B) depends on the intended use, but is not limited to kraft paper, high-quality paper, polyethylene, polypropylene, Synthetic resin films such as polyethylene terephthalate and polyamide, or laminated films of these and papers, non-woven fabrics, woven fabrics and the like can be used.

The composition A is laminated on a substrate by a roll while being extruded into a film by an extruder. In this case, in order to improve the radiation irradiation yield, it is possible to set the roll in contact with the composition A at a temperature close to the melting point of the resin A used in the composition A.

The composition A is extruded in the form of a film by an extruder to be laminated on a base material, and the composition A is sent to a pressure-bonding roll arranged in front of a radiation irradiation device. In this case, another extruder is used between the composition A and the base material for the purpose of improving the adhesive strength with the base material, reinforcing the strength of the laminate, and reducing the thickness of the composition A. It is also possible to stack B while extruding at the same time.

The set temperature of the pressure bonding roll can be selected within a wide range depending on the purpose, but the composition A to be used is
It is possible to use a pressure-bonding roll having a melting point of the resin A used for the above, or a temperature close to that of the thermoplastic resin having a lower melting point when the resin B is used, for example, 10 to 20 ° C. lower than the melting point. It is preferable for improving the quantum yield.

Further, both the roll used for adhering the substrate and the composition A and the pressure-bonding roll arranged in front of the radiation irradiator are used for the composition A and the resin B, respectively. By setting the temperature close to the melting point, the quantum efficiency of radiation irradiation can be further improved.

The laminate thus pressure-bonded by the pressure-bonding roll is subsequently sent to the radiation processing apparatus. In this case, the laminate is inserted so that the radiation transparent film side faces the radiation source. As a method of performing the radiation treatment, electron beam, X-ray, γ-ray and the like can be used, but electron beam is preferable.

The irradiation dose can be varied within a wide range depending on the required performance of the object to be irradiated. Generally, 2
It is 0 megarad or less, and preferably 3 to 10 megarad.
When the irradiation dose exceeds 20 megarads, not only the mechanical properties of the matrix are significantly deteriorated and the practicality is lost, but also the number of times of repeated use of the radiation transmitting film is significantly reduced.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of an apparatus for producing a peelable material used for carrying out the present invention. In the figure, 1 is an extruder equipped with a hopper 2 and a T die 3. A thermoplastic resin composition (composition A) 4 having the above-mentioned peelable compound is put into the hopper 2, and is heated and melted in the extruder 1 and then extruded from the T die 3 to form an extruded film 5. It Reference numeral 6 denotes a base material supply roll in which the base material 7 is wound, the base material 7 is fed from the roll 6, and the extruded film of the composition A from the T die 3 is adhered by the pressure bonding roll 10.
It becomes the laminated body 11. Reference numeral 8 denotes a radiation-transmissive film supply roll around which the radiation-transmissive film 9 is wound.
Separate pressure roll 12 supplied from the top of the die film
It is pressure-bonded by and becomes the laminated body 13.

At this time, the temperature of the pressure-bonding roll 10 for bonding the T-die film and the substrate and another pressure-bonding roll 12 for pressure-bonding the radiation transmissive film 9 and the laminate 11 is close to the melting point of the thermoplastic resin used. When set to, it is effective in promoting crosslinking and curing of the peelable compound.

Next, the laminate 13 travels in the direction of the arrow and passes through the radiation irradiator 14 to obtain a laminate 15 irradiated with radiation. The used radiation transparent film 16 is peeled off from the laminate 15 and wound by a used radiation irradiation film winding roll 17. Further, the peelable material 18 from which the used radiation transparent film has been peeled off from the laminate is wound up on the peelable material winding roll 19.

FIG. 2 shows another apparatus for producing a peelable material used in the practice of the present invention, which includes two extruders 1a and 1b.
A peelable material is manufactured by a coextrusion lamination method using a single extruder.

To one extruder, a thermoplastic resin composition (composition A) containing a compound having a composition capable of exhibiting peelability upon irradiation with radiation and a thermoplastic resin was charged, and the remaining one extruder was charged. Another thermoplastic resin composition (resin B) is charged into the extruder. The heated melt of the composition A and the resin B from the two extruders is arranged so that the resin B is in contact with the base material 7 side to form the laminate 11, and the composition A is further in contact with the radiation transmissive film. Thus, the laminate 13 is obtained.

[0028]

In the present invention, the radiation-transmissive film / composition A (or composition A / resin B) / substrate laminate is irradiated with radiation from the side of the radiation-transmissive film to prepare the composition A. Is a method of producing a peelable material by cross-linking and curing the peelable compound blended in the above, and then peeling the radiation transparent film from this laminate.

At the time of this irradiation, the laminate is passed through a nitrogen atmosphere to crosslink and cure the peelable compound, but the laminate must be passed through the irradiation device at a high speed in order to improve productivity. Therefore, the chances of bringing air into the system increase, so the amount of nitrogen used increases.

In the present invention, even in such a case, since the composition A is covered with the radiation permeable film (the substrate on the opposite side) at a high temperature, there is very little opportunity for oxygen to intervene. The crosslinking / curing reaction proceeds smoothly, and the amount of nitrogen used to maintain the atmosphere is completely unnecessary, or even when it is necessary, the amount can be greatly reduced and high radiation quantum efficiency is achieved. Can be maintained.

[0031]

EXAMPLES The present invention will be specifically described with reference to Examples and Comparative Examples. Peel strength, residual adhesiveness, and stability of samples prepared under various conditions in Examples and Comparative Examples were measured. The peel strength and the residual adhesiveness were measured as follows.

(A) Peel strength BPS8170 (manufactured by Toyo Ink Co., Ltd.) was used as an adhesive on the laminate surface of the sample prepared by the method of the present invention in an amount of 25 μm.
m, and dried at 100 ° C. for 3 minutes, and then a PET film (38 μm) as a surface base material was attached by a rubber roll. Then, a load of 20 g / cm ² was applied to the above-mentioned adhesive-coated sample, allowed to stand at 23 ° C. for a predetermined time (one day, one week, one month), and then cut into a width of 50 mm, using a tensile tester. , Pulling speed 0.3m / min, pulling angle 180
The force required for peeling was measured under the condition of °, and this was taken as the peel strength.

(B) Residual Adhesion Rate As a standard tape, neocraft tape (manufactured by Lintec Co., Ltd.) was attached to the laminated surface of the sample prepared by the method of the present invention, and a tape roller having a weight of 2 kg was reciprocated once. It was Next, a load of 20 g / cm ² was applied to the tape, left at 70 ° C. for 20 hours, and then cooled to 23 ° C. (3 hours). This tape was peeled from the sample, adhered to a stainless steel plate # 280, and reciprocated once with a 2 kg tape roller. Next, a load of 20 g / cm ² is applied to the tape,
After leaving it in an atmosphere of 23 ° C. for 3 hours, the tape was peeled off from the stainless plate, and the force required for this was measured. On the other hand, the standard tape that was not attached to the sample was attached to the stainless steel plate in the same manner as above, peeled off from the stainless steel plate under the same conditions, and the force required for this was measured. The former peel strength was expressed as a percentage with respect to the latter peel strength, and this was taken as the residual adhesiveness.

Example 1 Composition A has an MFR of 12
g / 10min, high density low density polyethylene with a density of 0.916g / cm ³ and viscosity at 25 ° C of 30,000
10% by weight of dimethylpolysiloxane having CS (centistokes) blocked at both ends with trimethylsilyl groups (hereinafter,%
), Triallyl isocyanurate (hereinafter TAI
C) 2% and octadecyl 3- (3,5-di-t
-Butyl-4-hydroxyphenyl) propionate was mixed with 0.10% of the resin composition on kraft paper laminated with low-density polyethylene (LD) as a substrate.
The resin temperature was 290 ° C. and the laminate thickness was 20 μm. Next, the PET film (38
μm) to a pressure roll installed immediately before the electron beam irradiation device to form a 4-layer laminate of PET film / composition A / LD / kraft paper, and subsequently under air atmosphere, line speed 50 m / min, After irradiating with an electron beam at an irradiation dose of 5 Mrad after passing through the PET film, the PET film was peeled off to obtain a releasable material, and the characteristics of the releasable material were measured.

(Example 2) MFR is 12 g / 10 mi.
n, a density of 0.916 g / cm ³ of LD-A, a mercapto group-containing dimethylpolysiloxane having a viscosity at 25 ° C. of 10,000 CS of 10%, octadecyl 3-
(3,5-di-t-butyl-4-hydroxyphenyl)
A sample was prepared in the same manner as in Example 1 except that 0.10% of propionate was added, and each measurement was performed.

Example 3 In Example 2, 7% of dimethylpolysiloxane containing a vinyl group having a viscosity of 10000 CS at 25 ° C. and a viscosity of 10000 C were used.
A sample was prepared and each measurement was performed in the same manner as in Example 2 except that 3% of dimethylpolysiloxane containing S mercapto group was added.

(Example 4) MFR was 12 g / 10 mi.
n, LD-A having a density of 0.916 g / cm ³ and 7% of dimethylpolysiloxane containing a vinyl group having a viscosity of 10000 CS at 25 ° C. and a viscosity of 10000 C.
3% dimethylpolysiloxane containing a mercapto group of S, octadecyl 3- (3,5-di-t-butyl-4)
-Hydroxyphenyl) propionate mixed with 0.10% of resin composition to Kraft paper together with high pressure low density polyethylene (hereinafter referred to as LD-B) with MFR of 8 g / 10 min and density of 0.917 g / cm ^3. The resin composition was coextruded at a temperature of 270 ° C., the temperature of LD-B was 290 ° C., and the lamination thickness was 10 μm for resin composition A and 20 μm for LD-B. Next, the PET film (38 μm) was supplied from the sand feeding machine to a pressure roll installed immediately before the electron beam irradiation device to form a 4-layer laminate of PET / resin composition / LD-B / kraft paper, and After irradiation with an electron beam in an air atmosphere at a line speed of 50 m / min and an irradiation dose of 5 Mrad after passing through the PET film, the characteristics of the release material of the sample from which the PET film was peeled off were measured.

Comparative Example 1 In Example 4, the PET film was not supplied from the sand feeding machine, and the pressure-sensitive adhesive roll installed immediately before the electron beam irradiation device was not used, but the resin composition / LD-B / A sample was prepared and each measurement was performed in the same manner as in Example 4 except that a three-layer laminate of kraft paper was molded.

Comparative Example 2 A sample was prepared in the same manner as in Comparative Example 1 except that the electron beam irradiation was not carried out, and each measurement was carried out.

(Comparative Example 3) A sample was prepared in the same manner as in Example 4 except that the electron beam irradiation was not performed, and each measurement was carried out. The measurement results of Examples 1 to 4 and Comparative Examples 1 to 3 are collectively shown in Table 1.

[0041]

[Table 1]

[0042]

EFFECTS OF THE INVENTION Since the method for producing a peelable material of the present invention is a type in which a peelable compound is kneaded into a thermoplastic resin and crosslinked and cured by irradiation with radiation, a conventional emulsion or organic solvent solution for a substrate is used. Since a large-scale application of a type silicone release agent, a dry crosslinking device, or a solvent recovery device associated therewith is not required, the equipment can be made small and the investment can be reduced. Further, it is easy to adjust the peeling performance that is exhibited by changing the composition of the composition A. In addition, since both sides of the composition A are formed as a laminate sandwiched between the radiation transmissive film and the substrate, the opportunity for oxygen to intervene is eliminated, and the amount of nitrogen used is completely eliminated or minimized, and the production speed is increased. be able to.
This can increase productivity and is very useful. Furthermore, the radiation irradiation temperature of the laminate can be kept high by pressure-bonding the laminate and / or the laminate with a roll and / or a pressure roll set to a temperature close to the melting point of the thermoplastic resin, and the peelability can be improved. It is possible to promote the bleeding of the compound to be expressed to the surface of which the peeling property is expressed, and to significantly increase the irradiation efficiency of radiation. This is very useful because it can save the irradiation energy required for exhibiting peelability.

[Brief description of drawings]

FIG. 1 is a schematic side view showing an example of a peelable material manufacturing apparatus used for carrying out a manufacturing method of the present invention.

FIG. 2 is a schematic side view showing another example of an apparatus for producing a peelable material used for carrying out the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Extruder 2 Hopper 3 T die 4 Raw material 5 Extrusion film 6 Base material supply roll 7 Base material 8 Radiation permeable film supply roll 9 Radiation permeable film 10 Pressure bonding roll 11 Laminated product [Composition A / (Resin B) / group Material] 12 Separate pressure-bonding roll 13 Laminated product [Radiation transparent film / Composition A / (Resin B) / Substrate] 14 Radiation irradiation device 15 Laminate irradiated with radiation 16 Used radiation transparent film 17 Used radiation Irradiation film take-up roll 18 Peelable material 19 Peelable material take-up roll

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C08J 3/28 CFH 9268-4F

Claims (9)

[Claims] 1. A thermoplastic resin composition (composition A) containing a compound having a composition exhibiting releasability by being crosslinked / cured by irradiation with radiation and a thermoplastic resin (resin A) is extruded into a film. After laminating the base material / composition A on one side with a pressure-bonding roll to form a laminate of the substrate / composition A, a radiation-permeable film is formed by using another pressure-bonding roll immediately before irradiation with the composition of the laminate. Laminating on the layer A side to form a laminate of substrate / composition A / radiation transparent film, and then irradiating radiation from the side of the radiation transparent film of the laminate, and the releasability contained in the composition A layer. A method for producing a peelable material, which comprises cross-linking and curing a compound and peeling the radiation transparent film from the laminate. 2. A thermoplastic resin composition (composition A) containing a compound having a composition exhibiting releasability by being crosslinked / cured by irradiation with radiation and a thermoplastic resin (resin A) is extruded into a film. After the pressure-sensitive adhesive roll set to a temperature close to the melting point of the resin A is laminated on the one surface with the base material to form a laminate of the base material / composition A, immediately before the irradiation of radiation, radiation is applied using another pressure-sensitive adhesive roll. A transparent film is laminated on the composition A layer side of the laminate to form a substrate / composition A /
A laminate of a radiation transparent film is formed, and radiation is applied from the radiation transparent film side of the laminate to crosslink and cure the peelable compound contained in the composition A layer, and the radiation transparent film is laminated. A method for producing a peelable material, which comprises peeling from a material. 3. A thermoplastic resin composition (composition A) containing a compound having a composition exhibiting releasability by being crosslinked / cured by irradiation with radiation and a thermoplastic resin (resin A) is extruded into a film. After forming a laminate of the substrate / composition A by laminating one surface of the substrate with a substrate by a pressure roll, immediately before irradiation with radiation, another pressure roll set to a temperature close to the melting point of the thermoplastic resin is used. A film that transmits radiation is laminated on the composition A layer side of the laminate to form a laminate of substrate / composition A / radiation transparent film, and the laminate is irradiated with radiation from the radiation transparent film side. Then, the peelable compound contained in the composition A layer is crosslinked and cured, and the radiation transmissive film is peeled off from the laminate. 4. A thermoplastic resin composition (composition A) containing a compound having a composition exhibiting releasability by being crosslinked / cured by irradiation with radiation and a thermoplastic resin (resin A) is extruded into a film. , One side of which is laminated with a base material by a pressure-bonding roll set to a temperature close to the melting point of the thermoplastic resin to form a base material / composition A laminate, and immediately before irradiation with radiation, close to the melting point of the thermoplastic resin A radiation-transmissive film is laminated on the composition A layer side of the laminate using another pressure roll set to a temperature to form a laminate of substrate / composition A / radiation transparent film, and the laminate Radiation is applied from the side of the radiation-transparent film of the product to crosslink and cure the peelable compound contained in the composition A layer, and the radiation-permeable film is peeled from the laminate to produce a peelable material. Method. 5. A thermoplastic resin composition (composition A) containing a compound exhibiting releasability by being crosslinked / cured by irradiation with radiation and a thermoplastic resin (composition A) and a base material, etc. The method for producing a peelable material according to claim 1, wherein the laminate is formed by sandwiching the thermoplastic resin B. 6. The production method according to claim 1, 2, 3, or 4, wherein the thermoplastic resins A and B are polyolefin resins. 7. The manufacturing method according to claim 1, wherein the irradiation radiation is an electron beam, an X-ray, or a γ-ray. 8. The method according to claim 1, wherein the radiation transparent film is made of an aromatic polyester resin. 9. The method according to claim 1, wherein the radiation dose is 20 megarads or less.