JPH0912985A - Mold release material sheet and mold release sheet - Google Patents

Abstract

PURPOSE: To obtain a mold release material sheet, comprising a specific polyolefin (co)polymer, producible by removing a solvent, excellent in mold releasability and nonmigrating properties and hardly causing the fall of the load from a truck even when stacking packaged materials packaged with corrugate boards in many stages at the time of storing thereof, etc. CONSTITUTION: This mold release material sheet is obtained by forming a layer, comprising a polyolefin (co)polymer, prepared by (co)polymerizing a 6-30C olefin such as 1-hexene and having >=100 average degree of polymerization and <=3 molecular weight distribution and having the mold releasability (having preferably 0.1-1000μm thickness) on a substrate such as woodfree paper.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a release material sheet and a release sheet.

[0002]

2. Description of the Related Art A pressure sensitive adhesive tape or pressure sensitive adhesive sheet is provided with a protective sheet for protecting the pressure sensitive adhesive surface thereof until it is finally used. Since the protective sheet must be finally peeled off, the adhesive force between the adhesive surface and the protective sheet must be light. In order to achieve this, the protective sheet is provided with a releasable layer using a release agent on the surface in contact with the pressure-sensitive adhesive, and most products that are stored by winding like an adhesive tape are Instead of using a separate material as a protective sheet, a releasable layer is provided by using a release agent on the opposite surface (back surface) of the adhesive tape or the base material of the adhesive sheet on which the adhesive layer is provided. ing. The back surface of the pressure-sensitive adhesive tape or sheet is subjected to a release treatment, including the base material, and the protective sheet is usually referred to as a release sheet.

The release agent used in the release sheet includes
In addition to the releasability that reduces the peeling force when peeling the release sheet from the adhesive layer, the release agent layer does not cause cohesive failure to contaminate the adhesive and adversely affect the adhesiveness. Performance called migration is also required. As an example of the release agent having the above performance, a silicone-based release agent made of polyorganosiloxane, a release agent made of a substance such as a long-chain alkyl modified polyvinyl alcohol and a long-chain alkyl modified polyethyleneimine, and the like, Organic release agents are used. These release agents are used in the form of being applied on a substrate as a solution dissolved in an organic solvent and then dried to form a release layer.

However, in recent years, due to safety or environmental problems, a method of forming a releasable layer which does not use an organic solvent when producing a release sheet, that is, a so-called solvent-free method has been demanded. As an attempt to eliminate the solvent, for example, Japanese Patent Publication No. 57-4578.
No. 9 discloses a pressure-sensitive adhesive tape or adhesive sheet having a release layer, wherein the release layer in contact with the adhesive layer has a thickness of 1 μm or more and a shear modulus of 2.0 × 10 ⁸ according to JIS K 7213 test. dyne / cm ² or less, and the surface wetting property is 55 ° or more (equal to 20 ± 1 ° C., 65 ± 5% RH measurement conditions) in equilibrium contact angle with respect to a surface tension 50 dyne / cm standard solution used for JIS K-6768 test. Lower) and a density of 0.80 to 0.90 g / c
m ³ , the embrittlement temperature of -7 according to ASTM D 746 test
0 ° C or less, melting point 80 ° C or less by differential thermal analysis, JIS
K6301 hardness of 70 or less ethylene-propylene copolymer and / or ethylene-1-butene consisting of an elastomer containing a random copolymer as a main component, and the adhesive layer contains a polyacrylate ester as a main component A pressure-sensitive adhesive tape or adhesive sheet consisting of

Further, in Japanese Patent Publication No. 1-36877, an adhesive comprising a support having a release layer on one surface and a pressure-sensitive adhesive layer containing natural rubber and / or synthetic rubber as a main component on the other surface. A tape or an adhesive sheet, wherein the main component of the release layer is a composition containing a tack-reducing compound consisting of an ethylene-α-olefin copolymer, a reinforcing polymer and a fatty acid amide as a main component. A sheet is disclosed.

However, the release performance of the release sheet disclosed in any of the above publications is, as evaluated with respect to the adhesive tape or the adhesive sheet obtained in each example, the above-mentioned conventional polyorganosiloxane. For release performance of release sheet using organic release agent such as silicone release agent, long-chain alkyl modified polyvinyl alcohol, long-chain alkyl modified polyethyleneimine, etc. In comparison, the degree is extremely low, and the non-migration property is not sufficient, which limits the field of use.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above facts, and an object thereof is to make it solvent-free at the time of its production, to have releasability and non-migration property. Another object of the present invention is to provide a release material sheet and a release sheet having excellent release performance such as.

[0008]

The present invention according to claim 1 is characterized by comprising a polyolefin (co) polymer obtained by (co) polymerizing an olefin having 6 to 30 carbon atoms. Sheet,

According to the second aspect of the present invention, a layer having releasability made of a polyolefin (co) polymer obtained by (co) polymerizing an olefin having 6 to 30 carbon atoms is provided on a substrate. The release sheet is characterized in that

The above-mentioned olefin having 6 to 30 carbon atoms is
Alkenes with 6 to 30 carbon atoms having one double bond in the molecule, such as 1-hexene, 2-hexene, 4-methyl-1-pentene, 1-octene, 1-dodecene, 1 -Octadecene, 1-docosene and the like can be mentioned. Of these, α-olefins having a double bond at the α-position are preferably used because they are easy to polymerize. When the number of carbon atoms is less than 6, a sufficient releasing effect cannot be obtained, and the alkenes having the number of carbon atoms of more than 30 are difficult to obtain.

The polyolefin (co) polymer obtained by (co) polymerizing the above olefin having 6 to 30 carbon atoms is a polymer obtained by independently polymerizing the above olefin having 6 to 30 carbon atoms. It may be present, or it may be a polymer obtained by copolymerizing two or more kinds of the above-mentioned olefins, and it is mainly composed of the above-mentioned olefin having 6 to 30 carbon atoms and can be copolymerized therewith. It may be a polymer obtained by copolymerizing with another compound.

Other compounds that can be copolymerized with the olefin having 6 to 30 carbon atoms are, for example, ethylene, propylene, 1-butene, 2-butene, 1-pentene and 3-.
An olefin having 5 or less carbon atoms such as methyl-1-butene,
Unsaturated carboxylic acids such as (meth) acrylic acid, crotonic acid, maleic acid (anhydride), fumaric acid, itaconic acid, styrene, o-methylstyrene, m-methylstyrene, p
-Methyl styrene, α-methyl styrene, p-ethyl styrene, 2,4-dimethyl styrene, pn-hexyl styrene, pn-octyl styrene, p-methoxy styrene, p-phenyl styrene, 3,4 dimethyl chloro Styrene and its derivatives such as styrene, vinylnaphthalenes such as α-vinylnaphthalene, vinyl halides such as vinyl chloride, vinyl bromide and vinyl fluoride, vinyl acetates such as vinyl acetate, vinyl propionate and vinyl butyrate,
Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, (meth)
N-octyl acrylate, lauryl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth)
2-chloroethyl acrylate, α-chloro (meth) acrylate, phenyl (meth) acrylate, (meth)
(Meth) acrylic acid ester such as dimethylaminoethyl acrylate, dicyclopentanyl (meth) acrylate, isobornyl (meth) acrylate, benzyl (meth) acrylate, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, Examples thereof include vinyl ketones such as vinyl methyl ketone and vinyl ethyl ketone, N-vinyl compounds such as N-vinyl pyrrole and N-vinyl indole, (meth) acrylonitrile, and (meth) acrylic acid amides.

The copolymerization ratio of the other compound capable of copolymerizing with the olefin having 6 to 30 carbon atoms to the olefin having 6 to 30 carbon atoms is less than 50 mol%, preferably 3 mole%.
When it is less than 0 mol% and the copolymerization ratio is 50 mol% or more, the releasing performance is deteriorated.

The means for (co) polymerizing the olefin having 6 to 30 carbon atoms to obtain a polyolefin (co) polymer is not particularly limited, but for example, "polymer"
Volume 43, August (1994) pp. 534-538
If you select a polymerization method using a metallocene catalyst introduced on the page, you can easily control various items such as molecular weight (polymerization degree), molecular weight distribution, tacticity, random / block polymerizability of the obtained (co) polymer. can do.

The above (co) polymer has an average degree of polymerization of 100.
As described above, the molecular weight distribution is 3 or less, or the melting point is 40.
It is preferable that the composition does not contain a low molecular weight component having a temperature of ℃ or less. If it deviates from the above range, the release property of the obtained release material sheet or the release sheet, in particular, the non-migration property is lowered,
It deteriorates the adhesive properties of the adhesive layer.

The release material sheet of the present invention according to claim 1 is
It is composed of a polyolefin (co) polymer obtained by (co) polymerizing the above olefin having 6 to 30 carbon atoms, and the sheet is temporarily attached to an adhesive layer of an adhesive tape or an adhesive sheet and is stored. It is used as a protective sheet or the like for protecting the pressure-sensitive adhesive layer.

The release sheet of the present invention according to claim 2 is a polyolefin (co) polymer obtained by (co) polymerizing the above-mentioned olefin having 6 to 30 carbon atoms on a separately prepared substrate. A protective sheet for protecting the pressure-sensitive adhesive layer during storage, which is provided by laminating layers having releasability and is temporarily adhered to the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape or pressure-sensitive adhesive sheet as in the case of the release material sheet. Used as.

The release agent sheet and the means for producing the release sheet are not particularly limited, but the release agent sheet may be, for example, on a temporary support such as a polyethylene terephthalate film surface-release treated. An organic solvent solution of the above polyolefin (co) polymer may be formed into a sheet by a solution casting method, and the above polyolefin (co) polymer may be formed into a sheet by a T-die method or an inflation method in a single layer or multiple layers. The film may be formed by melt extrusion.

Further, the release sheet is provided by laminating the release material sheet at the same time as the base material or separately on a prepared base material, and the means for producing the release sheet is as follows. Like the release material sheet, the film is formed by a solution casting method, a T-die method, or a melt extrusion method such as an inflation method. As the base material, a polyethylene film,
Plastic film such as polypropylene film, polyester film, cellophane paper, paper such as high quality paper, kraft paper, crepe paper, glassine paper, cloth, impregnated paper,
Examples include processed paper such as plastic-coated paper and composites thereof, and these are appropriately selected and used depending on the application of the pressure-sensitive adhesive tape or pressure-sensitive sheet that is the protected object.

When a release sheet is produced on the above-mentioned substrate by a solution casting method or a lamination method, the surface of the substrate is subjected to corona discharge treatment, plasma treatment, primer treatment or the like to remove the olefin having 6 to 30 carbon atoms. It is preferable to increase the adhesiveness between the release agent layer made of a polyolefin (co) polymer obtained by (co) polymerization and the substrate.

The release material sheet and release sheet can be easily produced by a single-layer or multi-layer melt extrusion method such as the T-die method or the inflation method. From the viewpoint, it is preferable to adopt this method.

The thickness of the release sheet and the release sheet is preferably about 5 to 1000 μm, and the release layer made of the polyolefin (co) polymer is laminated on the base material of the release sheet. Thickness is 0.1-1000μ
About m is preferable. If the thickness of the release sheet is less than 5 μm, the balance of releasability and the breaking strength of the sheet is poor and it becomes difficult to use.
If it is less than μm, peelability is difficult to be exhibited, and neither is preferable. It is no longer necessary to use both sheets having a thickness of more than 1000 μm, which results in high cost.

The release material sheet according to the present invention comprises a polyolefin (co) polymer obtained by (co) polymerizing an olefin having 6 to 30 carbon atoms. Not only does it exhibit solvent-free properties and exhibits excellent release and non-migration properties, but it can also be drawn on the release-treated surface with magic ink, etc. Since adhesive tape can be overlaid on the mold processing surface, sealing can be reliably performed, and the mold processing surfaces are difficult to slip and non-slip, and are packaged in a corrugated cardboard during storage. It is possible to exhibit excellent performance that cannot be obtained by a release material sheet using a conventional silicone-based release agent, such as that the load does not easily collapse even when they are stacked in multiple stages, which is practically preferable.

The release sheet of the present invention according to claim 2 has a release property made of a polyolefin (co) polymer obtained by (co) polymerizing an olefin having 6 to 30 carbon atoms on a substrate. Since it is provided with a layer having, it can be solvent-free during its production, and not only exhibits excellent performance with respect to releasability and non-migration property, but it is also drawn on the release-treated surface with magic ink or the like. Moreover, since the pressure-sensitive adhesive tape using the release sheet can be further laminated with the pressure-sensitive adhesive tape, the sealing can be surely performed, and the release-processed surfaces do not easily slip, It has a non-slip property, and it is practically preferable because it does not easily collapse even when stacking cardboard-packaged items in multiple stages such as during storage. It is possible to give properties, The release material sheet using a cone-based release agent as it is capable of exhibiting not obtained excellent performance.

[0024]

Embodiments of the present invention will be described below. (Example 1) A release material sheet having a thickness of 75 µm was prepared by melt-extruding poly (1-octene) with a T-die.

(Example 2) Poly (1-octene) having a thickness of 100 μm was formed by a melt extrusion lamination method using a T-die.
m was extruded on a kraft paper, and a layer having a releasability of 15 μm was laminated to produce a release sheet having a total thickness of 115 μm.

(Example 3) Poly (1-octadecene) having a thickness of 5 μm and polypropylene having a thickness of 100 μm were formed by a two-layer melt extrusion method using a T-die to give a total thickness of 105.
A release sheet of μm was prepared.

Example 4 A copolymer of 95 mol% of 1-octene and 5 mol% of methyl acrylate was formed to a thickness of 5 μm.
m and polyethylene were melt-extruded onto kraft paper with a thickness of 100 μm by a melt-extrusion lamination device equipped with a two-layer mold with a T-die so as to have a thickness of 15 μm, and a release sheet with a total thickness of 120 μm was produced.

(Example 5) 1-octadecene 70 mol%
And a copolymer consisting of 30 mol% of ethylene with a thickness of 15 μm
So as to obtain a release sheet having a total thickness of 115 μm by melt-extruding on a kraft paper having a thickness of 100 μm by a melt-extrusion lamination device using a T-die.

Example 6 A composition obtained by adding 5% by weight of stearic acid to a copolymer consisting of 95 mol% of 1-octene and 5 mol% of methyl acrylate has a thickness of 5 μm and polyethylene has a thickness of 15 μm. The thickness is 100μ by the melt extrusion lamination device equipped with the two-layer mold by the T-die.
m kraft paper was melt extruded to prepare a release sheet having a total thickness of 120 μm.

Comparative Example 1 A copolymer consisting of 80% by weight of ethylene and 20% by weight of 1-butene was melt extruded to a thickness of 15 μm on a kraft paper having a thickness of 100 μm by a melt extrusion lamination apparatus using a T-die, Total thickness 1
A 15 μm release sheet was prepared.

Comparative Example 2 A copolymer consisting of 80% by weight of ethylene and 20% by weight of propylene was melt-extruded to a thickness of 15 μm on a kraft paper having a thickness of 100 μm by a melt-extrusion lamination device using a T-die to obtain a total thickness. 1
A 15 μm release sheet was prepared.

(Comparative Example 3) 98% by weight of addition type silicone release agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KNS-320), platinum catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: CAT-PL-)
56) A release agent composition consisting of 2% by weight is uniformly mixed,
Using an offset gravure coater, apply onto a polyethylene surface of 100 μm-thick kraft paper laminated with corona discharge-treated 15 μm-thick polyethylene to a thickness of 0.5 μm, and at 5 ° C. at 120 ° C. It heat-processed for 2 seconds and produced the release sheet.

The performances of the release sheets obtained in Examples and Comparative Examples are as follows: releasability (developing force), non-migrating property (adhesive force residual rate), drawing property, lapability (self-back adhesive force) and The non-slip property was measured and evaluated by the method described below.
The measurement and evaluation results are shown in Table 1.

Release property (deployment force): An adhesive tape having a width of 25 mm (manufactured by Sekisui Chemical Co., Ltd., trade name: Sekisui Craft Tape # 504) conforming to JIS Z 0237 is applied to the release-treated surface of the release sheet. Stick with a pressure roller, 23 ℃
After being left for 24 hours at 180 ° C., a 180 ° peeling force was measured at a speed of 10 m / min using a high-speed peeling tester. The peeling force was shown as a developing force for evaluating releasability. The smaller the value of the deploying force, the better the releasability.

Non-migratory property (adhesive force residual rate): Adhesive having a width of 25 mm, which was affixed to the release-treated surface of the release sheet and peeled from the release-treated surface of the release sheet, as in the previous release test. The tape was adhered to a stainless steel plate according to JIS Z 0237, left at 23 ° C. for 24 hours, and then speed 30
The peeling force of 180 degrees was measured at 0 mm / min. The peeling force was divided by the 180 ° peeling force of the adhesive tape of the same type that was not attached to the release-treated surface of the release sheet, and the percentage of the value was shown as the adhesive force residual rate for evaluating non-migration property. The 180 degree peeling force of the adhesive tape of the same type not attached to the release-treated surface of the release sheet is 20
It was 10 g / 25 mm.

Drawability: On the release-treated surface of the release sheet, write a character with an oil-based ink (trade name: Magic Ink No. 500), leave it at 23 ° C. for 5 seconds, and then check whether the character is faint, bleeding, or repelling. Also, observing whether or not the ink is easily removed by rubbing with a finger, ○: There is no blur, bleeding or repellency of the characters, and the ink does not easily come off by rubbing with the finger,
X: Evaluation was made on a two-point scale, in which the characters were faint, bleeding, and cissing, and the ink was easily removed by rubbing with a finger.

Overlapping property (self-back adhesive strength): As in the front mold releasability test, it is adhered to the mold release treated surface of the mold release sheet,
The adhesive tape having a width of 25 mm peeled from the release-treated surface of the release sheet was adhered to a stainless steel plate according to JIS Z 0237, left at 23 ° C. for 24 hours, and then speed 3
The peeling force of 180 degrees was measured at 00 mm / min. The peeling force was shown as the self-backside adhesive force for evaluating the stacking property. Numerical value of self adhesiveness is 100g / 2
When it is less than 5 mm, when the same kind of adhesive tape is laminated and adhered to the back surface of the adhered adhesive tape during the actual packaging and packing work, the adhesive tape is easily peeled off, which is not practical. Incidentally, if it is too large, such as 500 to 600 g / 25 mm, it becomes difficult to unwind and develop the rolled adhesive tape. Therefore, it is preferably in the range of about 200 to 400 g / 25 mm.

Non-slipperiness: A 30 cm × 30 cm test release sheet is adhered to a plate-like body whose release-treated surface is the surface, the inclination angle of which can be arbitrarily changed, and the mold-release adhered to the plate-like body. A rectangular test piece of 5 cm × 12 cm was cut out from the same release sheet as the release sheet on the bottom surface of a weight composed of a rectangular parallelepiped having a weight of 200 g and a bottom of 5 cm × 12 cm at the center of the release-treated surface of the sheet. What is bonded so that the release processing surface of the release sheet is exposed to the outside, placed so that the release processing surfaces overlap, gradually increasing the inclination of the plate-shaped body from the horizontal position, The angle from the horizontal position where the weight slipped out was measured as a non-slippery evaluation scale. The larger the angle is, the more difficult it is to slip, and the more practically preferable, the less the load collapses even when the corrugated cardboard-packaged items are stacked in multiple stages during storage.

[0039]

[Table 1]

[0040]

EFFECT OF THE INVENTION Since the release sheet and release sheet of the present invention are constructed as described above, they can be solvent-free in the production thereof and exhibit excellent performance in releasability and non-migration property. Not only is it possible to draw on the release-treated surface with magic ink, etc. Also, since the adhesive tape can be stacked on the release-treated surface such as the adhesive tape using the release material sheet, sealing is sure. Further, it is hard to slip between the release treated surfaces, has non-slip properties, and is practically preferable even when the cardboard-packaged packaged items are stacked in multiple stages such as during storage, etc. It is possible to exhibit excellent performance that cannot be obtained with a release material sheet using a conventional silicone-based release agent.

Claims (2)

[Claims] 1. An olefin having 6 to 30 carbon atoms (co)
A release material sheet comprising a polyolefin (co) polymer obtained by polymerization. 2. A release layer made of a polyolefin (co) polymer obtained by (co) polymerizing an olefin having 6 to 30 carbon atoms is provided on a base material. Release sheet to do.