JPH1017216A - Plastic core for adhesive tape and adhesive tape laminate using the plastic core - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plastic core for an adhesive tape to keep the peel strength of the innermost peripheral adhesive tape of a roll at a comparatively low value even when a roll-form adhesive tape is mounted on an adherend by using an automatic machine, prevent the adhesive tape from being mounted on the adherend in a state that the adhesive tape is unnecessarily stretched, and improve deformation resistance during long term preservation at a high temperature in a state that the adhesive tape is wound. SOLUTION: The core of a hollow cylinder body formed of plastic is used for forming a laminate of an adhesive tape by winding the adhesive tape therearound. Plastic containing polyorefin having characteristics D1 having density of 0.88-0.94g/cm and characteristics Ml having a modulus of bending elasticity of 600-10,000kg/cm<2> is use as the core of the hollow cylinder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a plastic core for an adhesive tape and an adhesive tape laminate using the same. More particularly, the present invention relates to a plastic core for an adhesive tape suitably used for attaching an adhesive tape to various parts by an automatic machine, and an adhesive tape laminate using the same.

[0002]

2. Description of the Related Art Heretofore, as a winding core of an adhesive tape, a core having a paper tube shape in which paper is spirally laminated has been used. However, the innermost one turn wound in contact with the paper tube could not be used because the paper powder adhered to the adhesive surface when unwound. By using this one round, it is possible to improve the cost, and at the same time, the tape can be unwound smoothly in terms of function, so that when using tape, it is possible to greatly improve workability, especially in automatic machines. it can. This is because the tape is stretched and affixed so that the tape cannot be unwound smoothly, and they later deform the adherend itself as shrinkage stress. Therefore, a core for an adhesive tape that solves the above-mentioned problems has been strongly desired.

[0003] In order to meet such demands, various types of peeling functions have been attempted on the winding surface of these paper tubes. For example, a core that uses paper coated with a release agent such as silicone on the outermost periphery of the laminated paper was used, but although the releasability could be improved, the tape adhesion performance was reduced due to the transfer of the release agent to the adhesive surface. There was a problem of remarkable reduction. In addition, a method of sticking a plastic film such as polyethylene directly to the surface of the paper tube or via an adhesive was also practiced, but due to insufficient adhesion between the film and the paper, when a tape was used, the abutting portion of the film was used. There was a drawback of peeling off. In addition to the plastic core, there are practical examples of several kinds of synthetic resins such as an acrylic core, and various plastic cores and adhesive tapes as described below have been proposed.

I. Plastic core for pressure-sensitive adhesive tape using polyolefin such as polyethylene (1) A thin film heating layer and a low density polyethylene foam having an expansion ratio of about 5 to 10 times, and a thick film layer disposed inside a core A core body comprising a core, and a pressure-sensitive adhesive tape roll obtained by winding a pressure-sensitive adhesive tape on the surface of the core (Japanese Patent Laid-Open No. 5-156218). A laminated film core (Japanese Patent Application Laid-Open No. H06-26139) in which a film laminate of seven or more layers including a biaxially stretched polyethylene film layer is formed in a layer, and the laminate is formed into a cylindrical body by heat fusion. No. 206669) (3) Ultra-high molecular weight polyethylene (generally having a density of 0.9
4 to 0.95 g / cm ³ ) and a polyethylene having a lower molecular weight than that, and an ultra-high molecular weight polyethylene is contained in an amount of 15 to 40% by weight based on the total amount of the two, and is injected from a polyolefin composition. Tape reels for video tapes and the like formed by molding (Japanese Unexamined Patent Publication No.
No. 87)

II. Pressure-sensitive adhesive tape having a release layer containing ultra-low-density polyethylene (4) The release layer in contact with the pressure-sensitive adhesive layer has a thickness of 1 μm or more, and has a flexural rigidity of 1,000 according to ASTM D747.
kg / cm ² or less, and its surface wetting characteristics are JIS K
It has a wetting index of not more than 34 dyn / cm, a melting temperature of more than 80 ° C., a density of 0.910 g / cc or less and a low-density polyethylene as a main component, and the pressure-sensitive adhesive layer has an acrylic pressure-sensitive adhesive. Adhesive tape consisting of a main component (Japanese Utility Model Application Laid-Open No. 63-85642)

However, the core of (1) is not intended to improve the peelability of the pressure-sensitive adhesive tape, and has no function of imparting mechanical strength to the core for preventing deformation of the core.
Further, the core of (2) is relatively hard to impart mechanical strength to the core for improving deformation resistance during long-term storage (or high-temperature storage) with the adhesive tape wound thereon. This is an unfavorable manufacturing method, and the molding by laminating such a plurality of layers of film requires relatively troublesome production. The tape reel of (3) is made of ultra-high molecular weight polyethylene (generally having a density of 0.94 to 0.95 g / cm).
^{Since 3} ) is included in the surface layer of the reel, it is relatively disadvantageous for improving the releasability when used for a core for an adhesive tape.
Furthermore, the adhesive tape of (4) cannot prevent the deformation of the core due to the improvement of the mechanical strength of the entire core simply by sticking such an adhesive tape or the like on the surface of a normal plastic core. Depending on the material of the plastic core, the pressure-sensitive adhesive tape attached to the core surface is liable to peel off from the butt portion. Therefore, the above (1)
All of (4) to (4) were not always satisfactory in the following points. To keep the peel strength of the adhesive tape on the innermost periphery of the roll relatively low, and to prevent the adhesive tape from being unnecessarily stretched and adhered to an adherend. Improve the resistance to deformation during long-term or high-temperature storage with the adhesive tape wound.

[0007]

More specifically, a roll-shaped pressure-sensitive adhesive tape (pressure-sensitive adhesive tape laminate) is usually formed by winding a pressure-sensitive adhesive tape on a paper core or a plastic core in multiple rolls. It is formed. Accordingly, when unwinding (unwinding) the roll-shaped pressure-sensitive adhesive tape, a release layer is provided on the back surface of the tape that is in contact with the pressure-sensitive adhesive layer so that the pressure-sensitive adhesive tape that has overlapped many layers can be easily peeled off. (For example, the aforementioned Japanese Utility Model Application Laid-Open No.
issue). When the pressure-sensitive adhesive tape is a double-sided pressure-sensitive adhesive tape, a release paper (liner) having a release layer is disposed between the two layers of the double-sided pressure-sensitive adhesive tape. However, the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape on the innermost periphery of the roll is in contact with the surface layer of the core for both single-sided and double-sided pressure-sensitive adhesive tapes. That is, in the unwinding operation of the adhesive tape on the innermost periphery of the roll, it is necessary to peel the adhesive tape from the core surface layer.
For example, in a manual unwinding operation, even if the force (peeling strength) for peeling the adhesive tape from the surface layer of the core is large, by adding or subtracting to the pulling force or the pulling speed for peeling, unnecessary adhesive tape is removed. Tension can be prevented from being applied. However, in the case of an automatic sticking device (automatic machine), the tension is always constant.
Since the wound roll-shaped adhesive tape is unwound, such adjustments cannot be made. That is, when the adhesive tape has a relatively large stretchability, for example, including a foam substrate, when unnecessary tension is applied to the adhesive tape when the adhesive tape at the innermost peripheral portion of the roll is peeled off,
The tape is attached to the adherend in a stretched state. The tape stuck in the stretched state in this manner causes deformation such as warpage of the adherend after sticking, and spoils spontaneously when worsened. Therefore, usually, in the sticking operation using an automatic machine, the adhesive tape on the innermost circumference cannot be used. In addition, a core including a laminate of a stretched film (for example, as described in JP-A-6-206669)
In the above-mentioned publication, deformation resistance during long-term storage (or high-temperature storage) with the adhesive tape wound thereon was not sufficient.

[0008] The present invention has been made in view of the above-mentioned problems, and even when a roll-shaped pressure-sensitive adhesive tape is adhered to an adherend using an automatic machine, the peel strength of the innermost circumference of the roll can be reduced. Keeping it relatively low, preventing the adhesive tape from being unnecessarily stretched and sticking to the adherend, and improving the deformation resistance during long-term or high-temperature storage with the adhesive tape wound An object is to provide a plastic core for tape.

[0009]

According to the present invention, there is provided, according to the present invention, a hollow cylinder made of plastic, which is used for forming a laminate of adhesive tape by winding an adhesive tape on an outer surface thereof. In the body core, this plastic has a D1 (density): 0.88-0.94 g /
cm ³ and M1 (flexural modulus): 600 to 10,000
A plastic core for an adhesive tape is provided, which comprises a polyolefin having a property of 0 kg / cm ² .

[0010] In the core of a hollow cylindrical body made of plastic, which is used for forming a laminated body of an adhesive tape by winding an adhesive tape around its outer surface, at least the hollow cylindrical body is directly connected with the adhesive tape. It has a multilayer structure having a surface portion including an outer surface wound in contact with an inner core portion including an inner surface, and the plastic of the surface portion is D2 (density): 0.85 to 0.93 g / cm. ³ and M
2 (flexural modulus): containing the first polyolefin having the characteristic of 500 to 5,000 kg / cm ² , and the plastic of the inner core portion is D3 (density):
A plastic core for an adhesive tape, comprising a second polyolefin having a property of 0.90 to 0.96 g / cm < ³ > and M3 (flexural modulus): 1,000 to 20,000 kg / cm < ² >; Provided.

In a preferred embodiment, there is provided a plastic core for an adhesive tape, wherein the adhesive tape is an acrylic adhesive tape using an acrylic adhesive as a main component.

Further, there is provided an adhesive tape laminate, wherein an adhesive tape is wound and laminated on the outer surface of the plastic core for the adhesive tape.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below. I. Plastic core for pressure-sensitive adhesive tape The plastic core for pressure-sensitive adhesive tape of the present invention includes two types of so-called integral type and composite type.

1. Integral core The integral core means a core having no layer structure, unlike a composite core having a multilayer structure described later. (1) Shape There is no particular limitation on the shape, and an adhesive tape can be wound around its outer surface to form a laminate of the adhesive tape, and a shaft of an unwinder (unwinding machine) can be inserted. If so, there is no particular limitation, but for example, a hollow cylindrical body can be mentioned as a preferred example.

(2) Material (Plastic Type) The integrated core of the present invention is characterized by comprising a polyolefin having the following properties D1 and M1. Such a polyolefin is not particularly limited, and examples thereof include one or more polyolefins selected from the group consisting of a polyethylene homopolymer, a polypropylene homopolymer, an ethylene-based copolymer, and a propylene-based copolymer. This polyolefin is a simple substance,
Or any of mixtures. Here, the ethylene-based copolymer means a copolymer containing ethylene and an α-olefin having 3 or more carbon atoms as a polymerization component. In addition, the propylene-based copolymer means a copolymer containing propylene and an α-olefin having 4 or more carbon atoms as polymerization components.

Characteristic D1 (density) The characteristic D1 (density) of the polyolefin used for the integral core is 0.88 to 0.94 g / cm ³ ,
9~0.93g / cm ³ is preferable. When the density of the polyolefin exceeds 0.94 g / cm ³ , it gives a high peel strength to the pressure-sensitive adhesive tape and it is difficult to reduce the unwind strength. Conversely, when the density is less than 0.88 g / cm ^3. However, relatively low molecular weight components are relatively large, so that an appropriate sliding property with the shaft of the unwinder cannot be obtained, and it becomes difficult to adjust the unwind tension. Further, the wear resistance is reduced, and the surface is easily scratched. Where the density is
It measured by the test method based on JISK7112.

The characteristic M1 (flexural modulus) properties M1 (flexural modulus) of the polyolefin used in the integrated core is a 600~10,000kg / cm ^2, preferably 1,000~9,000kg / cm ² .
When it is less than 600 kg / cm ² , when the adhesive tape is wound (the tape is wound around the core in a roll),
Alternatively, when stored in that state, the core may be crushed or deformed, making it unusable. 10,000kg
If it exceeds / cm ² , although the core has excellent deformation resistance, a high peel strength of, for example, more than 80 g / mm is given to the pressure-sensitive adhesive tape, and it is difficult to reduce the unwind strength. The flexural modulus in the present invention is JIS
It was measured by a test method according to K7203.

Preferred examples of the polyolefin having such a density and a flexural modulus are 0.91 to 0.93 g.
/ Cm ³ and 1,000-4,000 kg / cm
^One comprising a medium-density polyethylene or ethylene-based copolymer having a flexural modulus of ² can be mentioned. Further, as another preferred example, 0.89 to 0.89
A density of 0.92 g / cm ³ and 1,000 to 10,000
One comprising polypropylene or a propylene-based copolymer having a flexural modulus of 0 kg / cm ² can be mentioned. Another preferred example is a mixture of polypropylene and ultra low density polyethylene (PP / VLD).
PE). Polypropylene has excellent mechanical strength and relatively good compatibility with ultra-low density polyethylene. Using a polyolefin consisting of a mixture of polypropylene and ultra-low density polyethylene,
Effectively reduce unwind strength and effectively improve core deformation resistance. In this case, the mixing weight ratio (PP: VLDPE) of the polypropylene (PP) and the very low density polyethylene (VLDPE) is usually 5:95 to
A range of 95: 5 is preferred, particularly preferred is 30: 7.
The range is 0 to 80:20.

(3) Manufacturing Method The method for manufacturing the integrated core of the present invention is not particularly limited. For example, injection molding using a molten resin may be used.
Molding by an integral molding method such as compression molding and transfer molding can be mentioned. Above all, injection molding
This is advantageous for imparting mechanical strength to the integral core for improving the deformation resistance of the core. In the case of this integrated core, there is no interface inside the core, so that the strength of the core can be increased. The pressure-sensitive adhesive tape wound around the integral core according to the present invention is not particularly limited, but, for example, exhibits the best performance with respect to an acrylic pressure-sensitive adhesive tape using an acrylic pressure-sensitive adhesive as a main component. I do. This is the same in the case of the composite core described later.

2. Composite type core The composite type core means a core having a multilayer structure having a surface layer portion including an outer surface and an inner core portion including an inner surface around which an adhesive tape is wound in direct contact. In this case, the inner surface of the inner core means a portion in contact with the surface of the shaft such as an unwinder. (1) Shape Regarding the outer shape, as in the case of the integrated core, for example,
A preferred example is a hollow cylindrical body. As described above, the outer shape is not particularly different from that of the integrated core, but is different in that it has a multilayer structure of different kinds of polyolefins.

(2) Multilayer structure In the composite core of the present invention, the surface layer portion comprises a first polyolefin having the following characteristics D2 and M2, and the inner core portion has the following characteristics D3 and M3.
Having a multilayer structure comprising a second polyolefin having The reason why the polyolefin is used for both the surface layer portion and the inner core portion is that the interfacial adhesive force between the surface layer portion and the inner core portion can be easily increased. In order to improve the interfacial adhesion, it is preferable that the difference between the densities of the two polyolefins is 0.1 or less. Further, an adhesive layer containing polyolefin may be provided between the surface layer portion and the inner core portion. Further, the inner core itself may have a multilayer structure. The type of polyolefin used for the composite core is also
The same thing as the case of the said integral type can be used.

Surface Layer The surface layer comprises the first polyolefin. Its characteristic D2 (density) is 0.85 to 0.93 g / cm ³
And preferably 0.88 to 0.92 g / cm ³ .
If it exceeds 0.93 g / cm ³ , it is easy to give a high peel strength to the adhesive tape, and it is difficult to reduce the unwind strength. Conversely, if it is less than 0.85 g / cm ³ ,
The wear resistance is reduced, and the surface is easily scratched. In the case of the composite core, the surface layer is provided on the surface of the inner core containing a relatively high hardness and high strength polyolefin, so that a lower density polyolefin can be used than in the case of the integrated core. The characteristic M2 (flexural modulus) of the first polyolefin is 500 to 5,000 kg / cm ² ,
It is preferably from 50 to 4,000 kg / cm ² . 5,000
If it exceeds kg / cm ² , the crystallinity becomes relatively high,
It tends to be difficult to reduce the unwind strength of the acrylic adhesive tape. On the other hand, if it is less than 500 kg / cm ² , the surface hardness relatively decreases and the surface of the core is easily scratched. In addition, as thickness of a surface layer part, 1-2000 micrometers is usually preferable.

Inner Core The inner core is made of a material containing a second polyolefin.
Its characteristic D3 (density) is 0.90 to 0.96 g / cm.
³ , preferably 0.91 to 0.95 g / cm ³ .
If it is less than 0.90 g / cm ^3, a relatively low molecular weight component is increased, easily lowered appropriate sliding property between the shaft of the unwinder, exceeds 0.96 g / cm ³ Conversely, impact And the durability of the core tends to decrease. The characteristic M3 (flexural modulus) of the second polyolefin is 1,000 to 20,000 kg / cm ² , and preferably 5,000 to 18,000 kg / cm ² . When it is less than 1,000 kg / cm ² , the effect of preventing the core from being crushed or deformed when the adhesive tape is wound or stored in that state is reduced. In addition, in the slitting step of the adhesive tape or at the time of use, appropriate sliding with the shaft on which the core is mounted cannot be obtained, and adjustment of unwind tension tends to be difficult. Conversely, 20,
If it exceeds 000 kg / cm ² , the impact resistance tends to decrease, and the durability of the core itself may decrease.
The flexural modulus (M3) of the second polyolefin is
Preferably, it is larger than that of the first polyolefin (M2). By doing so, it is easy to achieve both peelability and deformation resistance. Further, even when the flexural modulus (M3) of the second polyolefin is the same as or smaller than that of the first polyolefin (M2),
The effect of the present invention can also be achieved by increasing the strength of the inner core portion by incorporating a second polyolefin, a filler described later, and a polymer other than the olefin into the resin of the inner core portion.
The addition of a filler or the like to the resin of the inner core portion is, for example, to increase the impact resistance of the core by using a polyolefin having a relatively low modulus of elasticity in the inner core portion and to improve the deformation resistance of the core. Useful for

Preferred Examples Preferred examples of the composite core include a second polyolefin having a density of 0.93 to 0.95 g / cm ³ ,
Examples include those containing high-density polyethylene having a flexural modulus of 00 to 15,000 kg / cm ² . In such a case, an ultra-low-density polyethylene (having a density of 0.85 to 0.91 g / cm ³ and a flexural modulus of 50
0 to 1,000 kg / cm ² ).
That is, in this example, while effectively improving the deformation resistance of the core and the durability of the core itself, and the surface layer containing ultra-low density polyethylene, the unwind strength of the adhesive tape on the innermost circumference of the roll Is effectively reduced (for example, about 20 to 30 g / 6 mm), and it becomes easy to improve the unwinding property.

(3) Manufacturing Method There is no particular limitation on the manufacturing method of the composite core of the present invention. For example, first, the inner core is formed in the same manner as the above-mentioned integral mold so that no interface exists inside the inner core. I do. Such an integral structure of the inner core portion is advantageous in increasing the strength of the entire core, but may be a multilayer structure. Preferably, the thickness of the inner core is usually in the range of 0.5 to 20 mm. next,
On the outer peripheral surface of the inner core thus formed, a layer to be a surface layer is compounded to form a composite core. This surface layer portion can be formed by a two-color molding method, an extrusion molding method, a coating method, a film laminating method, or the like. For example, a composite core is formed by extruding the above resin into a layer by extrusion molding and melt-coating the outer peripheral surface of the inner core. Alternatively, a two-color molding method is used in which a molded inner core is placed in a mold for injection molding, and a molten surface layer resin is injected and solidified so as to contact the outer peripheral surface of the inner core. Can be. In this case, the thickness of the surface layer is usually 1 to 2,0.
It is preferable to be in the range of 00 μm.

3. Hardness Regardless of the integral type or composite type, the surface condition of the plastic core plays an important role in obtaining a stable and high initial adhesive strength of the tape. In fact, it is known that the initial adhesive strength of the pressure-sensitive adhesive tape decreases when the roughness of the film derived from the scratch on the core surface is reprinted (transferred) onto the pressure-sensitive adhesive surface of the pressure-sensitive adhesive tape. For these reasons, JIS K
The hardness (surface hardness) of the polyolefin used for the surface layer portion in the case of the composite type (the entire core in the case of the integral type), measured by a test method based on 7215 (D scale), is preferably 25 to 70. If the hardness is less than 25, the surface of the core is easily scratched. In the case of an integral core, if the hardness is less than 25, proper slip with the shaft to which the core is mounted cannot be obtained during the slitting step of the adhesive tape or during use, and the adjustment of unwind tension tends to be difficult. is there. Conversely, a polyolefin having a hardness of more than 70 is advantageous in scratch resistance,
Since it is relatively brittle, it has poor impact resistance and tends to have reduced durability as a plastic core. From such a viewpoint, in the case of an integral core, 30 to 65 is more preferable. In the case of an integral core, 40 to 60 is more preferable from the viewpoint of facilitating adjustment of unwind tension in addition to scratch resistance and durability. On the other hand, in the case of a composite core having a relatively hard inner core, the hardness of the polyolefin in the surface layer is preferably 28 to 50.

4. Polymer Mixture (Blend) Regarding the resin forming the plastic core of the present invention, whether it is an integral type or a composite type, a mixture (blend) of a polyolefin and a polymer other than the polyolefin in addition to a resin composed of only a polyolefin Can also be used. For example, when a blend of ultra-low-density polyethylene or polypropylene and an ethylene-alkyl (meth) acrylate copolymer is used as the resin forming the surface layer of the integral core or the composite core, the density of the resin in the surface layer is reduced. In addition, good peelability can be realized while increasing surface hardness and improving abrasion resistance and scratch resistance. In this case, the polyethylene has a density of 0.88 to 0.9.
It is preferable to use 0 g / cm ³ ultra-low density polyethylene because the unwind strength can be effectively reduced. In this case, very low density polyethylene (VLDP)
E) and blend weight ratio of ethylene-alkyl (meth) acrylate copolymer (EA) (VLDPE: EA)
Is usually preferably in the range of 99: 1 to 70:30.

When a blend of polyethylene or polypropylene and an ethylene-propylene rubber copolymer (elastomer) is used as the resin forming the surface layer of the integral core or the composite core, the wear resistance of the surface layer is reduced. It is possible to effectively lower the flexural modulus of the surface layer resin and improve the releasability while improving the properties and scratch resistance. In this case, as polyethylene, the density is 0.9.
It is preferable to use a low-density polyethylene having a density of 1 to 0.93 g / cm ³ because the wear resistance and scratch resistance of the surface layer are further improved. Low density polyethylene (LDPE)
And a blend weight ratio (LDPE: EP) of the ethylene-propylene rubber copolymer (EP) is usually 99: 1 to 7
It is preferable to set the range to 0:30. Furthermore, as long as the effects of the present invention are not impaired, polymers other than those described above (including elastomers) other than polyolefins can be blended.

5. Additives Regardless of the integral type or the composite type, the resin forming the plastic core of the present invention can contain additives such as fillers, pigments and dyes. For example, talc, glass beads, hollow glass beads, magnesium carbonate, silica particles, alumina oxide, magnesium carbonate, mica, aluminosilicate, calcium phosphate, zeolite, and the like may be added to the resin forming the surface layer of the integrated core or the composite core. ,
0.1 to 100 parts by weight, preferably 1 to 60 parts by weight, more preferably 5 to 5 parts by weight of an inorganic filler such as an oxide such as titanium, tin, magnesium and zinc with respect to 100 parts by weight of the resin.
In the case of containing 30 parts by weight, while increasing the bending elastic modulus and surface hardness of the resin, while improving the wear resistance and scratch resistance,
Good releasability can be realized. In this case, the polyethylene has a density of 0.91 g / cm ^{3 to} 0.93.
g / cm ³ low density polyethylene or 0.8 density
Using the ultra low density polyethylene ^{9g / cm 3 ~0.92g / cm 3} , to form an integrated core, while reducing the unwind strength effectively, easily increase that resistance to deformation of the core Is preferred.

As long as the effects of the present invention are not impaired, a plasticizer or a dispersant may be used within a range not affecting the pressure-sensitive adhesive tape for the purpose of imparting good dispersibility to the filler. For example, other additives such as hydrocarbon-based mineral oils and waxes, silicone-based polymers, and fatty acid amides typified by stearic acid amide can be appropriately contained.

Further, the inclusion of pigments and / or dyes is extremely effective in easily classifying the core according to the present invention by classification or the like visually. For example,
By using a different color for each width, it is possible to improve the workability of winding the adhesive tape, and there is an advantage that it is possible to prevent a user from erroneously using the tape width. The type of the coloring agent is not particularly limited, and examples thereof include carbon black, organic pigments, inorganic pigments, white titanium, and organic dyes.

II. Pressure-sensitive adhesive tape laminate The pressure-sensitive adhesive tape laminate using the plastic core of the present invention reduces the peel strength of the pressure-sensitive adhesive tape on the innermost circumference of the roll even when performing an adhering operation using an automatic machine, eliminating the need for a pressure-sensitive adhesive tape The adhesive tape can be suitably used when the adhesive tape contains a foam base material having relatively high stretchability, since the adhesive tape can be prevented from being stretched and adhered to an adherend. Also,
The foam substrate is excellent in vibration absorption, so that when an external force such as vibration is applied to the roll-shaped adhesive tape, it effectively prevents the winding deviation between the core surface layer and the innermost peripheral portion of the adhesive tape. be able to. That is, a roll-shaped foam adhesive tape (adhesive tape laminate) formed by winding and laminating an adhesive foam tape as the adhesive tape on the plastic core in the form of a roll is attached using an automatic machine as described above. Work can be performed favorably, deformation resistance of the core during long-term storage can be improved, and defective winding of the tape can be effectively prevented. Adhesive foam tape, those having an acrylic adhesive on the surface of the foam substrate, or
The foam substrate itself containing the adhesive acrylic polymer also includes both the one that also functions as the adhesive layer, and may be either a single-sided or double-sided adhesive tape. The thickness of the foam base material should be 0.2 to 0.2 in consideration of the balance between adhesion performance, vibration absorption, and small bulk when pasted.
A range of 4.0 mm is preferred. Further, the density of the foam base material is usually preferably in the range of 0.3 to 0.95 g / cm ³ . As such an adhesive foam tape, an acrylic foam tape manufactured by Sumitomo 3M Limited; 4213
(Thickness of foam base material: 0.8 mm); 4
211 (the thickness of the foam base material is 1.2 mm).

[0033]

The present invention will be described more specifically with reference to the following examples. Example 1 As polyolefin, the density was 0.90 g /
Using an injection molding machine, an integrated plastic core for pressure-sensitive adhesive tape was manufactured using an ultra-low-density polyethylene of cm ³ (manufactured by Sumitomo Chemical Co., Ltd., trade name “Exelen VL700”). Outside diameter 8
The diameter was 0.7 mm, the inner diameter was 76.7 mm, and the width was 6 mm. In addition, the said density is a value measured based on JISK7112. Hardness of the above polyethylene (JI
(SK 7215: D scale) was 43, the scratch resistance and durability were good, and the adjustment of unwind tension during use was easy. The flexural modulus of the polyethylene was 830 kg / cm ² . When the properties of the obtained plastic core were evaluated as follows, the unwind strength of the innermost pressure-sensitive adhesive tape at the time of unwinding was 20 g / 6 mm, and the unwinding property was good (in the innermost circumference). At the time of unwinding, the adhesive tape was smoothly unwound without being unnecessarily stretched), and the deformation resistance was good (the change in core inner diameter was 5% or less).

Unwind strength Acrylic foam tape No. manufactured by Sumitomo 3M Limited was added to the obtained core. 4211 (width 6 mm, length 30 m) was uniformly wound and left at room temperature (23 ° C.) for one week. The tape roll sample thus prepared was unwound from the winding core under the following conditions using a tensile tester manufactured by Shimadzu Corporation and an unwind jig for the same, [g /
6 mm]. Testing machine: Autograph made by Shimadzu Corporation Unwind speed: 300 mm / min

When the unwind strength is measured, the foam tape is deformed,
When the liner was unwound without floating (partial peeling) of the liner from the foam tape, it was evaluated as good.

Deformation resistance Acrylic foam tape No. manufactured by Sumitomo 3M Ltd. was applied to the obtained core. 4211 (width 6 mm, length 30 m) is evenly wound and left for one week in an oven adjusted to 70 ° C.
The deformation of the core was measured. Core inner diameter change is 5% or less: good Core inner diameter change exceeds 5%: bad

Examples 2 and 3 and Examples 7 to 9 The procedure of Example 1 was repeated, except that the polyolefin used therein was changed to the materials shown in Table 1. The properties of the obtained core are shown in [Table 1].

[Examples 4 to 6] The inner core portion of the core was first prepared by the production method described in Example 1 using the polyolefin described in [Table 1], and the outer peripheral surface thereof was manufactured by Tanabe Plastic Machinery Co., Ltd. Using an extruder PS40, the outer peripheral material described in [Table 1] was melt-coated with a thickness of about 30 μm to form a surface layer portion, thereby producing a core. The characteristics of the obtained core are shown in [Table 1].

[Comparative Examples 1 and 2] The procedure of Example 1 was repeated, except that the polyolefin used in Example 1 was changed to those shown in Table 1. The properties of the obtained core are shown in [Table 1].

The materials used in the examples and comparative examples are listed below. 1. Exelen VL700 (ultra low density polyethylene) manufactured by Sumitomo Chemical Co. 2. Exelen VL100 (ultra low density polyethylene) manufactured by Sumitomo Chemical Co. 3. Aclift WD301 (ethylene / methyl methacrylate copolymer) Sumitomo Chemical Co., Ltd. 4. Ultrazex 20100J (Polyethylene) manufactured by Mitsui Petrochemical Co., Ltd. 5. Ultzex 25100J (polyethylene) manufactured by Mitsui Petrochemical Industries, Ltd. 6. Ultoxex 4570 (polyethylene) manufactured by Mitsui Petrochemical Industries, Ltd. 7. P280 (polyethylene) manufactured by Mitsui Petrochemical Industries, Ltd. 8. Showrex 5110 (polyethylene) Showa Denko KK 9. AO502 (aluminosilicate) Admatech 10. EP912P (ethylene / propylene rubber) Nippon Synthetic Chemical Company 11. Thermal black (carbon) Asahi Carbon 12.AH585A (Polypropylene) 13. Sumitomo Chemical Selenium VL200 (ultra low density polyethylene) manufactured by Sumitomo Chemical Co., Ltd. The characteristics of the surface layer of Example 6 and the cores of Examples 7 to 9 are values of each mixture (blend, additive mixture), not polyolefin alone. .

[0041]

[Table 1]

[0042]

As described above, even when a roll-shaped adhesive tape is adhered to an adherend using an automatic machine, the plastic core for an adhesive tape of the present invention and the adhesive tape laminated body using the same can be used. , Keeping the peel strength of the adhesive tape on the innermost circumference of the roll relatively low, preventing the adhesive tape from being unnecessarily stretched and sticking to the adherend, and in a state where the adhesive tape is wound, A plastic core for an adhesive tape having improved resistance to deformation during long-term or high-temperature storage can be provided. Further, with the pressure-sensitive adhesive tape laminate of the present invention, it is possible to effectively prevent the winding deviation between the core surface layer portion and the innermost peripheral portion of the pressure-sensitive adhesive tape.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication location C09J 7/02 C09J 7/02

Claims (4)

[Claims] 1. A hollow cylindrical core made of plastic, which is used for forming an adhesive tape laminate by winding an adhesive tape around its outer surface, wherein the plastic has polyolefin having the following properties D1 and M1. A plastic core for an adhesive tape, comprising: Characteristic D1 (density): 0.88 to 0.94 g / cm ³ Characteristic M1 (flexural modulus): 600 to 10,000 kg /
cm ² 2. A core of a hollow cylindrical body made of plastic, which is used for forming an adhesive tape laminate by winding an adhesive tape around its outer surface, wherein at least the hollow cylindrical body is directly It has a multilayer structure having a surface layer portion including an outer surface wound in contact with an inner core portion including an inner surface, and the plastic of the surface layer portion includes a first polyolefin having the following properties D2 and M2. A plastic core for an adhesive tape, wherein the plastic of the inner core contains a second polyolefin having the following properties D3 and M3. Characteristic D2 (density): 0.85 to 0.93 g / cm ³ Characteristic M2 (flexural modulus): 500 to 5,000 kg / c
m ² Characteristics D3 (Density): 0.90~0.96g / cm ³ Characteristics M3 (flexural modulus): 1,000~20,000k
g / cm ² 3. The plastic core for an adhesive tape according to claim 1, wherein the adhesive tape is an acrylic adhesive tape using an acrylic adhesive as a main component. 4. A pressure-sensitive adhesive tape laminate obtained by winding and laminating a pressure-sensitive adhesive tape on the outer surface of the plastic core for a pressure-sensitive adhesive tape according to claim 1.