JP2003277702A - Double-sided pressure-sensitive adhesive tape and adsorptive fixing sheet using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double-sided pressure-sensitive adhesive tape capable of easily and surely fixing an object, leaving no residue of the adhesive after peeled off, and hardly affecting the adsorptive performance by securing air permeability, and to provide an adsorptive fixing sheet made by adhering the tape on a porous sheet. <P>SOLUTION: The double-sided pressure-sensitive adhesive tape T has a plurality of through-holes 4 and the adhesive strength of one side is different from that of the other side. The adsorptive fixing sheet comprises a porous sheet 11 essentially comprising an ultrahigh molecular weight polyethylene resin adhered on the side of the tape T where the adhesive strength is higher. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a breathable double-sided pressure-sensitive adhesive tape and a suction-fixing sheet obtained by sticking the double-sided pressure-sensitive adhesive tape to a porous sheet. It is useful as a sheet for adsorption and fixation for vacuum adsorption and fixation.

[0002]

2. Description of the Related Art In processes such as the transportation of semiconductor parts and the cutting of liquid crystal glass, defective peeling due to the generation of static electricity and adhesion of foreign matter greatly affect the yield of products. Electrical·
In the transportation of electronic parts, fixing by suction is widely used, and there is an advantage that a constant fixing force can be obtained regardless of the shape of the work. A porous body is used for the adsorption / fixing portion, and for example, a ceramic sintered body, a metal sintered body, a plastic porous body or the like has been used. These have continuous holes, and the work is adsorbed and desorbed by the flow of air.

Among the above, the plastic porous body is effective as an elastic body and is characterized in that it does not damage the work. Moreover, when replacing when clogged,
It is cheaper than the porous ceramics and sintered metal,
Advantageous (Japanese Patent Application Laid-Open No. 8-258198, Japanese Patent Application Laid-Open No. 9-258198)
No. 022935, JP 2001-28390).

Usually, when performing vacuum suction, on the upper surface of a perforated metal plate that is mechanically perforated, which constitutes a suction fixing portion of a suction head that suctions from a vacuum pump (vacuum suction machine),
It is usual to install a plastic porous body. At this time, for fixing, the porous metal plate and the porous body were adhered by a method such as sticking a double-sided adhesive tape on a part or spraying a paste and adhering.

[0005]

However, in the method of partially attaching the double-sided pressure-sensitive adhesive tape, unevenness occurs due to the difference in thickness between the adhered portion and the non-adhered portion, and if the adhesive tape is not attached at a predetermined position, a metal hole is formed. The air passage is eliminated by blocking the valve and the desired performance cannot be obtained. Further, in spraying the spray glue, if the spray amount is large, the air permeability of the porous body may be impaired, and conversely, if the spray amount is too small, the adhesive strength becomes insufficient and the adhesive may peel off from the metal plate by repeated suction operations. was there. In addition, problems such as adhesive residue may occur. These problems cause heavy cost and time load because it is necessary to severely adjust the spray amount.

Therefore, an object of the present invention is to provide a double-sided pressure-sensitive adhesive tape which can be easily and surely fixed, has no adhesive residue at the time of peeling, and is less likely to deteriorate adsorption performance by ensuring air permeability, and a double-sided pressure-sensitive adhesive tape attached to a porous sheet. It is to provide a sheet for adsorption and fixation formed by wearing.

[0007]

The above object can be achieved by the present invention as described below. That is, the double-sided adhesive tape of the present invention is characterized by having different adhesive strengths on both sides and having a plurality of through holes.

On the other hand, the adsorption fixing sheet of the present invention is a porous sheet mainly composed of ultra high molecular weight polyethylene resin,
The surface of the double-sided pressure-sensitive adhesive tape on the side having a high adhesive strength is attached.

[Advantages] According to the double-sided pressure-sensitive adhesive tape of the present invention, the double-sided pressure-sensitive adhesive tape allows the adherend to be easily and surely fixed, and has different adhesive strengths on both sides. By sticking to the adherend that is easy to adhere, it is possible to prevent the adhesive residue from remaining when peeling. Further, since the plurality of through holes are formed, it is possible to make it difficult to lower the adsorption performance by ensuring the air permeability.

On the other hand, according to the adsorption fixing sheet of the present invention, the surface of the double-sided pressure-sensitive adhesive tape having the large adhesive strength is adhered to the porous sheet mainly composed of ultra-high molecular weight polyethylene resin. Due to the action and effect as described above,
It can be fixed easily and surely, and there is no adhesive residue at the time of peeling, and it is difficult to lower the adsorption performance by ensuring air permeability.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an example of the double-sided pressure-sensitive adhesive tape of the present invention, and FIG. 2 is a sectional view showing an example of a usage state of the double-sided pressure-sensitive adhesive tape of the present invention.

As shown in FIG. 1, the double-sided pressure-sensitive adhesive tape of the present invention is characterized by having different adhesive strengths on both sides and having a plurality of through-holes 4 formed therein. The pressure-sensitive adhesive layers 1 and 3 thus formed are provided. The double-sided pressure-sensitive adhesive tape of the present invention can be suitably used for, for example, a sheet for adsorption and fixation as shown in FIG. That is, the adsorption-fixing sheet of the present invention is one in which the surface of the double-sided pressure-sensitive adhesive tape T of the present invention on the side having a high adhesive strength is attached to the porous sheet 11 mainly composed of ultra-high molecular weight polyethylene resin. .

In such a suction / fixing sheet, adhesive residue is apt to occur on the porous metal plate 12a of the suction / fixing portion 12. This is because the adhesiveness of the polymer porous body is poor, so that if an adhesive tape having a stronger adhesive force is used, as a result, the porous metal plate 12a is
This is because the adhesive on the double-sided adhesive tape T remains.

The adhesive strength of the double-sided pressure-sensitive adhesive tape used in the present invention has a weakly adhesive surface of 3 to 5 N / 25 mm with respect to the SUS plate.
It is preferable that the strongly adhesive surface exhibits different adhesive strengths in the range of 7 to 10 N / 25 mm. The strong adhesion surface is used for the porous sheet 11 and the weak adhesion surface side is used for the porous metal plate 12a, and they are bonded together.

The above adhesive strength has a sheet width of 25 mm,
Cut to a length of 100 mm, width 50 mm, length 15
A rubber roller having a weight of 2 kg was reciprocated twice on a 0 mm SUS-304 plate for pressure bonding, and then left at room temperature for 30 minutes.
Tensile tester at 22 ° C, 180 ° at a speed of 300 mm / min
Peel off with a peel and measure.

The double-sided pressure-sensitive adhesive tape is perforated to maintain air permeability and prevent the adsorption performance from deteriorating. As a method for forming the through holes 4, punching, Thomson blade punching, or the like can be used while using a separator as necessary, and any method can be used.

As a forming area of the through-hole 4, sufficient adsorption
1cm per area of 6cm x 6cm for obtaining force² 
The above is preferable and 2 to 25 cm² Is more preferable. 1c
m²If it is less than, the air permeability will be low and the adsorption force will be insufficient.
25 cm ² If it exceeds, double-sided adhesive
Strength and handling tend to be insufficient.
It

The shape of the through hole 4 may be circular, elliptical, polygonal or the like. However, the minor axis or the length corresponding to the minor axis is 1 in order to maintain the surface flatness of the porous sheet 11.
It is preferably 0 mm or less. Especially when the through hole 4 is circular, a diameter of 1 to 6 mm is preferable in consideration of air permeability.

The substrate sheet 2 is not particularly limited, but a plastic film can be used particularly suitably. As typical materials thereof, for example, low density polyethylene, linear polyethylene, medium density polyethylene, high density polyethylene, ultra low density polyethylene, random copolymer polypropylene, block copolymer polypropylene, homopolypropylene, polybutene, polymethylpentene. Such as polyolefin, ethylene-vinyl acetate copolymer, ionomer resin, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester (random, alternating) copolymer, ethylene-butene copolymer,
Ethylene-hexene copolymer, polyurethane, polyester such as polyethylene terephthalate, polyimide,
Polyetherketone, polystyrene, polyvinyl chloride,
Examples thereof include polymers such as polyvinylidene chloride, fluororesins, silicone resins, cellulosic resins and cross-linked products thereof. The above-exemplified materials forming the base sheet may be grafted with a functional group, a functional monomer, a modifying monomer or the like, if necessary.

The substrate sheet can be formed by a conventionally known film forming method. For example, calender film formation, casting film formation, inflation extrusion, T-die extrusion and the like can be preferably used.

The thickness of the substrate sheet thus obtained is usually 10 to 300 μm, preferably 30 to 200 μm. The base sheet may be either a single-layer film or a multi-layer film, and may be a blend base material obtained by dry blending the two or more resins. The multi-layer film can be produced using the above-mentioned resins by a conventional film laminating method such as a co-extrusion method and a dry laminating method. Further, the base material sheet may be used without stretching, or may be subjected to uniaxial or biaxial stretching treatment as necessary. On the surface of the substrate sheet thus formed, mat treatment, corona discharge treatment, primer treatment, if necessary,
Conventional physical or chemical treatment such as crosslinking treatment can be applied.

The adhesive layers 1 and 3 preferably have a thickness of 1 to 50 μm, and the adhesive strength can be adjusted by the thickness and the composition of the adhesive. For forming such a pressure-sensitive adhesive layer, a known or common pressure-sensitive adhesive can be appropriately selected and used. The pressure-sensitive adhesive is not limited at all, for example, rubber-based,
Various adhesives such as acrylic, silicone, and polyvinyl ether adhesives are used. Among them, acrylic adhesives having an acrylic polymer as a base polymer are preferable from the viewpoint of versatility.

The acrylic polymer is, for example, a polymer of (meth) acrylic acid alkyl ester or a (meth) acrylic acid alkyl ester copolymerizable monomer for the purpose of modifying cohesive force, heat resistance and the like as required. A copolymer obtained by copolymerizing is used. (Meta)
Acrylic acid ester means acrylic acid ester and / or methacrylic acid ester, and (meth) of the present invention has the same meaning. Examples of the alkyl ester of (meth) acrylic acid alkyl ester include methyl ester, ethyl ester, butyl ester, 2-ethylhexyl ester, octyl ester, isononyl ester and the like. Among them, the glass transition temperature of homopolymer (hereinafter, Tg
(Referred to as “) is -25 ° C. or higher is suitable as the main monomer. Those containing 50% by weight or more of such a main monomer are preferable.

As the copolymerizable monomer, a hydroxyalkyl ester of (meth) acrylic acid (eg, hydroxyethyl ester, hydroxybutyl ester, hydroxyhexyl ester, etc.), (meth) acrylic acid glycidyl ester, (meth) acrylic acid, Itaconic acid, maleic anhydride, (meth) acrylamide, (meth) acrylic acid N-hydroxymethylamide, (meth) acrylic acid alkylaminoalkyl ester (eg, dimethylaminoethyl methacrylate, t-butylaminoethyl methacrylate, etc.), acetic acid Examples thereof include vinyl, styrene, acrylonitrile and the like. These copolymerizable monomers are
One kind or two or more kinds can be used. Furthermore, since the acrylic polymer is crosslinked, a polyfunctional monomer or the like can be included as a monomer component for copolymerization, if necessary.

The acrylic polymer can be obtained by polymerizing a single monomer or a mixture of two or more kinds of monomers. The polymerization can be carried out by any method such as solution polymerization, emulsion polymerization, bulk polymerization and suspension polymerization. The number average molecular weight of the acrylic polymer is preferably 300,000 or more, more preferably about 600,000 to 3,000,000.

A cross-linking agent may be appropriately added to the pressure-sensitive adhesive in order to increase the number average molecular weight of the acrylic polymer as the base polymer. Examples of the cross-linking agent include polyisocyanate compounds, epoxy compounds, aziridine compounds, melamine resins, urea resins, anhydrous compounds, polyamines and carboxyl group-containing polymers. When a cross-linking agent is used, its amount is generally preferably 0.01 to 5 parts by weight based on 100 parts by weight of the base polymer in order to obtain an appropriate adhesive strength. Further, the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer contains, if necessary, conventional additives such as various conventionally known tackifiers, antioxidants, fillers, antioxidants, colorants, etc., in addition to the above components. Can be made.

In the double-sided pressure-sensitive adhesive tape of the present invention, for example, the pressure-sensitive adhesive solution is applied to the surface of the base sheet 2 and dried (heat-crosslinking if necessary) to form pressure-sensitive adhesive layers 1 and 3. It can be manufactured by pasting a separator on the surface of the pressure-sensitive adhesive layers 1 and 3 as required. In addition, separately
After forming the pressure-sensitive adhesive layers 1 and 3 on the release liner, a method of bonding them to the base material sheet 2 can be adopted.

The separator is optionally provided for label processing or for the purpose of smoothing the pressure-sensitive adhesive. Examples of the constituent material of the separator include paper, synthetic resin films such as polyethylene, polypropylene, and polyethylene terephthalate. The surface of the separator may be subjected to a peeling treatment such as a silicone treatment, a long-chain alkyl treatment and a fluorine treatment, if necessary, in order to enhance the peelability from the pressure-sensitive adhesive layer.

As the porous sheet 11, UHMWPE
It is preferred to use (ultra high molecular weight polyethylene).
It has a viscosity average molecular weight of 500,000 or more, is not easily worn, is not easily damaged by scratches, and does not damage the work on the fixed surface. Also, due to the low coefficient of friction, it is easy to release.

UHMWPE constituting the porous sheet 11
Is characterized by showing a high value of about 500,000 or more, whereas the molecular weight of general polyethylene (measured by a viscosity method) is about 100,000 or less. Such UHMWPE is
For example, they are commercially available under the trade names of "HIZEX Million" from Mitsui Petrochemical Industry Co., Ltd. and "Hostalen GUR" from Hoechst.

Further, this UHMWPE porous sheet 11
Has a friction coefficient of preferably 0.3 or less, more preferably 0.2 or less. If the coefficient of friction exceeds 0.3, the service life tends to be shortened when used for suction fixation.

The thickness, porosity and pore diameter of this UHMWPE porous sheet 11 are 0.1 to 5 mm in thickness and 5 to 5 in porosity.
60%, pore diameter 5 to 200 μm is preferable, thickness 0.5 to
3 mm, porosity 20 to 40%, and pore diameter 10 to 150 μm are more preferable.

Next, this UHMWPE porous sheet 11
An example of the manufacturing method of will be described. According to this method, a UHMWPE powder is filled in a mold, which is then sintered in a steam atmosphere heated to a temperature equal to or higher than the melting point of UHMWPE to form a block-shaped compact, which is then cooled to a predetermined thickness. It is to cut into a sheet of wood.

In this method, first, UHMWPE
Fill the mold with powder (usually 30-200 μm particle size),
Then, this is sintered in a steam atmosphere heated to a melting point of UHMWPE or higher to obtain a block-shaped molded body. As described above, since the UHMWPE powder is filled in the mold and is sintered in a heated steam atmosphere, a mold having at least one opening (for introducing heated steam) is used. The time required for sintering varies depending on the powder filling amount, the temperature of steam, and the like, but is usually about 1 to 12 hours.

Since the water vapor used at this time is heated to a temperature higher than the melting point of UHMWPE and is in a pressurized state, it can easily enter between the UHMWPE powders filled in the mold. In order to make it easier for the heated steam to enter between the UHMWPE powders, the powders were filled in a mold, the molds were placed in a pressure resistant container, and deaeration operation was performed to reduce the pressure, and then the powders were heated. You may make it sinter in a steam atmosphere. The degree of pressure reduction at this time is not particularly limited, but is preferably about 1 to 100 mmHg.

Therefore, for the sintering of the UHMWPE powder filled in the mold, a steam inlet tube and its opening / closing valve are provided in the pressure resistant container, and air between the powders is degassed.
It can be carried out by a method of opening the steam valve and introducing heated steam while stopping or continuing the depressurization.

During this sintering, the UHMWPE powder is heated to a temperature equal to or higher than the melting point, but its melt viscosity is high, so that it does not flow so much, the powder shape is maintained partially or largely, and the adjacent powders are not separated from each other. At the contact portion, heat fusion is performed to form a porous block-shaped molded body (the non-contact portions of the powders become fine pores of the porous molded body). During sintering, pressure may be applied if desired, but the pressure is usually preferably about 10 kg / cm ² or less.

After sintering is performed as described above, it is cooled. When cooling, it is preferable to avoid rapid cooling in order to prevent cracks from occurring in the block-shaped molded body, and for example, a method of cooling by leaving it at room temperature can be adopted. The cooling may be performed while the block-shaped molded body is kept in the mold, or may be taken out from the mold. After cooling the block-shaped compact in this manner, the porous sheet 11 can be obtained by cutting to a predetermined thickness with a lathe or the like.

Porous sheet 11 obtained by the above method
The pore size and porosity of the micropores are determined by the particle size of the UHMWPE powder used and the presence or absence of pressure during sintering. If the other conditions are the same, the larger the particle size of the powder used, the larger the pore size of the fine pores, and the porous sheet 11 having a high porosity can be obtained. Further, when the pressure is not applied during the sintering, the pore size of the micropores is larger than that when the pressure is applied, and the porous sheet 1 having a high porosity is obtained.
1 is obtained. Furthermore, when pressure is applied during sintering, the higher the pressure, the smaller the pore size of the fine pores, and the porous sheet 11 having a low porosity can be obtained.

UHMWP obtained by such a method
The E porous sheet 11 has UHMs adjacent to each other as described above.
The WPE powder maintains a part or most of its shape and has a microstructure in which the powders are heat-fused at their contact parts to form a sheet shape, and the non-contact parts of the powders are micropores. ing. The microstructure of the porous sheet 11 is obtained by, for example, cutting the porous sheet 11 along the thickness direction, and observing the cut surface with a scanning electron microscope (the magnification is appropriately set, but usually about 100). ~ 1000 times).

The porous sheet 11 according to the present invention may be antistatic-treated. By carrying out the antistatic treatment, for example, sparks due to the electrification of the porous sheet 11 can be avoided in the dicing step of the semiconductor wafer, and the wafer damage due to the sparks can be prevented. Further, it is possible to prevent dust and dirt from adhering to a work piece such as a semiconductor wafer.

The antistatic treatment on the porous sheet 11 does not have to be special, and a usual method can be adopted. For example,
When the porous sheet 11 is manufactured by the above method, U
Prior to filling the HMWPE powder into the mold, the powder may be mixed with the antistatic agent and the mixture may be used for the operation.
Further, a method is adopted in which the porous block-shaped molded body or the porous sheet 11 obtained by cutting the block-shaped molded body or sheet is contacted (immersed, coated, etc.) with the antistatic agent-containing liquid to impregnate the molded body or sheet with the antistatic agent. You can also The amount of the antistatic agent used when performing this treatment is not particularly limited, but usually,
The proportion of the antistatic agent in the weight of the treated porous sheet 11 is set in the range of 0.5 to 2% by weight.

As the above-mentioned antistatic agent, "ELECTNON OR"
Commercially available products such as "W (manufactured by New Fine Chemical Co., Ltd.)" and "Electro Stripper (manufactured by Kao Co., Ltd.)" can be used, and an inorganic conductive material such as carbon black powder and metal powder can be used.

The adsorption fixing sheet of the present invention is shown in FIG.
As shown in, the weakly adhered surface is used by being adhered to the porous metal plate 12a of the adsorption fixing portion 12 which performs air suction. The adsorbent 13 is adsorbed and fixed on the surface of the porous sheet 11.

[0045]

EXAMPLES Examples and the like specifically showing the constitution and effects of the present invention will be described below. The evaluation items in Examples and the like were measured as follows.

(1) Adhesive strength A sheet having a width of 25 mm and a length of 100 mm was cut, and this was cut on a SUS-304 plate having a width of 50 mm and a length of 150 mm.
After reciprocating a rubber roller weighing 2 kg twice,
Leave at room temperature for 30 minutes. Tensile tester at 22 ℃, 300mm
It was peeled off at a speed of 180 ° peeling at a speed of / minute and measured.

(2) Adhesive residue test The adhesive residue was evaluated by sticking to an SUS plate and then at 60 ° C. × 24.
When it was peeled off after holding for h, it was visually inspected whether or not the adhesive remained on the SUS plate, and when it remained, it was determined that there was adhesive residue.

(3) Adsorption force test SUS suction panel (110 × 110 mm, hole diameter 0.
5 mmφ, pitch 0.5 mm), a sheet for adsorbing and fixing was adhered, and a SUS plate (thickness 1 mm) was sucked at a reduced pressure of 80 kPa or 50 kPa (adsorption surface was 100 × 100).
mm) was measured by a tensile test at a speed of 300 mm / min.

Example 1 A double-sided adhesive tape of different strength was prepared in which an acrylic adhesive (20 μm thick) was applied to both surfaces of a polyester substrate (Nitto Denko KK, No 537B, thickness 20 μm). At that time, the adhesive strength is adjusted by changing the addition amount of Rheocoat, xylene resin, and butylated melamine resin contained in the acrylic pressure-sensitive adhesive. The adhesive strength is 3 N / 20 mm for weakly adhesive surface and 6 N / 20 for strong adhesive surface.
mm. Holes with a size of 2 mmφ were made in this with a pitch of 6 mm, and the strongly adhesive surface was made of a porous sheet (SU manufactured by Nitto Denko, SU
NMAP, Air permeability Frazier 2.0, Average pore size 35μ
It was stuck to m) to prepare a sheet for adsorption and fixation.

Example 2 The same adhesive tape as in Example 1 was punched with holes having a size of 4 mmφ at a pitch of 6 mm, and the strongly adhesive surface was similarly attached to SUNMAP to prepare a sheet for adsorption and fixation.

(Example 3) The same adhesive tape as in Example 1 was punched with holes of 2 mmφ at a pitch of 10 mm and strongly bonded.
The surface was attached to SUNMAP to prepare an adsorption fixing sheet.

(Comparative Example 1) Holes of 4 mm in size were punched in a double-sided adhesive tape at a pitch of 6 mm.
And a sheet for adsorption and fixation were prepared. The adhesive strength of this double-sided tape to the SUS plate is 5 to 6 N / on both sides.
It is 20 mm.

(Comparative Example 2) A hole having a size of 60 mm x 60 mm was made in the same adhesive tape as in Comparative Example 1, and SUNUM was used.
A sheet for adsorption and fixation was produced by sticking to the AP.

Table 1 shows the results of the evaluations (2) and (3) using the above-described adsorption-fixing sheet. In addition, FIG. 3 is a graph showing the results of the adsorption force test of Examples and Comparative Examples.

[0055]

[Table 1]

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a double-sided adhesive tape of the present invention.

FIG. 2 is a sectional view showing an example of a usage state of the double-sided adhesive tape of the present invention.

FIG. 3 is a graph showing the results of the adsorption force test of Examples and Comparative Examples.

[Explanation of symbols]

1 Adhesive layer (high adhesive strength) 2 Base sheet 3 Adhesive layer (low adhesive strength) 4 through holes 11 Porous sheet T double-sided adhesive tape

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Junichi Moriyama             1-2 1-2 Shimohozumi, Ibaraki City, Osaka Prefecture Nitto             Electric Works Co., Ltd. (72) Inventor Seiichi Takaoka             1-2 1-2 Shimohozumi, Ibaraki City, Osaka Prefecture Nitto             Electric Works Co., Ltd. F-term (reference) 4J004 AA05 AA10 AA11 AB01 CA03                       CA04 CA05 CA06 CC07 CE02                       EA05 FA04                 4J040 CA001 DD051 DF001 DF041                       DF051 EB132 EC231 EF281                       EH012 EK001 JA09 JB09                       NA20

Claims (2)

[Claims] 1. A double-sided adhesive tape having different adhesive strengths on both sides and having a plurality of through holes formed therein. 2. A sheet for adsorption and fixation in which the surface of the double-sided pressure-sensitive adhesive tape according to claim 1 having a high adhesive strength is attached to a porous sheet mainly composed of ultra-high molecular weight polyethylene resin.