JPH0819965A - Polishing tape - Google Patents

Abstract

PURPOSE:To produce a grinding tape, in which an abrasive layer firmly adheres to a base film, with excellent productivity. CONSTITUTION:A primer coating layer mainly consisting of 70-95% by weight of copolymer polyester (A), in which a rate of a dicarboxylic acid component having a sulfonate group to the whole dicarboxylic acid component in a molecule is 2-18 mole % and a second order transition point is 15-45 deg.C, and 5-30% by weight of particles (B) with a mean particle diameter of 30-500nm and having thickness of 0.015-0.3mum is arranged on at least one face of a base film made of a biaxial orientated polyester film with thickness of 15-100mum. A polishing tape is constructed by additionally arranging an abrasive layer on at least one surface of the primer coating layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing tape having an abrasive layer firmly adhered to a base film via an easy-adhesion layer, and more specifically to a base film made of a biaxially stretched polyester film, which has blocking resistance and slippage. Is excellent
The present invention also relates to an abrasive tape manufactured by a method having excellent productivity by providing a primer coating layer having excellent adhesiveness.

[0002]

2. Description of the Related Art Polyester films, particularly polyethylene terephthalate films, have been widely used as base films for polishing tapes. However, in recent years, the properties required for polishing tapes have become higher, and in particular, the adhesive strength between the abrasive layer and the base film (hereinafter sometimes referred to as "adhesive strength") has been made stronger than conventional ones.
Alternatively, a polishing tape having excellent durability has been required, but a conventional polishing tape using a polyester film as a base film does not meet this requirement.

In order to improve the above-mentioned adhesive strength and durability, a method of applying a primer layer made of, for example, polyurethane, polyester urethane, polyester or the like on the base film is used, but the method of using polyurethane or polyester urethane is used. There are drawbacks that the adhesive strength of the abrasive layer is still insufficient, and that when the film coated with the primer layer is collected and reused for the film, it is difficult to reuse due to marked coloring. Further, in the method using polyester, for example, a primer layer containing a cross-linking agent is used, but such a method has a drawback that the abrasive layer is likely to fall off from the base film when the polishing tape is scratched (scratched). However, there is no solution.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a polishing tape in which a polyester film is used as a base film, an abrasive layer is firmly adhered to the base film, and which can be produced with excellent productivity. It is in.

[0005]

The present invention has the following constitution in order to achieve such an object.

On at least one side of a base film made of a biaxially stretched polyester film having a thickness of 15 to 100 μm, 2 to 18 mol of the dicarboxylic acid component having a sulfonate group is present with respect to all dicarboxylic acid components in the molecule (A). %
70% to 95% by weight of a copolyester having a secondary transition point of 15 to 45 ° C., and (B) an average particle diameter of 30 to 50.
A primer coating layer having a thickness of 0.015 to 0.3 μm as a main component containing 5 to 30% by weight of 0 nm fine particles is provided, and an abrasive layer is further provided on at least one surface of the primer coating layer. Polishing tape

The biaxially stretched polyester film used in the base film of the present invention is a film obtained by biaxially stretching an unstretched film made of an aromatic polyester, and the aromatic polyester is a dicarboxylic acid component. It is a polyester composed of a glycol component.

Preferred examples of the above aromatic dicarboxylic acid component include terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid and 4,4'-diphenyldicarboxylic acid, and the above glycol component. For example, ethylene glycol, 1,4
Butanediol, 1,6-hexanediol, 1,4-
Aliphatic or alicyclic glycols such as cyclohexanedimethanol can be mentioned as preferable examples, and among these, ethylene glycol is particularly preferable.

In addition to the aromatic dicarboxylic acid component, an alicyclic or aliphatic dicarboxylic acid component such as 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid or the like may be partially used as a constituent component of the aromatic polyester. I can, but
The aromatic polyester which forms the base film of the present invention has an amount of 70 mol% or more, especially 80% or more of the total dicarboxylic acid components.
It is preferred that more than mol% is an aromatic dicarboxylic acid. If the aromatic dicarboxylic acid component in the polyester is less than 70 mol%, the mechanical properties of the polishing tape will be insufficient.

Preferred examples of the aromatic polyester include polyethylene terephthalate and polyethylene-2,6-.
Examples thereof include natalenedicarboxylate, terephthalic acid-isophthalic acid-ethylene glycol copolymerized polyester, terephthalic acid-isophthalic acid-adipic acid-ethylene glycol copolymerized polyester and the like. Copolymerized polyesters containing the above polyester as a main component can also be used.

If desired, organic or inorganic fine particles may be added to the polyester used for the base film in order to improve the winding property when the polyester film is produced.

As such fine particles, those usually added to a polyester film can be used. For example, calcium carbonate, calcium oxide, aluminum oxide, titanium oxide, kaolin, silicon oxide, zinc oxide, carbon black, silicon carbide, Tin oxide, crosslinked acrylic resin particles, crosslinked polystyrene resin particles, melamine resin particles,
Examples thereof include silicone resin particles. Furthermore, colorants, antistatic agents, antioxidants, organic lubricants, catalysts, other resins and the like can be appropriately added to the polyester.

The thickness of the aromatic polyester film used for the base film of the present invention is 15 to 100 μm,
It is preferably 20 to 90 μm. This thickness is 15 μm
If it is thinner than 100 μm, the mechanical strength of the polishing tape is insufficient, and if it is thicker than 100 μm, the rigidity of the tape becomes too large when the polishing tape is used, and the usability is deteriorated.

In the present invention, (A) the total dicarboxylic acid component in the molecule is provided on at least one side of the base film,
The dicarboxylic acid component having a sulfonate group is 2 to 18 mol%, 70 to 95 wt% of a copolyester having a secondary transition point of 15 to 45 ° C., and (B) an average particle diameter of 30 to
A primer coating layer having a thickness of 0.015 to 0.3 [mu] m as a main component containing 5 to 30% by weight of fine particles of 500 nm is provided.

In the copolymerized polyester (A) used as a component constituting the primer coating layer of the present invention, a dicarboxylic acid component having a sulfonate group for imparting hydrophilicity is added in an amount of 2 to 2 with respect to all dicarboxylic acid components in the molecule. A copolymer of 18 mol% is used. If this copolymerization ratio is less than 2 mol%, the hydrophilicity is insufficient, and it is difficult to prepare a good aqueous liquid when the primer coating layer is applied using an aqueous liquid, for example.
If it exceeds 18 mol%, the water resistance is poor. As the dicarboxylic acid component having a sulfonate group, polybasic acids such as 5-sodium sulfoisophthalic acid and 5-potassium sulfoterephthalic acid can be used.

Examples of the polybasic acid component other than the dicarboxylic acid component having a sulfonate group of the above copolymerized polyester include terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, 2,6-naphthalene dicarboxylic acid, 4,4.
Examples thereof include'-diphenyldicarboxylic acid, 1,4 cyclohexanedicarboxylic acid, adipic acid, sebacic acid, trimellitic acid, pyromellitic acid and dimer acid. Two or more kinds of these components can be used. Further, a small proportion of an unsaturated polybasic acid component such as maleic acid, fumaric acid, itaconic acid or the like and a hydroxycarboxylic acid component such as p-hydroxybenzoic acid or p- (β-hydroxyethoxy) benzoic acid are used together with these components. be able to. The content of unsaturated polybasic acid component and hydroxycarboxylic acid component is at most 10 mol%, preferably 5 mol% or less.

Examples of the hydroxy compound component used together with the polybasic acid component include ethylene glycol,
1,3-propanediol, 1,4-butanediol,
Examples thereof include hydroxy compound components such as 1,6-hexanediol, neopentylene glycol, diethylene glycol, 1,4-cyclohexanedimethanol, p-xylylene glycol, tetraethylene glycol, and bisphenol A alkylene oxide adduct.

The second-order transition point of the (A) copolymerized polyester (a sample was measured at 20 ° C. using a differential calorimeter (DSC)).
Measured by raising the temperature at a temperature rising rate of / min. Below "T
g)) is 15 to 45 ° C. If the Tg is less than 15 ° C, the film has insufficient blocking resistance,
If it exceeds 45 ° C, the adhesive strength will be insufficient.

The fine particles (B) used as a component constituting the primer coating layer of the present invention are organic or inorganic fine particles and have an average particle diameter of 30 to 500 nm, preferably 50 to 50 nm.
It is 300 nm. If the average particle size is less than 30 nm, the blocking resistance of the film is insufficient, and if it exceeds 500 nm, the adhesive strength is insufficient.

Examples of such fine particles include inorganic particles such as silica, alumina, titanium oxide, zinc oxide, magnesium oxide, carbon black, tin oxide, calcium carbonate, calcium oxide, aluminum oxide, kaolin, and silicon oxide, crosslinked polystyrene resin particles, Preferable examples include crosslinked polymer particles such as crosslinked acrylic resin particles, and organic particles such as melamine resin particles and silicone resin particles. Of these, silica, using crosslinked polymer particles,
It is particularly preferable because the blocking resistance when the film coated with the primer coating layer is wound is good, and the sliding property of the film coated with the primer coating layer when the abrasive layer is coated is good.

Amount ratio (% by weight) of these (A) copolyester (hereinafter sometimes simply referred to as "(A)") and (B) fine particles (hereinafter sometimes simply referred to as "(B)"). Is (A) 70-95% by weight, (B) is 5-30
% By weight. If (A) exceeds 95% by weight and (B) is less than 5% by weight, the blocking resistance of the film is insufficient,
If (B) is more than 30% by weight and (A) is less than 70% by weight, the adhesive strength of the film is insufficient.

In order to laminate the primer coating layer of the present invention on a base film (biaxially stretched polyester film made of aromatic polyester), for example, a method of coating the base film with a coating agent containing components constituting the primer coating layer is used. Can be mentioned.

The coating agent is preferably used in the form of an aqueous solution such as an aqueous solution, an aqueous dispersion or an emulsion. In the aqueous solution, for example, an antiblocking agent, an antistatic agent, an antioxidant, a heat stabilizer, Lubricants, plasticizers, ultraviolet absorbers, other binder resins, rubbers, surfactants, softeners and the like can be optionally added.

When the application of the coating agent to the base film (hereinafter sometimes referred to as "coating") is performed in a normal coating step, that is, a step separated from the film manufacturing step,
It is not preferable because it easily catches garbage and dust. From this viewpoint, coating in a clean atmosphere, that is, coating in a film manufacturing process is preferable.

The coating agent is preferably applied to a stretchable polyester film. The stretchable film is an unstretched film, a uniaxially stretched film or a biaxially stretched film, particularly preferably applied to a film uniaxially stretched in the machine direction, in this case, after applying a coating agent, dried Then, the film may be stretched in the transverse direction and, if necessary, re-longitudinal stretching or re-lateral stretching, and further heat treated.

The coating agent has a primer coating layer thickness of 0.0.
An amount of 15 to 0.3 μm is applied, but 0.02 to
It is more preferable to apply an amount of 0.2 μm. When the thickness of the primer coating layer is less than 0.015 μm, the adhesive strength is insufficient, while when it exceeds 0.3 μm, the film is apt to cause blocking, which is not preferable.

As a coating method of the coating agent, any known coating method can be applied. For example, a roll coating method, a gravure coating method, a roll brushing method, a spray coating method, an air knife coating method, an impregnation method and a curtain coating method can be used alone or in combination.

The abrasive layer of the present invention comprises a binder resin component and an abrasive particle component, and examples of the binder resin component include a copolyester resin and a polyurethane resin. It is preferable to use such a resin because the adhesive strength of the abrasive layer to the base film, the adhesive bond of the abrasive particles, and the dispersibility are improved.

Examples of the abrasive particle component include particles of alumina, silicon carbide, iron oxide, chromium oxide, diamond and the like. It is preferable to use such particles because a polishing tape excellent in lapping action and polishing action can be obtained.

The preferred average particle size of the above abrasive particles is 0.1 to 35 μm. If the average particle size is larger than 35 μm, the surface roughness becomes too large, which is not preferable. If the average particle size is smaller than 0.1 μm, the lapping action becomes insufficient, which is not preferable.

The weight ratio of the binder resin component to the polishing particle component of the abrasive layer used in the present invention is preferably 10 to 90% by weight of the binder resin component. When the ratio of the binder resin component is within the above range, dispersibility and abradability are improved, which is preferable.

If the thickness of the abrasive layer is 1 to 30 μm, the lapping action is good and the surface roughness is also good. If the thickness is more than 30 μm, the strength balance with the base film is poor, and if it is less than 1 μm, the polishing power and durability are insufficient, which is not preferable.

For the abrasive layer of the present invention, for example, a paint prepared by dispersing abrasive particles in a solution prepared by dissolving the above binder resin in an organic solvent is applied by a gravure coater, reverse coater, kiss roll coater, die coater or the like. rear,
It is possible to use a method of applying by heating and drying.

[0034]

EXAMPLES The present invention will be described in more detail with reference to examples. In the examples, a coating liquid prepared by the following method was used for evaluation coating, and the adhesive strength was evaluated by the following method.

(Preparation of coating liquid for evaluation) Terephthalic acid (52
50% by weight, isophthalic acid (48% by mole), ethylene glycol (93% by mole), neopentyl glycol (7% by mole) copolyester (Tg = 48 ° C.), tolylene diisocyanate 2% by weight and aluminum oxide 48% by weight (average particle size 3.4 μm) was dispersed and dissolved in toluene / methyl ethyl ketone (60% by weight / 40% by weight) to prepare a polishing coating having a concentration of 65% by weight.

(Adhesive Strength of Abrasive Layer) The above-mentioned polishing coating liquid for evaluation was applied to the surface of the sample polyester film to which the primer coating layer was applied by means of a Meyer bar so that the thickness after drying was about 9 μm, and at 110 ° C. Dry for 3 minutes. Then 50
The coated surface was aged for 24 hours at 0 ° C., and the coated surface was tested with a Haydon scratch tester to measure the load (g) when scratches were generated.

[Example 1] Polyethylene terephthalate having an intrinsic viscosity of 0.68 was melt extruded and cooled to obtain an unstretched sheet, which was then stretched 3.5 times in the machine direction to obtain a uniaxially stretched film. Obtained. On one side of this film, terephthalic acid [40 mol%] (hereinafter, the value in [] indicates mol%), isophthalic acid [48], 5-Na sulfoisophthalic acid [12] and 1,4 butanediol [52].・
Copolyester consisting of ethylene glycol [38] and diethylene glycol [10] (12 mol% of sulfonate group component, Tg = 28 ° C .: hereinafter referred to as “A-1”) 70% by weight, styrene-divinylbenzene having an average particle size of 148 nm An aqueous liquid having a solid content concentration of 5% by weight consisting of 15% by weight of the system crosslinked polymer fine particles (hereinafter referred to as "B-1") and 15% by weight of ethylene oxide / propylene oxide copolymer was applied by a roll coater. Then, the uniaxially stretched film coated with the aqueous solution was stretched 4 times in the transverse direction while being dried, and was further heat-set at 235 ° C. to obtain a 26 μm-thick film coated with a primer coating layer. The thickness of the primer coating layer was 0.08 μm. The properties of the polishing tape using this film are shown in Table 1.

[Examples 2 to 7, Comparative Examples 1 and 2] Example 1 except that the composition and coating thickness of the primer coating layer are shown in Table 1.
The characteristics of the polishing tape obtained in the same manner as in Table 1 are shown in Table 1.

[Comparative Example 3] Table 1 shows the characteristics of the film obtained in the same manner as in Example 1 except that the aqueous liquid was not applied.

[0040]

[Table 1]

The following were used as the copolyester and the fine particles in Table 1. A-2: 2,6-Natalenedicarboxylic acid [6] / isophthalic acid [84] / 5-Na sulfoisophthalic acid [10]
-Diethylene glycol [2] -Neopentylene glycol [26] -1,4-Butanediol [72] Copolyester (sulfonate group component 10 mol%,
Tg = 33 ° C.) A-3: terephthalic acid [36] · 4,4′diphenyldicarboxylic acid [42] · 5-K sulfoisophthalic acid [2]
2] -Ethylene glycol [85] -Neopentylene glycol [15] Copolyester (22 mol% sulfonate group component,
Tg = 97 ° C.) B-2: Methyl methacrylate [86] / Ethyl acrylate [6] / Divinylbenzene [8] Copolymerized crosslinked polymer (average particle diameter 200 nm) B-3: Styrene [93] / Divinylbenzene [8] 7] Copolymerized crosslinked polymer (average particle size 190 nm) B-4: Melamine resin fine particles (average particle size 1.2 μm)

[0042]

The polishing tape of the present invention thus obtained uses a copolyester having a specific second-order transition temperature as a constituent component of the primer coating layer in a specific ratio, and therefore is added to the polishing agent. The shearing stress is relaxed by the primer coating layer and the destruction at the interface is suppressed, so that the adhesion between the abrasive layer and the base film becomes strong.

Claims (2)

[Claims] 1. A base film composed of a biaxially stretched polyester film having a thickness of 15 to 100 μm has at least one surface thereof a dicarboxylic acid component having a sulfonate group with respect to all dicarboxylic acid components in the molecule (A). 18 mol%, 70-95% by weight of a copolyester having a secondary transition point of 15-45 ° C., and (B) an average particle size of 30-5.
A primer coating layer having a thickness of 0.015 to 0.3 μm as a main component containing 5 to 30% by weight of fine particles of 00 nm is further provided, and an abrasive layer is further provided on at least one surface of the primer coating layer. Polishing tape 2. The polishing tape according to claim 1, wherein the fine particles are silica particles and / or crosslinked polymer particles.