KR101709313B1 - Method for Preparing Polishing Pad comprising Polyurethane Layer - Google Patents

Abstract

The present invention relates to a method of manufacturing a polishing pad and a polishing pad manufactured by the method. The polishing pad manufactured by the manufacturing method of the present invention is excellent in durability as compared with a conventional polishing pad, Method can shorten the time required for manufacturing a conventional polishing pad and can provide an economical effect.

Description

[0001] The present invention relates to a method of preparing a polishing pad comprising a polyurethane layer,

The present invention relates to a method of manufacturing a polishing pad comprising a polyurethane layer.

Abrasive work to process various tool surfaces has been used in various industries for the processing of woodworking, metal, glass, ceramics, jewelry, semiconductor wafers, etc. by using a variety of hardness polishing pads. However, in the case of the polishing pad used in the polishing operation, the urethane polymer layer supporting the abrasive and the abrasive is easily separated from the substrate film due to the repeated rubbing with the surface of the material requiring processing.

Representative methods of polishing are classified into dry polishing and wet polishing. Commercial polishing pads require various physical properties such as abrasion resistance, heat resistance and water resistance depending on the working environment of dry and wet. This dry polishing has an advantage in that the polishing state of the surface is smooth and the dust generated after polishing is easy compared with the wet polishing, but the polishing rate is lower than that of the wet polishing using water and the abrasive of the pad is consumed in a large amount . Therefore, a process for firmly fixing the substrate to the substrate is required in order to prevent the abrasion of the surface of the substrate in order to improve the consumption of the pad caused by the polishing operation. This process requires a process that can be applied to the actual polishing pad process by rapidly and strongly bonding the fixation of the abrasive article. Currently, fused alumina, silicon carbide, artificial diamond, CBN (cubic boron nitride), SG (Seeded Gel) and the like are generally used for the dry polishing.

The industrial polishing pad is manufactured by fixing the above-described abrasive to a flexible plastic substrate. In general, polyethylene terephthalate (PET) films are widely used, but this is not necessarily an example of a conventional polishing pad. PET films are used in various fields such as optical materials, electronic materials, electrical insulating materials, solar light materials, and food packaging. In addition, since PET films have excellent mechanical properties and transparency, thermal stability, moisture resistance, chemical resistance, and possibility of use in a wide temperature range (-70 ° C to -260 ° C), various types of polishing pads used in mechanical and chemical polishing operations It is suitable as a base film (0 base film).

In order to fix the abrasive used in the commercially produced PET film to the surface, an adhesive of an intermediate layer of a polymer material is used. Adhesives commonly used in polishing pads are synthesized by the reaction of polyurethane with polyisocyanate and polyol. The isocyanate group (-N = C = O) is easily bonded to a hydroxyl group (urethane bond) (urethane bond) and has excellent physical properties and workability through formation of a three-dimensional network structure. Generally, toluene diisocyanate is used as the diisocyanate, and polyether or polyester is used as the molecule having the hydroxyl group (polyol). The polyether is softened, the polyester is used as hard plastic, and the polyurethane made by using molecules having three or more hydroxyl groups as polyol is three-dimensionally bonded. Therefore, the polyurethane having such a structure has a characteristic that it does not deform against heat. However, in the process of manufacturing most abrasives, a one-step fixing method is used in which the abrasive is fixed after spraying the polyurethane directly on the surface in the abrasive fixing step. At this time, the stability between the PET substrate and the abrasive agent often weakens the strength of the abrasive pad, thereby frequently causing a problem of weakening the performance of the abrasive pad. For example, the method disclosed in Korean Patent No. 10-0828627 is similar to the method of applying the polyurethane mixed solution, but there is a problem in economical efficiency due to the thickness variation of the surface or the complexity of the process by the wet production method, The method disclosed in Patent No. 10-0955032 is effective for an LCD glass substrate and the like due to the property of a heterogeneous elastic body between a substrate and a polyurethane because a rubber layer such as polybutadiene is inserted. .

Numerous papers and patent documents are referenced and cited throughout this specification. The disclosures of the cited papers and patent documents are incorporated herein by reference in their entirety to better understand the state of the art to which the present invention pertains and the content of the present invention.

The present inventors have made efforts to produce a polishing pad having improved adhesion of the abrasive layer. As a result, the present invention has been accomplished by coating a polyurethane layer between a substrate and an abrasive layer to manufacture a polishing pad having improved durability over existing polishing pads.

Accordingly, it is an object of the present invention to provide a method of manufacturing a polishing pad.

Another object of the present invention is to provide a polishing pad.

Other objects and advantages of the present invention will become more apparent from the following detailed description of the invention, claims and drawings.

According to one aspect of the present invention, the present invention provides a method of making a polishing pad comprising the steps of:

(a) providing on the substrate (i) a polyurethane; (Ii) a solvent; And (iii) mixing a curing agent to coat the polyurethane layer;

(b) coating the abrasive on the polyurethane layer; And

(c) coating the epoxy on the abrasive.

The present inventors have made efforts to produce a polishing pad having improved adhesion of the abrasive layer. As a result, a polyurethane primer layer was coated between the substrate and the abrasive layer to prepare a polishing pad having improved durability than the conventional polishing pad.

The method of manufacturing the polishing pad of the present invention will be described step by step.

Step (a): coating the polyurethane layer

First, on the substrate, (i) polyurethane; (Ii) a solvent; And (iii) a curing agent are mixed to coat the polyurethane layer.

One of the main features of the present invention is to include a polyurethane layer between the substrate of the polishing pad and the abrasive layer.

The substrate is a substrate for a polishing pad selected by those skilled in the art.

According to one embodiment of the present invention, the substrate includes but is not limited to PET (polyethylene terephthalate), polyamides, and polyimides. The polyamides include polyphthalamides such as Aliphatic polyamides such as PA6 and PA66, hexamethlenediamine + terephthalic acid (PA 6T), aromatic polyamides (aramides), and combinations thereof. The polyimide includes polyetherimide homopolymers, polyetherimide copolymers, and combinations thereof.

According to another embodiment of the present invention, the substrate is PET.

Typically, the substrate may be primarily coated with a polyurethane primer layer. In this case, the thickness of the polyurethane primer layer is 1 占 퐉 or less. If the substrate is a substrate having a polyurethane primer layer, the polyurethane layer is coated according to the present invention, and if the substrate is a substrate having no polyurethane primer layer, only the polyurethane layer of the present invention is coated.

A key feature of the present invention is that it comprises a polyurethane layer between the substrate and the abrasive.

Said polyurethane layer comprising (i) polyurethane; (Ii) a solvent; And (iii) a curing agent.

According to one embodiment of the present invention, the polyurethane layer is prepared by mixing 10-50 wt% polyurethane, 45-65 wt% solvent and 1-5 wt% curing agent.

The solvent for preparing the polyurethane layer of the present invention may be selected from the group consisting of methyl ethyl ketone, toluene, methyl isobutyl ketone, ethyl acetate, xylene, Water, methanol, ethanol, propanol, butanol, isopropyl alcohol, acetone, ethylene glycol, propylene glycol, And glycerin, but are not limited thereto.

According to one embodiment of the present invention, the solvent is a mixture of methyl ethyl ketone and toluene.

According to another embodiment of the invention, the solvent is a 1: 1 mixture of methyl ethyl ketone and toluene.

The curing agent for preparing the polyurethane layer of the present invention is selected from the group consisting of polyamide resin, cyanoguanidine, benzoguanamine, plasticised urea resin and magnesium hydroxide But are not limited to, one or more curing agents selected.

According to one embodiment of the present invention, the curing agent is a polyamide resin.

The polishing pad of the present invention allows the abrasive to be firmly fixed on the substrate through the wet coating of the polyurethane layer.

As used herein, the term " wet coating " refers to a coating that passes through a solvent volatilization and curing process after a coating material (e.g., polyurethane and curing agent) is mixed with a solvent and transferred to the surface of the material with a constant viscosity.

According to one embodiment of the present invention, the polyurethane layer is dried after the wet coating of 1-10 占 퐉, 2-8 占 퐉, or 2-6 占 퐉. The polyurethane layer forms a polyurethane layer of 1-5 占 퐉, 1-4 占 퐉, or 1-3 占 퐉 thickness after drying.

The polyurethane layer is fully cured within 5 minutes at a temperature condition of 110 ° C to 150 ° C. In order to shorten the time required for the curing, a hardening catalyst may be additionally included.

According to one embodiment of the present invention, the polyurethane layer further comprises a curing catalyst.

The curing catalyst may be selected from the group consisting of tris (3-dimethylamino) propyl hexahydrotriamine, N-methylmorpholine, N-ethylmorpholine, N-octadecylmorpholine, bis [2- (N, N, N, N ', N'-tetramethylbutane, N, N'-dimethyldiethanolamine, N, N, N'-dimethylbenzylamine, N, N ', N'-tetramethyl-1,3-butanediamine, -Dimethyl cyclohexylamine, N, N, N ', N', n'-pentamethyldiethylenetriamine, triethylamine, tripropylamine, triisopropanolamine, tributylamine, trioctylamine, pentamethylenediamine diamine (PMDETA), tetraethylenediamine (TEDA) hexadecyldimethylamine, triethylenediamine, formic acid and other salts of triethylenediamine, amino groups of primary and secondary amines and oxyalkylene Aminocarbonyls of N, N ', N'-trialkylaminoalkylhexahydrotriazides and azelaic compounds such as N, N, N-dialkylpiperazines, and N, N' But is not limited thereto.

According to one embodiment of the present invention, the curing catalyst comprises 0.1-5.0 wt%, 0.5-4.0 wt%, or 0.5-2.5 wt% of the subject (polyurethane and solvent).

Another of the main features of the present invention is that the polyurethane layer included between the substrate of the polishing pad and the abrasive layer constitutes a single layer or a double layer.

According to an embodiment of the present invention, the method further comprises a step (ab) of additionally coating a polyurethane layer between the steps (a) and (b).

The polishing pad of the present invention includes a polyurethane layer as a single layer or a double layer for fixing the abrasive to the substrate between the substrate and the abrasive layer.

The polyurethane layer of step (ab) is coated so as to be suitable for adhesion of the abrasive.

According to one embodiment of the invention, the polyurethane layer of step (ab) has 10-30%, 14-26%, 15-25% or 18-22% thickness of abrasive. This thickness can be controlled by the amount of solvent.

If the polyurethane layer in the step (ab) is 30% or more, it is warped after drying and the durability is poor.

The polyurethane layer of step (ab) is fully cured within 5 minutes at a temperature of 110 [deg.] C to 150 [deg.] C. In order to shorten the time required for the curing, a hardening catalyst may be additionally included.

According to one embodiment of the present invention, the polyurethane layer further comprises a curing catalyst.

Step (b): The coating film of the abrasive

Next, an abrasive is coated on the polyurethane layer.

The coating film of the abrasive may be carried out by a conventional method selected by a person skilled in the art. For example, an abrasive is scattered on the surface of the polyurethane layer before curing after the coating of the polyurethane layer of step (a).

The abrasive comprises any abrasive selected by those skilled in the art. For example, fused alumina, cofused alumina-zirconia, sintered alumina-zirconia, silicon carbide, cubic boron nitride, diamond diamond, flint, garnet, bubbled alumina, bubbled alumina-zirconia, aluminum oxide, cerium oxide, silicon dioxide ), Zirconium oxide and titanium oxide, and mixtures thereof.

According to one embodiment of the present invention, the abrasive is fused alumina, fused alumina-zirconia or semi-fused alumina-zirconia.

According to another embodiment of the present invention, the abrasive is fused alumina.

Step (c): coating of epoxy

Next, epoxy is coated on the abrasive.

The epoxy comprises any epoxy selected by one of ordinary skill in the art. For example, one or more epoxy selected from the group consisting of bisphenol A epoxy, bisphenol F, novolac epoxy, aliphatic epoxy, glycidyl amine epoxy, and mixtures thereof, but is not limited thereto.

According to one embodiment of the present invention, the epoxy is a fresh ETC, a colored epoxy EP-7 green 106 (GREEN).

According to another embodiment of the present invention, there is provided a polishing pad manufactured by the method of manufacturing the polishing pad.

Since the polishing pad of the present invention utilizes the method of manufacturing the polishing pad, the description common to both of them is omitted in order to avoid the excessive complexity of the present specification.

The features and advantages of the present invention are summarized as follows:

(a) The present invention provides a method of manufacturing a polishing pad and a polishing pad produced by the method.

(b) The polishing pad manufactured by the manufacturing method of the present invention is superior in durability as compared with the conventional polishing pad.

(c) The polishing pad manufacturing method of the present invention can shorten the time required for manufacturing a conventional polishing pad, and thus can provide economic effects.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flowchart sequentially showing a method for manufacturing a polishing polypentan adsorption pad. FIG.
2 is a cross-sectional view of a general polishing pad having a urethane primer layer inserted therein.
FIGS. 3A and 3B show a state before the coating of the make coat layer using the polyurethane, after the coating, and after the coating of the abrasive material, the abrasive material is impregnated with the abrasive material and dried.
Fig. 4 is a view of a polishing pad which is completely cured by applying an upper layer epoxy resin.
FIG. 5 shows a state in which no abrasive layer cracks or abrasive release are observed as compared to a commercial polishing pad when folded or bent for comparison of durability of the manufactured polishing pad.

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these embodiments are only for describing the present invention in more detail and that the scope of the present invention is not limited by these embodiments in accordance with the gist of the present invention .

Example

Experimental material

The curing agent used in the present invention is a H-10 curing agent (high molecular weight polymer) and a TORAY TORAY high-tech two-sided urethane XG-352, XG-5022X70 (Kukdo G-5022X70 Polyamide resin solution) 5P2 and corona discharge treated transparent film XG-210. The two-pack type polyurethane used was purchased from CJ International and Sejong Chemical. The micrometer used for thickness measurement is Mitotoyo, Coolant proof micrometer IP65 (0-25 mm measurement, error range 0.001 mm).

Urethane coating on PET substrate

The polishing pad aiming at development in the present invention has a structure as shown in Fig. Since the polishing pad must have flexible characteristics for various types and applications, a PET film having a thickness of 50-200 micrometers is generally used. This conventional PET film directly applies the polyurethane layer for fixing the lower layer abrasive on the PET film using a polyurethane solvent proportional to the size of the abrasive for immobilizing the abrasive on the substrate (Fig. 2). Polyurethane for showing the excellence of this patent uses various methods according to the abrasive process. Two-liquid type which requires a curing time of about 1 hour is generally used depending on characteristics to be thickly applied. In this patent, The application method of the polyurethane layer is not specifically described.

The primary urethane primer coating of FIG. 2 is carried out on the purchase of Toray's double-sided urethane-coated PET film, and proceeded from the secondary urethane primer coating. A 1-2 μm thick coating film is formed after drying using a bar coater which is generally 1 micrometer or less in thickness for the primary and a wet film thickness of 4 micrometers in the secondary. Two - component urethane was used and the curing time was shortened by using a catalyst. In the case of the polyurethane for bonding the lower abrasive, it is preferable to form a coating film having a thickness of 20% of the abrasive. Since the size of the abrasive of the present invention is approximately 1 mm, a bar coater forming a wet coating film having a thickness of 200 탆 was used. However, in this case, it was confirmed that the thickness of the coating film after drying was reduced by about 10 times as compared with that of the wet film. The thickness of the coating thus measured was about 20 micrometers. When the urethane was dissolved in the solvent, the amount of the solvent was adjusted to increase the thickness of the coating after drying to 30 쨉 m. However, when the coating film having a thickness of 30 쨉 m was formed, Respectively. Therefore, it is preferable to form the thickness of the coating film not exceeding 20 탆 (20% of the abrasive thickness), preferably after drying. In the case of applying the polyurethane layer for bonding the lower layer abrasive, the two-component urethane was used, and the curing time was shortened by increasing the amount of the catalyst introduced in proportion to the amount of urethane. Curing time is about 30 minutes. In the case of the polyurethane for bonding the lower layer abrasive, the abrasive must be contained, so that the hardening is carried out after spreading the abrasive. The method of spraying the abrasive is preferably a method in which the wet film is uniformly sprayed in the state where the wet film is formed before curing the polyurethane for bonding the lower layer abrasive. In the laboratory, they scattered directly by hand. After the application of the abrasive material, the abrasive material was firmly bonded to the wet coating film by physically pushing it with a flat plate. However, when the abrasive material naturally settled at a room temperature for a while without such a process, the abrasion material naturally showed a similar durability. Also, during this process, urethane and acrylic spray could be sprayed to increase the bonding force. The polishing pad thus prepared was dried for about 20 minutes, and then an epoxy spray was applied and dried for 60 minutes to complete the polishing pad. The temperature is all 130 ° C.

The particle size of the abrasive used in the present invention is # 46, and the thickness of the coating film is 20 μm using a bar coater.

The urethane primer layer applied to the urethane primer layer proposed in the present invention is coated with a urethane primer layer by using a two-component polyurethane solvent in order to enhance bonding strength with an abrasive having various particle sizes. These urethane primers are used in a ratio of urethane: curing agent: solvent = 100: 5: 150 and thinly coated using a bar coater to form a wet film thickness. This forms a coating film having a thickness of 2 micrometers or less after curing. If necessary, a thin coating film having a thickness of 1 micrometer or less can be added after the primary curing. The coating film of the urethane primer layer is completely cured within 1 to 2 minutes at a temperature of 130 ° C, in which the curing time is shortened by introducing a catalyst of 1-2% of the base, and no stickiness occurs.

The coating layer of the polyurethane layer

In order to compare the results according to the present invention, the following secondary urethane primer layer was applied and then the lower layer polyurethane fixing layer was immersed in a two-component polyurethane solvent having a ratio of 100: 5: 150 (urethane: curing agent: solvent) Lt; / RTI > The thickness of the coating film is controlled according to the amount of the solvent in proportion to the size of the abrasive. The particle size of the abrasive used in the present invention was # 46 to form a film thickness of 20 micrometers. The make coat layer applied by the above method causes a part of the coat to be impregnated through the application of the abrasive before curing. The type of abrasive is fused alumina series, and it is applied to a make coat and then a physical pressure is applied to help impregnation. The PET film impregnated with the abrasive is completely cured at a temperature of 130 ° C within 20 minutes for curing of the make coat, which shortens the curing time and prevents tackiness by introducing 1-2% of the catalyst compared to the base. After curing of the make coat, a size coat is formed through application of an epoxy resin by a spray coating method, thereby additionally supporting the abrasive and assisting adhesion. The applied epoxy resin is cured at room temperature for 20 minutes and completely cured at 130 ° C within 1 hour. A photograph of the application of the lower layer polyurethane layer until the abrasive is applied is shown on the left side of Fig. 3, and a photograph of the abrasive applied on the right side of Fig. Thereafter, epoxy coating by spraying used in a general polishing pad process was performed to produce a final polishing pad to which the present invention process was added (FIG. 4).

Durability test

The prepared polishing pad observes the abrasion of the abrasive article by folding or bending to test the durability of the polishing pad. 5, in the case of the commercial polishing pad, although the abrasive particle size is small, when the abrasive is impregnated with the abrasive, the lower layer polyurethane layer is separated from the PET, and then, when it is physically scratched Abrasion of the abrasive was observed. In the case of the polishing pad manufactured by the present invention, no crack was observed in the polishing pad when the size of the abrasive pad was folded and the abrasive did not separate from the abrasive pad even when the size of the abrasive pad was relatively large.

Therefore, it can be seen that the polishing pad according to the present invention has remarkably improved durability as compared with the commercial polishing pad, and the economical effect of shortening the curing time by shortening the curing time through the introduction of the catalyst can be expected.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the present invention. It is therefore intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

Claims (9)

A method of manufacturing a polishing pad comprising the steps of:
(a) 10 to 50 parts by weight of a polyurethane (i) on a substrate; (Ii) 45 to 65 parts by weight of a solvent; And (iii) 1 to 5 parts by weight of a curing agent is prepared and wet-coated to form a 1-5 mu m polyurethane layer;
(b) forming a polyurethane layer for abrasive adhesion having a thickness of 10-30% of the polishing pad on the polyurethane layer;
(c) spraying an abrasive on the polyurethane layer for adhering the abrasive and curing the same; And
(d) coating the epoxy on the abrasive.
delete 2. The method of claim 1, wherein the polyurethane layer further comprises a hardening catalyst.
The method of claim 1, further comprising the step (ab) of additionally coating a polyurethane layer between steps (a) and (b).
A polishing pad produced by the method of any one of claims 1, 3, and 4.
The polishing pad according to claim 5, wherein the polyurethane layer is prepared by mixing 10-50 parts by weight of polyurethane, 45-65 parts by weight of a solvent, and 1-5 parts by weight of a curing agent.
6. The polishing pad of claim 5, wherein the polyurethane layer is located between the substrate and the abrasive.
6. The polishing pad of claim 5, wherein the polyurethane layer further comprises a hardening catalyst.
6. The polishing pad of claim 5, wherein the polishing pad comprises at least one polyurethane layer.

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