JPH0791396B2 - Polishing film - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to a novel polishing film,
More specifically, the present invention relates to a polishing film suitably used for removing unnecessary resin attached to the glass surface, for example, unnecessary resin attached to the back surface of a glass liquid crystal color filter.

[0002]

2. Description of the Related Art Conventionally, unnecessary ultraviolet-curing resin adhered to a glass surface is almost impossible to elute with an organic solvent or water, so it is usually scraped off with a bamboo spatula or rubber. Was extremely difficult and required a lot of work.

On the other hand, there is known a polishing film using fine particles which are harder than glass such as α-alumina, silicon carbide, chromium oxide, diamond, silicon nitride, zirconia, boron nitride and emery as abrasive grains. When the conventional polishing film is used to remove the unnecessary resin adhering to the glass surface by polishing, there is a drawback that the glass surface is damaged by the polishing process and the original function is lost.

[0004]

DISCLOSURE OF THE INVENTION The present invention is a polishing method capable of easily removing an unnecessary portion of a cured resin adhering to a glass surface, which hardly dissolves with an organic solvent or water, without damaging the glass surface. It was made for the purpose of providing a film for use.

[0005]

DISCLOSURE OF THE INVENTION The inventors of the present invention have conducted various studies on a polishing film for removing an unnecessary portion of a cured resin attached to a glass surface, and as a result, have obtained at least one surface of a synthetic resin film. In addition, a water-soluble urea-formalin initial condensation product, an acrylic emulsion and a water-based composition of a specific composition mainly composed of specific inorganic fine particles or a cured layer of a composition of a specific composition mainly composed of an aqueous urethane resin and specific inorganic fine particles It has been found that the film provided with can remove unnecessary cured resin without damaging the glass surface, and has completed the present invention based on this finding.

That is, according to the present invention, (A) a water-soluble urea-formalin initial condensate, (B) an acrylic emulsion, and (C) an average particle size of 0.5 to 10.0 μm on at least one surface of the synthetic resin film. A composition comprising inorganic fine particles having a Mohs hardness of 7 or less and (D) a crosslinking catalyst, or (a)
Water-based urethane resin, (b) aziridine-based curing agent, (c)
The present invention provides a polishing film provided with a cured layer of a composition comprising an inorganic fine particle having an average particle size of 0.5 to 10.0 μm and a Mohs hardness of 7 or less and (d) a curing retarder.

The polishing film of the present invention can be obtained by coating the composition or the composition as an aqueous dispersion on at least one surface of a synthetic resin film and curing the composition. The synthetic resin film is not particularly limited, and those conventionally used for polishing films can be used, but those having high mechanical strength and excellent dimensional stability and heat resistance are preferable, for example polyethylene terephthalate. A film, a stretched polypropylene film, a diacetyl cellulose film, a triacetyl cellulose film and a polycarbonate film are preferably used.

The thickness of these synthetic resin films is usually selected in the range of 20 to 200 μm, preferably 25 to 75 μm, and at least one surface to which the composition is applied is subjected to physical treatment such as electrical discharge machining. Pretreatment by chemical treatment such as coating with a chemical substance is desirable.

In the hardened layer provided on at least one surface of the synthetic resin film, the water-soluble urea-formalin initial condensate used as the component (A) is prepared by a known method, for example, urea and formalin in the presence of a base such as ammonia. It is obtained by condensing and. The initial condensate has a methylol group at the terminal, and this methylol group may be etherified with a lower alcohol such as methyl alcohol, ethyl alcohol, n-propyl alcohol or isopropyl alcohol, if desired.

The component (A) acts as a curing agent for the acrylic emulsion (binder) of the component (B),
By increasing the curability of the coating layer to improve water resistance and solvent resistance, the coating layer is protected by water, alcohol, grinding oil, etc. used for the purpose of preventing scattering of polishing powder and improving slipperiness during polishing. It has the effect of preventing elution or peeling and falling off. The object of the present invention can also be achieved by replacing a part of the component (A) with a melamine-formalin initial condensate.

The acrylic emulsion of the component (B) in the composition (1) has the general formula

[Chemical 2] An aqueous emulsion containing acrylic polymer fine particles having a monomer unit represented by the formula (R in the formula is a hydrogen atom, a methyl group, an ethyl group, a propyl group or the like), wherein acrylic acid and methyl acrylate are used. It can be obtained by emulsion polymerization of at least one acrylic monomer selected from acrylic acid esters such as ethyl acrylate and propyl acrylate. The component (B) has a function of holding the inorganic fine particles of the component (C) as a binder and imparting adhesiveness between the synthetic resin film and the coating layer.

The inorganic fine particles of component (C) have an average particle size of 0.5 to 10.0 μm, preferably 1.
It is necessary to use one having a Mohs hardness of 7 or less in the range of 0 to 5.0 μm. This average particle size is 0.
If it is less than 5 μm, the polishing property is poor, and it is difficult to remove unnecessary cured resin. If it exceeds 10.0 μm, a composition in which inorganic fine particles are uniformly dispersed cannot be obtained, and a uniform coating surface cannot be obtained during coating. In addition, in the polishing process, an unfavorable situation such as scratching even on the glass surface is brought about. If the Mohs hardness exceeds 7, the glass surface is likely to be scratched during the polishing process.

As such inorganic fine particles, for example, natural silica fine particles and synthetic silica fine particles are suitable,
Examples of the natural silica fine particles include silica sand containing quartz as a main component, silasperlite, and the like. Examples of the synthetic silica particles include those obtained by the reaction of sodium silicate and acid, those obtained by the hydrolysis of alkoxysilane, and those obtained by the reaction of calcium silicate and acid. In the present invention, one kind of these silica fine particles may be used, or 2
You may use it in combination of 2 or more types.

As the crosslinking catalyst of the component (D) in this composition, ammonium salts such as ammonium chloride and ammonium oxalate are preferably used. This cross-linking catalyst has a function of cross-linking and hardening the water-soluble urea-formalin initial condensate, and also has a part of cross-linking action to the acrylic emulsion. For example, ammonium chloride is decomposed into ammonia and hydrogen chloride by heating, and hydrogen chloride acts as a crosslinking catalyst, and then the decomposed product is discharged out of the system in the drying step and does not finally remain in the coating film.

Regarding the mixing ratio of each component in this composition, 100 parts by weight of the solid content of the water-soluble urea-formalin initial condensate which is the (A) component, the acrylic emulsion of the (B) component is converted into the solid content. 50 to 90 parts by weight,
50 to 400 parts by weight, preferably 70 to 200 parts by weight of the inorganic fine particles of the component (C) and 1 to 5 parts by weight, preferably 2 to 4 parts by weight of the crosslinking catalyst of the component (D) are blended. Good. When the blending ratio of each component is within the above range, the obtained polishing film can sufficiently exhibit the initial effect.

When the amount of the acrylic emulsion as the component (B) is less than 50 parts by weight in terms of solid content, the cross-linking density is low and the coating film is poor in water resistance and solvent resistance.
The use of alcohol, grinding oil, etc. is not preferable because the coating film may be eluted or peeled off. Further, if the amount of the inorganic fine particles of the component (C) is less than 50 parts by weight, the polishing ability will be inferior.
If the amount is more than parts by weight, the resin component cannot hold the inorganic fine particles, and the particles are likely to be shed, which is not preferable. Furthermore, it is desirable to appropriately select the preferable amount of the curing catalyst within the above range in consideration of the balance between the pot life and curability of the composition.

In the composition for forming the other cured layer, the aqueous urethane resin used as the component (a) has a urethane bond introduced into a prepolymer having a main chain skeleton of polyester, polyether or polyacrylic acid. And has an action of holding the inorganic fine particles of the component (c) as a binder and imparting adhesiveness between the synthetic resin film and the coating layer.

Examples of the aziridine-based curing agent as the component (b) in this composition include diphenylmethane-bis-
4,4'-N, N'-diethyleneurea and 2,2-bishydroxymethylbutanol-tris [3- (1-aziridinyl) propionate] are commonly known and may be used alone or in combination. You may use. The component (b) acts as a curing agent for the aqueous urethane resin of the component (a), enhances the curability of the coating layer, improves water resistance and solvent resistance, and prevents scattering of polishing powder during polishing treatment. It also has the function of preventing the coating layer from being eluted or peeled off by water, alcohol, grinding oil, etc. used for the purpose of improving the slipperiness. Further, the object of the present invention can be achieved by replacing a part of the component (b) with a blocked isocyanate compound.

As the inorganic fine particles of the component (c) in this composition, those similar to the inorganic fine particles of the component (C) in the composition described above are used.

Further, the curing retarder of the component (d) in this composition has the action of making the pH of the composition alkaline and preventing the curing reaction in the composition to prolong the pot life of the composition. As such, for example, alkali such as ammonium hydroxide, sodium hydroxide, potassium hydroxide is preferably used, and these may be used alone or in combination of two or more. Ammonium hydroxide is particularly preferable because it is discharged to the outside of the system during the drying step and facilitates the subsequent curing reaction.

Regarding the blending ratio of each component in this composition, the solid content of the aqueous urethane resin which is the component (a) is 1
3 to 25 parts by weight, preferably 5 to 15 parts by weight, of the aziridine-based curing agent as the component (b), and 50 to 400 parts by weight of the inorganic fine particles as the component (c), relative to 00 parts by weight, 70 to 200 parts by weight and 2 to 15 parts by weight, and preferably 5 to 10 parts by weight of the curing retarder as the component (d). When the blending ratio of each component is within the above range, the obtained polishing film can sufficiently exhibit the initial effect.

When the amount of the aziridine-based curing agent as the component (b) is less than 3 parts by weight in terms of solid content, the crosslink density is small and the coating film is poor in water resistance and solvent resistance. The use of oil or the like is not preferable because the coating film may be eluted or peeled off. Further, if the amount of the inorganic fine particles of the component (c) is less than 50 parts by weight, the polishing ability is poor, and if it exceeds 400 parts by weight, the resin component cannot hold the inorganic fine particles,
This is not preferable because shedding tends to occur. Furthermore, it is desirable to appropriately select a preferable amount of the curing retarder within the above range, in consideration of the balance between pot life and curability of the composition.

Each composition forming the cured layer of the present invention comprises:
If desired, other additive components, for example, a colorant such as an organic pigment or an inorganic pigment may be blended within a range that does not impair the object of the present invention.

To apply these compositions, for example, a predetermined ratio of (A), (B),
The components (C) and (D) or the components (a), (b), (c) and (d) and optionally added components are homogeneously dissolved or dispersed.

As the aqueous medium, for example, water or a mixture of water and a water-miscible organic solvent is used. Examples of the water-miscible organic solvent include methyl cellosolve, ethyl cellosolve, propyl cellosolve, butyl cellosolve, diacetone alcohol and methyl ethyl ketone.

In the polishing film of the present invention, at least one surface of the synthetic resin film is usually pretreated, and then the aqueous dispersion prepared as described above is treated with, for example, a roll coater or a blade. It can be manufactured by coating using a coater, a bar coater or the like, and then heating, drying and curing. The thickness of the cured coating layer thus formed is preferably in the range of 1 to 10 μm, and in this range, good coating film smoothness and polishing properties are exhibited.

[0027]

EFFECT OF THE INVENTION The polishing film of the present invention can easily remove the unnecessary portion of the cured resin attached to the glass surface, which can hardly be eluted with an organic solvent or water without damaging the glass surface. For example, it is preferably used for removing unnecessary resin adhering to the back surface of a glass liquid crystal color filter.

[0028]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 100 parts by weight of urea-formalin initial condensation product (solid content), 74 parts by weight of acrylic emulsion (solid content), 100 parts by weight of natural silica powder having an average particle diameter of 1.5 μm (Mohs hardness 7). Parts, 3 parts by weight of ammonium chloride, 0.3 parts by weight of a blue organic pigment, 15 parts by weight of methyl cellosolve and 200 parts by weight of water, and uniformly dispersing the resulting dispersion to obtain a polyethylene having a thickness of 75 μm. A terephthalate film (manufactured by Dia foil Co., Ltd.) was coated on one surface so that the film thickness after drying was 5 μm, and dried and cured to obtain a polishing film.

Example 2 100 parts by weight of aqueous urethane resin (solid content), 6.3 parts by weight of aziridine curing agent (solid content), 100 parts by weight of natural silica powder having an average particle size of 1.5 μm, ammonium hydroxide 5.5 parts by weight and 100 parts by weight of water were mixed and uniformly dispersed to obtain a polishing film in the same manner as in Example 1 using a dispersion liquid.

Example 3 Same as Example 1 except that natural silica powder having an average particle size of 3.0 μm (Mohs hardness 7) was used in place of the natural silica powder having an average particle size of 1.5 μm. To obtain a polishing film.

Comparative Example 1 As in Example 1, except that α-alumina powder (Mohs hardness 12) having an average particle size of 1.5 μm was used in place of the natural silica powder having an average particle size of 1.5 μm. A polishing film was obtained in the same manner.

Comparative Example 2 Same as Example 1 except that natural silica powder having an average particle size of 0.1 μm (Mohs hardness 7) was used in place of the natural silica powder having an average particle size of 1.5 μm. To obtain a polishing film.

Comparative Example 3 In the same manner as in Example 1, except that natural silica powder having an average particle size of 15 μm (Mohs hardness 7) was used in place of the natural silica powder having an average particle size of 1.5 μm. A polishing film was obtained.

The cured UV ink (manufactured by Toyo Ink Co., Ltd.) adhered to the glass surface was polished using each of the obtained polishing films, and the removal ability and the presence or absence of scratches on the glass surface were evaluated. The results are shown in Table 1.

[0036]

[Table 1]

Claims (14)

[Claims] 1. A synthetic resin film having (A) a water-soluble urea-formalin initial condensate, and (B) on at least one surface thereof.
Acrylic emulsion, (C) average particle size 0.5 to 1
A polishing film provided with a cured layer of a composition comprising an inorganic fine particle having a Mohs hardness of 7 or less and a cross-linking catalyst (D) having a thickness of 0.0 μm. 2. The polishing film according to claim 1, wherein the synthetic resin film is a polyethylene terephthalate film, a stretched polypropylene film, a diacetyl cellulose film, a triacetyl cellulose film or a polycarbonate film. 3. The polishing film according to claim 1, wherein the water-soluble urea-formalin initial condensate has a methylol group or an alkoxymethyl group at the terminal. 4. An acrylic emulsion has the general formula: 4. An aqueous emulsion containing fine particles of an acrylic polymer having a monomer unit represented by the formula (R in the formula is a hydrogen atom, a methyl group, an ethyl group or a propyl group). The polishing film described in 1. 5. The polishing film according to claim 1, wherein the inorganic fine particles are at least one selected from natural silica fine particles and synthetic silica fine particles. 6. The polishing film according to claim 1, wherein the crosslinking catalyst is at least one selected from ammonium salts. 7. The composition comprises 50 to 90 parts by weight of the component (B), 50 to 400 parts by weight of the component (C), and (D) with respect to 100 parts by weight of the solid content of the component (A). The polishing film according to any one of claims 1 to 6, which comprises 1) to 5 parts by weight of the component). 8. An (a) aqueous urethane resin, (b) an aziridine-based curing agent, (c) an inorganic material having an average particle size of 0.5 to 10.0 μm and a Mohs hardness of 7 or less on at least one surface of the synthetic resin film. A polishing film provided with a cured layer of a composition comprising fine particles and (d) a curing retarder. 9. The polishing film according to claim 8, wherein the synthetic resin film is a polyethylene terephthalate film, a stretched polypropylene film, a diacetyl cellulose film, a triacetyl cellulose film or a polycarbonate film. 10. The water-based urethane resin is a polyester type,
10. The polishing film according to claim 8, which is prepared by introducing a urethane bond into a prepolymer having a main chain skeleton of a polyether type or a polyacrylic acid type and emulsified. 11. An aziridine-based curing agent is diphenylmethane-bis-4,4'-N, N'-diethyleneurea and 2,2-bishydroxymethylbutanol-tris [3].
The polishing film according to any one of claims 8 to 10, which is at least one selected from-(1-aziridinyl) propionate]. 12. The polishing film according to claim 8, wherein the inorganic fine particles are at least one selected from natural silica fine particles and synthetic silica fine particles. 13. The polishing film according to claim 8, wherein the curing retarder is at least one selected from ammonium hydroxide, sodium hydroxide and potassium hydroxide. 14. The composition has a solid content of component (a) of 100.
The component (b) is 3 to 25 parts by weight, the component (c) is 50 to 400 parts by weight, and the component (d) is 2 to 15 parts by weight based on parts by weight. A polishing film as described in Crab.