JP2022079881A - Resin composition and forming method for coating layer on plate - Google Patents

Abstract

To provide a resin composition capable of suppressing stress generated internally when forming a coating layer on a plate and maintaining high productivity and a forming method for the coating layer on a plate using the resin composition.SOLUTION: The resin composition is composed by including a photopolymerization initiator in a composition including (meth)acrylate, a plasticizer or reactive diluent, and an adhesive agent. By mixing these multiple materials in appropriate portions, it is possible to achieve a resin composition that can be cured in a short time while suppressing shrinkage. It is possible to prevent so-called springback, which is caused by the reappearance of warpage or undulation when a coating layer formed on a plate-like object is removed.SELECTED DRAWING: Figure 4

Description

The present invention relates to a resin composition used for forming a coating layer on a plate-shaped material such as a wafer, and a method for forming a coating layer on a plate-shaped material using the resin composition.

Wafers used as materials for semiconductor devices (devices) are usually cut out from ingots made of semiconductors such as silicon, silicon carbide, and gallium nitride with tools such as band saws and wire saws.

The wafer (as sliced wafer) immediately after being cut out in this way has warpage and waviness. Therefore, a resin is applied to one side of this wafer and cured to form a coating layer, and after forming a reference surface with this coating layer, the surface to be ground exposed to the other side while holding the reference surface side on a table. A processing method for flattening a wafer by removing warpage and waviness by grinding the wafer has been proposed (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2009-148866

Generally, a resin containing a liquid such as water or a solvent shrinks when the liquid is volatilized. Further, the curable resin that is cured by light or heat tends to shrink due to a change in volume before and after curing. When a resin having a high shrinkage rate during curing is used to form a coating layer on a plate-like material such as a wafer, stress is generated inside the plate-like material due to the shrinkage of the resin.

When a plate-like object is ground and flattened with internal stress generated, the internal stress is released when the resin is removed, and warpage and swelling reappear (so-called springback). To solve this problem, a resin having a sufficiently low shrinkage rate during curing may be used to keep the force applied to the plate-like material small.

However, a resin having a low shrinkage rate is difficult to cure and is not suitable for forming a coating layer on a plate-like material. In addition, it takes a long time to complete the curing, which reduces the productivity.

Therefore, there is a demand for a resin composition that can be easily cured in a shorter time while suppressing the shrinkage rate at the time of curing to a lower level.

The present invention has been made in view of the above, and is a resin composition capable of suppressing the stress generated inside when forming a coating layer on a plate-like material to a low level and maintaining high productivity. It is an object of the present invention to provide a method for forming a coating layer of a plate-like material using a resin composition.

The problem to be solved by the present invention is as described above, and next, the means for solving this problem will be described.

According to one aspect of the present invention, a resin composition for fixing a plate-like substance, which is composed of a (meth) acrylate, a plasticizer or a reactive diluent, and a tackifier, initiates photopolymerization. The resin composition is characterized by containing an agent.

Further, according to one aspect of the present invention, the resin composition contains 25% by mass or more and 55% by mass or less of the (meth) acrylate and 35% by mass or more and 65% by mass or less of the plasticizer or the reactive diluent. The tackifier is contained in an amount of 0.1% by mass or more and 10% by mass or less.

Further, according to one aspect of the present invention, the (meth) acrylate comprises either (meth) acrylate having a urethane bond or (meth) acrylate having no urethane bond, or a mixture thereof. Is to be.

Further, according to one aspect of the present invention, there is a method for forming a coating layer on a plate-like material using a resin composition, which comprises a resin composition supply step of supplying the resin composition onto a film and the film sheet. A contact step in which the first surface of the plate-shaped material is brought into contact with the resin composition above so as to face each other, a mounting step in which the film is placed on the stage together with the plate-shaped material, and a second plate-shaped material. A pressing step of applying a force from the surface side toward the first surface to press the plate-like object toward the stage and spreading the resin composition over the entire first surface, and the first of the plate-like objects. The resin composition covering the surface is provided with a curing step of irradiating the resin composition with light to cure the resin composition.

Further, according to one aspect of the present invention, the film contains (meth) acrylate.

According to one aspect of the present invention, a resin composition that can be cured in a short time while suppressing shrinkage can be realized, and warpage and waviness reappear when the coating layer formed on the plate-like material is removed, so-called spring. Backing can be prevented.

Further, according to one aspect of the present invention, the inclusion of (meth) acrylate in the film allows the coating layer and the film to be more firmly fixed, and the coating layer can be easily peeled off together with the film in a later step, resulting in a plate-like product. It is possible to prevent the remaining of the upper coating layer.

(A) is a perspective view schematically showing an example of a plate-like material in which a coating layer is formed by the resin composition of the present embodiment. (B) is a cross-sectional view schematically showing an example of a plate-shaped object. It is a perspective view which shows the structural example of the covering layer forming apparatus which forms a covering layer on a plate-like object schematically. It is a flowchart of the covering layer formation method which concerns on one Embodiment of this invention. (A) is a partial cross-sectional side view schematically showing a method for forming a coating layer on a plate-like material using a resin composition. (B) is a figure explaining a pressing step. (A) is a figure explaining a curing step. (B) is a figure which shows the state which finished the curing step.

Embodiments of the present invention will be described with reference to the accompanying drawings. The resin composition according to this embodiment is used, for example, to form a coating layer on a plate-like material such as a wafer. FIG. 1A is a perspective view schematically showing an example of a plate-like material in which a coating layer is formed on the resin composition of the present embodiment, and FIG. 1B is an example of a plate-like material. It is sectional drawing which shows schematically.

As shown in FIG. 1A, the plate-shaped object 11 has a disk-like shape cut from a columnar ingot made of a semiconductor such as silicon, silicon carbide, or gallium nitride with a tool such as a band saw or a wire saw. Wafer (as slice wafer). As shown in FIG. 1 (B), the plate-shaped object 11 has warpage and waviness due to cutting out from the ingot.

The plate-like object 11 having a warp or a swell is not suitable for forming a device or the like. Therefore, it is necessary to form a coating layer of the resin composition on the plate-shaped material 11 and flatten it. For example, the resin composition applied to the back surface (first surface) 11b side of the plate-shaped object 11 is cured to form a flat reference surface, and then the front surface (second surface) 11a side of the plate-shaped object 11 is ground. By doing so, the warp and swell of the plate-shaped object 11 can be removed.

FIG. 2 is a perspective view schematically showing a configuration example of a coating layer forming apparatus for forming a coating layer on a plate-shaped object 11. As shown in FIG. 2, the coating layer forming apparatus 2 includes a delivery roller 4 on which the film 13 wound in a roll shape is mounted, and a take-up roller 6 for winding the film 13 delivered from the delivery roller 4. Be prepared.

The feed roller 4 and the take-up roller 6 are each connected to a rotation drive source (not shown) such as a motor, and the film 13 is moved from the feed-out roller 4 side to the take-up roller 6 side. The film 13 is made of a resin material such as (meth) acrylate (acrylic resin).

A resin supply unit 8 such as a slit coater is arranged above the delivery roller 4. The resin supply unit 8 supplies the resin composition 15 (see FIGS. 4 and 5) according to the embodiment of the present invention to the surface 13a side of the film 13 fed from the feed roller 4.

Above the resin supply unit 8, a pair of upper and lower rollers 10 and 12 for positioning the plate-shaped object 11 on the surface 13a of the film 13 to which the resin composition 15 is supplied are provided. The lower roller 10 changes the traveling direction of the film 13 to position the surface 13a side to which the resin composition 15 is supplied upward.

The plate-like material 11 is placed on the surface 13a of the film 13 via the resin composition 15. In the present embodiment, the back surface 11b side of the plate-shaped object 11 is brought into contact with the resin composition 15. However, the surface 11a side of the plate-shaped material 11 may be brought into contact with the resin composition 15. After that, the upper roller 12 comes into contact with the plate-shaped object 11 placed on the film 13 and rotates. The plate-shaped object 11 is sandwiched between the rollers 10 and 12 together with the film 13, and is positioned at a predetermined position.

The plate-shaped object 11 positioned at a predetermined position by the rollers 10 and 12 is conveyed to the adjacent resin curing unit 14 together with the film 13. The resin curing unit 14 includes a substantially rectangular parallelepiped base 16 having a space inside. At the upper part of the base 16, a stage 18 having a substantially flat upper surface is arranged so as to close the internal space.

The stage 18 is made of, for example, borate glass, quartz glass, or the like, and transmits light having a wavelength that cures the resin composition 15. The upper surface of the stage 18 is a holding surface for holding the film 13 conveyed from the rollers 10 and 12 sides. The film 13 placed on the stage 18 is suction-held on the holding surface by a suction mechanism (not shown) or the like.

Below the stage 18, a light source 20 that emits light having a wavelength that cures the resin composition 15 is arranged. A shutter 22 for blocking the light from the light source 20 is provided between the stage 18 and the light source 20. Further, above the shutter 22, a filter 24 that blocks light having a wavelength that is not necessary for curing the resin composition 15 is arranged.

When the shutter 22 is completely closed, the light from the light source 20 is blocked by the shutter 22 and does not reach the stage 18. On the other hand, when the shutter 22 is opened, the light from the light source 20 passes through the filter 24 and the stage 18 and irradiates the film 13. The film 13 is configured to transmit light having a wavelength that cures the resin composition 15, and the resin composition 15 is cured by the light transmitted through the film 13.

An exhaust pipe 26 connected to the internal space is provided on the side wall of the base 16. The exhaust pipe 26 is connected to an exhaust pump (not shown) or the like outside the base 16. When the temperature inside the base 16 rises due to the light from the light source 20, the stage 18 is deformed and the flatness of the holding surface is lowered. Therefore, the inside of the base 16 is exhausted by an exhaust pump or the like connected to the exhaust pipe 26 to suppress the temperature rise.

A support structure 28 is provided at a position adjacent to the stage 18. The support structure 28 includes a wall portion 28a erected on the base 16 and an eaves portion 28b extending horizontally from the upper end of the wall portion 28a. At the center of the eaves 28b located above the stage 18, a pressing mechanism 30 for downwardly pressing the plate-shaped object 11 on the film 13 is provided.

The pressing mechanism 30 includes a central main rod 32 extending in the vertical direction and a plurality of (four in the present embodiment) auxiliary rods 34 arranged in parallel with the main rod 32. The plurality of sub rods 34 are arranged around the main rod 32 at substantially equal intervals. A disk-shaped pressing pad 36 corresponding to the shape of the plate-shaped object 11 is fixed to the lower ends of the main rod 32 and the plurality of sub-rods 34.

The main rod 32 and the plurality of sub rods 34 are each connected to an elevating mechanism (not shown) including a motor and the like. By lowering the main rod 32 and the plurality of sub rods 34 by this elevating mechanism, the pressing pad 36 can press the surface 11a side of the plate-shaped object 11. The elevating mechanism independently elevates and elevates the main rod 32 and the plurality of sub rods 34 to adjust the pressing force applied to the plate-shaped object 11.

After superimposing the back surface 11b side of the plate-shaped material 11 on the resin composition 15 on the film 13, the front surface 11a side is pressed by the pressing mechanism 30 described above to form the front surface 13a of the film 13 and the back surface 11b of the plate-shaped material 11. The resin composition 15 is evenly spread between the two. After that, by irradiating the resin composition 15 with the light of the light source 20, the resin composition 15 can be cured to form a coating layer on the plate-shaped material 11.

The film 13 preferably contains (meth) acrylate. By containing the (meth) acrylate in the film 13, the coating layer and the film are more firmly and firmly fixed, and the coating layer is easily peeled off together with the film in a later step, and the coating layer on the plate-like material is prevented from remaining. be able to.

The plate-like material 11 on which the coating layer is formed by the resin composition 15 is conveyed to the adjacent film cutting unit 38. The film cutting unit 38 includes a base 40 having a substantially rectangular parallelepiped shape. A table 42 having a substantially flat upper surface is arranged on the upper part of the base 40. The upper surface of the table 42 is a holding surface for holding the film 13 conveyed from the resin curing unit 14 side.

Further, a support structure 44 is provided at a position adjacent to the table 42. The support structure 44 includes a wall portion 44a erected on the base 40 and an eaves portion 44b extending horizontally from the upper end of the wall portion 44a. A cutting mechanism 46 for cutting the film 13 in a circular shape is provided in the center of the eaves portion 44b located above the table 42.

The cutting mechanism 46 includes a rod 48 extending in the vertical direction and a cutter 50 having a ring-shaped blade having a diameter larger than that of the plate-shaped object 11. The cutter 50 is fixed to the lower end of the rod 48 and moves up and down by an elevating mechanism (not shown) such as an air cylinder connected to the upper portion of the rod 48. If the cutter 50 is lowered by this elevating mechanism and brought into contact with the film 13 on the table 42, the film 13 can be cut into a circular shape corresponding to the outer shape of the plate-shaped object 11.

In the plate-like material 11 on which the coating layer is formed by the coating layer forming device 2, for example, the resin composition 15 and the film 13 are removed after the surface 11a side is ground by a grinding device (not shown).

Since the resin composition 15 according to the embodiment of the present invention is cured in a short time while suppressing shrinkage, the stress generated inside when the coating layer is formed on the plate-shaped material 11 is suppressed to a low level, and the productivity is suppressed. It is possible to keep the temperature high.

The resin composition 15 is composed of a composition A composed of a (meth) acrylate, a plasticizer or a reactive diluent, and a tackifier, and containing a photopolymerization initiator. By mixing such a plurality of materials in an appropriate amount, a resin composition that can be cured in a short time while suppressing shrinkage can be realized, and warpage and waviness occur when the coating layer formed on the plate-like material is removed. It is possible to prevent so-called springback due to reappearance.

The resin composition 15 is composed of the following three components in a predetermined mass% ratio.
Component 1: (meth) acrylate 25% by mass or more and 55% by mass or less Component 2: Plasticizer or reactive diluent 35% by mass or more and 65% by mass or less Component 3: Adhesive-imparting agent 0.1% by mass or more and 10% by mass %Less than

Those containing the above components 1, 2 and 3 are referred to as composition A in the present specification.

The (meth) acrylate shall consist of either (meth) acrylate having a urethane bond or (meth) acrylate having no urethane bond, or a mixture thereof.

When the content of the (meth) acrylate having a urethane bond in the composition A increases, the curability becomes high and the shrinkage rate at the time of curing becomes low.

When the content of the (meth) acrylate having no urethane bond in the composition A increases, the curability becomes high and the shrinkage rate at the time of curing becomes high.

In the composition A, a (meth) acrylate having a urethane bond and a (meth) acrylate having no urethane bond can be mixed and contained. Here, the (meth) acrylate having a urethane bond tends to have a large molecular weight and a high viscosity due to having a urethane bond in the molecule. On the other hand, the (meth) acrylate having no urethane bond has a high shrinkage rate at the time of curing, but has a lower viscosity and a higher hardness than the (meth) acrylate having a urethane bond. Therefore, the curability, shrinkage rate, and hardness can be adjusted by mixing and containing two types of (meth) acrylates with and without urethane bond.

The (meth) acrylate indicates an acrylate which is an acrylic acid compound or a methacrylate which is a methacrylic acid compound, and the (meth) acrylate having a urethane bond (urethane group) means an acrylate having a urethane group in the molecule. ..

Specific examples of the (meth) acrylate having a urethane bond include light acrylates IAA, AT-600, UA-306H, UA-306T, UA-306I, UA-510H, UF-8001G, DAUA-167, and UF-07DF. (All manufactured by Kyoeisha Chemical Co., Ltd.), R-1235, R-1220, RST-201, RST-402, R-1301, R-1304, R-1214, R-1302XT, GX-8801A, R-1603, R-1150D, DOCR-102, DOCR-206 (all manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), UX-3204, UX-4101, UXT-6100, UX-6101, UX-7101, UX-8101, UX-0937. , UXF-4001-M35, UXF-4002, DPHA-40H, UX-5000, UX-5102D-M20, UX-5103D, UX-5005, UX-3204, UX-4101, UX-6101, UX-7101, UX -8101, UX-0937, UXF-4001-M35, UXF-4002, UXT-6100, DPHA-40H, UX-5000, UX-5102D-M20, UX-5103, UX-5005 (all by Nippon Kayaku Co., Ltd.) Made) can be used.

A (meth) acrylate having no urethane bond means one having no (urethane group) in the molecule.
Specific examples thereof include tetrahydrofurfuryl acrylate, isobornyl acrylate, phenylglycidyl ether acrylate, 1,9-nonanediol diacrylate and the like, and specific examples thereof include tetrahydrofurfuryl acrylate and isobornyl acrylate. Can be used.

As the plasticizer, an ester can be used. Esters as plasticizers show low shrinkage.
A plasticizer is a material that prevents the resin from orienting regularly by entering the gaps between the resins and can maintain an amorphous state even below the glass transition point. Since this plasticizer has a property of not easily reacting with the acrylic group of the (meth) acrylate, the shrinkage rate of the resin composition 15a can be suppressed when the (meth) acrylate and the plasticizer are mixed and polymerized. .. Specific examples of the plasticizer include dimethylphthalate, which is a phthalate ester, ethylphthalylethylglycolate, bis [2- (2-butoxyethoxy) ethyl] adipate, which is an aliphatic dibasic acid ester, and sulfonamide. N-butylbenzene sulfonamide or benzoic acid glycol ester can be used.

As the reactive diluent, an ether having a single epoxy group can be used.
Reactive diluents show a low shrinkage. The reactive diluent lowers the viscosity without impairing the properties of the (meth) acrylate. Examples of the reactive diluent include glycidyl ether, specifically, glycididi 2-ethylhexyl-glycidyl ether, p-sec-butylphenyl-glycidyl ether (Epiol® SB (NOF CORPORATION)), or , P-tert-butylphenyl-glycidyl ether and the like can be used.

The tackifier is called a tack fire, and is, for example, a terpene resin, a rosin resin, a petroleum resin, an alkylphenol resin, or a xylene resin.
In the composition A, the purpose of containing the tackifier is to eliminate the curing defect associated with the inclusion of the plasticizer or the reactive diluent. That is, the plasticizer or the reactive diluent inhibits the reaction between the (meth) acrylates and inhibits the binding between the (meth) acrylates, resulting in poor curing. Therefore, by containing a tackifier, the (meth) acrylates are adhered to each other under the condition that the reaction is inhibited, and the curing defect is eliminated.

The photopolymerization initiator is a substance for initiating the light (ultraviolet) polymerization of the above-mentioned composition A.
In the present embodiment, as the photopolymerization initiator, 1-hydroxycyclohexylphenylketone (for example, Irgacure (registered trademark) 184 manufactured by BASF) and α-hydroxyalkylphenone (for example, manufactured by IGM Resins B.V.) Omnirad (registered trademark) 184 etc.) is used. The amount of the photopolymerization initiator is arbitrarily adjusted within a range in which the curability of the resin composition 15 can be maintained.

Hereinafter, the apparatus configuration described above and the method of forming the coating layer on the plate-like material using the resin composition will be described in the order of the flowchart shown in FIG.

<Resin composition supply step>
In the production method according to the present embodiment, first, the resin composition supply step of supplying the resin composition 15 onto the film 13 is carried out. Specifically, as shown in FIG. 2, the resin composition 15 is supplied to the surface 13a side of the film 13 delivered from the delivery roller 4 by the resin supply unit 8. The amount of the resin composition 15 supplied is set so that the clothing layer formed by the resin composition 15 can form a sufficient thickness to absorb the warp and waviness of the plate-shaped material 11.

<Contact step>
Next, a contact step is carried out in which the first surface (back surface 11b) of the plate-shaped object 11 is brought into contact with the resin composition 15 on the film 13 so as to face each other. Specifically, as shown in FIG. 2, the film 13 and the plate-shaped material 11 placed on the film 13 are sandwiched between the upper and lower rollers 10 and 12, and the plate-shaped material is placed in the resin composition 15. 11 is brought into contact.

<Placement step>
Next, a mounting step of placing the film 13 on the stage 18 together with the plate-shaped object 11 is performed. Specifically, by transporting the film 13 as shown in FIG. 2, the plate-shaped object 11 is carried onto the stage 18 of the resin curing unit 14.

<Pressing step>
Next, a force is applied from the second surface (front surface 11a) side of the plate-shaped object 11 toward the first surface (back surface 11b) to press the plate-shaped object 11 toward the stage 18, and the resin composition 15 is pressed against the first surface (front surface 11b). A pressing step is performed to spread the entire back surface 11b). Specifically, first, as shown in FIG. 4A, the film 13 is sucked and held on the holding surface of the stage 18 in a state where the plate-shaped object 11 is positioned below the pressing mechanism 30.

Then, as shown in FIG. 4 (B), the pressing pad 36 is lowered to a predetermined position and stopped. As a result, the plate-shaped object 11 is pressed downward, and the resin composition 15 is placed on the first surface (back surface 11b) of the plate-shaped object 11 between the front surface 13a of the film 13 and the first surface (back surface 11b) of the plate-shaped object 11. It spreads evenly over the entire surface of the back surface 11b).

<Curing step>
Next, a curing step of irradiating the resin composition 15 covering the first surface (back surface 11b) of the plate-shaped object 11 with light to cure the resin composition 15 is performed. Specifically, as shown in FIG. 5A, the shutter 22 is opened with the light 21 emitted from the light source 20, and the light 21 of the light source 20 irradiates the resin composition 15. As a result, the resin composition 15 is cured, and a coating layer is formed on the plate-shaped material 11.

Since the upper surface of the stage 18 serving as the holding surface is formed to be substantially flat, the lower surface of the resin composition 15 in contact with the surface 13a of the film 13 is also substantially flat. In the present embodiment, since the above-mentioned resin composition 15 is used, it can be cured in a short time while suppressing shrinkage to form a coating layer on the plate-shaped material 11.

In the process of the curing step, the change in the load acting on the pressing pad 36 is measured by a load measuring device (not shown). When the curing starts, the load change starts, and when the curing is completed, the load change ends. By measuring the time from the start to the end of this load change, the measured time can be evaluated as the curing time.

After the curing is completed, as shown in FIG. 5B, the shutter 22 is closed to stop the irradiation of light, and the pressing pad 36 is raised to open the plate-shaped object 11 to form a resin layer on the lower side. The plate-shaped object 11 is transported downstream.

The device used for forming the coating layer is not limited to the above-mentioned device configuration. For example, a coating layer can be formed on the plate-shaped object 11 by using a coating layer forming apparatus provided with a holding mechanism for holding the plate-shaped object 11 above the stage. In this case, the plate-shaped material 11 is held by a holding mechanism so as to face the stage, the resin composition 15 is supplied onto the stage, and then the plate-shaped material 11 is pressed onto the stage to uniformly spread the resin composition 15. spread. After that, the coating layer can be formed on the plate-shaped material 11 by irradiating the resin composition 15 with light.

Next, an experiment conducted to confirm the effectiveness of the resin composition 15 according to the present embodiment will be described.

<Experiment 1: No adhesive>
In this experiment, the shrinkage rate and curability were evaluated when the tackifier was not contained.
A coating layer was formed on a silicon wafer (as slice wafer) with a plurality of resin compositions having different mixing ratios of (meth) acrylate and a reactive diluent.

In this experiment, 0.2% by mass of the photopolymerization initiator was added to the total amount of the (meth) acrylate and the reactive diluent.
As the (meth) acrylate, UF-8001G (Kyoeisha Chemical Co., Ltd.) was used (with urethane bond).
Epiol (registered trademark) SB (NOF CORPORATION) was used as the reactive diluent.
As the photopolymerization initiator, Omnirad (registered trademark) 184 (IGM Resins B.V.) was used.
The results of this experiment are shown in the following table.

The shrinkage rate (unit:%) was determined by determining the volume A of the supplied resin composition before curing and the volume B after curing by the following formula (1).
Shrinkage rate = (AB) / A × 100 (unit:%)
As for the curability, when the curing time was 10 seconds or less, the curing was fast and the curability was good.

<Experiment 2: With adhesive>
In this experiment, the shrinkage rate and curability were evaluated when the tackifier was contained.
As the (meth) acrylate, UF-8001G (Kyoeisha Chemical Co., Ltd.) was used (with urethane bond).
Epiol (registered trademark) SB (NOF CORPORATION) was used as the reactive diluent.
As the tackifier, YS Polystar UH115 (Yasuhara Chemical Co., Ltd.) was used.
As the photopolymerization initiator, Omnirad (registered trademark) 184 (IGM Resins B.V.) was used.

<Evaluation>
As described above, in Experiment 2, it was confirmed that in Samples 2-2 to 2-8, both low shrinkage and good curability can be achieved at the same time.

<About shrinkage rate>
As is clear from the comparison of Tables 1 and 2, it was confirmed that the shrinkage rate (%) was reduced by containing the tackifier. For example, when Sample 1-2 and Sample 2-1 having the same (meth) acrylate in an amount of 60% by mass are compared, the shrinkage rate (%) is reduced to 2.88 and 1.18, which are less than half. From this, it was confirmed that the inclusion of the tackifier was effective in reducing the shrinkage rate (%).

Here, in Experiment 1 (Table 1), the reactive diluent is contained for the purpose of reducing the shrinkage rate (%), but in Experiment 2 (Table 2), the tackifier is added to the reactive diluent. It was confirmed that the shrinkage rate (%) was further reduced by the inclusion of. Therefore, it can be said that the combination of the reactive diluent and the tackifier is effective in reducing the shrinkage rate (%).

<About curability>
As is clear from Table 2, it was confirmed that good curability was realized in Samples 2-2 to 2-8 by containing the tackifier. From this, it was confirmed that the inclusion of the tackifier provides good curability while reducing the shrinkage rate (%).

Here, regarding the curability, there is a concern that the reaction and binding between the (meth) acrylates may be inhibited by containing the reactive diluent, but the (meth) acrylates may be adhered to each other by the tackifier. Therefore, it is considered that good curability can be obtained. Further, since the curability can be complemented by the tackifier, the content of the reactive diluent can be increased, and the function of shortening the curing time by the reactive diluent can be utilized. That is, the curing time can be adjusted by setting the contents of the tackifier and the reactive diluent.

In Experiments 1 and 2 above, (meth) acrylate having a urethane bond was used as the (meth) acrylate, but (meth) acrylate having no urethane bond or a mixture of both was used. As for, it is possible to realize the same decrease in shrinkage rate and good curability. The effect of the tackifier can be achieved by using either the presence or absence of the urethane bond or both (meth) acrylates, and it is determined which type of (meth) acrylate is used. It is appropriately selected depending on the curability, shrinkage rate, and hardness. Further, even when a plasticizer is used instead of the reactive diluent, it is possible to realize the same decrease in shrinkage rate and good curability.

11 Plate-shaped object 11a surface (second surface)
11b back side (first side)
13 Film 13a Surface 15 Resin composition 2 Coating layer forming device 4 Feeding roller 6 Winding roller 8 Resin supply unit 10 Roller 12 Roller 14 Resin curing unit

Claims (5)

A resin composition for fixing a plate-like material,
With (meth) acrylate
With a plasticizer or reactive diluent,
Adhesive and
A resin composition comprising a photopolymerization initiator contained in the composition. The resin composition is
25% by mass or more and 55% by mass or less of the (meth) acrylate,
35% by mass or more and 65% by mass or less of the plasticizer or reactive diluent,
The tackifier is contained in an amount of 0.1% by mass or more and 10% by mass or less.
The resin composition according to claim 1. The (meth) acrylate consists of either (meth) acrylate having a urethane bond or (meth) acrylate having no urethane bond, or a mixture thereof.
The resin composition according to claim 1 or 2. A method for forming a coating layer on a plate-like material using the resin composition according to any one of claims 1 to 3.
A resin composition supply step for supplying the resin composition onto the film, and
A contact step in which the first surface of the plate-like material is brought into contact with the resin composition on the film sheet so as to face each other.
A mounting step in which the film is placed on the stage together with the plate-like object,
A pressing step of applying a force from the second surface side of the plate-shaped object toward the first surface to press the plate-shaped object toward the stage and spreading the resin composition over the entire first surface.
A method for forming a coating layer on a plate-shaped material, which comprises a curing step of irradiating the resin composition covering the first surface of the plate-shaped material with light to cure the resin composition. The method for forming a coating layer on a plate-like material according to claim 4, wherein the film contains (meth) acrylate.

Images