TWI522243B - Method for producing laminate, and laminate - Google Patents

Description

Laminated body manufacturing method and laminated body

The present invention relates to a method and a laminate for producing a laminate using a photocurable resin composition. More specifically, the present invention relates to a method for producing a laminate in which a laminate film using a photocurable resin composition is bonded to an adherend, and a laminate in which the laminate film can follow a printing step or the like. The generation of bubbles was prevented, and white turbidity did not occur in the endurance test under high temperature and high humidity conditions after irradiation with UV.

In addition, the term "printing step difference" in the present specification means a printing layer calculated from the surface of the substrate in a state where a black frame and/or a printed layer of a pattern is formed on the surface of the substrate composed of a transparent resin film. thickness.

In a liquid crystal panel used as a display such as a portable telephone, in order to prevent cracking of the liquid crystal panel, a protective plate for absorbing impact is attached to the front surface of the liquid crystal panel via an air layer. However, recently, in order to achieve weight reduction, thinning, and improved definition, an air layer is not provided in front of a liquid crystal panel of a portable telephone, and an adhesive layer is directly used to directly bond a thin protective sheet.
In addition, before the display (display device) is shipped from the factory, as one of the performance tests of the display, the endurance test is performed under the conditions of using a high temperature and high humidity environment of the oven.
Since a black frame of a light shielding layer formed by screen printing or the like is provided on the surface of the front glass plate of the display, a step having a thickness of about 10 μm to 50 μm is generated between the front glass plate and the black frame of the light shielding layer. Further, in order to improve the design, a printing having a thickness of about 10 μm to several tens of μm is often applied to a protective plate of a portable telephone or the like. When the various optical films and protective sheets are attached to the display using the adhesive layer, if there is a step formed by the printed layer or the like on the surface of the adhered body, the adhesive layer cannot follow the step, and, due to the adhesive layer Floats and entraps into the air layer to create bubbles between the adhesive layer and the adherend.
By heating and simultaneously pressurizing the protective sheet or the like adhered via the adhesive layer, the generated bubbles are dispersed and cannot be visually observed, but when the test piece is subjected to a heating test by an oven, the adhesive is used. The layer changes to cause the bubbles to agglomerate again, thereby forming bubbles of a visually identifiable size, which causes the adhesive layer to peel off from the adherend.
Further, when the test piece was taken out from the oven, there was a case where the adhesive layer was cloudy. When a film is attached to one side of the adhesive layer, the white turbidity disappears and becomes transparent after several hours.
However, when a hard substance such as a glass or an acrylic plate is bonded to each other by an adhesive layer, the white turbidity may remain for several days, which may impair the commercial value of the display.
As described above, when the optical film or the protective sheet is attached to the display through the adhesive layer, minute bubbles are generated in the adhesive layer due to the step difference existing on the surface of the adherend. Further, as one of the performance tests of the display, after the durability test was carried out under the conditions of using a high-temperature and high-humidity environment of the oven, when it was taken out from the oven, white turbidity was generated in the adhesive layer. In order to solve the above problems, various efforts have been made in the past.
For example, Patent Document 1 discloses a laminate in which a liquid crystal panel and a protective panel are closely adhered by a polyorganosiloxane chain. The polyorganosiloxane chain has a plasticity value of 100 to 800 (temperature: 25 ° C) according to JIS K6249, and a shear modulus G' of 0.01 to 5 MPa (temperature: 30 ° C, frequency: 0.1 Hz), total light. The transmittance is above 85%. Since the predetermined polyorganosiloxane composition has moderate flexibility, it can be buried in a space between the liquid crystal panel and the protective panel without a gap, and can prevent reflection and absorption of incident light while preventing light. Light scattering caused by refraction.
Further, Patent Document 2 discloses a transparent adhesive sheet for a flat panel display for achieving integration of a display module and a protective transparent plate by using a compound having a hydrogenated decyl group and a hydrogenation sulfonation catalyst. The polyoxyalkylene-based polymer and the polyoxyalkylene-based polymer having an alkenyl group are crosslinked. Since the shear storage modulus G' at -30 ° C is less than 6.0 × 10 ⁵ Pa and does not become rigid at low temperatures, it maintains high adhesion at temperatures below freezing point, so the adhesion at low temperatures is stable. Excellent sex.
Further, Patent Document 3 discloses an adhesive tape having an adhesive layer having a thickness of 10 to 30 μm, the adhesive layer being composed of an adhesive having a total solid content of 100 parts by weight of the acrylic adhesive. The conductive filler having a predetermined shape aspect ratio is contained in an amount of 14 to 45 parts by weight, and the ratio of the conductive filler to the total amount of the filler of the adhesive is 90% by weight or more. There is a relationship between the particle size of the filler and the thickness of the adhesive layer, d ₈₅ > thickness of the adhesive layer > d ₅₀ , and the storage modulus of the crosslinked structured adhesive in the range of 0 to 40 ° C in the dynamic viscoelasticity test. 'It is 1 × 10 ⁴ Pa or more and less than 1 × 10 ⁶ Pa, and the peak temperature of the loss tangent tan δ is 0 ° C or less. Although the adhesive tape is a film, it has both adhesiveness and electrical conductivity, and even if it adheres to a portion having a step, it does not "float" from the adhered body, thereby improving the production efficiency of electric/electronic equipment and the like. Improve quality.
Further, Patent Document 4 discloses an acrylic transparent adhesive film or an adhesive sheet comprising ultrafine particles having a refractive index close to that of an acrylic adhesive and having a hydroxyl group on its surface. Even if it is kept under a high temperature and humidity environment, warm water immersion or boiling, the whitening of the acrylic adhesive film or the adhesive sheet can be suppressed.
Further, Patent Document 5 discloses a resin composition for absorbing an impact required for protecting an image display device or the like, and containing an acrylic derivative, an acrylic derivative polymer, and a high molecular weight crosslinking agent. It is described that it is effective for preventing cracks or mitigating stress and impact of the panel for image display, and is excellent in transparency. In addition, after the resin sheet was placed in a high-temperature and high-humidity test cell of 60° C. and 90% RH for 50 hours to carry out a moisture absorption test, it was confirmed by visual inspection that foaming was small and transparency was excellent.
CITATION LIST Patent Literature Patent Literature 1: Japanese Laid-Open Patent Publication No. JP-A No. Hei. No. Hei. No. Hei. No. Hei. Patent Document No. 348546: Japanese Laid-Open Patent Publication No. 2008-248221

Problems to be Solved by the Invention In recent years, as the use of displays has expanded, the demand for cost reduction of various components used for displays has increased. In addition, the quality required for various components used in displays is required to have durability under environmental conditions that are more stringent than conventional environmental test conditions. For example, an adhesive tape for bonding an optical film used for an in-vehicle display must be an adhesive composition which does not cause white turbidity of the adhesive layer even under environmental conditions of 85 ° C and 85% RH, and the use of the adhesive composition Adhesive tape of the adhesive composition.
In the adhesive composition and the adhesive layer described in Patent Documents 1 to 3 of the related art, in order to improve the step followability, the storage modulus of the adhesive is set within a predetermined range.
However, since the polyorganosiloxane composition described in Patent Document 1 and the polyoxyalkylene-based polymer cured product described in Patent Document 2 are expensive, it is desirable to solve the problem by using a relatively inexpensive acrylic adhesive.
Further, the adhesive tape described in Patent Document 3 is an opaque adhesive tape containing a large amount of a conductive filler, and cannot be used as a transparent adhesive film. Therefore, there is no description about transparency and white turbidity. Although there is a description of an acrylic adhesive, it is necessary to have an adhesive property when a large amount of a conductive filler is contained. Therefore, a tackifying resin such as a polymerized rosin is contained in the adhesive. However, since the polymerized rosin has a yellow to brown color, it is not suitable for use in an optical film requiring high transparency.
Further, the adhesive film described in Patent Document 4 can suppress whitening of the acrylic adhesive film or the adhesive sheet even under conditions such as high temperature and humidity, warm water immersion or boiling. However, since it is a special particle in which hydrophilic ceria ultrafine particles are added, it is difficult to reduce the cost. Further, a configuration for causing the adhesive layer to follow the step is not described.
Further, the adhesive composition described in Patent Document 5 is an adhesive composition obtained by crosslinking reaction by adding the following compound: an alkyl acrylate having an alkyl group having 4 to 18 carbon atoms (A) A copolymer obtained by polymerization with a mixture of a hydroxy group-containing acrylate (B), a monomer mixture of the above (A) and (B), and a high molecular weight crosslinking agent. In the case of the above-described adhesive composition of Patent Document 5, there is no description of a white turbid adhesive composition which does not cause an adhesive layer under the environmental conditions of 85 ° C and 95% RH, and an adhesive tape using the same. In addition, since the (meth)acrylic acid alkyl ester monomer is introduced in excess, as shown in the example of Patent Document 5, after the resin is poured into the template, it is necessary to irradiate the glass with ultraviolet light for a long time, and the like, and the device must be subjected to the device. improve. Further, although it is described as an adhesive composition which does not cause an opaque adhesion layer even under an environmental condition of 60° C. and 90% RH, and an adhesive tape using the composition, it is required to irradiate weak ultraviolet rays for a long period of time, so that productivity is high. difference.
As described above, in the prior art, there is no known method for producing a laminate in which a laminate film using a photocurable resin composition is bonded to an adherend having a step on the surface, and a laminate. The laminated film can follow the step difference between the front glass plate of the display as the adherend and the black frame of the light shielding layer, and can prevent the generation of bubbles during the bonding, and even at a very high temperature and high temperature. The white turbidity of the adhesive layer (photohardenable resin layer) does not occur under wet environmental conditions, for example, under the conditions of 85 ° C and 95% RH suitable for a vehicle-mounted display.

In view of the above, an object of the present invention is to provide a method for producing a laminate in which a laminate film using a photocurable resin composition is bonded to an adherend having a step on the surface thereof, and a laminate. When the laminated film is bonded to the adherend having a step on the surface, generation of bubbles can be prevented, and after irradiation with ultraviolet rays, the oven is used in a high-temperature and high-humidity environment such as 85 ° C and 85% RH. No white turbidity occurred during endurance testing and after removal from the oven.
In order to solve the above problems, the present invention provides a method for producing a laminated body in which a laminated film in which a photocurable resin layer for filling the step is laminated is bonded to an adherend having a step on the surface thereof. The method for producing a body, wherein the production is performed at least sequentially through the following steps (1) to (5):
(1) a step of preparing (A) a main agent polymer composed of an acrylic resin having an acid value of 0 to 33;
(2) a step of preparing a photocurable resin composition, wherein the photocurable resin composition has a storage modulus (G') at 24 ° C and 1 Hz of 1 × 10 ⁴ Pa or more and less than 9 × 10 ⁴ Pa, And (C) photopolymerization reaction of at least one of (B) at least one of (B) a (meth) acrylate monomer having a hydroxyl group, and 0.5 to 1 part by weight, based on 100 parts by weight of the above-mentioned main polymer The initiator and the crosslinking point with respect to the polymer are 0.2 to 0.8 parts by weight of the (D) difunctional crosslinking agent in an amount of 0.1 equivalent or less;
(3) a step of producing a laminated film by applying the photocurable resin composition to one side of a substrate or a separator, followed by heating and drying to form a laminated film of a cured layer on which a photocurable resin layer is formed;
(4) a step of laminating a laminated film, wherein the laminated film is bonded to an adherend having a step on the surface by a hardened layer of the photocurable resin layer;
(5) A hardening step of irradiating light from the substrate or the separator to carry out a polymerization reaction and performing a crosslinking reaction based on aging to cure the hardened layer of the photocurable resin layer.
Moreover, the present invention provides a laminate obtained by the above-described production method in which a laminated film in which a photocurable resin layer for filling the step is laminated is laminated on an adherend having a step on the surface thereof. to make.
Moreover, the present invention provides a laminate in which the adherend is an optical member used in a display and a laminated film in which the photocurable resin composition is laminated.
According to the method for producing a laminate in which a laminated film is bonded according to the present invention, a laminate film having the following resin coating layer is bonded to an adherend having a printing step, and can follow a printing step of 50 μm or more. The resin coating layer is obtained by laminating a photocurable resin composition containing (B) a main component polymer composed of (A) an acrylic resin having an acid value of 0 to 33. A hydroxyl group-containing (meth)acrylic acid alkyl ester monomer, (C) a photopolymerization initiator, and (D) a bifunctional crosslinking agent. Further, by bonding the laminated film to the adherend and then performing UV irradiation, aggregation of water molecules can be prevented, and generation of white turbidity can be prevented even after the durability test in a high-temperature and high-humidity environment.
Further, a photocurable resin layer having a (meth) group having a hydroxyl group added to a main polymer composed of an acrylic resin having an acid value of 0 to 33 is formed on the laminate of the present invention. At least one of an alkyl acrylate monomer, a photopolymerization initiator, and a bifunctional crosslinking agent are photopolymerized. Therefore, the corrosion resistance to the metal is weak, and even if the photocurable resin layer of the laminate of the present invention is bonded to the ITO surface of the transparent conductive film, the change in the resistance value of the transparent conductive film (ITO) can be controlled to be low.

1. . . Substrate

2. . . Photohardenable resin layer

3, 13. . . Diaphragm

5. . . Laminated film

11. . . The substrate or diaphragm being transported

12. . . Coating layer

twenty one. . . Mold coating machine

twenty two. . . Support roller

twenty three. . . Drying room

twenty four. . . Diaphragm supply device

25. . . Pinch roller

Fig. 1 is a schematic cross-sectional view showing an example of a laminated film having a photo-curable resin layer formed by using the photo-curable resin composition of the present invention.
Fig. 2 is a schematic explanatory view showing an example of a method for producing a laminated film having a photocurable resin layer formed by using the photocurable resin composition of the present invention.

Hereinafter, preferred embodiments of the present invention will be described.
The photocurable resin composition of the present invention is obtained by mixing at least one monomer having a hydroxyl group in a photopolymerization initiator, a host polymer, and a polymer for polymerizing the monomer. Made of cross-linking cross-linking agent. The photocurable resin composition contains, as a photopolymerizable compound polymerized by an energy ray, at least one (meth) acrylate having a hydroxyl group. The (meth) acrylate monomer is a polymerizable compound having a vinyl group, that is, a (meth) acryl fluorenyl group which can be radically polymerized with a photopolymerization initiator, for example, ultraviolet rays in the range of 300 nm to 400 nm. A curable ultraviolet curable resin material.
Further, in the present specification, "(meth) acrylate" is a generic term for acrylate and methacrylate.
The main agent polymer may be a main agent polymer which is a main component of the photocurable resin composition and which has an acrylic monomer having a hydroxyl group which is easily dispersed.
In order to facilitate the dispersion of the monomer having a hydroxyl group, it is preferred that the main agent polymer is an acrylic polymer, and it is more preferable to copolymerize a hydrophilic monomer. This is because the monomer having a hydroxyl group is acrylic and contains a hydroxyl group.
In addition, the photocurable resin composition used in the laminate of the present invention needs to have transparency from the viewpoint of application to optical applications, and it is also preferred that the main component polymer is acrylic from the viewpoint of easily controlling the strength of the adhesive force. Polymers.
The photocurable resin composition is produced by at least the following steps (1) to (2):
(1) a step of preparing (A) a main agent polymer composed of an acrylic resin having an acid value of 0 to 33;
(2) a step of preparing a photocurable resin composition, wherein the photocurable resin composition has a storage modulus (G') of 1 × 10 at 24 ° C and 1 Hz ⁴ Above Pa and below 9×10 ⁴ Pa, and containing 5 to 10 parts by weight of (B) at least one of (B) a (meth) acrylate monomer having a hydroxyl group, and 0.5 to 1 part by weight based on 100 parts by weight of the above-mentioned main agent polymer (C) The photopolymerization initiator and the crosslinking point with respect to the main polymer are 0.2 to 0.8 parts by weight of the (D) difunctional crosslinking agent in an amount of 0.1 equivalent or less.
By sequentially performing the following steps, a laminate in which a laminated film in which the photocurable resin layer of the present invention is laminated is obtained can be obtained:
a step of producing a laminated film by using the above-mentioned photocurable resin composition to form a laminated film in which a cured layer of a photocurable resin layer is formed on one surface of a substrate (or a separator); and a step of laminating the laminated film The laminated film is bonded to the adherend having a step on the surface by the hardened layer of the photocurable resin layer, and the curing step is performed by irradiating light from the substrate or the separator to carry out polymerization and curing. The crosslinking reaction causes the hardened layer of the aforementioned photo-curable resin layer to be hardened.
Further, in the photo-curable resin composition of the present invention, the content of the crosslinking agent is preferably less than 1 equivalent (preferably, 0.5 equivalent or less) to the crosslinking point of the polymer. Based on this, even if the crosslinking agent is a crosslinking agent capable of crosslinking reaction with a hydroxyl group of a monomer having a hydroxyl group like an isocyanate compound, at least a part of hydroxyl groups of a monomer having a hydroxyl group are not crosslinked, and the uncrosslinked by the crosslinking The dispersion of the hydroxyl group is present, and a photocurable resin composition excellent in moisture adsorption performance can be obtained. Furthermore, as described above, the content of the (D) bifunctional crosslinking agent is preferably 0.2 to 0.8 parts by weight which is 0.1 equivalent or less of the crosslinking point of the main polymer with respect to 100 parts by weight of the main polymer.
An example of the laminated film 5 having the photo-curable resin layer 2 formed by using the photo-curable resin composition of the present invention is schematically shown in Fig. 1. In the laminated film 5, the photo-curable resin layer 2 is formed on one surface of the substrate 1 as a support of the photo-curable resin layer 2, and the surface of the photo-curable resin layer 2 is protected by the separator 3. At the time of use, the separator 3 is peeled off to expose the photo-curable resin layer, and the substrate 1 is laminated on the back surface of the photo-curable resin layer 2, and bonded to the adherend.
In addition, although it is not specifically illustrated, the laminated film which has the structure which has the photo-hardening resin layer on the both surfaces of the base material, and the surface of the photo-hardened resin layer is protected by the separator.
In the present invention, it is possible to prevent the effect of improving the white turbidity in a high-temperature and high-humidity environment, and in the case where the permeability to water such as glass (inorganic glass) or acrylic resin (acrylic glass) is poor, a particularly remarkable effect can be obtained. The reason is as follows.
When a resin film having good water molecule permeability is attached, water molecules dispersed in the photo-curable resin layer can easily pass through the resin film, thereby reducing the probability of aggregation of water molecules. Further, even if water molecules agglomerate, they quickly pass through the resin film, so the time for white turbidity is shortened. However, when a material having poor water permeability is bonded, if water molecules are agglomerated and white turbidity occurs, the water molecules will disappear after being diffused to the peripheral end portion of the photo-curable resin layer, so that white turbidity will persist for a long time.
In the present invention, the monomer to be the raw material of the main component polymer is preferably contained in an acrylic monomer having an ester group (-COO-) in an amount such that the acid value of the main polymer is from 0 to 33. At least one of at least one and an acrylic monomer having a carboxyl group (-COOH) can be used in addition to various compounds. As the acrylic monomer having an ester group (-COO-), for example, it is exemplified by the formula CH ₂ =CR ¹ -COOR ² (where, R ¹ Represents hydrogen or methyl, R ² A (meth)acrylic acid ester such as an alkyl (meth)acrylate represented by an alkyl group having 1 to 14 carbon atoms or a (meth)acrylate having a hydroxyl group.
Further, in the present invention, as the monomer which becomes the raw material of the main polymer, it is also possible to use at least one of the acrylic monomers having an ester group (-COO-) and not including a carboxyl group (-COOH). In addition to the acrylic monomer of the acrylic monomer, various compounds can be used.
As a general formula CH ₂ =CR ¹ -COOR ² (where, R ¹ Represents hydrogen or methyl, R ² Specific examples of the alkyl (meth)acrylate represented by the alkyl group having 1 to 14 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, and (methyl). ) n-propyl acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate , isoamyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, (a) Isodecyl acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, and the like. These may be used alone or in combination of two or more. Among them, 2-ethylhexyl (meth)acrylate and n-butyl (meth)acrylate are preferably used.
The alkyl group of the alkyl (meth)acrylate is set from the viewpoint of the adhesion of the photo-curable resin layer. ² The number of carbon atoms is 1 to 14. When the number of carbon atoms of the alkyl group is 15 or more, the adhesion may be lowered, which is not preferable. Preferred alkyl R ² The number of carbon atoms is from 1 to 12, more preferably from 4 to 12, still more preferably from 4 to 8.
In addition, in the alkyl R ² In the alkyl (meth) acrylate having 1 to 14 carbon atoms, the alkyl group R may be used. ² The alkyl (meth) acrylate having 1 to 3 or 13 to 14 carbon atoms is used as a part of the monomer, but the alkyl group R is preferably used. ² The alkyl (meth)acrylate having 4 to 12 carbon atoms is used as an essential component (for example, 50 to 100 mol%).
In addition, these alkyl groups R ² It can be either a straight chain or a branch.
Further, examples of the (meth) acrylate having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Ester, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, cyclohexane dimethanol mono (meth) acrylate, and the like.
Further, examples of the acrylic monomer having a carboxyl group include acrylic acid, methacrylic acid, maleic acid, itaconic acid, and 2-propenylethyl succinate.
Other monomers may also be added to the raw material monomers of the main polymer. For example, a monomer having a hydrophilic group such as a carboxyl group, an alkoxyalkyl group, an amino group, a hydroxyl group or a sulfonic acid group can be used.
The mixing ratio of the alkyl (meth) acrylate in the monomer constituting the main component polymer to the monomer having a hydrophilic group, although according to characteristics required for the photocurable resin composition, monomer type, and The weight ratio of the hydrophilic group in the molecule is different, and it is preferable that, for example, 5 to 50% by weight is a monomer having a hydrophilic group, and 50 to 95% by weight is an alkyl (meth)acrylate.
Further, examples of the acrylic monomer containing an alkoxyalkyl group include γ-(trimethoxydecyl)propyl (meth)acrylate and γ-methyldimethoxy (meth)acrylate. Base alkyl propyl ester, γ-triethoxy decyl propyl (meth) acrylate, and the like.
Further, examples of the non-acrylic monomer containing an alkoxyalkyl group include vinyl methoxy decane and vinyl trimethoxy decane.
Further, examples of the acrylic monomer having an amino group include dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, and t-butylaminoethyl (meth)acrylate. (meth)acrylate having an amino group such as monomethylaminoethyl (meth)acrylate, and examples thereof include decyl (meth)acrylate, decylamine itaconate, and dimethylaminopropane. (meth) acrylamide, dimethylaminoethyl (meth) acrylamide, N-methoxymethyl propylene amide, N-ethoxymethyl (meth) acrylamide, N- Methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, and the like.
For the main polymer, it is preferred that most of it (for example, 50% by weight or more, more preferably 80% by weight or more) is composed of an acrylic monomer (alkyl (meth) acrylate and an acrylic monomer having a hydrophilic group) The composition is not limited to the effect of the present invention, and a monomer other than the acrylic monomer (non-acrylic monomer) may be used in combination.
When the acrylic monomer constituting the main component polymer and the optional non-acrylic monomer are polymerized, it can be carried out by a known method such as solution polymerization, bulk polymerization, suspension polymerization or emulsion polymerization, but it is preferably used for heat dissipation. Solution polymerization. Specific examples of the organic solvent to be used in the solution polymerization include aromatic hydrocarbons such as toluene and xylene, aliphatic esters such as ethyl acetate and butyl acetate, and alicyclic groups such as cyclohexane. Hydrocarbons, aliphatic hydrocarbons such as hexane and pentane, and the like. However, it is not particularly limited as long as it does not inhibit the above polymerization reaction. These solvents may be used alone or in combination of two or more. The amount of the solvent can be appropriately determined. It is preferred to use a suitable catalyst as needed.
Generally, in solution polymerization, as the polymerization temperature increases, the molecular weight of the resulting polymer decreases. When the polymerization reaction is carried out at the reflux temperature of the solvent, by using a solvent having a boiling temperature suitable for the polymerization reaction, the polymer can be obtained while removing the heat of polymerization.
The molecular weight distribution of the main agent polymer is preferably 70,000 or more in terms of number average molecular weight (Mn) and 1,000,000 or more in terms of weight average molecular weight (Mw). Further, it is more preferable that the weight average molecular weight (Mw) is 12,000,000 or more. As described above, when the molecular weight of the polymer is large, heat resistance and weather resistance are further improved.
If the molecular weight is too large, the viscosity is too high and the processing suitability is deteriorated. Although it is possible to further expand the upper limit by trying to improve the coating method by increasing the temperature of the coating material or the like, it is preferable to use a material having a Mw of less than 5,000,000, for example, when coating at room temperature.
As the main agent polymer, an acrylic polymer having a small content of an acrylic monomer having a carboxyl group (-COOH) or a monomer having another acidic functional group can also be used. Preferably, the main agent polymer has an acid value of from 0 to 33. Here, the "acid value" is one of the indexes indicating the content of the acid, and is expressed by the number of mg of potassium hydroxide required to neutralize 1 g of the polymer. When the acid value of the main agent polymer is 0, it means that the monomer having an acidic functional group is completely absent. When the adherend is an adherend which is likely to be corroded or deteriorated due to an acid, it is preferred that the acid value of the main agent polymer is small, and it is preferred that the additive other than the main polymer also avoids the use of an acid.
Further, the photocurable resin composition of the present invention contains at least one of (meth) acrylate monomers having a hydroxyl group.
In a preferred embodiment of the photocurable resin composition of the present invention, an acrylic polymer obtained by polymerizing an alkyl (meth)acrylate having no hydroxyl group and an acrylic monomer, and a (meth) group having a hydroxyl group The acrylate monomers are not copolymerized but are present in a separately dispersed mixed state. Further, in another preferred embodiment, the main agent polymer obtained by polymerizing a monomer including a hydrophilic monomer and the (meth) acrylate monomer having a hydroxyl group are all contained in the photocurable resin composition.
The content of the monomer having a hydroxyl group (the total amount when the monomer having a hydroxyl group is two or more) is 4 to 20 parts by weight with respect to 100 parts by weight of the main agent polymer; when it is carried out at 85 ° C × 85 When testing such as a %RH environment requires high durability, it is more preferably 4 to 15 parts by weight. Further, it is more preferable that at least one of (B) the (meth) acrylate monomer having a hydroxyl group is 5 to 10 parts by weight based on 100 parts by weight of the main polymer.
Further, a known photocurable resin composition composed of an acrylic polymer having a hydroxyl group may be an unreacted monomer and contain a small amount of a (meth) acrylate monomer having a hydroxyl group, but the content thereof is In other words, it is only a very low content as compared with the content of the (meth) acrylate having a hydroxyl group in the photocurable resin composition of the present invention.
The photocurable resin composition of the present invention is in the state of an acrylic resin syrup comprising a main component polymer, a (meth) acrylate monomer having a hydroxyl group, a photopolymerization initiator, and a crosslinking agent, or for coating Further, the monomer having a hydroxyl group is uniformly dispersed. Therefore, the photocurable resin composition of the present invention is formulated into a resin solution in which the above acrylic resin slurry is dissolved in an organic solvent.
In the step of dissolving a monomer having a hydroxyl group in the aforementioned main agent polymer to obtain an acrylic resin slurry, it is preferred to remove the organic solvent used in the polymerization reaction before dissolving the monomer having a hydroxyl group in the main agent polymer. The obtained liquid base polymer is separated, and washed with water, an organic solvent or the like as needed. Thereby, the polymerization reaction of the main agent polymer can be completely stopped and the unreacted acrylic monomer can be removed from the main agent polymer. Further, by more accurately quantifying the weight of the main polymer, it is possible to prepare an acrylic resin slurry in which the content of the monomer having a hydroxyl group, the crosslinking agent and the photopolymerization initiator used in the next step is more appropriately adjusted. In the preparation of the acrylic resin syrup, the operation of removing the organic solvent used in the above polymerization reaction may be carried out after dissolving the monomer having a hydroxyl group in the main polymer.
Further, when a photopolymerization initiator is added to the acrylic resin syrup, once the ultraviolet light contained in the indoor light or the sunlight acts on the acrylic resin syrup, the polymerization reaction may occur and it is difficult to control. Therefore, it is preferred to add a photopolymerization initiator as soon as possible before the coating step as a later step. In the case where the acrylic resin slurry is dissolved in a resin solution in an organic solvent, the same treatment is also performed, that is, care is taken to prevent the photoreaction starter from reacting before coating and grinding due to some external factors. The phenomenon.
In order to impart fluidity suitable for coating on a substrate, the photocurable resin composition of the present invention is preferably prepared as a coating liquid of a photocurable resin composition containing an appropriate amount of an organic solvent. Specific examples of the organic solvent to be used in the coating liquid of the photo-curable resin composition include aromatic hydrocarbons such as toluene and xylene, and aliphatic esters such as ethyl acetate and butyl acetate. An alicyclic hydrocarbon such as an alkane, an aliphatic hydrocarbon such as hexane or pentane, or the like. However, it is not particularly limited as long as the above coating and dispersion can be achieved.
When the coating liquid of the photo-curable resin composition is prepared, as long as it is a compound capable of obtaining a main agent polymer, a monomer having a hydroxyl group, a photopolymerization initiator, and a crosslinking agent, it is dissolved in an organic compound at an appropriate mixing ratio. The organic solution in the solvent may be used, and the order of dissolution therein is not particularly limited. For example, a monomer having a hydroxyl group, a photopolymerization initiator, a crosslinking agent may be directly added to the acrylic resin slurry obtained by polymerizing the main agent polymer, or a monomer having a hydroxyl group may be dissolved by adding an appropriate amount of an organic solvent. A solution of a body, a photopolymerization initiator, and a crosslinking agent.
In the present invention, a (meth) acrylate monomer having a hydroxyl group used as a monomer having a hydroxyl group may, for example, be 2-hydroxyethyl (meth)acrylate or 2-hydroxypropyl (meth)acrylate. , 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, (meth)acrylic acid 7-hydroxyheptyl ester, 8-hydroxyoctyl (meth)acrylate, 7-methyl-8-hydroxyoctyl (meth)acrylate, 2-methyl-8-hydroxyoctyl (meth)acrylate, ( 9-hydroxydecyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxydodecyl (meth)acrylate, and the like. They may be used alone or in combination of two or more. It is particularly preferable to use 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, or 4-hydroxybutyl (meth)acrylate.
As the (meth) acrylate having a hydroxyl group, it is preferably obtained by esterifying one of two hydroxyl groups of a diol (diol compound) by acrylic acid or methacrylic acid, and each of them has one molecule A hydroxyl group and a vinyl hydroxyalkyl (meth) acrylate.
The type of the monomer (the monomer constituting the main polymer and the monomer having a hydroxyl group) used in the present invention differs depending on the adhesion of the laminated film and the storage modulus required, but when it is necessary to have a rework In the case of the laminated film, the photocurable resin composition having a high storage modulus and a high hardness may be used. Therefore, as a general standard of the monomer, a monomer having a glass transition temperature Tg of at least room temperature is preferable. In contrast, when the adhesion is required to be strong or when it is desired to lower the storage modulus, a monomer having a Tg lower than room temperature, preferably a Tg below zero, is required.
The photopolymerization initiator (polymerization catalyst) is not particularly limited, and examples thereof include an acetophenone photopolymerization initiator, a benzoin photopolymerization initiator, and a benzophenone lamp. A polymerization initiator, a thioxanthone photopolymerization initiator, and the like.
As the acetophenone photopolymerization initiator, acetophenone, p-(tert-butyl) 1', 1', 1'-trichloroacetophenone, chloroacetophenone, 2', 2'-diethoxyacetophenone, hydroxyacetophenone, 2,2-dimethoxy-2'-phenylacetophenone, 2-aminoacetophenone, dialkylaminoacetophenone, and the like.
As the starter of the benzoin photopolymerization reaction, there may be mentioned: benzamidine, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 1-hydroxycyclohexyl benzophenone, 2-hydroxyl 2-methyl-1-phenyl-2-methylpropan-1-one, 1-(4-isopropylphenyl)-2-hydroxy 2-methylpropan-1-one, benzoin dimethyl ether, etc. .
As a benzophenone photopolymerization initiator, benzophenone, benzamidine benzoic acid, methyl benzoic acid benzoate, methyl benzyl benzoate (Methyl o-Benzoylbenzoate) ), 4-phenylbenzophenone, hydroxybenzophenone, hydroxypropyl benzophenone, acryl benzophenone, 4,4'-bis(dimethylamino)benzophenone, and the like.
Examples of the thioxanthone photopolymerization initiator include thioxanthone, 2-chlorothiazinone, 2-methylthiaxanone, diethyl thioxanthone, and dimethyl group. Xanthone and the like.
As other photopolymerization initiators, α-decyl ester, benzyl-(o-ethoxycarbonyl)-α-monofluorene, mercaptophosphine oxide, glyoxy ester, and fragrance are exemplified. Bean 3-ketone, 2-ethyl hydrazine, camphorquinone, tetramethyl thiuram sulfide, azobisisobutyronitrile, benzammonium peroxide, dialkyl peroxide, peroxypivalic acid Tert-butyl ester and the like.
These photopolymerization initiators may be used alone or in combination of two or more. When the total amount of the polymerizable compound (the (meth) acrylate having a hydroxyl group in the case of the present invention) is 100% by mass, the content of the photopolymerization initiator is preferably 0.02 to 10% by mass, particularly It is preferably 0.1 to 5 mass%. When the content of the photopolymerization initiator is 0.02% by mass or more, the polymerizable compound can be polymerized in a short time. When the content of the photopolymerization initiator is 10% by mass or less, the residue of the photopolymerization initiator is less likely to remain in the cured product. Further, it is preferred that the (C) photopolymerization initiator is 0.5 to 1 part by weight based on 100 parts by weight of the main agent polymer.
Further, as described above, the (meth) acrylate monomer having a hydroxyl group (the total amount when two or more kinds are used) is preferably 4 to 20 parts by weight, based on 100 parts by weight of the main agent polymer, when it is carried out at 85 ° C. When the test in an environment of 85% RH or the like requires high durability, it is more preferably 4 to 15 parts by weight; further, (B) a (meth) acrylate single having a hydroxyl group with respect to 100 parts by weight of the main polymer. At least one of the bodies is preferably 5 to 10 parts by weight, and therefore, the content of the photopolymerization initiator based on 100 parts by weight of the main polymer is preferably 0.1 to 5 parts by weight, more preferably 0.1 to 0.5. Parts by weight. Further, the (C) photopolymerization initiator is preferably 0.5 to 1 part by weight based on 100 parts by weight of the main polymer.
In the present invention, in the photocurable resin composition after photopolymerization, 40 to 80% by weight of the monomer is preferably polymerized, and preferably 50 to 75% by weight of the monomer is polymerized. That is, it is desirable that the unreacted monomer remains in the range of 60 to 20% by weight, preferably 50 to 25% by weight. When the polymerization rate is less than 40% by weight, sufficient adhesion cannot be imparted to the obtained polymer; and when the polymerization ratio exceeds 80% by weight, the cohesive force is lowered, and resin residue occurs when the photocurable resin layer is peeled off and removed. .
The present invention can also be used as a component (D) to add a bifunctional crosslinking agent to the photocurable resin composition to crosslink the polymer.
The (D) bifunctional crosslinking agent is not particularly limited as long as it is a compound having two crosslinking reaction functional groups in one molecule. Examples of such a bifunctional crosslinking agent include a difunctional epoxy compound, a difunctional isocyanate, and the like.
Examples of the difunctional epoxy compound include ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, and dipropylene glycol diglycidyl ether. An aliphatic difunctional epoxy compound such as polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether or 1,6-hexanediol diglycidyl ether; hydrogenated bisphenol A diglycidyl ether, phthalic acid An aromatic difunctional epoxy compound such as diglycidyl ester, diglycidyl terephthalate or resorcinol diglycidyl ether. The epoxy group of the difunctional epoxy compound can be crosslinked with the carboxyl group of the polymer.
Examples of the difunctional isocyanate include aliphatic difunctional isocyanates such as hexamethylene diisocyanate and isophorone diisocyanate (IPDI); and aromatic difunctional isocyanates such as toluene diisocyanate and diphenylmethane diisocyanate. The NCO group of the difunctional isocyanate is capable of undergoing a crosslinking reaction with the carboxyl group and the hydroxyl group of the polymer.
The content of the bifunctional crosslinking agent is in the range of 0.1 equivalent or less with respect to the crosslinking point of the polymer, and is, for example, preferably 0.5 to 3.0 parts by weight, more preferably 1.0 to 100 parts by weight of the main polymer. 3.0 parts by weight, more preferably 0.2 to 0.8 parts by weight.
Here, the material of the base material used when the photocurable resin composition is applied to form a laminated film of the coating layer of the photocurable resin preferably has transparency, heat resistance, and hardening of the ultraviolet curable resin composition. A material that scatters and absorbs less in the ultraviolet region around 350 nm to 400 nm. For example, polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyfluorene, polyether oxime, polystyrene, polyacrylate, and poly Ether ether ketone, polycarbonate, polyethylene, polypropylene and other polyolefins, polyamine, nylon, polyimine, triethylene sulfonate (triacetate), cellulose diacetate, poly (methyl Alkyl acrylate, poly(meth) acrylate copolymer, polymethyl methacrylate, fluororesin such as polytetrafluoroethylene, polytrifluoroethylene, polyvinyl chloride, polyvinylidene chloride copolymer, chlorine Ethylene-vinyl acetate copolymer, polyvinyl alcohol, cellophane, cellulose film, and the like. These materials may be used alone or in combination of two or more.
In particular, polyethylene terephthalate in the above-mentioned base material is preferably used from the viewpoint of heat resistance, ultraviolet ray permeability, and price.
Further, the thickness of the substrate is preferably 16 μm to 200 μm, and more preferably 50 μm to 188 μm. If the thickness of the substrate is too thin, workability is poor. Further, if the thickness of the substrate is too thick, it is disadvantageous in terms of cost and workability.
The coating device for applying the photocurable resin composition to the substrate may be any device that can apply the photocurable resin composition uniformly to the substrate, but preferably has a photocurable resin composition. A device (not shown) having a structure composed of a container, a liquid supply pump, a pipe, an impurity removal screening program, and a coating head, can continuously apply the photocurable resin composition to the substrate. As the coating head, for example, a die coater or the like is preferably used.
A film layer (coating film) of the photo-curable resin composition is formed on one surface of the substrate by a coating device. The photocurable resin composition immediately after application by the coating device is an uncured liquid and has fluidity suitable for coating.
The thickness of the coating layer of the photocurable resin composition in the laminated film of the present invention is preferably between 50 μm and 3 mm, and more preferably between 100 μm and 300 μm. The reason for this is that, in the white turbidity defined in the present invention, it is apparent that the white turbidity preventing effect is 50 μm or more, and when a hard adherend such as a glass plate or an acrylic plate is bonded to each other, The thicker the adhesive tape, the easier it is to bond without generating bubbles, which is preferable. However, from the viewpoint of cost, it is considered to be appropriate below 300 μm.
When the photo-curable resin composition is a resin syrup, the thickness of the coating layer is approximately equal to the thickness of the photo-curable resin layer obtained by photopolymerization.
When the photo-curable resin composition is a solution, the thickness of the coating layer before drying is thicker than that of the resin syrup, and is a value obtained by dividing the thickness of the coating layer by the concentration. The thickness of the dried coating layer is the same as that of the resin syrup.
When the coating layer is too thin, the thickness of the photo-curable resin layer is also reduced, so that the absorption performance against impact is also deteriorated. Further, if the coating layer is too thick, the cost rises, which is disadvantageous from this point of view.
An example of a method of producing a laminated film of the present invention is schematically shown in Fig. 2. In the apparatus shown in Fig. 2, the photo-curable resin composition is supplied from the press coater 21 to the substrate 11 to form the coating layer 12. Reference numeral 22 is a backup roll 22 disposed opposite the mold coater 21 and used to support the substrate 11. The substrate 11 on which the coating layer 12 is formed is conveyed along its length direction, and the solvent in the coating layer 12 is removed in the drying chamber 23 to be dried. On the coated layer 12 after drying, the separator 13 is supplied onto the coating layer 12 from the separator supply device 24, and bonded by the nip roller 25.
The temperature in the drying chamber 23 may be a temperature at which the solvent in the coating layer 12 is sufficiently volatilized, and it is preferable to maintain the temperature at which the polymerizable compound does not thermally polymerize.
The diaphragm supply device 24 is constituted by a roller body around which the diaphragm 13 is wound, a shaft for holding the roller body, and the like.
The nip roller 25 is composed of a pair of rollers that sandwich the base material 11 and the separator 13 on which the coating layer 12 is formed, and is a device that bonds the two. It is preferable to provide a pressurizing means for lamination, and preferably at least one of the rolls is made of rubber so as to easily apply a uniform pressure to the film.
As the separator, for example, a polycarbonate film, a polyarylate film, a polyether ruthenium film, a polyfluorene film, a polyester film, a polyamide film, or a polyfluorene film can be used. A single layer or a plurality of layers of a plastic film represented by an amine film, a polystyrene film, a polyolefin film, a norbornene film, a phenoxyether type polymer film, or an organic gas-permeable film is subjected to a release treatment to at least one side a release film having releasability; a release paper having a release property by applying a release treatment to the paper by an anthrone-based release agent or the like; a film having a peeling property such as a fluorine-based resin film or a polyolefin film; A film obtained by adding a release agent to the inside and the like. The thickness of the separator is not limited, but in many cases, it is usually 5 to 500 μm, preferably 10 to 100 μm. The separator can be selected depending on the photocurable resin composition to be used and the intended use (peel strength).
Further, as the laminated film of the present invention, when a laminated film such as a transfer film (TransferTape) which has no support and adheres on both sides is produced, not only the separator 13 but also the substrate 11 for transportation is supplied. A separator is also supplied, and a coating layer of a photo-curable resin layer is formed on the separator.
Further, in the laminated film of the present invention, when a coating film having a coating layer of a photo-curable resin layer on both sides of a support is produced and both surfaces are adhered on both sides, the coating liquid can be simultaneously or sequentially applied to each surface. Coating, drying and photopolymerization of the coating layer.
After the light irradiation for the photopolymerization reaction, aging for the crosslinking reaction is carried out. The method of aging is not particularly limited, and for example, a laminated film wound on a roll is placed under a predetermined temperature and time. The temperature of the ripening depends on the type of the crosslinking agent, etc., but it is preferred to carry out heating as needed (for example, 40 to 80 ° C).
Further, since the laminated film having the photocurable resin layer of the present invention is bonded to the adherend having a step on the surface, it is preferable to store the modulus at 24 ° C and 1 Hz in order to follow the step of the adherend. ') at 1×10 ⁴ Above Pa and below 9×10 ⁴ Pa. When the storage modulus is a low value within the numerical range, the photo-curable resin layer is soft and easily deformed, so that it can be easily adhered to follow the step of the adherend, and it is possible to prevent the bubbles from entering the vicinity of the step. Here, the storage modulus is a storage modulus of the "photocurable resin layer", and specifically, it is preferable to use a storage selected from the "coating layer of the photocurable resin layer" coated with the photocurable resin composition as appropriate. The number of modules, the storage modulus of the "hardened layer of the photo-curable resin layer" after heat drying, the hardening of the photo-curable resin layer after hardening the photo-curable resin layer by the polymerization reaction by light irradiation and the crosslinking reaction by aging Any of the storage modules of the layer "stores the modulus.
Specifically, as shown in Examples 1 to 3 to be described later, the elastic modulus (unit: Pa) of the photo-curable resin layer in the laminated film when bonded to the adherend having a step is preferably 1 × 10 ⁴ Above Pa and below 9×10 ⁴ Pa. It is preferable that the laminated film which is bonded to the adherend having a step is a laminated film which is not irradiated with UV, or a laminated film which is low in UV irradiation even if it is somewhat irradiated with UV during use.
Since the laminated film having the photo-curable resin layer of the present invention is transparent, the photo-curable resin layer can be preferably applied to various types of displays such as liquid crystal panels and organic electroluminescence panels. Use.
The step difference existing on the surface of the adherend is not only a step due to a printed layer such as ink, but also a step caused by a wiring layer, a mesh pattern of a metal or a conductor, an adhesive tape, or the like.
The height of the step is various depending on the use of the adherend. When the light-shielding property is not required, it is sufficient to be less than 10 μm. However, when the light-shielding property is required, a thickness of 10 μm or more is required. Further, for the thickness of the printed layer, the thickness of each color is 7 to 10 μm, and the number of colors is increased as needed. Therefore, for example, in the case of four colors, the thickness is 40 μm, and it is necessary to be able to fill these various steps. Laminated film. The height of the step which can be tolerated in the laminated film having the photo-curable resin layer of the present invention is not particularly limited because the thickness of the photo-curable resin layer can be increased or decreased depending on the step height. When the photocurable resin composition of the present invention is bonded to an adherend having a printing step having a surface of 50 μm or more, generation of bubbles can be prevented, and after the ultraviolet ray is irradiated, the oven is used at 85 ° C, 85% RH, or the like. In the high-temperature and high-humidity environment, the endurance test and the removal from the oven do not cause white turbidity. Therefore, it is preferably applied to the adherend having a step of 50 μm or more.

Example
Hereinafter, the present invention will be specifically described based on examples.
(Example 1)
(A) a base polymer composed of an acrylic resin having an acid value of 0 to 33 as a photocurable resin composition, and "SK-Dyne 2094" (acid value: 33, manufactured by Amika Chemical Co., Ltd.) was used. . The main agent polymer and E-AX (hardener, manufactured by Soken Chemical Co., Ltd.) as a (D) bifunctional crosslinking agent were respectively blended in an amount of 100 g: 0.27 g to obtain a main agent-crosslinking agent mixture. Solution. In the obtained main agent-crosslinking agent mixed solution, 10.0 g of 4-hydroxybutyl acrylate (4HBA, Osaka Organic Materials Industrial Co., Ltd.) as (B) (meth) acrylate monomer having a hydroxyl group was further added. Co., Ltd.) and 1.0 g of (C) alkylphenone-based photopolymerization initiator (product name "Irgacure 184", manufactured by Ciba Japan KK), formulated Photohardenable resin composition.
The photocurable resin composition was applied to a separator (product name: "125E-0010DG2.5AS", and the thickness was set by using an applicator so that the thickness of the coating layer of the dried photocurable resin was 175 μm. 125 μm; manufactured by Fujimori Industrial Co., Ltd.), on one surface of a release film formed, and then dried to form a laminated film of a coating layer on which a photocurable resin is laminated.
Next, a separator (product name: "38E-0010BDAS", thickness: 38 μm; manufactured by Fujimori Industrial Co., Ltd.) was bonded to the upper surface of the photocurable resin coating layer of the obtained laminated film to prepare a laminated photocurable resin. The laminated film of Example 1 of the coating layer.

(Example 2)
(A) a base polymer composed of an acrylic resin having an acid value of 0 to 33 as a photocurable resin composition, "SK-Dyne 2147" (acid value: 0, manufactured by Amika Chemical Co., Ltd.) was used. . The main component polymer and TD-75 (manufactured by Soken Chemical Co., Ltd.) as a (D) bifunctional crosslinking agent were respectively blended in an amount of 100 g: 0.06 g to obtain a main component-crosslinking agent mixed solution. In the obtained main agent-crosslinking agent mixed solution, 5.0 g of 4-hydroxybutyl acrylate (4HBA, Osaka Organic Materials Industrial Co., Ltd.) as (B) (meth) acrylate monomer having a hydroxyl group was further added. Co., Ltd.) and 0.50 g of (D) alkylphenone photopolymerization initiator (product name "Irgacure 184", manufactured by Ciba Japan KK), formulated into a photocurable resin A laminate film of Example 2 was obtained in the same manner as in Example 1 except for the composition.

(Example 3)
(A) a base polymer composed of an acrylic resin having an acid value of 0 to 33 as a photocurable resin composition, "SK-Dyne 2147" (acid value: 0, manufactured by Amika Chemical Co., Ltd.) was used. . The main component polymer and TD-75 (manufactured by Soken Chemical Co., Ltd.) as a (D) bifunctional crosslinking agent were respectively blended in an amount of 100 g: 0.06 g to obtain a main component-crosslinking agent mixed solution. In the obtained main agent-crosslinking agent mixed solution, 10.0 g of 4-hydroxybutyl acrylate (4HBA, Osaka Organic Materials Industrial Co., Ltd.) as (B) (meth) acrylate monomer having a hydroxyl group was further added. (manufactured by Ltd.) and 1.0 g of (C) alkylphenone photopolymerization initiator (product name "Irgacure 184", manufactured by Ciba Japan KK), formulated into a photocurable resin A laminate film of Example 3 was obtained in the same manner as in Example 1 except for the composition.

(Comparative Example 1)
(A) a base polymer composed of an acrylic resin having an acid value of 0 to 33 as a photocurable resin composition, and "SK-Dyne 2094" (acid value: 33, manufactured by Amika Chemical Co., Ltd.) was used. . The main agent polymer and E-AX (hardener, manufactured by Soken Chemical Co., Ltd.) as a (D) bifunctional crosslinking agent were respectively blended in an amount of 100 g: 0.27 g to obtain a main agent-crosslinking agent mixture. Solution. The obtained main agent-crosslinking agent mixed solution was applied to the separator (product name "125E-0010DG2." by using an applicator so that the thickness of the coating layer of the dried photocurable resin was 175 μm. 5S", a thickness of 125 μm; manufactured by Fujimori Industrial Co., Ltd.), the upper surface of the release film, and then dried to form a laminated film of a coating layer on which a photocurable resin is laminated.
Next, a separator (product name: "38E-0010BDAS", thickness: 38 μm; manufactured by Fujimori Industrial Co., Ltd.) was bonded to the upper surface of the coating layer of the photocurable resin of the obtained laminated film to form a laminated photohardenable layer. The laminated film of the comparative example 1 of the coating layer of resin.

(Comparative Example 2)
(A) a base polymer composed of an acrylic resin having an acid value of 0 to 33 as a photocurable resin composition, "SK-Dyne 2147" (acid value: 0, manufactured by Amika Chemical Co., Ltd.) was used. . The main agent polymer and TD-75 (manufactured by Soken Chemical Co., Ltd.) as a (D) bifunctional crosslinking agent were respectively blended in an amount of 100 g: 0.06 g to obtain a mixed solution of a main agent-crosslinking agent. The operation was carried out in the same manner as in Comparative Example 1, except that the laminated film of Comparative Example 2 was obtained.

(Comparative Example 3)
(A) a base polymer composed of an acrylic resin having an acid value of 0 to 33 as a photocurable resin composition, and "SK-Dyne 2094" (acid value: 33, manufactured by Amika Chemical Co., Ltd.) was used. . The main agent polymer and E-AX (hardener, manufactured by Soken Chemical Co., Ltd.) as a (D) bifunctional crosslinking agent were respectively blended in an amount of 100 g: 0.27 g to obtain a main agent-crosslinking agent mixture. Solution.
The main agent-crosslinking agent mixed solution was applied to the separator (product name "125E-0010DG2.5AS" by using an applicator so that the thickness of the coating layer of the dried photocurable resin became 175 μm. The upper surface of the peeling film which consists of 125 micrometers of the thickness of 125 micrometers, and the manufacturing of the coating film of the photo-hardening resin laminated|stacked.
Next, a separator (product name: "38E-0010BDAS", thickness: 38 μm; manufactured by Fujimori Industrial Co., Ltd.) was bonded to the upper surface of the photocurable resin coating layer of the obtained laminate to prepare a photocurable resin. A laminated film of a coating layer.
Then, while the obtained laminated film was conveyed, a continuous UV irradiation apparatus using a high-pressure mercury lamp was used so that the irradiation amount became about 800 mJ/cm. ² In this manner, the transport speed of the laminated film of the photocurable resin coating layer as the substrate, the amount of UV irradiation, and the like are adjusted, UV irradiation is performed, and polymerization is carried out using a photopolymerization initiator to finally obtain photohardening by lamination. The laminated film of Comparative Example 3 of the resin layer.

(Comparative Example 4)
(A) a base polymer composed of an acrylic resin having an acid value of 0 to 33 as a photocurable resin composition, "SK-Dyne 2147" (acid value: 0, manufactured by Amika Chemical Co., Ltd.) was used. . The main agent polymer and TD-75 (manufactured by Soken Chemical Co., Ltd.) as a (D) bifunctional crosslinking agent were respectively blended in an amount of 100 g: 0.06 g to obtain a mixed solution of a main agent-crosslinking agent. The operation was carried out in the same manner as in Comparative Example 3 except that the laminated film of Comparative Example 4 was obtained.

(Comparative Example 5)
(A) a base polymer composed of an acrylic resin having an acid value of 0 to 33 as a photocurable resin composition, and "SK-Dyne 2094" (acid value: 33, manufactured by Amika Chemical Co., Ltd.) was used. . The main agent polymer and E-AX (hardener, manufactured by Soken Chemical Co., Ltd.) as a (D) bifunctional crosslinking agent were respectively blended in an amount of 100 g: 0.27 g to obtain a main agent-crosslinking agent mixture. Solution.
In the obtained main agent-crosslinking agent mixed solution, 5.0 g of 4-hydroxybutyl acrylate (4HBA, Osaka Organic Materials Industrial Co., Ltd.) as (B) (meth) acrylate monomer having a hydroxyl group was further added. Co., Ltd.) and 0.50 g of (C) alkylphenone photopolymerization initiator (product name "Irgacure 184", manufactured by Ciba Japan KK), formulated into a photocurable resin combination.
The photocurable resin composition was applied to a separator (product name: "125E-0010DG2.5AS", and the thickness was set by using an applicator so that the thickness of the coating layer of the dried photocurable resin was 175 μm. 125 μm; manufactured by Fujimori Industrial Co., Ltd.) The upper surface of the release film formed and then dried to form a laminated film of a coating layer on which a photocurable resin is laminated.
Next, a separator (product name: "38E-0010BDAS", thickness: 38 μm; manufactured by Fujimori Industrial Co., Ltd.) was bonded to the upper surface of the coating layer of the photocurable resin of the obtained laminated film to form a laminated photohardenable layer. The laminated film of the comparative example 5 of the coating layer of resin.

(Comparative Example 6)
(A) a base polymer composed of an acrylic resin having an acid value of 0 to 33 as a photocurable resin composition, and "SK-Dyne 2094" (acid value: 33, manufactured by Amika Chemical Co., Ltd.) was used. . The main agent polymer and E-AX (hardener, manufactured by Soken Chemical Co., Ltd.) as a (D) bifunctional crosslinking agent were respectively blended in an amount of 100 g: 0.27 g to obtain a main agent-crosslinking agent mixture. Solution.
In the obtained main agent-crosslinking agent mixed solution, 5.0 g of 4-hydroxybutyl acrylate (4HBA, Osaka Organic Materials Industrial Co., Ltd.) as (B) (meth) acrylate monomer having a hydroxyl group was further added. Co., Ltd.) and 0.50 g of (C) alkylphenone photopolymerization initiator (product name "Irgacure 184", manufactured by Ciba Japan KK), formulated into a photocurable resin combination.
The photocurable resin composition was applied to a separator (product name: "125E-0010DG2.5AS", and the thickness was set by using an applicator so that the thickness of the coating layer of the dried photocurable resin was 175 μm. 125 μm; manufactured by Fujimori Industrial Co., Ltd.) The upper surface of the release film formed and then dried to form a laminated film of a coating layer on which a photocurable resin is laminated.
Next, a separator (product name: "38E-0010BDAS", thickness: 38 μm; manufactured by Fujimori Industrial Co., Ltd.) was bonded to the upper surface of the photocurable resin coating layer of the obtained laminated film to prepare a laminated photocurable resin. A laminated film of a coating layer.
Then, while the obtained laminated film was conveyed, a continuous UV irradiation apparatus using a high-pressure mercury lamp was used so that the irradiation amount became about 800 mJ/cm. ² In the manner of adjusting the transport speed of the laminated film of the photocurable resin composition as the substrate, the amount of UV irradiation, etc., UV irradiation is carried out, and polymerization is carried out using a photopolymerization initiator to finally obtain a photocurable resin laminated. The laminated film of Comparative Example 6 of the layer.

(Comparative Example 7)
(A) a base polymer composed of an acrylic resin having an acid value of 0 to 33 as a photocurable resin composition, and "SK-Dyne 2094" (acid value: 33, manufactured by Amika Chemical Co., Ltd.) was used. . The main agent polymer and E-AX (hardener, manufactured by Soken Chemical Co., Ltd.) as a crosslinking agent were blended in an amount of 100 g: 0.27 g, respectively, to obtain a main component-crosslinking agent mixed solution. In the obtained main agent-crosslinking agent mixed solution, 10.0 g of 4-hydroxybutyl acrylate (4HBA, Osaka Organic Materials Industrial Co., Ltd.) as (B) (meth) acrylate monomer having a hydroxyl group was further added. (manufactured by Ltd.) and 1.0 g of (C) alkylphenone photopolymerization initiator (product name "Irgacure 184", manufactured by Ciba Japan KK), formulated into a photocurable resin A laminate film of Comparative Example 7 was obtained in the same manner as in Comparative Example 6, except that the composition was used.

(Comparative Example 8)
(A) a base polymer composed of an acrylic resin having an acid value of 0 to 33 as a photocurable resin composition, "SK-Dyne 2147" (acid value: 0, manufactured by Amika Chemical Co., Ltd.) was used. . The main agent polymer and TD-75 (manufactured by Soken Chemical Co., Ltd.) as a crosslinking agent were respectively blended in an amount of 100 g: 0.06 g to obtain a main component-crosslinking agent mixed solution. In the obtained main agent-crosslinking agent mixed solution, 5.0 g of 4-hydroxybutyl acrylate (4HBA, Osaka Organic Materials Industrial Co., Ltd.) as (B) (meth) acrylate monomer having a hydroxyl group was further added. Co., Ltd.) and 0.50 g of (C) alkylphenone photopolymerization initiator (product name "Irgacure 184", manufactured by Ciba Japan KK), formulated into a photocurable resin A laminate film of Comparative Example 8 was obtained in the same manner as in Comparative Example 6, except that the composition was used.

(Comparative Example 9)
(A) a base polymer composed of an acrylic resin having an acid value of 0 to 33 as a photocurable resin composition, "SK-Dyne 2147" (acid value: 0, manufactured by Amika Chemical Co., Ltd.) was used. . The main agent polymer and TD-75 (manufactured by Soken Chemical Co., Ltd.) as a crosslinking agent were respectively blended in an amount of 100 g: 0.06 g to obtain a main component-crosslinking agent mixed solution. In the obtained main agent-crosslinking agent mixed solution, 10.0 g of 4-hydroxybutyl acrylate (4HBA, Osaka Organic Materials Industrial Co., Ltd.) as (B) (meth) acrylate monomer having a hydroxyl group was further added. (manufactured by Ltd.) and 1.0 g of (C) alkylphenone photopolymerization initiator (product name "Irgacure 184", manufactured by Ciba Japan KK), formulated into a photocurable resin A laminate film of Comparative Example 9 was obtained in the same manner as in Comparative Example 6, except that the composition was used.

(made laminated film)
The laminated films of Examples 1 to 3 and Comparative Examples 1 to 9 are summarized in Table 1.

In addition, in Table 1, "2094" and "2147" respectively represent "SK-Dyne (registered trademark) 2094" and "SK-Dyne (registered trademark) 2147". "E-AX" and "TD-75" are trade names of bifunctional cross-linking agents manufactured by Zaken Chemical Co., Ltd. "4HBA" means "4-hydroxybutyl acrylate" and "Irg 184" means "Irgacure (registered trademark) 184". Here, the active ingredient of the photopolymerization initiator of the product name "Irgacure (registered trademark) 184" is 1-hydroxycyclohexyl phenyl ketone.
Although the specific composition of SK-Dyne (registered trademark) 2094 and SK-Dyne (registered trademark) 2147 is unclear, it corresponds to (A) polymerization of a main component composed of an acrylic resin having an acid value of 0 to 33 in the present invention. Things.

(White turbid confirmation test)
The test piece of the produced laminated film was placed in a high-temperature, high-humidity environment at a temperature of 85 ° C × humidity 85% RH under light-shielding conditions, and taken out after 12 hours. Then, it was placed in an environment of a temperature of 23 ° C × a humidity of 50% RH, and the appearance change of the test piece was confirmed by visual inspection. The person who had become white turbid was evaluated as (×), and the person who could not confirm white opacity was evaluated as (○). Further, the same test and evaluation were carried out after irradiating the sample which was not irradiated with UV to UV.

(Follow-up confirmation test for print step difference and fit under atmospheric pressure)
An acrylic plate having a printing step difference of 50 μm in thickness and a flat glass plate are formed by screen printing, and the photohardenable resin layer obtained by peeling off the separator on both sides of the formed laminated film is subjected to an atmospheric pressure environment. fit. A laminating device (product name: SE320) manufactured by CLIMB PRODUCTS CO., LTD (product company) was used for the lamination. After the bonding, the pressure-heating treatment was carried out, and after standing at room temperature for 24 hours, the appearance after lamination was visually observed from the side of the acrylic sheet, and it was confirmed that there was a bubble in the printing step portion (×), and it was impossible to confirm. The evaluation is (○).

(Measurement of storage modulus)
The sample of the produced laminated film was cut into 1 cm square, and the photocurable resin layer obtained by peeling the double-sided separator was bonded to a jig. At this time, the single-sided separator may be peeled off, and the photo-curable resin layer may be bonded to the jig, and then the other single-sided separator may be peeled off. The dynamic viscoelasticity test of the sample was carried out using a dynamic viscoelastic device (Rheogel-E4000, manufactured by UBM) in a linear region and at a frequency of 1 Hz. The storage modulus of the photo-curable resin layer was measured at a temperature of from -40 ° C to +80 ° C and at a temperature increase rate of 2 ° C / min under room temperature of 24 ° C.

<test result>
The above test results are shown in Table 2. In G', G'', tan δ, "mE+n" means "m×10 ⁺ⁿ "(where m is an arbitrary real number and n is a positive integer).

(Results of white turbidity confirmation test of laminated film)
In Comparative Examples 6 to 9 in which UV irradiation was applied before the produced laminated film was bonded to the adherend, no white turbidity was observed. In Examples 1 to 3 and Comparative Examples 1 to 5, it was confirmed that there was a clouding phenomenon.
In Examples 1 to 3 and Comparative Example 5, although the photocurable resin composition contained (B) a (meth) acrylate monomer having a hydroxyl group and (C) a photopolymerization initiator, it was not applied. Due to the UV irradiation, the monomer having a hydroxyl group did not polymerize. In Comparative Examples 1 to 4, since the photocurable resin composition does not contain a monomer having a hydroxyl group or a photopolymerization initiator, it is not affected by UV irradiation, and no monomer having a hydroxyl group is polymerized. .
In addition, the same experiment was carried out after irradiating UV to the laminated film which was not irradiated with UV, and as a result, the white turbidity phenomenon was not confirmed in Examples 1-3 and the comparative example 5.
According to the above examples, it was confirmed that polymerization of a monomer having a hydroxyl group can improve the generation of white turbidity.
This evaluation is a change caused when the separators are applied to each other or a resin film such as polyethylene terephthalate (PET). In the samples with poor gas permeability, between the acrylic plate and the glass, the timing of white turbidity is the same, but the disappearance of white turbidity may take several days.
In addition, all the white turbidity generated in the heat and humidity resistant environment test was made transparent by leaving it to stand at room temperature for several hours.

(Results of the follow-up confirmation test for the printing step difference)
When the laminated film is bonded to the adherend at atmospheric pressure, when the height of the printing step is 50 μm, in Examples 1 to 3, the bonding can be performed in a portion where the bubbles do not enter the printing step.
However, in Comparative Examples 1 to 9, there was a bubble entering the portion where the printing step was poor. The reason for this is considered to be that in Comparative Examples 1 to 9, the storage modulus is high, the resin is hard, and the followability to the printing step difference existing on the adherend is poor.
Thus, when the height of the printing step is more than 50 μm, it is preferable that the photo-curable resin layer in the case where the adherend having the step is bonded in Examples 1 to 3, that is, the coating layer of the photo-curable resin which is not irradiated with UV ( The storage modulus G' of the photohardenable resin layer obtained not by the light irradiation-based polymerization reaction and the ripening-based crosslinking reaction) is 9 × 10 ⁴ Pa below.

(Results of storage modulus measurement)
As shown in Table 2, when the height of the printing step is 50 μm, it can be seen from the comparison of Examples 1 to 3 and Comparative Examples 1 to 9 that, as shown in Examples 1 to 3, it is preferable to apply photohardening to the step. The elastic modulus (unit: Pa) of the photo-curable resin layer in the resin layer, that is, the laminate film not irradiated with UV is 1 × 10 ⁴ Above Pa and below 9×10 ⁴ Pa. Further, in order to obtain such a laminated film, it is preferable to prepare a storage modulus (G') of 1 × 10 at 1 Hz. ⁴ Above Pa and below 9×10 ⁴ The photocurable resin composition of Pa is applied.
By using the photocurable resin composition of the present invention and the laminated film using the photocurable resin composition, even if there is a printing step difference on the adherend, it is possible to bond the bubbles so as not to enter the portion where the printing step is poor.

11. . . Substrate or diaphragm to be transported

12. . . Coating layer

13. . . Diaphragm

twenty one. . . Mold coating machine

twenty two. . . Support roller

twenty three. . . Drying room

twenty four. . . Diaphragm supply device

25. . . Pinch roller

Claims (3)

A method for producing a laminate in which a laminated film having a step of laminating a step of forming a film of a photocurable resin layer is formed on a surface of a bonded body having a stepped surface, wherein at least the following is sequentially passed through Steps (1) to (5) are carried out: (1) a step of preparing (A) a main agent polymer composed of an acrylic resin having an acid value of 0 to 33; and (2) a step of preparing a photocurable resin composition, Here, the photocurable resin composition has a storage modulus G' of 1 × 10 ⁴ Pa or more and less than 9 × 10 ⁴ Pa at 24 ° C and 1 Hz, and contains 100 parts by weight of the above-mentioned main component polymer. 5 to 10 parts by weight of (B) at least one of (meth) acrylate monomers having a hydroxyl group, 0.5 to 1 part by weight of (C) photopolymerization initiator, and crosslinking with respect to the main polymer The joint is 0.2 to 0.8 parts by weight of (D) a bifunctional crosslinking agent in an amount of 0.1 equivalent or less; (3) a step of forming a laminated film by coating the photocurable resin composition on one side of the substrate or the separator Heating and drying to form a laminated film of a hardened layer on which a photo-curable resin layer is formed; (4) laminating the laminated film a method of bonding the laminate film to the adherend having a step on the surface by the hardened layer of the photocurable resin layer; and (5) a hardening step of irradiating light from the substrate or the separator to carry out polymerization And a crosslinking reaction based on aging is performed to harden the hardened layer of the photocurable resin layer. A laminate obtained by the production method according to the first aspect of the invention, wherein a laminated film having a photohardenable resin layer for laminating the aforementioned step is laminated on an adherend having a step on the surface Made. The laminate according to claim 2, wherein the adherend is an optical member used in a display.