JP2020032618A - Laminate - Google Patents

Abstract

To provide a laminate capable of preventing the deterioration of hydrophilicity of a resin layer surface due to the transferring of a mold release coat into a resin layer, which is used for protecting a high hydrophilic resin layer excellent in printability.SOLUTION: There is provided a laminate 5 in which a substrate 1, a resin layer 2 and a polyolefin resin layer 3 are adjacent in this order, wherein the polyolefin resin layer 3 is placed on one surface of the laminate 5 and the water contact angle of the surface of the resin layer on the side of the polyolefin resin layer 3 is less than 15 degrees.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laminate in which a substrate, a resin layer, and a polyolefin resin layer are adjacent in this order.

  Adhesive components for joining sheets are mainly classified into rubber-based, acrylic-based, and silicone-based when classified according to composition, and classified into organic solvent solutions, emulsions, solids (hot melts), and aqueous solutions when classified by state. Can be The main applications are those that do not require re-adhesiveness and that can be easily removed. In addition to the adhesive processing of temporary adhesive nameplates, temporary adhesion to labels, adhesive coatings of films, etc., materials with poor adhesion (PP, PE, PTFE, EPDM) Adhesive components suitable for each application include bonding, double-sided adhesive tape, primary processing on adhesive members, and re-adhesion, which requires re-adhesion and easy-release properties than temporary adhesion. You have to choose. In addition to the above classification, recently, a type of product called "adhesive" which reacts and cures after temporary temporary adhesive bonding has been put on the market.

  Thus, despite various adhesives and various purposes of use, it is difficult to print the surface thereof, and no solution has been found (see Patent Literature 1). Typical printing methods include offset printing, gravure printing, screen printing, letterpress printing, flexographic printing, etc.In all cases, the wettability of the ink to the adhesive is poor, Print fading due to poor coating, blurred printing, and contamination of the processing step due to ink that could not be completely transferred have become a problem. On the other hand, in recent years, there has been shown an example in which the above-described coating property is solved by imparting high hydrophilicity to the adhesive layer (see Patent Document 2).

  By the way, a release sheet provided with a release layer on the surface of a plastic film is a process sheet such as a ceramic sheet or a polyvinyl chloride sheet, or an adhesive label, an adhesive film, a polarizing plate film for liquid crystal and a PDP adhesive. It is widely used as a release film and a medical ship medicine adhesive separator (see Patent Documents 3 and 4). The release sheet has excellent mechanical strength, heat resistance, thermal dimensional stability, and chemical resistance, and is economical. A film in which a silicone-based resin layer is provided on at least one surface of a polyethylene terephthalate film to improve releasability. Is commonly used.

  However, when a release sheet having such a silicone-based resin layer is used as a protective film for a highly hydrophilic adhesive layer having excellent printing properties, the transfer of the silicone resin causes the hydrophilicity of the adhesive layer to be reduced. It is a problem that not only deterioration but also appearance defects such as printing bleeding are caused.

Japanese Patent No. 5,256,673 JP 2017-165945 A JP-A-5-194768 JP-A-2002-120210

  In view of the background of the related art, the present invention uses a release sheet for the purpose of protecting a highly hydrophilic resin layer having excellent printability, so that a release coat is transferred to the resin layer. Provided is a laminate which prevents the deterioration of hydrophilicity of the surface. Further, since the step of applying a release coat to the release sheet used in the laminate of the present invention can be omitted, productivity can be improved.

  The present invention employs the following means in order to solve such a problem.

The base material, the resin layer, and the polyolefin resin layer are a laminate adjacent in this order,
The polyolefin resin layer is on one surface of the laminate,
A laminate wherein the water contact angle of the surface of the resin layer on the side of the polyolefin resin layer is less than 15 degrees.

  An object of the present invention is to provide a laminate in which a resin layer having high hydrophilicity is protected.

It is sectional drawing of a laminated body.

  Hereinafter, the present invention will be described in detail with preferred embodiments, but the scope of the present invention is not limited to these embodiments. The laminate of the present invention is a laminate in which the base material, the resin layer, and the polyolefin resin layer are adjacent to each other in this order, and the polyolefin resin layer is on one surface of the laminate, and the polyolefin resin layer The water contact angle of the surface of the resin layer on the side is less than 15 degrees. FIG. 1 shows an example of a cross section of the laminate of the present invention.

  Hereinafter, a configuration in which a resin layer is laminated on a base material is referred to as a liquid developing sheet. Therefore, a configuration in which a polyolefin resin layer is bonded to the surface of the liquid spreading sheet on the resin layer side is the laminate of the present invention.

[Base material]
The substrate of the present invention is not particularly limited as long as it has a plate-like region where a resin layer and a polyolefin resin layer can be laminated, but a film is preferably used.

  The film suitable as a substrate preferably contains an organic polymer. As the organic polymer, a linear organic polymer is preferable. Further, the organic polymer preferably has a number average molecular weight of 5,000 to 20,000. As the organic polymer in the film, an organic polymer that has been partially crosslinked by adding a crosslinking agent having two or more functional groups in the molecule and reacting or irradiating it can also be used. . The organic polymer in the film preferably contains 50% by mass or more and 100% by mass or less in 100% by mass of the film. The film may contain various additives in addition to the organic polymer.

  Examples of the organic polymer suitable for the film used for the substrate include, for example, polyester, polyolefin, polyamide, polyesteramide, polyether, polyimide, polyamideimide, polystyrene, polycarbonate, poly-ρ-phenylene sulfide, polyetherester, and polychloride. Vinyl and poly (meth) acrylate. Further, these copolymers, blends, and further cross-linked compounds can also be used. Further, among the above organic polymers, polyesters such as polyethylene terephthalate, polyethylene 2,6-naphthalate, polyethylene α, β-bis (2-chlorophenoxy) ethane 4,4′-dicarboxylate, polybutylene terephthalate and the like can be used. Among them, a film made of polyethylene terephthalate is particularly preferably used in consideration of mechanical properties, quality such as workability, economy, and the like.

  The film used for the substrate may be a single-layer film or a film having two or more layers, for example, a film formed by a co-extrusion method. As the type of the film, a film stretched in a uniaxial direction or a biaxial direction may be used. On the surface of the substrate on which the resin layer is to be formed, a pretreatment such as a corona treatment, an ion bombardment treatment, a solvent treatment, or a roughening treatment has been performed to improve the adhesiveness with the resin layer. No problem. Further, on the surface of the base material on the side opposite to the side on which the resin layer is formed, a coating layer of an organic substance, an inorganic substance, or a mixture thereof may be applied for the purpose of improving slipperiness at the time of winding the film. I do not care.

  The base material used in the present invention may have a laminated structure having a layer (easily adhesive layer) having a thickness of 1 μm or less (easily adhesive layer) for the purpose of improving the adhesive strength between the adjacent resin layers.

  The thickness of the substrate used in the present invention is preferably 500 μm or less from the viewpoint of securing flexibility. Further, from the viewpoint of securing the strength against tension and impact, the thickness is more preferably 5 μm or more. Furthermore, the lower limit of the thickness of the substrate is more preferably 10 μm or more, and the upper limit is more preferably 200 μm or less, from the viewpoint of easiness of processing and handling of the film.

[Resin layer]
The resin layer of the present invention is disposed such that one surface is in contact with the base material and the other surface is in contact with the polyolefin resin layer, contains a resin, and further has a water contact angle of 15 degrees on the surface of the resin layer on the side of the polyolefin resin layer. It is a layer which becomes less than. Further, the resin layer of the laminate of the present invention preferably contains an adhesive component exhibiting adhesiveness and a hydrophilic component exhibiting hydrophilicity. The resin layer containing both the adhesive component and the hydrophilic component is preferably a layer having both an appropriate adhesive strength with an adjacent polyolefin resin layer and the hydrophilicity of the surface of the resin layer. The adhesive component and the hydrophilic component may be components derived from the same structure or components derived from different structures. The component derived from the same structure indicates that a compound having both a structure expressing adhesiveness and a structure expressing hydrophilicity is used. Although details will be described later, it is preferable to use a resin as the adhesive component.

  The thickness of the resin layer is not particularly limited, but is preferably 5 to 50 μm, and more preferably 15 to 40 μm. When the thickness of the resin layer is less than 5 μm, a uniform thickness in the plane may not be ensured due to insufficient processing accuracy of the resin layer, or sufficient adhesive strength with the base material may not be obtained. . On the other hand, when the thickness of the resin layer is greater than 50 μm, the manufacturing cost may increase due to the use of an excessive amount of the resin, and the resin layer may protrude from the edge in the conveying step or the slitting step of the laminated body, thereby contaminating the process. is there. Since the maximum thickness of the easy-adhesion layer in the base material is 1 μm, the resin layer and the easy-adhesion layer can be distinguished by the thickness.

  The resin layer may be provided with a printing layer on its surface by a method represented by offset printing, gravure printing, screen printing, letterpress printing, flexographic printing, or the like.

[Adhesive component]
Although the resin layer of the present invention contains at least a resin, it is preferable to use an adhesive component as the resin in the resin layer. The adhesive component in the resin layer is generally an adhesive (resin) that loses tackiness due to a curing reaction after bonding to an adherend, an adhesive (resin) that maintains tackiness even after bonding to an adherend, or heating. Adhesives (resins) that soften when heated to room temperature and solidify when returned to room temperature are known. As the resin serving as the adhesive component, either a thermoplastic resin or a thermosetting resin can be used. The resin used as the adhesive component in the resin layer in the present invention is not limited in composition, curing method, solid content and the like, but preferably exhibits sufficient adhesive strength to the substrate. The adhesive component in the resin layer is preferably, for example, a pressure-sensitive adhesive or a thermoplastic resin having a function of being softened by heat and exhibiting adhesiveness, ie, a hot-melt property. As described above, a thermoplastic resin having a hot-melt property that can be preferably used as an adhesive component in a resin layer may be hereinafter referred to as a hot-melt adhesive.

  Pressure-sensitive adhesive (Pressure Sensitive Adhesive) refers to a coating agent that bonds an adherend by applying pressure, while hot-melt adhesive (Hot-Melt Adhesive) refers to a coating agent that bonds an adherend by heating. Point to. Both pressure-sensitive adhesives and hot-melt adhesives are adhesives mainly composed of thermoplastic resins that are solid / semi-solid at room temperature and liquid at high temperatures, and are in the form of a solution diluted with water or an organic solvent as a coating solution. You may. Here, the main component refers to a component that occupies 80% by mass or more when the entire pressure-sensitive adhesive or hot melt adhesive is 100% by mass, and can be a component that has the greatest influence on the properties of the hot melt adhesive.

  Thermoplastic resins that can be used as a main component of the pressure-sensitive adhesive or hot melt adhesive include polyester resins, (meth) acrylic resins, polyolefin resins, ethylene-vinyl acetate copolymer resins, polyamide resins, chloroprene resins, aramid resins, and acrylic resins. It is preferable to include at least one resin selected from the group consisting of urethane resins. That is, the resin layer contains at least one resin selected from the group consisting of a polyester resin, a (meth) acrylic resin, a polyolefin resin, an ethylene-vinyl acetate copolymer resin, a polyamide resin, a chloroprene resin, an aramid resin, and an acrylic urethane resin. Is preferred. In particular, a hot melt adhesive is preferable because it melts at a lower temperature than a thermosetting resin, and thus can reduce the influence of heat on other members used in the laminate. Further, since the hot melt adhesive is solidified by cooling, it can be joined in a short time, and workability is improved.

  As the resin contained in the resin layer, it is preferable to use a polyester resin or a (meth) acrylic resin among the above groups from the viewpoint of the adhesive strength to the base material and the heat resistance. Further, it is particularly preferable that the resin layer use a polyester resin or a (meth) acrylic resin having a melting point of 40 ° C. or more and 150 ° C. or less as a hot melt adhesive. When the melting point is less than 40 ° C., the adhesive may flow to a portion not desired to be bonded because the hot melt adhesive flows at the time of thermal bonding, and may be bonded. If the melting point is higher than 150 ° C., Unless a high temperature is applied during thermal bonding, bonding may not be possible, resulting in reduced work efficiency or damage to the base material or polyolefin resin layer, which is the object to be bonded, due to heat. There are cases. Further, the hot melt adhesive preferably has an aromatic skeleton because the cohesive strength of the resin is improved and the adhesive strength of the resin layer is improved. Further, only one of the above-described resins may be used as the hot melt adhesive, or a plurality of resins may be used.

  A hot melt adhesive that can be used as a resin in the resin layer is exemplified, but the resin that can be used in the present invention is not limited to this. For example, "Aronmelt" (registered trademark) PES-120L, PES-140H, PES-111EE, PES310S30, PES375S40, PPET1008, PPET1025, PPET2102, PPET1303S (all manufactured by Toagosei Co., Ltd.), Y-167, H-930- S, H-180S (all manufactured by Tanaka Chemical Co., Ltd.), "Nichigo Polyester" (registered trademark) SP-154, SP-165, SP-170, SP-176, SP-180, SP-182, SP- 185 (manufactured by Nippon Synthetic Chemical Co., Ltd.), "Byron" (registered trademark) 200, 240, 300, 550, BX1001 (manufactured by Toyobo Co., Ltd.), "Polysol" (registered trademark) SE-1720, SE- 4210E, SE-6210, SE-6210L (hereinafter referred to as , It can be suitably used by Showa Denko Co., Ltd.) and the like.

  The laminate of the present invention can be manufactured by arranging a base material, a resin layer, and a polyolefin resin layer in contact with each other, and using a nip roller to adhere so as not to trap air bubbles.

[Hydrophilic component]
The resin layer of the present invention preferably contains a hydrophilic component in order to develop high hydrophilicity on the surface of the resin layer. The hydrophilic component may be contained as a hydrophilic skeleton in a part of the structure of the resin, or may be contained as a single component. When imparting hydrophilicity as a part of the resin structure, examples of functional groups that exhibit hydrophilicity include hydroxyl groups and carboxyl groups, which are highly polar, and these are introduced into a part of the resin structure. Is preferred.

  The hydrophilic component in the present invention is required to exhibit high hydrophilicity. In the method of introducing a hydrophilic functional group into the resin molecule, it is difficult to obtain high hydrophilicity because the ratio of the hydrophilic functional group appearing on the molecular surface is limited. On the other hand, when the hydrophilic component is contained as a single component, it is possible to select a compound having a relatively small molecular weight, and it is possible to efficiently contribute to improvement in hydrophilicity. Therefore, a surfactant is suitable as the hydrophilic component. That is, the resin layer preferably contains a surfactant.

  Surfactants have many structures and types, and it is easy to optimize hydrophilicity and compatibility with resins. Moreover, since it is industrially produced by a plurality of companies, it is easily available as a commercial product. Although the surfactant contained in the resin layer is not limited, the resin layer preferably contains a nonionic surfactant having a polyalkylene glycol skeleton. Hereinafter, a nonionic surfactant having a polyalkylene glycol skeleton may be simply referred to as a surfactant. The nonionic surfactant having a polyalkylene glycol skeleton used in the present invention has a polyalkylene glycol skeleton as a hydrophilic substituent and also has a skeleton described later as a hydrophobic substituent.

  Here, as the nonionic surfactant having a polyalkylene glycol skeleton, for example, polyoxyethylene-alkyl sulfate-sodium salt such as polyoxyethylene lauryl-sulfate sodium salt, polyoxyethylene-lauryl ether, Polyoxyethylene-alkyl ethers such as polyoxyethylene-cetyl ether, polyoxyethylene-oleyl ether, polyoxyethylene-stearyl ether, polyoxyethylene-2-ethylhexyl ether, and polyoxyethylene-isodecyl ether; Polyoxyethylene-alkyl esters such as monolaurate, polyoxyethylene-monostearate, polyoxyethylene-monooleate, and polyoxyethylene sorbitan-monolaurate Sorbitan ester / ethylene oxide addition type such as polyoxyethylene sorbitan-monostearate, polyoxyethylene sorbitan-monooleate, polyoxyethylene sorbitan-monooleate; monoglyceride / ethylene oxide addition type such as polyoxyethylene-coconut fatty acid glyceryl; polyoxyethylene Triglyceride / ethylene oxide addition type such as hydrogenated castor oil, polyoxyethylene-laurylamine, polyoxyethylene-alkyl (coconut) amine, polyoxyethylene-stearylamine, polyoxyethylene-oleylamine, polyoxyethylene-tallowalkylamine, Alkyl polyetheramine type polyoxyethylene-monomethyl ether such as polyoxyethylene alkyl-propylene diamine; Surfactants such as oxyethylene-dimethyl ether, polyoxyethylene-glyceryl ether, polyoxyethylene α, ω-bis-3-aminopropyl-ether, and polyethylene glycol-polypropylene glycol-polyethylene glycol (block copolymer) are included. The nonionic surfactant having a polyalkylene glycol skeleton that can be used in the present invention is not limited to this.

  Among the nonionic surfactants having a polyalkylene glycol skeleton, compounds having an alkyl substituent as a hydrophobic substituent are more preferable. Examples of commercially available specific examples include "Pionin" (registered trademark) D-1004, D-1007, D-1706-N, D-1715-N, D-1105, D-1110, D-1103-D, and D-1103-D. -1105-D, D-1103-S, D-1105-S, D-1107-S, D-1109-S, D-1004, D-1004, D-1004, "New Calgen" (registered trademark) D -1203, D-1205, D-1208, "Pionin" (registered trademark) D-1305-Z, D-1323-Z, D-1803, D-1402, D-1420, D-1504, D-1508, D-1518, D-1106DIR, D-1110DIR, D-1107SP3, D1301-P, D-1305-P (all manufactured by Takemoto Yushi Co., Ltd.), "Emulgen" (registered trademark) 1 2KG, 103, 104P, 105, 106, 108, 109P, 120, 123P, 130K, 147, 150, 210P, 220, 306P, 320P, 350, 404, 408, 409PV, 42430, 705, 707, 709, 1108, 1118S-70, 1135S-70, 1150S-60, "Emulgen" (registered trademark) 2020G-HA, 2025G (all manufactured by Kao Corporation), and the like. When the hydrophobic substituent is an alkyl group, it is easy to produce and obtain a surfactant having a different number of carbon atoms in the alkyl group, and thus has the advantage that the HLB value described later can be arbitrarily changed.

  Among the compounds represented by the nonionic surfactant having a polyalkylene glycol skeleton, specific examples of an allylphenyl ether type compound having an allylphenyl group containing an aromatic substituent as a hydrophobic substituent are commercially available. "Pionin" (registered trademark) D-6512, D-6414, DTD-51, D-6315, D-6112, Pionin D-7240, "New Cargen" (registered trademark) C-150, C-173, C- 200, C-314, CP-50, CP-80, CP-120, CP-15-200, E-200 (all manufactured by Takemoto Yushi Co., Ltd.) and the like. When the hydrophobic substituent is an allylphenyl group, for example, when a resin having aromaticity is used in combination, the adhesive strength is improved due to the effect of improving the cohesive force by stacking the aromatic ring of the resin and the surfactant, which is preferable. When the hydrophobic substituent is an allylphenyl group, it is easy to produce and obtain a surfactant in which the number of repetitions of the allylphenyl group is arbitrarily adjusted, so that the HLB value described later can be arbitrarily changed. There is.

  Among the compounds represented by the above-mentioned nonionic surfactants having a polyalkylene glycol skeleton, specific examples which are commercially available as sorbitan fatty acid derivatives include “Reodol” (registered trademark) TW-L120, TW-L106, TW- P120, TW-S120V, TW-S106V, TW-S-320V, TW-O120V, TW-O106V, TW-O320V, TW-IS399C, "Leo Doll Super" (registered trademark) TW-L120 (Kao Corporation) And "Pionin" (registered trademark) D-941, D-945, and D-945T (all manufactured by Takemoto Yushi Co., Ltd.).

  The number average molecular weight (Mn) of the nonionic surfactant having a polyalkylene glycol skeleton is preferably from 500 to 20,000, more preferably from 2,000 to 20,000, and particularly preferably from 5,000 to 18. , 000. That is, when the number average molecular weight is 500 or more, the surfactant component adheres to the surface or the cross section of the transport roll or the slit blade in the transporting process, the printing process, the slitting process, and the like when the laminate is rolled. Can be satisfactorily prevented, and as a result, the frequency of cleaning in each step is significantly reduced, which is preferable. When the number average molecular weight is 20,000 or less, the surfactant is easily dispersed uniformly in the resin layer, which is preferable.

  The melting point or freezing point of the surfactant is not particularly limited, but is preferably 30 ° C. or lower. More preferably, it is 25 ° C. or lower, and further preferably, 20 ° C. or lower. When the melting point or the freezing point is higher than 30 ° C., the surfactant tends to bleed out from the resin layer, and the adhesive strength of the resin layer varies, which may cause a decrease in the adhesive strength. Further, when the melting point or the freezing point is 30 ° C. or less, the work of heating and dissolving the surfactant becomes unnecessary when preparing a coating liquid in which the resin layer and the surfactant are mixed, which is preferable from the viewpoint of workability.

  In the resin layer of the present invention, the amount of the surfactant is preferably from 0.1 to 20 parts by mass, more preferably from 0.1 to 20 parts by mass, based on 100 parts by mass of all the resins contained in the resin layer. It is 12 parts by mass, more preferably 1 to 10 parts by mass. When the amount of the surfactant in the resin layer is less than 0.1 part by mass with respect to the total of 100 parts by mass of the resin in the resin layer, the hydrophilicity of the surface of the resin layer cannot be sufficiently obtained, and the liquid sample is not obtained. May not be sufficiently exhibited. Further, the effect of preventing the main component contained in the resin layer from adhering in the laminate transporting step or the slitting step may not be sufficiently exerted. If the amount of the surfactant in the resin layer is larger than 20 parts by mass with respect to 100 parts by mass of the total resin in the resin layer, the compounding ratio of the resin to the surfactant in the resin layer is reduced. Not only does the strength of the resin decrease, and stable film formation becomes difficult, but also the storage stability of a coating material in which a resin layer and a surfactant are mixed may decrease. In addition, it is difficult to obtain sufficient compatibility with the resin layer, the amount of surfactant bleeding out to the surface of the resin layer is increased, and the adhesiveness of the resin layer is impaired, so that a desired adhesive strength may not be obtained. When the surfactant bleeds out, the surfactant component adheres in the laminate transporting step, the slitting step, and the like, which may cause contamination in the processing step. When the amount of the surfactant in the resin layer is 0.1 to 20 parts by mass with respect to 100 parts by mass of the total resin of the resin in the resin layer, it is possible to obtain a resin layer which has solved the above-mentioned disadvantages. preferable.

  The water contact angle of the surface of the resin layer on the side of the polyolefin resin layer in the present invention is less than 15 degrees. When the contact angle with water is less than 15 degrees, high-speed and stable introduction of the liquid sample can be sufficiently realized, which is preferable. The lower limit of the water contact angle of the surface of the resin layer on the side of the polyolefin resin layer is not particularly limited as long as it is less than 15 degrees, but it is practically considered to be about 3 degrees from the viewpoint of the measurement technique. In the present application, when the contact angle of water is less than 15 degrees, it is expressed that the hydrophilicity is high, and the printing characteristics of the resin layer are dramatically improved. In order to make the water contact angle of the surface of the resin layer less than 15 degrees on the side of the polyolefin resin layer, an embodiment in which the resin layer contains a surfactant, in particular, a nonionic resin layer having a polyalkylene glycol skeleton This is possible by adopting an embodiment containing a surfactant.

  The surfactant used in the present invention is preferably a surfactant having an HLB value of 8 to 15. The use of a surfactant having an HLB value of 8 to 15 imparts hydrophilicity to the resin layer while maintaining compatibility with the resin layer, that is, compatibility with a hydrophilic component other than the adhesive component and the surfactant. It is preferred because it can be.

  The HLB (Hydrophile-Lipophile Balance) value is a hydrophilic-lipophilic balance, and is a value calculated by the Griffin method (all revised edition, new surfactant introduction p128) obtained from the following formula (1).

HLB value of surfactant = (number average molecular weight of hydrophilic group portion / number average molecular weight of surfactant) × 20: Formula (1)
When the HLB value of the surfactant is larger than 15, it is difficult to obtain sufficient compatibility between the surfactant and the main component of the resin, and more surfactant bleeds out to the surface of the resin layer, thereby impairing the adhesiveness of the resin layer. As a result, a desired adhesive strength may not be obtained. On the other hand, when the HLB value of the surfactant is less than 8, the hydrophilicity of the resin layer may not be sufficiently obtained. When the HLB value of the surfactant is from 8 to 15, it is preferable because compatibility with the resin and hydrophilicity of the resin layer can both be achieved.

[Polyolefin resin layer]
The release sheet is a layer provided by a method of bonding the resin layer to the resin layer in the process of manufacturing the laminate, and serves to protect the resin layer from dirt and, conversely, to prevent the resin layer component from adhering to the surroundings. Carry. In addition, it plays a role in preventing set-off of the resin layer when the laminate is in a roll state. The latter role is particularly necessary when a low molecular compound such as a surfactant is used in combination in the resin layer.

  The laminate of the present invention is a laminate in which a substrate, a resin layer, and a polyolefin resin layer are adjacent to each other in this order, and the polyolefin resin layer is disposed on one surface of the laminate. That is, in the laminate of the present invention, the polyolefin resin layer is a layer containing a polyolefin resin, is a layer disposed on one surface of the laminate so as to be adjacent to the resin layer, and has a function as a release sheet. Work as As the release sheet, generally, a film provided with a silicone-based resin layer is often used, but when a film provided with a silicone-based resin layer is used as a release sheet, that is, a substrate, a resin layer, When the film provided with the silicone-based resin layer is placed adjacent to the film in this order, and the film provided with the silicone-based resin layer is disposed on one surface of the laminate, the transfer of the silicone resin to the resin layer occurs, and the hydrophilicity is reduced. There is a problem that not only deterioration but also appearance defects such as printing bleeding are caused. Therefore, in the present invention, a polyolefin resin layer is disposed at a position on one surface of the laminate in contact with the resin layer. Even if a polyolefin resin is not provided with a water-repellent coating layer such as a silicone resin on a release sheet, the surface of the polyolefin resin has a small polarity, so that the adhesive force is kept low when the polyolefin resin is bonded to an adhesive resin layer. And can be easily peeled off. The polyolefin resin is a general term for polymers synthesized using simple olefins or alkenes as monomers. The polyolefin resin may be composed of one type of monomer, or may be composed of a plurality of types of monomers.

  Examples of the polyolefin resin that can be suitably used in the polyolefin resin layer of the present invention include polyethylene and its copolymer, and polypropylene and its copolymer. Polyethylene is mainly classified into low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), and ultra-high-molecular-weight polyethylene (UHPE) depending on the difference in density. A polyethylene copolymer is a resin formed by polymerizing ethylene and a monomer other than ethylene. When copolymerized with vinyl acetate, ethylene-vinyl acetate copolymer (EVA) is used. When copolymerized with methyl acrylate, When copolymerized with ethylene-methyl acrylate copolymer (EMA) or norbornene, ethylene-cycloolefin copolymer (COC) and the like can be mentioned. Polypropylene is mainly classified into non-oriented polypropylene (CPP) and oriented polypropylene (OPP) depending on the method of stretching. Among these, a resin made of expanded polypropylene (OPP) is particularly preferably used in consideration of mechanical properties, quality such as workability, economic efficiency, and the like. Stretched polypropylene (OPP) is suitable for the present invention because it is inexpensive and has excellent mechanical properties. When the polyolefin resin used in the present invention forms one layer of the laminate, that layer is referred to as a polyolefin resin layer.

  Although the content of the polyolefin resin in the polyolefin resin layer is not particularly limited, it is preferable that 50% by mass or more and 100% by mass or less of the total components in the polyolefin resin layer is the polyolefin resin. The polyolefin resin layer may contain various additives and other resins in addition to the polyolefin resin.

[Adhesive strength between resin layer and polyolefin resin layer]
With respect to the laminate of the present invention, the adhesive strength between the resin layer and the polyolefin resin layer at a peeling angle of 90 ° at a peeling speed of 50 mm / min in accordance with JIS Z0237: 2009 was evaluated by measuring the adhesive strength three times, and the average value was obtained. As a result, it is preferable to show an adhesive strength of 15 to 80 mN / cm. If the adhesive strength is less than 15 mN / cm, the polyolefin resin layer is peeled off from the resin layer because the adhesive strength is weak, and the laminate of the present invention cannot be obtained. For example, when the laminate is transported in a roll state, the polyolefin resin layer floats, or the floated polyolefin resin layer comes into contact with the resin layer again, leaving a mark on the surface of the resin layer. May occur. Further, when the laminate is punched and cut, the polyolefin resin layer peeled off from the resin layer adheres to the punching blade, which may lower the productivity. If the adhesive strength is greater than 80 mN / cm, the hydrophilic component contained in the resin layer is likely to adhere to the polyolefin resin layer when the polyolefin resin layer is separated from the resin layer. Increases the contact angle. In addition, when the polyolefin resin layer is peeled off, zipping may occur, resulting in appearance defects such as leaving traces of peeling on the surface of the resin layer.

[Method for producing liquid spread sheet and laminate]
The liquid spreading sheet refers to a configuration including two layers in which a resin layer is provided on one surface of a base material, and is a partial structure of a laminate. In addition, since the liquid developing sheet has a configuration obtained during the manufacturing process of the laminate, a method of manufacturing the liquid developing sheet will be described below first.

  The liquid spreading sheet is obtained by providing a resin layer on at least one surface of the base material. The resin layer is formed, for example, by applying a coating solution containing an adhesive component and a hydrophilic component constituting the resin layer to a substrate. Such a coating liquid can be obtained, for example, by mixing a hot-melt adhesive having functions of an adhesive component and a hydrophilic component and a surfactant, or by hot-melting them. The method of applying the coating solution to the substrate is not particularly limited, and a method such as a gravure coating method, a reverse coating method, a kiss coating method, a die coating method, and a bar coating method can be used. Select the most appropriate method according to the work thickness. The concentration of the coating solution, the drying conditions of the coating film, or the cooling conditions of the coating film are not particularly limited, but the drying conditions of the coating film are selected within a range that does not adversely affect various properties of the base material. It is desirable. The liquid spreading sheet is used when evaluating the contact angle of water, which is a method for evaluating hydrophilicity.

  Subsequently, a method for producing a laminate of the present invention will be described. The laminate refers to a configuration in which a polyolefin resin layer is arranged adjacent to the surface of the resin layer of the liquid spreading sheet, and has a configuration whose cross section is shown in FIG. The method of laminating the polyolefin resin layer on the surface of the resin layer of the liquid spreading sheet is not particularly limited, but when performing a single sheet, use a handy type laminating roller and cover the surface of the resin layer with the polyolefin resin layer. Paste in. In the case of using a roll, after laminating the resin layer on the base material, the polyolefin resin layer is fed out from the second feeding roller before the winding step, and is bonded by being sandwiched by a nip roller. The material of the laminating roller and the nip roller is not particularly limited, but synthetic rubber, which is an elastic material, is preferable from the viewpoint that the polyolefin resin layer can be handled without slipping and without being damaged, and from the viewpoint of suppressing the incorporation of air bubbles. Acrylonitrile butadiene rubber) is more preferred.

  Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples. In addition, the evaluation method of each characteristic in an Example is as follows.

[Thickness of substrate, resin layer and polyolefin resin layer [μm]]
The cross section of the laminate was obtained by the FIB method using a micro sampling system (FB-2000A manufactured by Hitachi, Ltd.). Thereafter, the cross section of the observation sample was observed at an acceleration voltage of 300 kV using a transmission electron microscope (H-9000UHRII manufactured by Hitachi, Ltd.), and the thickness of the base material, the resin layer, and the polyolefin resin layer relative to the standard scale [μm] ] Was calculated.

[Adhesion amount of resin layer [g / m ² ]]
The mass of 100 cm ² of the substrate to which the coating solution was applied was measured (A), and then the mass of 100 cm ² of the substrate before the application of the coating solution was measured (B). g / m ² ] was calculated.

[Adhesive strength between resin layer and polyolefin resin layer [mN / cm]]
For the laminate, the adhesive strength [mN / cm] was evaluated three times under the conditions of a peel angle of the polyolefin resin layer with respect to the liquid developing sheet of 90 ° and a peeling speed of 50 mm / min in accordance with JIS Z0237: 2009, and the average value was obtained. And

[Water contact angle of resin layer surface [degree] (initial value)]
In the production process of the laminate, a sample was prepared so that the surface of the resin layer was on the upper surface of the liquid spreading sheet before the polyolefin resin layer or the silicone resin film was bonded. Using DMo-501 (manufactured by Kyowa Interface Science Co., Ltd.), in accordance with JIS R3257: 1999, 5 seconds after the dropping of a drop formed when pure water (2.0 μl) was dropped on the surface of the resin layer. The water contact angle on the surface of the resin layer was measured five times, and the average value was taken as the result (water contact angle).

[Confirmation of deterioration over time (water contact angle [degree] after aging of the surface of the resin layer)]
Evaluation was performed in the same manner as in [Water contact angle of resin layer [degree] (initial value)] except for using the laminate after storage in a 40 ° C environment for 2 weeks, and numerical change from the initial value. , The magnitude of the deterioration over time was evaluated.

[Ink transferability to resin layer]
A 10 cm straight line was formed on the surface of the resin layer of the liquid spreading sheet using a felt-tip pen (product name: V Petit, model number: SV-15EF, thickness: 0.4 mm, black, water-based dye ink, manufactured by Pilot Corporation). Was pulled. After 10 seconds, observe the straight line. If the ink is repelled and droplets are formed, ×; if the ink is repelled a little, △; if the ink is not repelled and the straight line is drawn Was evaluated as ○.

(Example 1)
As a component constituting the hot melt adhesive used for the resin layer, a polyester-based adhesive having a melting point of 100 ° C., a glass transition temperature of −10 ° C., and a number average molecular weight of 22,000 was mixed with toluene / methyl ethyl ketone = 1/1 (mass ratio). A nonionic surfactant having a polyalkylene glycol skeleton [Reodol TW-L106 (HLB value: 13.3) manufactured by Kao Corporation) was converted to a solid content based on a solid content concentration of 40% by mass diluted using a mixed solvent. The coating liquid was obtained by adding and stirring the mixture so that the ratio was 100 parts by mass of the polyester adhesive / Reodol TW-L106 = 4 parts by mass. This coating solution is applied to a biaxially stretched polyethylene terephthalate (PET) film “Lumirror” (registered trademark) (type 100S28) manufactured by Toray Industries Co., Ltd. using a comma coater, and dried at 120 ° C. for 30 seconds to obtain 45 g of adhering amount on one side. The liquid spreading sheet 1 was obtained by providing the resin layer 1 of / m ² . Before winding the obtained liquid spread sheet 1, a biaxially oriented polypropylene (PP) film “Trefane” (registered trademark) (type 2500, thickness 40 μm) manufactured by Toray Industries, Inc. is bonded to the surface of the resin layer 1. Thus, a laminate 1 was obtained. The coating thickness of the resin layer 1 was 20 μm.

(Example 2)
As a pressure-sensitive adhesive component used for the resin layer, a solid content concentration of 40 mass% (a mixed solvent of ethyl acetate and n-hexane), Fine Tack CT-5020 (manufactured by DIC Corporation), which is an acrylic resin. Mass% (mixed solvent of ethyl acetate and n-hexane) as a fine tack curing agent D-40 and a nonionic surfactant having a polyalkylene glycol skeleton [Rhodol TW-L106 manufactured by Kao Corporation (HLB value: 13) .3)] was added so that the solid content conversion ratio would be the ratio of Fine Tack CT-5020 / Fine Tack Hardener D-40 / Reodol TW-L106 = 100 parts by mass / 2.5 parts by mass / 10 parts by mass. -A coating liquid was obtained by stirring. This coating solution is applied to a polyethylene terephthalate (PET) film “Lumirror” (registered trademark) (type 100S28) manufactured by Toray Industries, Inc. using a comma coater, and dried at 120 ° C. for 30 seconds to obtain an adhesion amount of 45 g / m ^{2 on} one surface. The liquid spreading sheet 2 was obtained by providing the resin layer 2 of FIG. Before winding the obtained liquid spreading sheet 2, a biaxially oriented polypropylene (PP) film “Trefane” (registered trademark) (type 2500, thickness 40 μm) manufactured by Toray Industries, Inc. is bonded to the surface of the resin layer 2. Thus, a laminate 2 was obtained. The coating thickness of the resin layer 2 was 20 μm.

(Example 3)
In Example 1, a uniaxially stretched polyethylene (OPE) film (PE3K-BT, thickness 50 μm) was used in place of the biaxially stretched polypropylene (OPP) film “Trefane” (registered trademark) (type 2500, thickness 40 μm) manufactured by Toray Industries, Inc. A laminate 3 was obtained in the same manner except that the above was used.

(Example 4)
In Example 1, the solid content conversion ratio of the polyester adhesive and the nonionic surfactant having a polyalkylene glycol skeleton [Reodol TW-L106 (HLB value: 13.3) manufactured by Kao Corporation] was 100 parts by mass / 2. Laminate 4 was obtained in the same manner as above except that the coating liquid was obtained by adding and stirring so as to have a ratio of 5 parts by mass.

(Example 5)
In Example 1, instead of using a polyester adhesive and a nonionic surfactant having a polyalkylene glycol skeleton [Rhodol TW-L106 (HLB value: 13.3) manufactured by Kao Corporation], a nonionic having a polyalkylene glycol skeleton was used. A surfactant [pionein D-1105-S (HLB value: 10.5) manufactured by Takemoto Yushi Co., Ltd.] is applied by adding and stirring so as to have a solid content conversion ratio of 100 parts by mass / 5 parts by mass. A laminate 5 was obtained in the same manner except that a liquid was obtained.

(Example 6)
Espel 9940Z-37, a polyester resin manufactured by Hitachi Chemical Co., Ltd., as an adhesive component used in the resin layer, and Anstex C-200X, a cationic surfactant manufactured by Toho Chemical Industry Co., Ltd., as a hydrophilic component. The coating liquid was obtained by adding and stirring so that the minute conversion ratio was 100 parts by mass / 5 parts by mass. This coating liquid is applied to a biaxially stretched polyethylene terephthalate (PET) film "Lumirror" (registered trademark) (type 100S28) manufactured by Toray Industries, Inc. using a gravure coater, and dried at 120 ° C. for 30 seconds to obtain an adhesion amount on one side of 1. The liquid spreading sheet 6 was obtained by providing the resin layer 5 of 5 g / m ² . Before winding the obtained liquid spreading sheet 6, a biaxially oriented polypropylene (PP) film “Trefane” (registered trademark) (type 2500, thickness 40 μm) manufactured by Toray Industries, Inc. is bonded to the surface of the resin layer 6. Thus, a laminate 6 was obtained.

(Example 7)
Example 6 except that Pesresin S140, a polyester resin manufactured by Takamatsu Yushi Co., Ltd., was used as the adhesive component used for the resin layer, and Chemistat 3500, an anionic surfactant manufactured by Sanyo Chemical Industries, Ltd., was used as the hydrophilic component. In the same procedure, the liquid developing sheet 7 and the laminate 7 were obtained.

(Example 8)
The coating liquid described in Example 1 is applied to a biaxially stretched polyethylene terephthalate (PET) film “Lumirror” (registered trademark) (type 100S28) manufactured by Toray Industries, Inc. using a comma coater, and dried at 120 ° C. for 30 seconds. The liquid developing sheet 8 was obtained by providing the resin layer 10 having an adhesion amount of 5 g / m ² on one side. Before winding the obtained liquid spreading sheet 8, a biaxially oriented polypropylene (PP) film “Trefane” (registered trademark) (type 2500, thickness 40 μm) manufactured by Toray Industries, Inc. is bonded to the surface of the resin layer 7. Thus, a laminate 8 was obtained. The coating thickness of the resin layer 8 was 2 μm.

(Comparative Example 1)
In Example 1, the solid content conversion ratio of the polyester-based adhesive and the nonionic surfactant having a polyalkylene glycol skeleton [Leodol TW-L106 (HLB value: 13.3) manufactured by Kao Corporation] was 100 parts by mass / 10 parts by mass. The laminate 9 was obtained in the same manner as above except that the coating liquid was obtained by adding and stirring the mixture so as to have the ratio of parts.

(Comparative Example 2)
Laminate 10 was obtained in the same manner as in Example 2, except that the nonionic surfactant having a polyalkylene glycol skeleton [Reodol TW-L106 (HLB value: 13.3) manufactured by Kao Corporation) was not used.

(Comparative Example 3)
Before winding up the liquid spreading sheet 1 obtained in Example 1, the laminated body 11 was obtained by laminating the silicone resin coated surface of the silicone resin film to the surface of the resin layer 1.

(Comparative Example 4)
In Example 1, the solid content conversion ratio of the polyester adhesive and the nonionic surfactant having a polyalkylene glycol skeleton [Leodol TW-L106 (HLB value: 13.3) manufactured by Kao Corporation] was 100 parts by mass / 1 mass. The laminate 12 was obtained in the same manner as above except that the coating liquid was obtained by adding and stirring the mixture so as to have a ratio of parts.

  Each of the laminates 1 to 12 has a configuration corresponding to FIG. Since the water contact angle of the surface of the resin layer at the initial stage and after the lapse of time in all Examples is less than 15 degrees, the ink transferability to the resin layer is excellent. Among them, in Examples 1 to 6 and 8, since the adhesive strength between the resin layer and the polyolefin resin layer is smaller than 80 mN / cm, when the polyolefin resin layer is separated from the resin layer, the hydrophilic component contained in the resin layer is It hardly adheres to the polyolefin resin layer, and the change in the contact angle on the surface of the resin layer after lapse of time is small. In Comparative Examples 1, 2 and 4, both the initial contact angle of water and the contact angle of water over time were values larger than 15 °. In Comparative Example 3, since the components from the silicone coating layer of the release sheet were transferred to the resin layer 4, the contact angle of water with time increased from 15 °. The operating conditions are summarized in Table 1, and the evaluation results are summarized in Table 2.

1: base material 2: resin layer 3: polyolefin resin layer 4: liquid spreading sheet 5: laminate

Claims (5)

The base material, the resin layer, and the polyolefin resin layer are a laminate adjacent in this order,
The polyolefin resin layer is on one surface of the laminate,
A laminate wherein the water contact angle of the surface of the resin layer on the side of the polyolefin resin layer is less than 15 degrees. 2. The laminate according to claim 1, wherein the adhesive strength at a peeling angle of 90 ° between the resin layer and the polyolefin resin layer according to JIS Z0237: 2009 is 15 to 80 mN / cm. The resin layer includes at least one resin selected from the group consisting of a polyester resin, a (meth) acrylic resin, a polyolefin resin, an ethylene-vinyl acetate copolymer resin, a polyamide resin, a chloroprene resin, an aramid resin, and an acrylic urethane resin. The laminate according to claim 1 or 2. The laminate according to any one of claims 1 to 3, wherein the resin layer contains a surfactant. The laminate according to claim 4, wherein the surfactant is a nonionic surfactant having a polyalkylene glycol skeleton.

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