WO2016063673A1

WO2016063673A1 - Composition and laminate

Info

Publication number: WO2016063673A1
Application number: PCT/JP2015/076910
Authority: WO
Inventors: 田邨奈穂子; 石田康之; 中道夏樹; 高橋宏光
Original assignee: 東レフィルム加工株式会社
Priority date: 2014-10-20
Filing date: 2015-09-24
Publication date: 2016-04-28
Also published as: JPWO2016063673A1; TWI665276B; JP2020186394A; TW201619326A

Abstract

The present invention relates to: a composition for providing a laminate that exhibits excellent adhesion characteristics and excellent processing characteristics if bonded to an object to be bonded; and a laminate which is configured from the composition. A composition which is characterized by satisfying the following conditions 1 and 2. Condition 1: The shear loss tangent (tanδ_0°C) at a frequency of 1 Hz at a temperature of 0°C is from 0.20 to 0.60 (inclusive). Condition 2: The shear loss tangent (tanδ_100°C) at a frequency of 1 Hz at a temperature of 100°C is from 0.40 to 0.80 (inclusive).

Description

Composition and laminate

The present invention relates to a composition for providing a laminate having excellent adhesion characteristics and processing characteristics when bonded to an adherend, and a laminate comprising the composition.

Products made of various materials such as synthetic resin, metal, and glass are often handled with a material that protects the surface in order to prevent scratches and dirt during processing, transportation, and storage. A typical example is a surface protective film, which generally uses a support substrate made of thermoplastic resin or paper, with an adhesive layer formed on it, and attaches the adhesive layer surface to the adherend. Then, the surface is protected by coating with a supporting substrate.

Particularly in recent years, liquid crystal displays and touch panel devices have been widely used, and these are composed of a number of members such as optical sheets and optical films made of synthetic resin. Since such optical members need to reduce defects such as optical distortion as much as possible, surface protection films are frequently used to prevent scratches and dirt that may cause defects.

As the characteristics of the surface protection film, it is not easily peeled off from the adherend when subjected to external force such as punching processing, environmental change such as temperature, humidity, etc., that it can be easily peeled off when peeled off from the adherend, Furthermore, it is required that the pressure-sensitive adhesive and the pressure-sensitive adhesive component do not remain on the adherend when peeled.

Among the above optical members, in the case of a member having an uneven surface such as a diffusion plate or a prism sheet, the contact area between the uneven portion and the adhesive layer is small immediately after the surface protective film is bonded, and therefore, punching processing, etc. When an external force is applied, the external force may not be sufficiently absorbed and may be peeled off from the adherend. For such a point, methods for softening the pressure-sensitive adhesive layer and methods for increasing the adhesive strength using a tackifier are known (for example, Patent Documents 1 to 4).

JP 2008-214437 A JP 2005-298630 A Japanese Patent Laid-Open No. 05-194923 JP 2012-111793 A

However, in the above method, the adhesive force increases with the passage of time, and the peelability may deteriorate, and it is difficult to achieve both the peelability and the processing characteristics.

In view of the above-described problems, an object of the present invention is to provide a composition for providing a laminate having excellent adhesion characteristics and processing characteristics when bonded to an adherend, and a laminate composed of the composition. There is to do.

In order to solve the above-mentioned problems, the present inventors have intensively studied and as a result, completed the following invention. That is, the present invention is as follows.
1) A composition satisfying the following conditions 1 and 2.
Condition 1 Shear loss tangent (tan δ _{0 ° C.} ) at a frequency of 1 Hz and a temperature of 0 ° _C. is 0.20 or more and 0.60 or less Condition 2 Shear loss tangent (tan δ _{100 ° C.} ) at a frequency of 1 Hz and a temperature of 100 ° _C. is 0. 0.80 2) the composition above 40, frequency 1 Hz, for a shearing loss tangent at a temperature _{60 ℃} (tanδ 60 ℃), and shear loss tangent at a temperature _{100 ℃} (tanδ 100 ℃), the following condition 3. The composition according to 1) satisfying 3.
Condition 3 0.20 ≦ tan δ _{100 ° C.−} tan δ _{60 ° C.} ≦ 0.60
3) The composition according to 1) or 2), wherein the composition has an endothermic peak in a range of 60 ° C. or more and 100 ° C. or less in differential scanning calorimetry.
4) The composition according to any one of 1) to 3), wherein the composition contains at least the following components (1) to (3):
(1) Styrenic elastomer (2) Propylene / α-olefin copolymer (3) Tackifier 5) In a laminate having an adhesive layer on one side of the substrate, the adhesive layer is 1) to 4) The laminated body containing the composition in any one.
6) The laminate according to 5), which is used for protecting the surface of the prism sheet.

According to the present invention, in view of the above-described problems, a composition for providing a laminate having excellent adhesion characteristics and processing characteristics when bonded to an adherend and a laminate composed of the composition are provided. be able to.

Hereinafter, the constituent requirements of the composition and laminate of the present invention will be described in detail.

<Composition>
The composition of the present invention is characterized by satisfying the following conditions 1 and 2.
Condition 1: Shear loss tangent (tan δ _{0 ° C.} ) at a frequency of 1 Hz and a temperature of 0 ° _C. is 0.20 or more and 0.60 or less.
Condition 2: Shear loss tangent (tan δ _{100 ° C.} ) at a frequency of 1 Hz and a temperature of 100 ° _C. is 0.40 or more and 0.80 or less.

By satisfy | filling said conditions 1 and 2, when the composition of this invention is used for the adhesion layer of the laminated body for protecting a to-be-adhered body, a favorable adhesion characteristic and processing characteristic can be obtained. That is, it is excellent in sticking to an adherend, hardly peels off during punching, and can be easily peeled off from the adherend. The tan δ _{0 ° C.} is more preferably 0.30 or more and 0.50 or less, and the tan δ _{100 ° C.} is more preferably 0.50 or more and 0.80 or less.

Here, the loss tangent means a value obtained by dividing the loss elastic modulus obtained by dynamic viscoelasticity measurement by the storage elastic modulus. The loss elastic modulus refers to a viscous component that releases its energy as heat when stress is applied, and the storage elastic modulus refers to an elastic component that stores energy therein and holds the stress.

Dynamic viscoelasticity measurement is a measurement that examines the mechanical properties of a sample by applying a strain or stress that changes (vibrates) over time to the sample and measuring the stress or strain generated thereby. There are a plurality of measurement modes such as tension / compression, shear, and three-point bending. In the present invention, the loss tangent is a value measured in the shear mode at a frequency of 1 Hz and a strain of 0.01%. Details of the measurement method will be described later.

When the tan δ _{0 ° C.} is less than 0.20, the processing characteristics may be deteriorated, and when it is greater than 0.60, the peelability may be deteriorated. Further, when the above tan δ _{100 ° C.} is less than 0.40, the processing characteristics may be deteriorated, and when it is greater than 0.80, the adhesive strength may increase with time and the peelability may be deteriorated.

Furthermore, the compositions of the present invention, frequency 1 Hz, and shear loss tangent at a temperature _{60 ℃} (tanδ 60 ℃), the difference between the shear loss tangent at a temperature _{100 ℃ (tanδ 100 ℃) (} tanδ 100 ℃ -tanδ 60 ℃ ) Is preferably 0.20 or more and 0.60 or less. More preferably, it is 0.30 or more and 0.60 or less, and further preferably 0.40 or more and 0.60 or less.

If the difference between tan δ _{100 ° C.} and tan δ _{60 ° C.} (tan δ _{100 °} _C.− tan δ _{60 °} _C. ) is less than 0.20, the processing characteristics may deteriorate, and if it exceeds 0.60, the peelability may decrease. is there.

The composition of the present invention preferably has an endothermic peak in the range of 60 ° C. to 100 ° C. in differential scanning calorimetry. More preferably, the composition has an endothermic peak in the range of 70 ° C. or higher and 100 ° C. or lower, particularly preferably in the range of 70 ° C. or higher and 90 ° C. or lower. By having an endothermic peak in the range of 60 ° C. or more and 100 ° C. or less, when the composition of the present invention is used for an adhesive layer of a laminate for protecting an adherend, the adhesion characteristics and processing characteristics are preferably controlled. can do.

When the endothermic peak is less than 60 ° C., the heat resistance may be deteriorated, and when it exceeds 100 ° C., the processing characteristics may be deteriorated.

The composition of the present invention is not particularly limited as long as the conditions 1 and 2 which are constituent requirements are satisfied. However, a crosslinking system such as an acrylic or silicone system, a non-crosslinking system such as a natural rubber system or a synthetic rubber system or a pseudo-crosslinking system Any material of (thermoplastic) may be used, but it is preferable that a thermoplastic resin is the main component from the viewpoint of recyclability. Here, the main component of the thermoplastic resin means that the ratio of the thermoplastic resin in the composition is 50% by mass or more, more preferably 70% by mass or more, and further preferably 90% by mass or more. .

The composition of the present invention preferably contains at least a styrene elastomer, a propylene / α-olefin copolymer and a tackifier.

In the present invention, the styrene-based elastomer means a resin having a structural unit derived from styrene and exhibiting rubber-like elasticity at room temperature, and a known one can be used. For example, a styrene / butadiene copolymer is used. Copolymers of styrene and diene such as (SBR), styrene / isoprene / styrene copolymer (SIS), styrene / butadiene / styrene copolymer (SBS), and hydrogenated products thereof, such as styrene / ethylene / butylene -Styrene copolymer (SEBS), styrene and isobutylene copolymer, for example, styrene-isobutylene-styrene triblock copolymer (SIBS), styrene-isobutylene diblock copolymer (SIB), or a mixture thereof And styrene / isobutylene block copolymers. These styrenic elastomers may be used alone or in combination of two or more. Among the styrene elastomers mentioned above, hydrogenated styrene / butadiene copolymer (HSBR), styrene / ethylene / butylene / styrene copolymer (SEBS), styrene / isobutylene / styrene triblock copolymer (SIBS), styrene An isobutylene diblock copolymer (SIB) or a mixture thereof is preferably used.

The weight average molecular weight of the styrene elastomer is preferably in the range of 50,000 to 400,000, more preferably in the range of 50,000 to 200,000. When the weight average molecular weight is less than 50,000, the cohesive force of the pressure-sensitive adhesive layer may be reduced, and adhesive residue may be generated when peeled from the adherend. When the weight average molecular weight exceeds 400,000, the viscosity increases and the productivity decreases. There is.

The styrene content in the styrene-based elastomer is preferably in the range of 5 to 30% by mass, and more preferably in the range of 8 to 20% by mass. When the styrene content is less than 5% by mass, the cohesive force of the adhesive layer is reduced, and adhesive residue may be generated when it is peeled off from the adherend. When it exceeds 30% by mass, the adherence to the adherend is likely. In particular, the adhesiveness may be insufficient for an adherend having unevenness.

The propylene / α-olefin copolymer refers to a copolymer composed of a structural unit derived from propylene and a structural unit derived from ethylene or α-olefin. For example, propylene / ethylene copolymer, propylene / 1-butene copolymer, propylene / 1-pentene copolymer, propylene / 1-hexene copolymer, propylene / 1-octene copolymer, propylene / ethylene / 1 -Butene copolymer and the like can be mentioned, but not limited thereto. In the present invention, only one type of propylene / α-olefin copolymer may be used, or two or more types may be used in combination.

The propylene / α-olefin copolymer preferably has a melting point in the range of 60 ° C. to 100 ° C. More preferably, it is the range of 70 degreeC or more and 100 degrees C or less, Most preferably, it is the range of 70 degreeC or more and 90 degrees C or less. The melting point of the propylene / α-olefin copolymer can be controlled by changing the type of α-olefin and the copolymerization ratio.

The tackifier is a material blended to enhance the adhesiveness of the adhesive layer as defined in JIS Z0109 (1992), and those having a softening point of 80 to 150 ° C. can be used. . For example, petroleum resins such as aliphatic copolymers, aromatic copolymers, aliphatic / aromatic copolymers and alicyclic copolymers, terpene resins, terpene phenol resins, rosin resins Commonly used materials such as alkylphenol resins, xylene resins or hydrogenated products thereof can be used. In the present invention, only one type of tackifier may be used, or two or more types may be used in combination.

In the composition of the present invention, the total content of the above-described styrene elastomer, propylene / α-olefin copolymer, and tackifier is preferably 60% by mass or more when the total composition is 100% by mass, 70 More preferably, it is more preferably 80% by weight or more. When the total content is less than 60% by mass, the balance between the adhesive property and the processing property may be lowered.

Further, when the total composition is 100% by mass, the content of the styrene elastomer is preferably 40% by mass or more, and more preferably 50% by mass or more. Further, the content of the propylene / α-olefin copolymer is preferably 10% by mass or more, and more preferably 15% by mass or more. Moreover, 5 mass% or more is preferable and, as for content of a tackifier, 10 mass% is more preferable.

The composition of the present invention is not limited to the above-described styrene elastomer, propylene / α-olefin copolymer, and tackifier, as long as the object of the present invention is not impaired. Additives and the like may be added as appropriate.

As other resin components for adjusting the adhesive strength, resins such as polyolefin can be used. For example, low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, low crystalline or amorphous Ethylene / α-olefin copolymer, polypropylene, propylene / ethylene copolymer (random copolymer and / or block copolymer), and propylene / α other than the above-mentioned propylene / α-olefin copolymer -Olefin copolymer, propylene / ethylene / α-olefin copolymer, ethylene / ethyl (meth) acrylate copolymer, ethylene / methyl (meth) acrylate copolymer, ethylene / n-butyl (meth) acrylate copolymer For example, ethylene and vinyl acetate copolymer. These resins may be used alone or in combination of two or more.

The total content of other resin components for adjusting the adhesive strength is preferably 20% by mass or less, and more preferably 10% by mass or less, based on 100% by mass of the entire composition. When the total content of other resin components for adjusting the adhesive strength exceeds 20% by mass, when the composition of the present invention is used for the adhesive layer of the laminate for protecting the adherend, It may be difficult to achieve both processing characteristics.

As the additive, for example, a lubricant, an antioxidant, a weathering agent, an antistatic agent, an antiadhesive agent and the like can be added. These additives may be used alone or in combination of two or more. The total content of additives is preferably 3% by mass or less, and more preferably 2% by mass or less, based on 100% by mass of the entire composition. When the total content of the additives is more than 3% by mass, the product may bleed out from the adhesive layer to cause defects in the product, or the adherend may be contaminated.

<Laminated body>
The laminate of the present invention is a laminate having an adhesive layer on one surface of a substrate, and the adhesive layer contains the above-described composition. Hereinafter, the laminate of the present invention will be described in detail.

<Base material>
Although the base material which comprises the laminated body of this invention is not specifically limited, For example, resin, such as polyolefin and polyester, can be used. Especially, it is preferable that polyolefin is a main component from viewpoints of productivity, processing appropriateness, etc. Here, having polyolefin as a main component means that the ratio of polyolefin is 50% by mass or more, more preferably 70% by mass or more, when the whole substrate is 100% by mass.

Examples of the polyolefin include, for example, low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, low crystalline or amorphous ethylene / α-olefin copolymer, polypropylene, propylene / ethylene copolymer. Polymer (random copolymer and / or block copolymer), propylene / α-olefin copolymer, propylene / ethylene / α-olefin copolymer, ethylene / ethyl (meth) acrylate copolymer, ethylene / methyl ( And a (meth) acrylate copolymer, an ethylene / n-butyl (meth) acrylate copolymer, and an ethylene / vinyl acetate copolymer. These may be used alone or in combination. The α-olefin is not particularly limited as long as it can be copolymerized with propylene or ethylene. For example, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-pentene, Examples include 1-heptene. Among the above-mentioned polyolefins, polypropylene, propylene / ethylene copolymer (random copolymer and / or block copolymer), propylene / ethylene / α-olefin copolymer, and propylene / α-olefin can be obtained with high rigidity. A propylene-based material such as a copolymer is more preferable.

The melt flow rate (measured under the conditions of MFR, 230 ° C. and 2.16 kg) of the polyolefin mainly used for the substrate of the present invention is preferably in the range of 2 to 30 g / min, particularly preferably in the range of 5 to 30 g / min. If the MFR is less than 2 g / min, the melt viscosity is too high, and the productivity may decrease. On the other hand, if the MFR is larger than 30 g / min, the base material becomes brittle and it may be difficult to handle at the time of manufacturing or using the laminate.

The base material in the present invention may have a two-layer structure or more.

Further, in the composition constituting the substrate of the present invention, a lubricant, an antioxidant, a weathering agent, an antistatic agent, a crystal nucleating agent, a pigment, etc., as long as the properties as the laminate of the present invention are not impaired. Various additives may be added as appropriate.

The thickness of the substrate can be appropriately adjusted in accordance with the required characteristics of the laminate, but is preferably 5 to 200 μm, more preferably 10 to 100 μm, and particularly preferably 10 to 80 μm. If it is thinner than 5 μm, the strength may be insufficient, and it may be difficult to convey in the manufacturing process, or may be torn during processing or use. If it is thicker than 200 μm, the transparency of the film may be insufficient or the productivity may be reduced.

<Adhesive layer>
The above-mentioned composition is preferably used for the pressure-sensitive adhesive layer constituting the laminate of the present invention.

The thickness of the pressure-sensitive adhesive layer of the present invention can be appropriately adjusted according to the material, thickness, surface shape and required level of the adherend, but is preferably 1 to 20 μm, more preferably 2 to 10 μm, and particularly preferably 2 to 8 μm. If the thickness of the adhesive layer is smaller than 1 μm, sufficient adhesive strength may not be exhibited on the adherend, and if it is larger than 20 μm, the adhesive strength may be excessive or the productivity may be reduced. .

<Release layer>
The laminated body of the present invention is a laminated body having at least a base material and an adhesive layer. However, it is a preferable aspect to provide a release layer on the surface opposite to the adhesive layer of the base material to form a three-layer laminated structure. is there. The material, thickness, and surface shape constituting the release layer may be selected and adjusted from the viewpoint of the adhesive strength of the adhesive layer and the processing suitability during the production and use of the laminate, and use techniques known in the art. be able to. Preferably, from the viewpoint of favorably controlling releasability, a propylene resin containing 0.5 to 10% by mass of a fluorine-containing compound having both a polyfluorohydrocarbon group and a polyoxyethylene group is mainly constituted. It is preferable.

The propylene-based resin may be the same as or different from the propylene-based resin constituting the base material, but at least a copolymer of propylene and ethylene and / or α-olefin is used. It is preferable to contain 20% by mass or more in order to roughen the surface roughness of the release layer described later to 3.0 μm or more in terms of Rz. When the propylene-based polymer is a copolymer with ethylene and / or α-olefin, the higher the monomer content, the lower the melting point of the copolymer. Since it is possible, the monomer content is more preferably in the range of 3 to 7% by mass. In addition, when adding heat resistance to a mold release layer, it can also select suitably so that such monomer content may be decreased and desired heat resistance may be acquired.

The MFR of the propylene resin at 230 ° C. is preferably in the range of 3 to 40 g / 10 minutes. In particular, those having an MFR in the range of 10 to 40 g / 10 min are more preferred because they can be extruded at low temperature and are easy to roughen the release layer when combined with low density polyethylene.

In order to roughen the release layer, it is preferable to contain at least 4% by mass of high-pressure low-density polyethylene having poor compatibility with the propylene resin.

Furthermore, it is preferable that the release layer is composed of a propylene-based resin containing 0.5% by mass to 10% by mass of a fluorine-containing compound containing a polyfluorohydrocarbon group and a polyoxyethylene group at the same time. Examples of the fluorine-containing compound having a polyfluorohydrocarbon group and a polyoxyethylene group include a (meth) acrylic acid ester having a C 1-18 perfluoroalkyl group as the monomer (a). The monomer (b) described later and the (meth) acrylic acid ester having a polyoxyethylene group of the monomer (c) can be copolymerized.

The perfluoroalkyl group of the monomer (a) preferably has 1 to 18 carbon atoms, more preferably 1 to 6 carbon atoms. Such a perfluoroalkyl group may be linear or branched. These may be used alone or in combination of two or more.

Such (meth) acrylic acid ester having a perfluoroalkyl group is commercially available from Kyoeisha Chemical Co., Ltd., or can be synthesized by a known method using a commercially available fluorine-containing compound as a raw material.

As the monomer (b) containing a polyoxyethylene group, those having a structure in which oxyethylene units (—CH ₂ —CH ₂ —O—) are linked in an amount of 1 to 30 are preferable. Are more preferred. An oxypropylene unit (—CH ₂ —CH (CH ₃ ) —O—) may be contained in the chain. Preferable examples include polyethylene glycol monomethacrylate having 8 oxyethylene units. The monomer (b) may be used alone or in combination of two or more.

Another monomer (c) containing a polyoxyethylene group is a di (meta) having a structure in which 1 to 30 oxyethylene units are linked and having double bonds at both ends. ) As a preferred specific example, acrylate, a polyethylene glycol dimethacrylate having a chain number of 8 can be exemplified. Such monomer (c) can also be used alone or in combination of two or more.

The proportions of the monomer (a), the monomer (b) and the monomer (c) are as follows: the monomer (a) is 1 to 80% by mass, and the monomer (b) is 1 to 80% by mass. The mass% and the monomer (c) are preferably 1 to 50 mass%.

The fluorine-containing compound having a polyfluorohydrocarbon group and a polyoxyethylene group is copolymerized with a monomer that can be copolymerized with these three monomers in a range of less than 50% by mass. May be. Such monomers include methylene, vinyl acetate, vinyl chloride, vinyl fluoride, vinyl halide, styrene, methylstyrene, (meth) acrylic acid and its esters, (meth) acrylamide monomers, (meth) allyl monomers. Examples include a polymer.

The polymerization method for obtaining the fluorine-containing compound having the polyfluorohydrocarbon group and the polyoxyethylene group using the monomer may be any of bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization. In addition to thermal polymerization, photopolymerization and energy ray polymerization can also be employed.

As the polymerization initiator, existing organic azo compounds, peroxides, persulfates and the like can be used.

The weight average molecular weight of the fluorine-containing compound used in the present invention is preferably from 1,000 to 100,000, particularly preferably from 5,000 to 20,000. The weight average molecular weight can be adjusted with a polymerization chain transfer agent such as thiol, mercaptan, or α-methylstyrene.

Further, the ratio of the fluorine-containing compound in the release layer of the present invention is preferably 0.5% by mass to 10% by mass. If it is less than 0.5% by mass, blocking with the adhesive layer is likely to occur, and it may be difficult to obtain a desired unwinding force. In addition, if the content exceeds 10% by mass, the solubility in the resin is low, so that it is difficult to mix uniformly, and at the time of melt extrusion, the propylene resin for forming the release layer is affected by the fluorine-containing compound. In some cases, it may be difficult to slide and uniformly discharge at the extrusion screw portion.

The release layer of the present invention preferably contains 0.1 to 10% by mass of inorganic or organic particles having an average particle size of 1 to 20 μm at the same time in addition to the fluorine-containing compound. Such inorganic or organic particles having an average particle size of 3 to 15 μm are particularly preferred from the viewpoint of slipperiness and blocking properties.

Examples of such inorganic particles include calcium carbonate, magnesium carbonate, titanium oxide, clay, talc, magnesium hydroxide, aluminum hydroxide, zeolite, etc., other than silica, among which silica is more preferable.

Examples of organic particles include polystyrene and polymethyl methacrylate.

The synergistic effect of the fluorine-containing compound, the inorganic or organic particles, and the surface roughness of the release layer described later makes it difficult to block and makes it easy to obtain good unwinding properties.

The surface roughness of the release layer of the present invention is preferably 3 μm or more in terms of 10-point average roughness (Rz). If Rz is less than 3 μm, wrinkles are likely to occur when the laminate is wound into a roll, and the quality may be lowered. Such surface roughness can be achieved by, for example, a method in which a small amount of an ethylene resin having poor compatibility is added to the main propylene resin as described above.

<Method for producing laminate>
Next, the manufacturing method of the laminated body of this invention is demonstrated.

The production method of the laminate of the present invention is not particularly limited. For example, in the case of a three-layer laminated structure of a base material, an adhesive layer, and a release layer, the resin composition constituting each is melt-extruded from an individual extruder, and a die is formed. The so-called coextrusion method for laminating and integrating the above, and the method of laminating by laminating after individually melting and extruding the base material, the adhesive layer, and the release layer are mentioned. Preferably, it is manufactured by the method. As the co-extrusion method, known methods such as an inflation method and a T-die method are used. From the viewpoint of excellent thickness accuracy and surface shape control, a hot-melt co-extrusion method by the T-die method is particularly preferable.

Here, when the tackifier is premixed uniformly with a styrene elastomer and / or propylene / α-olefin copolymer and used as a master pellet, when the resin constituting the adhesive layer is melt-extruded, It is preferable because a uniform adhesive layer is easily obtained. The content of the tackifier in the master pellet may be appropriately adjusted according to the physical properties of the tackifier and the resin to be mixed, but is preferably 30% by mass or more, more preferably 40% by mass or more from the viewpoint of productivity. .

<Application example>
The laminate composed of the composition of the present invention can be used as a surface protection film for the prevention of scratches during the production, processing and transportation of synthetic resin plates, metal plates, glass plates, etc. In particular, it is suitably used for adherends having irregularities on the surface. For example, it is used for a diffusion plate, a prism sheet or the like, which is a display member made of a synthetic resin, and a laminate composed of the composition of the present invention is particularly preferably used for protecting the surface of the prism sheet.

The prism sheet protected by the laminate composed of the composition of the present invention is one in which a triangular prism is arranged on one side of the sheet in parallel on the sheet surface so that the ridge line is the outer surface. Although the material which comprises a prism is not specifically limited, Resin which has translucency is used, for example, acrylic resin, a polycarbonate, etc. are mentioned. The distance between adjacent ridge lines of the prism is preferably 10 to 1,000 μm, and more preferably 10 to 300 μm. The height of the prism (the length of the perpendicular from the base of the triangular prism to the ridge line) is preferably 5 to 200 μm, and more preferably 10 to 100 μm. Moreover, the prism sheet protected by the present invention may be composed only of prisms having the same shape, or may be composed of two or more types of prisms having different shapes. When composed of prisms of different shapes, for example, there are cases where large and small prisms having different heights are alternately arranged one by one, or one large prism and a plurality of small prisms are alternately disposed. However, it is designed appropriately according to the purpose.

Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples. Various physical properties were measured and evaluated by the following methods.

(1) Dynamic viscoelasticity measurement Resins constituting the compositions shown in Examples and Comparative Examples are blended at a predetermined mixing ratio, and the temperature is 200 ° C. and the rotation speed is 20 rpm using a lab plast mill 100MR3 manufactured by Toyo Seiki Seisakusho. Kneaded for 15 minutes. Subsequently, the obtained kneaded material was melt-molded to a thickness of 2 mm, and the temperature was −80 to 120 ° C., the temperature rising rate was 3 ° C./min, the frequency was 1 Hz, using a rheometer AR2000ex manufactured by TA Instruments. The viscoelasticity of the composition was evaluated in shear mode at a strain of 0.01%. From the obtained results, the loss tangent at _{100 ° C.} (tan δ _{100 ° C.} ), the loss tangent at _{0 ° C.} (tan δ _{0 ° C.} ), the difference between the loss tangent at 60 ° C. and the loss tangent at 100 ° C. (tan δ _{100 ° C.} − tan δ _{60 ° C.} ).

(2) Differential scanning calorimetry After kneading the compositions shown in Examples and Comparative Examples in the same manner as in (1) above, the obtained kneaded material was melt-molded to a thickness of 50 μm, and further 5 mg was weighed and measured. A sample was prepared. Thereafter, the sample was collected in an aluminum pan, and heated at a rate of 40 ° C./min from room temperature to 230 ° C. in a nitrogen atmosphere using a differential scanning calorimeter (Seiko Denshi Kogyo RDC220), and at 230 ° C. for 5 minutes. After holding, the temperature was lowered to 20 ° C. at 40 ° C./min, and held at 40 ° C. for 5 minutes. Further, after that, the temperature was raised again to 230 ° C. at 40 ° C./min, and the temperature (T _m ) of the endothermic peak obtained at this time was confirmed.

(3) Bonding to prism sheet The laminates obtained in the examples and comparative examples were applied to a prism sheet having a thickness of 160 μm and a surface roughness (Rz) of 27 μm on a roll press machine (Special Yasuda Seisakusho Co., Ltd. roller). ) Was used under the condition of 0.35 MPa.

(4) Peelability After the sample obtained in (3) above was stored for 1 week under conditions of a temperature of 23 ° C. and a relative humidity of 50%, a tensile tester (Orientec “Tensilon” universal tester) Was used to measure the peel force (S) at a tensile speed of 300 mm / min and a peel angle of 180 °, and the peelability was evaluated according to the following criteria.
5: 0.02 N / 25 mm ≦ S ≦ 0.08 N / 25 mm
3: 0.08 N / 25 mm <S ≦ 0.12 N / 25 mm
1: S <0.02N / 25mm, or S> 0.12N / 25mm.

(5) Processing characteristics The sample obtained in the above (3) was stored for 24 hours under the conditions of a temperature of 23 ° C. and a relative humidity of 50%, and then punched with a Thomson die-cutting cutter. The state of sticking of the prism sheet and the laminated body after storage for 1 week under the conditions of ° C and 50% relative humidity was visually observed and evaluated according to the following criteria.
5: No peeling at all immediately after punching and after storage for 1 week at 40 ° C. 4: No peeling at all immediately after punching, but very slightly peeled off after storage for 1 week at 40 ° C. 3: The edge is slightly peeled off both immediately after punching and after storage for 1 week at 40 ° C. 2: After storage for 1 week at 40 ° C., the edge is peeled off more than 1/2 of the total length around the sample 1: immediately after punching The end is peeled off by more than half of the total length around the sample.

(Composition)
Materials of the following compositions A to E, X to Z, and S were prepared as shown in Examples 1 to 5 and Comparative Examples 1 to 4, and dynamic viscoelasticity measurement was performed as shown in the above (1) and (2). And differential scanning calorimetry was performed. The results are shown in Table 1.

(Example 1)
Composition A: 14% by mass of SEBS (Taftec H1052 manufactured by Asahi Kasei Chemicals Co., Ltd.) and 30% by mass of HSBR (1321P manufactured by JSR) as styrene elastomer, and propylene / 1-butene copolymer as propylene / α-olefin copolymer 20% by mass of coalescence (Tafmer XM-7080 manufactured by Mitsui Chemicals, melting point 83 ° C.) and 36% by mass of 50% by mass master pellets of hydrogenated terpene phenol (YS Polystar TH130 manufactured by Yasuhara Chemical) as a tackifier were used.

Here, the hydrogenated terpenephenol 50% by mass master pellets were obtained by preliminarily mastering 50% by mass of the hydrogenated terpenephenol and 50% by mass of the SEBS by using a twin screw extruder.

(Example 2)
Composition B: 8% by mass of SEBS (Taftec H1052 manufactured by Asahi Kasei Chemicals), 27% by mass of HSBR (1321P manufactured by JSR), propylene / 1-butene copolymer (Tafmer XM-7080 manufactured by Mitsui Chemicals, melting point 83 ° C.) Composition A was the same as composition A except that 40% by mass of 25% by mass, 50% by mass master pellets of hydrogenated terpene phenol (YS Polystar TH130 manufactured by Yasuhara Chemical) was used.

(Example 3)
Composition C: The same as Composition B, except that a propylene / 1-butene copolymer (Tafmer XM-7070, Mitsui Chemicals, melting point 75 ° C.) was used as the propylene / α-olefin copolymer.

Example 4
Composition D: 14% by mass of SEBS (Taftec H1052 manufactured by Asahi Kasei Chemicals), 30% by mass of HSBR (Dynalon 1321P manufactured by JSR), propylene / 1-butene copolymer (Tafmer XM-7080 manufactured by Mitsui Chemicals, melting point 83 ° C.) 10% by mass, hydrogenated terpenephenol (YShara Chemical YS Polystar TH130) 50% by mass master pellets 36% by mass, density 921 kg / m ³ , hexene copolymer polyethylene (LLDPE) at 190 ° C. and MFR 5 g / min The same as composition A except that 10% by mass was used.

(Example 5)
Composition E: 25% by mass of SEBS (Taftec H1052 manufactured by Asahi Kasei Chemicals), 30% by mass of HSBR (Dynalon 1321P manufactured by JSR), propylene / 1-butene copolymer (Tafmer XM-7080 manufactured by Mitsui Chemicals, melting point 83 ° C.) 10 mass%, hydrogenated terpenephenol (YShara Chemical YS Polystar TH130) 50 mass% master pellet 20 mass%, except that 15 mass% resin mainly made of amorphous polypropylene (Sumitomo Chemical Tough Selenium T3712) was used. The same as composition A.

(Comparative Example 1)
Composition X: 15% by mass of SEBS (Taftec H1052 manufactured by Asahi Kasei Chemicals), 30% by mass of HSBR (Dynalon 1321P manufactured by JSR), and 30% by mass of 50% by mass master pellet of hydrogenated terpene phenol (YS Polystar TH130 manufactured by Yasuhara Chemical) The same as composition A except that 25% by mass of LLDPE similar to that used in Example 4 was used.

(Comparative Example 2)
Composition Y: Same as Composition A except that 50% by mass of SEBS (Taftec H1052 manufactured by Asahi Kasei Chemicals) and 50% by mass of HSBR (Dynalon 1321P manufactured by JSR) were used.

(Comparative Example 3)
Composition Z: 70% by mass of propylene / 1-butene copolymer (Tafmer XM-7080, Mitsui Chemicals, melting point 83 ° C.) and 30% by mass of a resin mainly composed of amorphous polypropylene (Tuff Selenium T3712 manufactured by Sumitomo Chemical) Except for the above, it was the same as Composition A.

(Comparative Example 4)
Composition S: 35% by mass of SEBS (Taftec H1052 manufactured by Asahi Kasei Chemicals), 35% by mass of HSBR (Dynalon 1321P manufactured by JSR), and 30% by mass of a resin mainly composed of amorphous polypropylene (Tuff Selenium T3712 manufactured by Sumitomo Chemical) Except for the above, it was the same as the composition A.

(Laminate)
As shown in the following examples and comparative examples, laminates were prepared and evaluated. The evaluation results are shown in Table 2.

(Example 1 ')
The constituent resin of each layer was prepared as follows.

Adhesive layer: Composition A shown in Example 1 was used.

Substrate: Commercially available homopolypropylene having an MFR measured at 230 ° C. of 5 g / 10 min was used.

Release layer: 45% by mass of the same homopolypropylene used for the base material, 24% by mass of propylene-ethylene random copolymer measured at 230 ° C. with an MFR of 5 g / 10 min (ethylene content 5% by mass) ), A low density polyethylene having an MFR measured at 190 ° C. of 2 g / 10 min and a density of 919 kg / m ³ is added to 6% by mass, and 90% by mass of the homopolypropylene is 4% by mass of silica having an average particle diameter of 11 μm. A mixed composition comprising 6% by mass of a fluorine-containing compound having a fluorohydrocarbon group and a polyoxyethylene group was prepared as a master batch, and 25% by mass was uniformly mixed with a Henschel mixer.

Here, the fluorine-containing compound having a polyfluorohydrocarbon group and a polyoxyethylene group is a C ₆ F ₁₃ perfluoroalkyl acrylate (CH ₂ ═CHCOOC ₂ H ₄ C ₆ F ₁₃ ) as the monomer (a). 25% by mass, monomer (b), 50% by mass of polyethylene glycol monoacrylate {CH ₂ ═CHCOO (CH ₂ CH ₂ O) ₈ H} having ₈ oxyethylene repeating units, and monomer (c) As an example, a polyethylene glycol dimethacrylate having eight oxyethylene repeating units {CH ₂ ═C (CH ₃ ) COO (CH ₂ CH ₂ O) ₈ COC (CH ₃ ) ═CH ₂ } in a proportion of 25% by mass in a solvent Using fluorotoluene, 2,2'-azobis (2,4-dimethylvaleronitrile) as the polymerization initiator, Using lauryl mercaptan as a chain transfer agent, under nitrogen stream, stirring was polymerized for 5 hours at 60 ° C., after which was precipitated, filtered with methanol used was dried under reduced pressure.

Next, the multi-manifold T-die having a die width of 2,400 mm having three extruders each consisting of φ115 mm (for base material), φ90 mm (for adhesive layer), and φ65 mm (for release layer) is used as the constituent resin of each layer. The amount of each extruder is adjusted so that the adhesive layer thickness ratio is 12.5%, the release layer thickness ratio is 8.5%, and the base material thickness ratio is 79%. The composite T die was extruded at an extrusion temperature of 200 ° C. to form a three-layer laminated film having a film thickness of 40 μm. Then, after bonding to a prism sheet, peelability and processing characteristics were evaluated.

(Example 2 ')
A laminate was prepared and evaluated in the same manner as in Example 1 ′ except that the composition B shown in Example 2 was used for the adhesive layer.

(Example 3 ')
A laminate was prepared and evaluated in the same manner as in Example 1 ′ except that the composition C shown in Example 3 was used for the adhesive layer.

(Example 4 ')
A laminate was prepared and evaluated in the same manner as in Example 1 ′ except that the composition D shown in Example 4 was used for the adhesive layer.

(Example 5 ')
A laminate was prepared and evaluated in the same manner as in Example 1 ′ except that the composition E shown in Example 5 was used for the adhesive layer.

(Comparative Example 1 ')
A laminate was prepared and evaluated in the same manner as in Example 1 ′ except that the composition X shown in Comparative Example 1 was used for the adhesive layer.

(Comparative Example 2 ')
A laminate was prepared and evaluated in the same manner as in Example 1 ′ except that the composition Y shown in Comparative Example 2 was used for the adhesive layer.

(Comparative Example 3 ′)
A laminate was prepared and evaluated in the same manner as in Example 1 ′ except that the composition Z shown in Comparative Example 3 was used for the adhesive layer.

(Comparative Example 4 ′)
A laminate was prepared and evaluated in the same manner as in Example 1 ′ except that the composition S shown in Comparative Example 4 was used for the adhesive layer.

While the laminates of Examples 1 ′ to 5 ′ that satisfy the requirements of the present invention are excellent in peelability and processing characteristics, Comparative Examples 1 ′ to 4 ′ that do not satisfy the requirements of the present invention are excellent in peelability or processing characteristics. The result was inferior.

The composition and laminate of the present invention are not only a surface protective film for preventing scratches and stains on adherends having irregularities on the surface, but also surface protection for various products made of various materials such as synthetic resin, metal, and glass. It can be preferably used as a film application.

Claims

A composition satisfying the following conditions 1 and 2.
Condition 1 Shear loss tangent (tan δ 0 ° C. ) at a frequency of 1 Hz and a temperature of 0 ° C. is 0.20 or more and 0.60 or less Condition 2 Shear loss tangent (tan δ 100 ° C. ) at a frequency of 1 Hz and a temperature of 100 ° C. is 0. 40 to 0.80
2. The composition according to claim 1, wherein the composition satisfies the following condition 3 with respect to a shear loss tangent (tan δ 60 ° C. ) at a frequency of 1 Hz and a temperature of 60 ° C. and a shear loss tangent at a temperature of 100 ° C. (tan δ 100 ° C. ). Composition.
Condition 3 0.20 ≦ tan δ 100 ° C.− tan δ 60 ° C. ≦ 0.60
The composition according to claim 1 or 2, wherein the composition has an endothermic peak in a range of 60 ° C to 100 ° C in differential scanning calorimetry.
The composition according to any one of claims 1 to 3, wherein the composition contains at least the following components (1) to (3).
(1) Styrene elastomer (2) Propylene / α-olefin copolymer (3) Tackifier
A laminate comprising an adhesive layer on one surface of a substrate, wherein the adhesive layer comprises the composition according to any one of claims 1 to 4.
The laminate according to claim 5, which is used for protecting the surface of the prism sheet.