JP2020186394A - Laminate - Google Patents

Abstract

To provide a composition for providing a laminate that exhibits excellent adhesion characteristics and excellent processing characteristics when bonded to an object to be bonded; and a laminate which is configured from the composition.SOLUTION: A composition is characterized by satisfying the following conditions 1 and 2. Condition 1: The shear loss tangent (tanδ0°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 (tanδ100°C) at a frequency of 1 Hz at a temperature of 100°C is from 0.40 to 0.80 (inclusive).SELECTED DRAWING: None

Description

The present invention relates to a composition for providing a laminate having excellent adhesive properties and processing properties when bonded to an adherend, and a laminate composed of the above compositions.

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 stains that occur during the processing process, transportation process, and storage. A typical example thereof is a surface protective film, which generally has an adhesive layer formed on a supporting base material made of a thermoplastic resin or paper, and the adhesive layer surface is attached to an adherend. The surface is protected by coating with a supporting base material.

Particularly in recent years, liquid crystal displays and touch panel devices have become widespread, and these are composed of a large number of members such as optical sheets and optical films made of synthetic resins. Since it is necessary to reduce defects such as optical distortion as much as possible in such an optical member, a surface protective film is often used in order to prevent scratches and stains that may cause the defects.

The characteristics of the surface protective film are that it does not easily peel off from the adherend when it receives an external force such as punching or due to environmental changes such as temperature and humidity, and that it can be easily peeled off when peeling off from the adherend. Further, it is required that the adhesive and the adhesive component do not remain on the adherend when peeled off.

Among the above-mentioned optical members, for members having irregularities on the surface such as a diffuser plate and a prism sheet, since the contact area between the uneven portion and the adhesive layer is small immediately after the surface protective film is attached, punching processing or the like is performed. When an external force is applied to the film, the external force may not be absorbed sufficiently and the film may peel off from the adherend. With respect to such a point, a method of softening the adhesive layer, a method of increasing the adhesive strength by using a tackifier, and the like are known (for example, Patent Documents 1 to 4).

Japanese Unexamined Patent Publication No. 2008-214437 Japanese Unexamined Patent Publication No. 2005-298630 Japanese Unexamined Patent Publication No. 05-194923 Japanese Unexamined Patent Publication No. 2012-111793

However, with the above method, the adhesive strength may increase 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 problems, the subject of the present invention is to provide a composition for providing a laminate having excellent adhesive properties and processing properties when bonded to an adherend, and a laminate composed of the composition. To do.

In order to solve the above problems, the present inventors have completed the following inventions as a result of repeated diligent studies. That is, the present invention is as follows.
1) A composition characterized by satisfying the following conditions 1 and 2.
Condition 1 Shear loss tangent (tan δ _{0 ° C} ) at frequency 1 Hz and temperature 0 ° _C is 0.20 or more and 0.60 or less Condition 2 Shear loss tangent (tan δ _{100 ° C} ) at frequency 1 Hz and temperature 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 The composition according to 1), which satisfies 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 the range of 60 ° C. or higher and 100 ° C. or lower 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) Styrene-based elastomer (2) Propylene / α-olefin copolymer (3) Adhesive-imparting agent 5) In a laminate having an adhesive layer on one surface of a base material, the adhesive layers are 1) to 4). A laminate containing the composition according to any one.
6) The laminate according to 5) used for surface protection of a prism sheet.

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

Hereinafter, the constituent requirements of the composition and the 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 satisfying the above conditions 1 and 2, when the composition of the present invention is used for the adhesive layer of the laminated body for protecting the adherend, good adhesive characteristics and processing characteristics can be obtained. That is, it has excellent stickability to the adherend, is less likely to be peeled 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 the 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 inside and retains stress.

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

If the tan δ _{0 ° C.} is less than 0.20, the processing characteristics may be deteriorated, and if it is larger than 0.60, the peelability may be deteriorated. Further, when the above-mentioned tan δ _{100 ° C.} is less than 0.40, the processing characteristics may be deteriorated, and when it is larger than 0.80, the adhesive strength may be increased with time and the peelability may be lowered.

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. It is more preferably 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 tanδ _{100 ° C.} and tanδ _{60 ° C.} (tanδ _{100 ° C. −} tanδ _{60 ° C.} ) is less than 0.20, the processing characteristics may deteriorate, and if it is greater than 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. or higher and 100 ° C. or lower in differential scanning calorimetry. It is more preferable that the composition has an endothermic peak in the range of 70 ° C. or higher and 100 ° C. or lower, particularly preferably 70 ° C. or higher and 90 ° C. or lower. By having an endothermic peak in the range of 60 ° C. or higher and 100 ° C. or lower, when the composition of the present invention is used as an adhesive layer of a laminate for protecting an adherend, the adhesive characteristics and processing characteristics are preferably controlled. can do.

If the endothermic peak is less than 60 ° C, the heat resistance may be lowered, and if it exceeds 100 ° C, the processing characteristics may be lowered.

The composition of the present invention is not particularly limited as long as it satisfies the constituent requirements 1 and 2, but is a crosslinked system such as acrylic or silicone, a non-crosslinked system such as natural rubber or synthetic rubber, or a pseudo-crosslinked system (pseudo-crosslinked system). Any material (thermoplastic) may be used, but it is preferable to use a thermoplastic resin as a main component from the viewpoint of recyclability. Here, the fact that the thermoplastic resin is the main component means that the proportion 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. ..

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

In the present invention, the styrene-based elastomer refers to a resin having a structural unit derived from styrene and exhibiting rubbery elasticity at room temperature, and known ones can be used. For example, a styrene-butadiene copolymer. (SBR), styrene / isoprene / styrene copolymer (SIS), styrene / butadiene / styrene copolymer (SBS) and other styrene-diene copolymers and their hydroxides, such as styrene / ethylene / butylene. -Styrene copolymer (SEBS) and the like, styrene and isobutylene copolymer, for example, styrene-isobutylene-styrene triblock copolymer (SIBS), styrene-isobutyrene block copolymer (SIB), or a mixture thereof. Such as styrene / isobutylene block copolymer and the like. Only one type of these styrene-based elastomers may be used, or two or more types may be used in combination. Among the above-mentioned styrene-based elastomers, hydrogenated styrene / butadiene copolymer (HSBR), styrene / ethylene / butylene / styrene copolymer (SEBS), styrene / isobutylene / styrene triblock copolymer (SIBS), styrene. -Isobutyrene block copolymer (SIB) or a mixture thereof is preferably used.

The weight average molecular weight of the styrene-based elastomer is preferably in the range of 50,000 to 400,000, more preferably in the range of 50,000 to 200,000. If the weight average molecular weight is less than 50,000, the cohesive force of the adhesive layer may decrease and adhesive residue may occur when peeled from the adherend, and if it 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, more preferably in the range of 8 to 20% by mass. If 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 the adhesive layer is peeled off from the adherend. If the styrene content is more than 30% by mass, the adhesiveness to the adherend becomes poor. It will be lowered, and the adhesiveness may be insufficient especially for the adherend having unevenness.

Further, the propylene / α-olefin copolymer means 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, etc. can be mentioned, but the present invention is not limited to this. 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. or higher and 100 ° C. or lower. It is more preferably 70 ° C. or higher and 100 ° C. or lower, and particularly preferably 70 ° C. or higher and 90 ° C. or lower. The melting point of the propylene / α-olefin copolymer can be controlled by changing the type of α-olefin and the copolymerization ratio.

Further, the tackifier is a material blended to enhance the stickiness of the pressure-sensitive adhesive layer as defined in JIS Z0109 (1992), and a material 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. , Alkylphenol-based resin, xylene-based resin, or hydrogenated products thereof, and the like, which are generally used, 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-mentioned styrene-based elastomer, propylene / α-olefin copolymer, and tackifier is preferably 60% by mass or more, preferably 70% by mass or more, when the total content of the composition is 100% by mass. It is more preferably mass% or more, and further preferably 80% by mass or more. If the total content is less than 60% by mass, the balance between the adhesive property and the processing property may be deteriorated.

Further, when the whole composition is 100% by mass, the content of the styrene-based elastomer is preferably 40% by mass or more, more preferably 50% by mass or more. Further, the content of the propylene / α-olefin copolymer is preferably 10% by mass or more, more preferably 15% by mass or more. The content of the tackifier is preferably 5% by mass or more, more preferably 10% by mass.

The composition of the present invention contains, in addition to the above-mentioned styrene-based elastomer, propylene / α-olefin copolymer, and tackifier, other resin components for adjusting the adhesive strength, as long as the object of the present invention is not impaired. Additives and the like may be added as appropriate.

As another resin component for adjusting the adhesive strength, a resin 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. Sexual ethylene / α-olefin copolymer, polypropylene, propylene / ethylene copolymer (random copolymer and / or block copolymer), propylene / α different from 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 Examples thereof include coalescence, ethylene / vinyl acetate copolymer and the like. These resins may be used alone or in combination of two or more.

The total content of the other resin components for adjusting the adhesive strength is preferably 20% by mass or less, more preferably 10% by mass or less, when the entire composition is 100% by mass. When the total content of other resin components for adjusting the adhesive strength exceeds 20% by mass, the composition of the present invention has adhesive properties when used in 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 weather resistant agent, an antistatic agent, an adhesive propellant, and the like can be added. These additives may be used alone or in combination of two or more. The total content of the additive is preferably 3% by mass or less, more preferably 2% by mass or less, when the whole composition is 100% by mass. If the total content of the additive is more than 3% by mass, it may bleed out from the adhesive layer, causing defects in the product or contaminating the adherend.

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

<Base material>
The base material constituting the laminate of the present invention is not particularly limited, and for example, a resin such as polyolefin or polyester can be used. Among them, it is preferable to use polyolefin as a main component from the viewpoint of productivity and processing suitability. Here, the term "polyolefin as a main component" means that the proportion of polyolefin is 50% by mass or more, more preferably 70% by mass or more, when the entire base material is 100% by mass.

Examples of the polyolefin include low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, low-crystalline or amorphous ethylene / α-olefin copolymer, polypropylene, and propylene / ethylene copolymer. Combined (random copolymer and / or block copolymer), propylene / α-olefin copolymer, propylene / ethylene / α-olefin copolymer, ethylene / ethyl (meth) acrylate copolymer, ethylene / methyl ( Examples thereof include a meta) 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, and for example, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-pentene, etc. 1-Heptene and the like can be mentioned. Among the above-mentioned polyolefins, polypropylene, propylene / ethylene copolymer (random copolymer and / or block copolymer), propylene / ethylene / α-olefin copolymer, propylene / α-olefin, which can obtain high rigidity, A propylene-based material such as a copolymer is more preferable.

The melt flow rate of the polyolefin mainly used as the substrate of the present invention (measured under the conditions of MFR, 230 ° C. and 2.16 kg) is preferably in the range of 2 to 30 g / min, and 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 may be difficult to handle during the production or use of the laminate.

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

Further, in the composition constituting the base material of the present invention, a lubricant, an antioxidant, a weather resistant agent, an antistatic agent, a crystal nucleating agent, a pigment, etc. are included as long as the characteristics of the laminated body of the present invention are not impaired. Various additives may be added as appropriate.

The thickness of the base material can be appropriately adjusted according to 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 will be insufficient, and it may be difficult to transport it in the manufacturing process, or it 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 lowered.

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

The thickness of the 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 force may not be exhibited on the adherend, and if it is larger than 20 μm, the adhesive force may be excessive or the productivity may decrease. ..

<Release layer>
The laminated body of the present invention is a laminated body having at least a base material and an adhesive layer, but it is preferable 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 viewpoints of the adhesive strength of the adhesive layer and the processing suitability at the time of manufacturing or using the laminate, and techniques known in the art are used. be able to. Preferably, from the viewpoint of satisfactorily controlling the releasability, a propylene-based resin containing 0.5% by mass to 10% by mass of a fluorine-containing compound having a polyfluorohydrocarbon group and a polyoxyethylene group at the same time is mainly composed. 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 that the content is 20% by mass or more in order to roughen the surface roughness of the release layer, which will be described later, to 3.0 μm or more in Rz. When the propylene-based polymer is a copolymer of ethylene and / or α-olefin, the higher the monomer content, the lower the melting point of the copolymer, the ease of coextrusion and low temperature extrusion. Since it is possible, the monomer content is more preferably in the range of 3 to 7% by mass. If it is desired to add heat resistance to the release layer, the monomer content can be reduced and appropriately selected so as to obtain desired heat resistance.

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 minutes are more preferable because they can be extruded at a low temperature and the release layer can be easily roughened by combining 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-based resin.

Furthermore, the release layer is preferably 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 perfluoroalkyl group having 1 to 18 carbon atoms as the monomer (a). It can be obtained by copolymerizing with a (meth) acrylic acid ester having a polyoxyethylene group of the monomer (b) and the monomer (c) described later.

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

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

The monomer (b) containing a polyoxyethylene group preferably has a structure in which oxyethylene units (-CH _2- CH _2- O-) are linked by 1 to 30, and the units are particularly 1 to 20. Is more preferable. The oxypropylene unit (-CH _2- CH (CH ₃ ) -O-) may be contained in the chain. As a preferred example, polyethylene glycol monomethacrylate having eight oxyethylene units can be exemplified. The monomer (b) may be used alone or in combination of two or more.

Further, as another monomer (c) containing a polyoxyethylene group, di (meth) having a structure in which oxyethylene units are linked by 1 to 30 and having a double bond at both ends. ) Crylate, as a preferred specific example, polyethylene glycol dimethacrylate having 8 chains and the like can be exemplified. As for the monomer (c), only one type can be used alone, or two or more types can be used in combination.

The proportions of the monomer (a), the monomer (b), and the monomer (c) are 1 to 80% by mass for the monomer (a) and 1 to 80% for the monomer (b). It is preferable that the mass% and the monomer (c) are 1 to 50% by mass.

In the fluorine-containing compound having a polyfluorohydrocarbon group and a polyoxyethylene group, in addition to the above three monomers, a monomer copolymerizable with these is copolymerized in a range of less than 50% by mass. You may. Examples of such monomers include methylene, vinyl acetate, vinyl chloride, vinyl fluoride, vinyl halide, styrene, methylstyrene, (meth) acrylic acid and its ester, (meth) acrylamide monomer, and (meth) allyl monomer. Quantum and the like can be mentioned.

The polymerization method for obtaining a fluorine-containing compound having a polyfluorohydrogen group and a polyoxyethylene group using the above-mentioned monomer may be any of massive polymerization, solution polymerization, suspension polymerization, and emulsification polymerization. In addition to thermal polymerization, photopolymerization and energy ray polymerization can also be adopted.

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 1,000 to 100,000, particularly preferably 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.

The proportion 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 rewinding force. Further, if it is contained in an amount exceeding 10% by mass, it is difficult to mix uniformly because the solubility in the resin is low, and the propylene-based resin for the release layer structure is affected by the fluorine-containing compound during melt extrusion. , It may slip on the extrusion screw part and it may be difficult to discharge uniformly.

It is more preferable that the release layer of the present invention contains 0.1% by mass to 10% by mass of inorganic or organic particles having an average particle diameter of 1 to 20 μm at the same time in addition to the fluorine-containing compound. The average particle size of the inorganic or organic particles is 3 to 15 μm, which is particularly preferable from the viewpoint of slipperiness and blocking property.

Examples of such inorganic particles include calcium carbonate, magnesium carbonate, titanium oxide, clay, talc, magnesium hydroxide, aluminum hydroxide, zeolite and the like, in addition to silica, but silica is more preferable.

Examples of the organic particles include polystyrene and polymethylmethacrylate.

Due to the synergistic effect of the fluorine-containing compound, the inorganic or organic particles, and the surface roughness of the release layer described later, blocking is difficult and good unwinding property can be easily obtained.

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

<Manufacturing method of laminated body>
Next, a method for producing the laminate of the present invention will be described.

The method for producing the laminated body of the present invention is not particularly limited. For example, in the case of a three-layer laminated structure consisting of a base material, an adhesive layer, and a release layer, the resin compositions constituting each are melt-extruded from individual extruders to form a base. Examples include a so-called coextrusion method in which the base material, the adhesive layer, and the release layer are individually melt-extruded and then laminated by a laminating method. From the viewpoint of productivity, coextrusion is used. It is preferably manufactured by the method. As the coextrusion method, known methods such as an inflation method and a T-die method are used, but the heat-melt coextrusion method by the T-die method is particularly preferable from the viewpoint of excellent thickness accuracy and surface shape control.

Here, if the tackifier is prepared by uniformly mixing with a styrene elastomer and / or a propylene / α-olefin copolymer and forming a master pellet, the resin constituting the pressure-sensitive layer is melt-extruded when the resin is melt-extruded. It is preferable that a uniform adhesive layer can be 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 from the viewpoint of productivity, it is preferably 30% by mass or more, more preferably 40% by mass or more. ..

<Application example>
The laminate composed of the composition of the present invention can be used as a surface protective film for preventing scratches and stains during manufacturing, processing, and transportation of synthetic resin plates, metal plates, glass plates, etc. In particular, it is preferably used for an adherend having irregularities on its surface. For example, it is used for a diffuser plate, a prism sheet, etc., which are display members made of synthetic resin, and among them, a laminate composed of the composition of the present invention is particularly preferably used for surface protection of the prism sheet.

The prism sheet protected by the laminate composed of the composition of the present invention is one in which triangular columnar prisms are arranged in parallel on one side of the sheet so that the ridgeline is the outer surface. The material constituting the prism is not particularly limited, but a translucent resin is used, and examples thereof include acrylic resin and polycarbonate. The distance between the adjacent ridges of the prisms is preferably 10 to 1,000 μm, more preferably 10 to 300 μm. The height of the prism (the length of the perpendicular line from the bottom of the triangular prism to the ridgeline) is preferably 5 to 200 μm, more preferably 10 to 100 μm. Further, the prism sheet protected by the present invention may be composed of only prisms having the same shape, or may be composed of two or more types of prisms having different shapes. When composed of prisms having different shapes, for example, large and small prisms having different heights may be alternately arranged one by one, or one large prism and a plurality of small prisms may be alternately arranged. However, it is appropriately designed according to the purpose.

Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to these Examples. The measurement and evaluation of various physical properties were carried out by the following methods.

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

(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 product is melt-molded to a thickness of 50 μm, and further 5 mg is weighed and measured. It was used as a sample. Then, the sample was collected in an aluminum pan, and the temperature was raised from room temperature to 230 ° C. at 40 ° C./min using a differential scanning calorimeter (RDC220 manufactured by Seiko Electronics Co., Ltd.) in a nitrogen atmosphere at 230 ° C. for 5 minutes. After holding, the temperature was lowered to 20 ° C. at 40 ° C./min, and the temperature was kept 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) Laminating to a prism sheet The laminates obtained in Examples and Comparative Examples were put on a prism sheet with a thickness of 160 μm and a surface roughness (Rz) of 27 μm on a roll press machine (Yasuda Seiki Seisakusho Co., Ltd. special crimping roller). ) Was used for bonding under the condition of 0.35 MPa.

(4) Peelability After storing the sample obtained in (3) above for one week under the conditions of a temperature of 23 ° C. and a relative humidity of 50%, a tensile tester (Orientec Co., Ltd. "Tencilon" universal tester) The peeling force (S) was measured at a tensile speed of 300 mm / min and a peeling angle of 180 °, and the peelability was evaluated according to the following criteria.
5: 0.02N / 25mm ≦ S ≦ 0.08N / 25mm
3: 0.08N / 25mm <S ≦ 0.12N / 25mm
1: S <0.02N / 25mm, or S> 0.12N / 25mm.

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

(Composition)
The 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 the dynamic viscoelasticity measurement was performed as shown in (1) and (2) above. And differential scanning calorimetry was performed. The results are shown in Table 1.

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

Here, as the hydrogenated terpene phenol 50% by mass master pellet, the hydrogenated terpene phenol 50% by mass and the SEBS 50% by mass were previously master-pelletized using a twin-screw extruder.

(Example 2)
Composition B: SEBS (Tuftec H1052 manufactured by Asahi Kasei Chemicals) 8% by mass, HSBR (1321P manufactured by JSR) 27% by mass, propylene / 1-butene copolymer (Tufmer XM-7080 manufactured by Mitsui Chemicals, melting point 83 ° C.) The same as in Composition A, except that 25% by mass and 40% by mass of a 50% by mass master pellet of hydrogenated terpenephenol (YS Polystar TH130 manufactured by Yasuhara Chemical Co., Ltd.) were used.

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

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

(Example 5)
Composition E: SEBS (Tough Tech H1052 manufactured by Asahi Kasei Chemicals) 25% by mass, HSBR (Dynaron 1321P manufactured by JSR) 30% by mass, propylene / 1-butene copolymer (Toughmer XM-7080 manufactured by Mitsui Chemicals Co., Ltd., melting point 83 ° C.) 10% by mass, 50% by mass of hydrogenated terpenephenol (YS Polystar TH130 manufactured by Yasuhara Chemical Co., Ltd.), 20% by mass of master pellet, and 15% by mass of resin mainly composed of amorphous polypropylene (Tough Serene T3712 manufactured by Sumitomo Chemical Co., Ltd.). , The same as in composition A.

(Comparative Example 1)
Composition X: SEBS (Tough Tech H1052 manufactured by Asahi Kasei Chemicals) 15% by mass, HSBR (Dynaron 1321P manufactured by JSR) 30% by mass, 50% by mass of hydrogenated terpene phenol (YS Polystar TH130 manufactured by Yasuhara Chemicals) 30% by mass , The same as the 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 SEBS (Tough Tech H1052 manufactured by Asahi Kasei Chemicals Co., Ltd.) was used in an amount of 50% by mass and HSBR (Dynaron 1321P manufactured by JSR) was used in an amount of 50% by mass.

(Comparative Example 3)
Composition Z: 70% by mass of a propylene / 1-butene copolymer (Toughmer XM-7080 manufactured by Mitsui Chemicals, melting point 83 ° C.), and 30% by mass of a resin mainly composed of amorphous polypropylene (Tufselene T3712 manufactured by Sumitomo Chemicals). It was the same as the composition A except that it was present.

(Comparative Example 4)
Composition S: 35% by mass of SEBS (Tough Tech H1052 manufactured by Asahi Kasei Chemicals), 35% by mass of HSBR (Dynaron 1321P manufactured by JSR), and 30% by mass of a resin mainly composed of amorphous polypropylene (Tough Serene T3712 manufactured by Sumitomo Chemical Co., Ltd.) was used. Other than that, it was the same as the composition A.

(Laminated body)
As shown in the following Examples and Comparative Examples, a laminate was prepared and evaluated. The evaluation results are shown in Table 2.

(Example 1')
The constituent resins of each layer were prepared as follows.

Adhesive layer: The composition A shown in Example 1 was used.

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

Release layer: 45% by mass of the same homopolypropylene used for the base material, 24% by mass of propylene-ethylene random copolymer with an MFR of 5 g / 10 minutes measured at 230 ° C. (5% by mass of ethylene content) ), low density polyethylene measured MFR of 2 g / 10 min density 919 kg / ^{m 3} at 190 ° C. in addition to 6% by weight, of silica 4 weight% of the average grain size 11μm advance to the homopolypropylene 90% by weight, poly A mixed composition consisting of 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 perfluoroalkyl acrylate of C ₆ F ₁₃ as the monomer (a) (CH ₂ = CHCOOC ₂ H ₄ C ₆ F ₁₃ ). 25% by mass, 50% by mass of polyethylene glycol monoacrylate {CH ₂ = CHCOO (CH ₂ CH ₂ O) ₈ H} having ₈ oxyethylene repeating units, and the monomer (c). As a result, polyethylene glycol dimethacrylate {CH ₂ = C (CH ₃ ) COO (CH ₂ CH ₂ O) ₈ COC (CH ₃ ) = CH ₂ } with 8 oxyethylene repeating units was added to the solvent at a ratio of 25% by mass. Polymerization with fluorotoluene using 2,2'-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator and lauryl mercaptan as a chain transfer agent at 60 ° C. for 5 hours with stirring under a nitrogen stream. After that, the mixture was precipitated and filtered in methanol, and then dried under reduced pressure.

Next, the constituent resin of each layer is a multi-manifold T-die with a base width of 2,400 mm having three extruders consisting of φ115 mm (for the base material), φ90 mm (for the adhesive layer), and φ65 mm (for the release layer). It is charged into each extruder of the composite film forming machine, and the discharge 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%. , Each of the composite T-dies 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, the 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.

The laminates of Examples 1'to 5'that satisfy the requirements of the present invention are excellent in peelability and processing characteristics, while Comparative Examples 1'to 4'that do not satisfy the requirements of the present invention have excellent 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 an adherend 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 (6)

A composition comprising satisfying the following conditions 1 and 2.
Condition 1 Shear loss tangent (tan δ _{0 ° C} ) at frequency 1 Hz and temperature 0 ° _C is 0.20 or more and 0.60 or less Condition 2 Shear loss tangent (tan δ _{100 ° C} ) at frequency 1 Hz and temperature 100 ° _C is 0. 40 or more and 0.80 or less Wherein the composition, frequency 1 Hz, and shear loss tangent at a temperature _{60 ℃} (tanδ 60 ℃), the shear loss tangent at a temperature _{100 ℃} (tanδ 100 ℃), according to claim 1 satisfying the condition 3 below 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 the range of 60 ° C. or higher and 100 ° C. or lower 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-based elastomer (2) Propylene / α-olefin copolymer (3) Adhesive-imparting agent A laminate having an adhesive layer on one surface of a base material, wherein the adhesive layer contains the composition according to any one of claims 1 to 4. The laminate according to claim 5, which is used to protect the surface of a prism sheet.