KR101176811B1 - Surface protective film - Google Patents

Abstract

1 이상, Y 는 커플링제 잔기) 로 나타내는 구조의 공중합체 또는 그 수소 첨가물을 함유하고, 중합체 (ⅰ) (ⅱ) 전체의 방향족 알케닐 화합물 단위 함유율이 30 ～ 50 중량％, 중합체 (ⅰ) (ⅱ) 에 각각 함유되는 A 와 B 의 총량의 중량비가 5：95 ～ 25：75 인 것을 특징으로 하는 점착제 조성물 (상기 A 는 방향족 알케닐 화합물 단위를 주체로 하는 중합체 블록, B 는 방향족 알케닐-공액 디엔 랜덤 공중합체 블록이며 방향족 알케닐 화합물 단위 함유율이 10 ～ 35 중량％ 인 중합체 블록).Polymer (iii): Copolymer of the structure represented by general formula [AB] n (n = 1-3), or its hydrogenated substance, and polymer (ii): General formula ABA or general formula (AB) xY (x

1 or more, Y contains the copolymer of the structure represented by a coupling agent residue), or its hydrogenated substance, and the aromatic alkenyl compound unit content rate of the whole polymer (iii) (ii) is 30-50 weight%, and a polymer (v) ( A pressure-sensitive adhesive composition (wherein A is a polymer block mainly composed of aromatic alkenyl compound units, B is aromatic alkenyl-), wherein the weight ratio of the total amount of A and B contained in ii) is from 5:95 to 25:75, respectively. Polymer block having a conjugated diene random copolymer block having an aromatic alkenyl compound unit content of 10 to 35% by weight).

Description

Surface protection film {SURFACE PROTECTIVE FILM}

The present invention relates to a surface protective film.

In order to protect the surface of various members conventionally, such as an optical device, a metal plate, a coated metal plate, a resin plate, and a glass plate, the surface protection film by which the adhesive layer is laminated | stacked on one surface of a film-form base material (generally a protective tape, Masking tape, surface protection sheet, etc.) may be widely used. In particular, the surface protection film is used for the optical member for liquid crystal displays in recent years. The optical member may have an uneven surface such as a prism sheet or a diffusion film. In order not to damage this unevenness | corrugation, although the protection by the surface protection film of the surface (especially the outer surface of unevenness | corrugation) is performed prior to use, when a surface protection film is affixed on such an uneven surface Since a large contact area cannot be obtained, it is necessary to form an adhesive layer with strong adhesive force.

By the way, generally, a surface protection film is industrially manufactured as a winding body which wound the elongate film in roll shape. In the surface protection film made of such a winding body, it is known that the force (development force) required for rewinding of the wound body is large, and the rise of the development force tends to be large over time, but the development force is small, that is, the winding body is easily rewinded. There is a strong demand to be able to do so.

In addition, since the surface protective film is peeled off after use, it is required that there is a smooth peelability and there is no contamination of adherend by the adhesive residue.

On the other hand, as raw materials, such as a prism sheet and a diffusion film, polar polymers, such as an acrylic resin and polycarbonate resin, are used abundantly. Although these optical sheets are shipped to an optical device manufacturer after affixing a surface protection film, they may be exposed to high temperature in the transportation, storage, etc.

Here, especially when the surface of a to-be-adhered body becomes an uneven | corrugated shape, there exists a problem of the raise of adhesive force by what the contact area between a to-be-adhered body and an adhesive layer increases by external factors, such as time and temperature, and what is called a stickiness improvement.

In general, an acrylic pressure sensitive adhesive is widely used as the pressure sensitive adhesive, but an acrylic pressure sensitive adhesive has a particularly large increase in adhesive strength over time.

In such a point, especially in the case of the surface protection film applied to an optical sheet, the rubber adhesive rather than the acrylic adhesive was mainly used for the adhesive layer which comprises a surface protection film. Thereby, the increase of the adhesive force over time is avoided, and the surface protection film is peeled smoothly from the lens part (prism) surface of an optical sheet, etc. is aimed at.

However, since the rubber-based adhesive is generally a solution coating type, there are problems such as environmental pollution and energy waste during solvent drying, and a back surface of the general-purpose olefin base layer (the side opposite to the side on which the adhesive layer is laminated). You also need a release process for. In addition, if the hot-melt-type pressure-sensitive adhesive, the former problem can be solved or reduced, the back release treatment can not be avoided.

Regarding the problem of improving rewinding, for example, on the surface of the base material layer of a laminated film in which a base material layer composed of a polyorganosiloxane having at least one intramolecular double bond and a polyolefin resin and a pressure-sensitive adhesive layer are laminated, The manufacturing method of the surface protection film which irradiates an electron beam or (gamma) ray is proposed (patent document 1).

Moreover, after forming the laminated | multilayer film formation of the surface layer containing polyolefin resin and the adhesive layer containing a thermoplastic elastomer by coextrusion method, the surface protection film obtained by forming a mold release layer by the coating method on the back surface of the surface layer is proposed ( Patent document 2).

In addition, the surface protection film formed by coextrusion with an olefin base material layer using the adhesive layer which has a styrene-based elastomer as a main component instead of a natural rubber, The back surface of the base material layer is friction-processed, and is excellent in rewinding property A protective film is proposed (patent document 3).

On the other hand, with respect to the problem of suppressing the adhesion elevation, for example, polyethyleneimine having a higher alkyl group introduced therein is mixed into the base material layer and bleeded out to the surface of the adhesion layer to suppress adhesion elevation while securing initial adhesion to the adherend. Attempts have been made (Patent Document 4).

By the way, it is common to store the prism sheet on which the surface protection film was affixed and stored by the several tens of sheets until it introduces into a product.

In this case, the top part of the unevenness | corrugation of the prism sheet arrange | positioned below may be destroyed by the load of the prism sheet arrange | positioned upwards, and optical quality may deteriorate. This is considered to be due to the fact that the top part penetrates into the pressure-sensitive adhesive layer of the surface protection film and reaches the base material of the surface protection film by the load, and already exceeds the limit of the dispersion / relaxation effect of the load by the pressure-sensitive adhesive layer. In order to solve this problem, it can also be considered that what is necessary is just to make thickness of an adhesive layer thick enough. However, when the thickness of the pressure-sensitive adhesive layer is thickened, not only is it disadvantageous from the viewpoint of manufacturing cost, but also the penetration depth of the lens portion (prism) into the pressure-sensitive adhesive layer increases, and there is a fear that the increase in the adhesive force increases with time.

Also for this reason, there is an example of the surface protection film in which styrene-based elastomer is used instead of natural rubber. For example, Patent Literature 5 discloses a surface protective film using a pressure-sensitive adhesive layer having a thickness of 10 µm or more having a styrene-based elastomer as a main component. Thereby, it is described that sufficient protective function for an adherend and suitable adhesive characteristics can be satisfied simultaneously.

Japanese Patent Laid-Open No. 2-252783 Japanese Unexamined Patent Publication No. 2003-41216 Japanese Patent Application Laid-Open No. 07-62311 Japanese Patent Application Laid-Open No. 09-188857 Japanese Laid-Open Patent Publication 2000-80336

However, the above prior art also has the following problems.

Even with the surface protection film of patent document 1 or 3, development force cannot fully be reduced only by a back surface process, rewinding property of a winding object may not be enough, and workability may fall.

In the mold release treatment method of patent document 2, even when the back surface of a base material is coherent, sufficient drawability can be ensured, but there exists a possibility that a mold release agent may be transcribe | transferred to an adhesive layer, and the adhesiveness to a to-be-adhered body may fall.

The surface protection film disclosed in Patent Document 4, in the case of preservation in an extreme high temperature environment (for example, a tropical or subtropical region), the amount of polyethyleneimine bleed out to the surface in the case of preservation in a normal environment Contrary to this, there is a fear that the effect of suppressing sufficient adhesion improvement may not be exhibited.

Moreover, the surface protection film disclosed by patent document 5 is affixed in the severe state, for example, especially the prism surface of a prism sheet, and what is called fisheye on the surface (namely, the outer surface of a surface protection film) on the opposite side to the said prism surface side. Even in the case where projections such as the back are pressed, there is room for further improvement in view of protecting the shape of the top of the prism portion unevenness.

Accordingly, it is an object of the present invention to provide a surface protection film which eliminates the above-mentioned drawbacks of the prior art, secures an appropriate initial adhesive force, is excellent in developability, and prevents adhesive residue after peeling on the adherend. .

A further object of the present invention is to provide a surface protection film for a prism sheet in which adhesion improvement is suppressed even under an environment of extreme high temperature (for example, 70 ° C) while ensuring proper initial adhesive force.

A further object of the present invention is also to be attached to a prism face in a severe state, for example, a prism sheet, and a protrusion such as fisheye on the surface on the side opposite to the prism face side (that is, the outer surface of the surface protective film). Even in the case where it is pressurized, it is providing the surface protection film which can protect the top shape of a prism unevenness | corrugation.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining, the present inventors used the specific multiblock copolymer which has an aromatic alkenyl polymer block and an aromatic alkenyl-conjugated diene copolymer block for an adhesive layer, and is excellent in developability, ensuring an appropriate initial stage adhesive force, It turned out that the surface protection film in which the adhesive residue after peeling to the to-be-adhered body was prevented was obtained, and the result of further examination came to complete this invention.

The pressure-sensitive adhesive composition of the present invention,

Polymer (iii): The following polymer block A and the following polymer block B are contained, General formula [AB] n (In formula, A is a polymer block A, B is a polymer block B, n is an integer of 1-3. Copolymer (I) or its hydrogenated substance having a structure represented by

Polymer (ii): The following polymer block A and the following polymer block B are contained, General formula ABA (The symbol in a formula represents the same meaning as the above), or General formula (AB) xY (In formula, x represents an integer of 2 or more. Y represents a coupling agent residue, the other symbol represents the same meaning as the above), and contains the copolymer (II) or its hydrogenated substance which has a structure,

The aromatic alkenyl compound unit content rate (St (A + B)) of the said polymer (iii) and the said whole polymer (ii) is 30-50 weight%,

The weight ratio (A: B) of the total amount of the polymer block A and the total amount of the polymer block B contained in the polymer (iii) and the polymer (ii), respectively, is in the range of 5:95 to 25:75.

Polymer Block A:

Aromatic alkenyl compound units are continuous and the polymer block mainly having an aromatic alkenyl compound unit

Polymer block B:

An aromatic alkenyl-conjugated diene copolymer block containing a conjugated diene unit and an aromatic alkenyl compound unit randomly, wherein the polymer block has an aromatic alkenyl compound unit content (St (b)) of 10 to 35% by weight.

The surface protection film of this invention has a base material layer and the adhesive layer which consists of the adhesive composition of the said invention.

By using the adhesive composition of this invention, the surface protection film of this invention is excellent in developability, and the adhesive residue after peeling to a to-be-adhered body is prevented.

Preferably, in the surface protection film,

The base layer is a polyolefin base layer,

The pressure-sensitive adhesive composition further contains a tackifier, and

The temperature which becomes the maximum of tan-delta obtained by measuring dynamic viscoelasticity at -50 degreeC-80 degreeC of the said adhesive layer is -10 degreeC-20 degreeC.

As a result, the surface protection film may have a more preferable balance of development and initial adhesion.

Preferably, in the surface protection film,

The base layer is a polyolefin base layer,

The pressure-sensitive adhesive composition further contains a tackifier and a styrene-based block phase reinforcing agent,

The ratio (aromatic alkenyl compound unit content) with respect to the weight of the said adhesive layer of the unit weight of the aromatic alkenyl compound in the said polymer (iii), the said polymer (ii), and a styrene block type reinforcement agent is 20-50 weight%.

Thereby, the improvement of the adhesive force over time can be suppressed more preferably.

Preferably, in the said surface protection film, the storage elastic modulus (G ') in 70 degreeC of the said adhesive layer is 4.5 * 10 <^5> Pa ~ 6.0 * 10 <^5> Pa.

Thereby, the improvement of the adhesive force over time can be suppressed more preferably.

Preferably, when the said surface protection film is for surface protection of the prism surface of a prism sheet, it is affixed on the said prism surface, and when the load of 0.3 N / cm <2> is loaded in the atmosphere of 70 degreeC for 24 hours, The penetration depth to the pressure-sensitive adhesive layer of the prism vertex angle is 1% or more and less than 40% of the pressure-sensitive adhesive layer thickness.

Thereby, damage of a prism can be suppressed preferably, ensuring an appropriate adhesive force.

Preferably, when the said surface protection film is for the protection of the prism surface of a prism sheet, when it sticks to the said prism surface and the projection of 400 micrometers in diameter and 12 micrometers in height is pressed to the surface on the opposite side to the said prism surface side, The penetration depth to the said adhesive layer of the prism vertex angle of the said prism surface of is 1% or more and less than 100% of the thickness of the said adhesive layer.

Thereby, damage of a prism can be suppressed preferably, ensuring an appropriate adhesive force.

Preferably, when the said surface protection film is for the protection of the prism surface of a prism sheet, the outer surface of a base material layer has surface roughness (Ra) of 0.7-2.0 micrometers, the average height of the relief motif of 3 micrometers or more, and 350 micrometers or more It has an average length of ups and downs of 600 μm.

Thereby, while ensuring a moderate adhesive force, it is affixed to a severe state, for example, especially the prism surface of a prism sheet, and protrusions, such as a fisheye, on the surface on the opposite side to the said prism surface side (namely, the outer surface of a surface protection film). Even in the case where this pressurization is carried out, the shape of the top of the prism portion unevenness can be protected.

Preferably, the surface protection film is for surface protection of the diffusion film.

The surface protection film of this invention is excellent in developability, and the adhesive residue after peeling with respect to a to-be-adhered body is prevented.

Moreover, while the surface protection film of one aspect of this invention ensures moderate initial stage adhesive force, adhesion improvement is suppressed also in the environment of extreme high temperature (for example, 70 degreeC).

Moreover, the surface protection film of one aspect of this invention is stuck in the severe state, for example, the prism surface of a prism sheet especially, and it is what is called fish on the surface opposite to the prism surface side (namely, the outer surface of a surface protection film). Even in the case where projections such as a child are pressed, the shape of the top of the prism portion unevenness can be protected.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the relief of the outer surface of a base material layer.
2 is a perspective view of a prism sheet to which the surface protection film of one embodiment of the present invention is applied.
3 is a structure in which the surface protection film of one embodiment of the present invention is affixed to a prism sheet.

<Definition of Symbols in the Present Specification>

The symbol "-" used in order to show a numerical range in this specification is used with the intention that the said numerical range includes the numerical value of both ends, unless there is particular notice.

In the present specification, the term "content rate" of the repeating unit of the polymer used in the term "aromatic alkenyl compound unit content" or the like refers to the weight ratio in terms of the monomer derived from the repeating unit, that is, the weight of all monomers for forming the polymer. To the ratio of the weight of the monomer from which the repeating unit is derived (% by weight), ie, the aromatic alkenyl compound content of the polymer. Here, "weight of all the monomers for forming the said polymer" is approximated to the weight of the said polymer. In addition, similarly, in this specification, the "content rate" of the repeating unit of a polymer block means the weight ratio converted into the monomer from which a repeating unit originates, ie, the said repeating unit with respect to the weight of all the monomers for forming the said polymer block is derived. It means the ratio (weight%) of the weight of the monomer to make. Here, "weight of all the monomers for forming the said polymer block" approximates the weight of the said polymer block.

As used herein, "content of vinyl bond" means the total content of 1,2-vinyl bond and 3,4-vinyl bond calculated by the Morello method using the infrared absorption spectrum method.

<Adhesive Composition>

The adhesive composition of this invention contains the following polymer (iii) and the following polymer (ii).

In this specification, a "polymer" contains the following polymer block A and the following polymer block B, General formula [AB] n (In formula, A is a polymer block A, B is a polymer block B, n is 1 It is a copolymer (I) or its hydrogenated substance which has a structure shown by the integer of -3.

In this specification, "polymer (ii)" contains the following polymer block A and the following polymer block B, General formula ABA (The symbol in a formula represents the same meaning as the above), or General formula (AB) xY (In formula, x Is an integer of 2 or more, Y is a copolymer (II) or a hydrogenated substance having a structure represented by the coupling agent residue, and the other symbols represent the same meaning as described above.

In addition, the composition which consists of the said polymer (iii) and the said polymer (ii) in this specification may only be called "copolymer composition."

In the adhesive composition of this invention, the aromatic alkenyl compound unit content rate of the said polymer (iii) and the said whole polymer (ii) is 30-50 weight%, and is contained in the said polymer (iii) and the said polymer (ii) The weight ratio of the total amount of polymer block A to the total amount of polymer block B is in the range of 5:95 to 25:75.

In this specification, "polymer block A" is a polymer block in which an aromatic alkenyl compound unit is continuous and mainly contains an aromatic alkenyl compound unit.

In this specification, "polymer block B" is an aromatic alkenyl-conjugated diene copolymer block in which a conjugated diene unit and an aromatic alkenyl compound unit are randomly contained, and the aromatic alkenyl compound unit content (St (b)) is 10-35. It is a polymer block which is weight%.

<Polymer block A>

As mentioned above, "polymer block A" is a polymer block in which an aromatic alkenyl compound unit is continuous and mainly contains an aromatic alkenyl compound unit.

An "aromatic alkenyl compound unit" is a repeating unit derived from an aromatic alkenyl compound. Examples of the "aromatic alkenyl compound" include styrene, tert-butyl styrene, α-methyl styrene, p-methyl styrene, p-ethyl styrene, divinylbenzene, 1,1-diphenylethylene, vinyl naphthalene, and vinyl anthracene. , N, N-diethyl-p-aminoethylstyrene, vinylpyridine, and the like. Especially, it is preferable that a "aromatic alkenyl compound unit" is a styrene unit because a raw material is easy to obtain industrially.

"Polymer block A" needs to be comprised using an aromatic alkenyl compound unit as a main repeating unit. Specifically, the aromatic alkenyl compound unit content is 80% by weight or more. By raising the aromatic alkenyl compound unit content rate to 80 weight% or more, there exists an advantage that thermoplasticity of an adhesive composition can be improved and recycling of an adhesive composition becomes easier. As repeating units other than the aromatic alkenyl compound unit which may be contained in less than 20 weight%, the repeating unit derived from the compound copolymerizable with an aromatic alkenyl compound, for example, a conjugated diene compound and a (meth) acrylic acid ester compound The repeating unit derived from is mentioned. Especially, 1, 3- butadiene and isoprene are preferable from the reason that copolymerizability with an aromatic alkenyl compound is high.

<Polymer block B>

As described above, "polymer block B" is an aromatic alkenyl-conjugated diene copolymer block in which the conjugated diene unit and the aromatic alkenyl compound unit are randomly contained, and the aromatic alkenyl compound unit content (St (b)) is It is a polymer block which is 10 to 35 weight%.

The "conjugated diene compound unit" which comprises "polymer block B" is a repeating unit derived from a conjugated diene compound. As a "conjugated diene compound", for example, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-octadiene, 1, 3-hexadiene, 1,3-cyclohexadiene, 4,5-diethyl-1,3-octadiene, 3-butyl-1,3-octadiene, myrcene, chloroprene and the like. Especially, it is preferable that a "conjugated diene compound unit" is at least 1 sort (s) of repeating unit chosen from the group of 1, 3- butadiene unit and isoprene unit from the reason that polymerization reactivity is high and a raw material is easy to obtain industrially. Do.

"Polymer block B" needs to be comprised using the conjugated diene compound unit as a main repeating unit. It is preferable that the conjugated diene compound unit content rate exists in the range of 65 to 90 weight% from a viewpoint of exhibiting the effect of this invention.

Moreover, from the viewpoint of obtaining the effect of this invention, "polymer block B" needs to exist in the range of 10 to 35 weight% of aromatic alkenyl compound unit content (St (b)), and exists in the range of 13 to 33 weight%. It is preferable that it is preferable and it exists in the range of 16-30 weight%. When an aromatic alkenyl compound unit content rate is less than 10 weight%, developability is difficult and handling property may worsen. On the other hand, when it exceeds 35 weight%, the softness | flexibility of an adhesive composition is inferior and it may be unable to ensure sufficient adhesive force important for a surface protection film.

In addition, "polymer block B" may also contain repeating units other than a conjugated diene compound unit and an aromatic alkenyl compound unit in the range which does not prevent the effect of this invention.

Moreover, it is preferable that a vinyl bond content rate exists in 50 to 90% of range, and, as for "polymer block B", from a viewpoint of exhibiting the effect of this invention, it is more preferable to exist in 60 to 80% of range. Moreover, there exists an advantage that the adhesive composition excellent in the balance of a tack and adhesive force can be comprised by making vinyl bond content rate into 50% or more.

<Copolymer (I)>

"Copolymer (I)" contains the following polymer block A and the following polymer block B, general formula [AB] n (In formula, A is polymer block A, B is polymer block B, n is 1-3. It is a copolymer which has a structure shown by the following).

As is apparent from "n" representing an integer of 1 to 3, examples of the "structure represented by formula [A-B] n" include structures represented by A-B, A-B-A-B and A-B-A-B-A-B. In these block copolymers, A and B may be the same or different in repetition, respectively.

In the structure represented by [A-B] n, it is preferable that the terminal polymer block B occupies 2 weight% or more of the whole copolymer from a viewpoint which exhibits the effect of the polymer block B reliably. Moreover, even if the terminal of some copolymer (I) has a structure of -A, when the content rate of the terminal polymer block A is less than 2 weight% of the whole copolymer (I), the terminal is the same as that of the polymer block B It can exert an effect. That is, the structure can be considered to be substantially polymer block B at the end.

n needs to be an integer of 1-3. By bringing n into this range, industrial productivity will become favorable. Moreover, from a viewpoint of improving adhesive force and material strength, it is more preferable that n is 1-2, and it is especially preferable that it is 1. That is, as a "copolymer which has a structure represented by general formula [A-B] n", the block copolymer which has a structure represented by general formula A-B is especially preferable.

It is preferable that an aromatic alkenyl compound unit content rate exists in the range of 30-50 weight%, and, as for copolymer (I) or its hydrogenated substance (polymer), it is more preferable that it is 33-45 weight%. By carrying out an aromatic alkenyl compound unit content rate in this range, it becomes possible to comprise the adhesive composition which has moderate holding | maintenance power, the harvestability with respect to the unevenness | corrugation of the to-be-adhered body surface, and is excellent in developability.

Although there is no restriction | limiting in particular about the molecular weight of a polymer (i), It is preferable that a weight average molecular weights are 30,000-500,000, It is more preferable that it is 80,000-300,000, It is especially preferable that it is 100,000-200,000. By carrying out a weight average molecular weight in the range of 30,000-500,000, industrial production of the copolymer composition which consists of a polymer (i) and also a polymer (i) and a copolymer (II) or its hydrogenated substance (polymer (ii)) is carried out. It can be made easy. If the weight average molecular weight is less than 30,000, the polymer may adhere to a manufacturing facility or the like in a step of desolventing and drying the polymer, and the industrial production of the polymer may be difficult. On the other hand, when a weight average molecular weight is 500,000 or more, solubility to a solvent and heat meltability worsen, and the process with respect to an adhesive may become difficult.

Since the hydrogenated substance of the copolymer (I) has excellent heat resistance and weather resistance, the double bond derived from the conjugated diene monomer is 80% or more, preferably 90% or more, more preferably 95% or more, hydrogenated It is preferable that the unsaturated bond is a hydrogenated product hydrogenated with a saturated bond.

In addition, in this specification, the ratio of hydrogenation (hydrogenation rate) means the hydrogenation rate computed from 270 MHz, <^1> H-NMR spectrum, using carbon tetrachloride as a solvent.

A polymer (i) may be individual (1 type) or a combination of 2 or more types.

<Copolymer (II)>

"Copolymer (II)" contains the following polymer block A and the following polymer block B, and general formula ABA (the symbol in the formula shows the same meaning as the above) or general formula (AB) xY (where x is 2 The above integer is represented and Y is a copolymer which has a structure represented by the coupling agent residue and the other symbol shows the same meaning as the above).

As is apparent from the above general formula, copolymer (II) has a polymer block A at all its molecular ends.

It is preferable that the terminal polymer block A occupies 2 weight% or more of the whole copolymer (II). This is to reliably exert the effect of the polymer block A. In addition, even if the terminal of some copolymer (II) has a structure of -B, when the content rate of the terminal polymer block B is less than 2 weight% of the whole copolymer (II), the terminal is the same as that of the polymer block A It can exert an effect. That is, the structure can be considered to be substantially polymer block A at the end.

The copolymer which has a structure represented by general formula (AB) xY (wherein x represents an integer of 2 or more, Y represents a coupling agent residue and other symbols represent the same meaning as the above), in other words, a copolymer (I) This has a structure coupled by Y. Therefore, in the case of (A-B) x-Y, since the mixture of (I) and (II) can be synthesize | combined in the same reaction kiln, (A-B) x-Y is preferable from an industrial viewpoint. When x is 3 or more, the said copolymer is what is called a star polymer. From the viewpoint of suppressing side reactions during the production of the copolymer and controlling the physical properties of the copolymer, x is preferably 2 to 4.

Moreover, it is preferable that copolymer (II) or its hydrogenated substance (polymer (ii)) is also within the range of 30-50 weight% of aromatic alkenyl compound unit content rates, for the same reason as polymer (b), 33-45 weight It is more preferable that it is%.

The polymer (ii) has an 80% or more, preferably 90% or more, more preferably 95% or more, double bond derived from the conjugated diene monomer in that excellent heat resistance and weather resistance are obtained. It is preferable that it is a hydrogenated substance hydrogenated by this saturated bond.

Although there is no restriction | limiting in particular about the molecular weight of polymer (ii), It is preferable that weight average molecular weights are 50,000-500,000, and it is more preferable that it is 50,000-300,000. By carrying out a weight average molecular weight in the range of 50,000-500,000, industrial production of the copolymer composition which consists of a polymer (ii) and also a polymer (iii) and a polymer (ii) can be made easy. If the weight average molecular weight is less than 30,000, the polymer may adhere to the production facility or the like in the step of desolventing and drying the polymer, which may make industrial production of the copolymer (II) or its hydrogenated product difficult. On the other hand, when a weight average molecular weight is 500,000 or more, solubility to a solvent and heat meltability worsen, and the process with respect to an adhesive may become difficult.

Polymer (ii) may be single (1 type) or a combination of 2 or more types.

<Copolymer Composition>

As mentioned above, the adhesive composition of this invention is an adhesive composition which contains the copolymer composition which consists of a polymer (i) and a polymer (ii) as a structural component. In this copolymer composition, the weight ratio of polymer (i) and polymer (ii) needs to exist in the range of 90: 10-10: 90. By containing 10 weight part or more of polymers (VIII) in 100 weight part of total amounts of a polymer (iii) and a polymer (ii), the problem (lifting) that the adhesive layer rises from the surface of a to-be-adhered body and peels off effectively can be prevented effectively. It can exert the preferable effect that it can. On the other hand, by containing 10 weight part or more of polymers (ii) in 100 weight part of total amounts of a polymer (iii) and a polymer (ii), when peeling a film from the surface of a to-be-adhered body, an adhesive remains on the surface of a to-be-adhered body, It is possible to exert the desirable effect of effectively preventing the problem of contaminating the surface of the adherend (adhesive residue).

It is preferable that the weight ratio of a polymer (i) and a polymer (ii) exists in the range of 50: 50-15: 85 from a viewpoint of preventing the lifting of an adhesive layer and an adhesive residue more reliably.

From the viewpoint of exerting the effect of the present invention, the weight ratio of the total amount of the polymer block A and the total amount of the polymer block B contained in the polymer (iii) and the polymer (ii) must be within the range of 5:95 to 25:75. have. Further, by containing 5 parts by weight or more of the polymer block A in 100 parts by weight of the total amount of the polymer block A and the polymer block B, a preferable effect of being able to impart a suitable holding force to the pressure-sensitive adhesive layer formed can be exhibited. On the other hand, by containing 75 weight part or more of polymer block B in 100 weight part of total amounts of the polymer block A and the polymer block B, since the adhesive layer formed shows favorable harvestability with respect to the unevenness | corrugation of a to-be-adhered body surface, the to-be-adhered body surface The desirable effect of being able to reliably protect can be exhibited. The weight ratio of the total amount of the polymer block A and the total amount of the polymer block B is preferably in the range of 5:95 to 25:75, more preferably in the range of 7:93 to 23:77, and more preferably in the range of 10:90 to 21:79. It is especially preferable to exist in the range of.

<Surface protection film>

The surface protection film of this invention has a base material layer and the adhesive layer which consists of the adhesive composition of this invention demonstrated above.

Preferably, the said adhesive layer is laminated | stacked on one surface of the said base material layer.

<Base layer>

As the said base material layer, Preferably it is a polyolefin base material layer.

Examples of the "polyolefin" include low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, ethylene-α-olefin copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, and ethylene-. Methyl acrylate copolymer, ethylene-n-butyl acrylate copolymer, and polypropylene (homopolymer, random copolymer, block copolymer) and the like.

These can be used individually or in combination of 2 or more types. Moreover, the polyolefin which has a substituent may be sufficient as "polyolefin", and resin other than polyolefin may be added. In addition, the cutting material of the polyolefin base material layer and the cutting material of a surface protection film which generate | occur | produced in the manufacturing process of a surface protection film may be added.

The base material layer may be a single layer, or may be a layer having two or more types of multilayer structures having different compositions.

The base material layer can adjust the thickness suitably according to the use of a surface protection film, etc. Usually, it is suitable to set to thickness of about 10-100 micrometers.

Preferably, the outer surface (that is, the surface opposite to the pressure-sensitive adhesive layer side) of the substrate layer has a surface roughness (Ra) of 0.7 to 2.0 µm, an average height of a relief motif of 3 µm or more, and a relief of 350 µm or more and 600 µm or less. Motif average length.

Thereby, even when the surface protection film of this aspect is affixed and laminated | stacked and stored on the surface of a prism sheet, since damage can not occur easily to the lens part (prism) of a prism sheet, it is preferable for the protection of the prism surface of a prism sheet. Can be used.

In particular, when the surface roughness of the back surface of the said base material layer, the average height of relief motifs, and the average length of relief motifs are in the said predetermined range, when a plurality of prism sheets with which the surface protection film was stuck were laminated | stacked and stored several sheets, the fine mixed foreign material Even if there existed, it is thought that the minute mixed foreign matter may enter the valley portion of the surface relief, so that the stress concentrated in the lens portion of the prism sheet can be reduced as compared with the case where the surface is smooth.

In addition, in this specification, "surface roughness Ra" is the "arithmetic mean height" prescribed | regulated to JISB0601-2001. The relief motif average height W is computed by following Formula as an average value of Wj in the schematic diagram which shows the relief of the surface of the polyolefin base material layer of FIG. 2, and the relief motif average length AW as an average value of AWj.

In this specification, "a relief motif average length" and "a relief motif average height" are the "average length of an outline curve element" and the "average height of an outline curve element" prescribed | regulated to JISB0601: 2001, respectively.

<Adhesive layer>

The pressure-sensitive adhesive layer is made of the pressure-sensitive adhesive composition of the present invention. In addition to the said polymer (iii) and the said polymer (ii), the said adhesive composition is a tackifier, a styrenic block shape reinforcing agent, a softener, antioxidant, a light stabilizer, a ultraviolet absorber, a filler, a pigment, and adhesive improvement as needed. You may appropriately contain well-known additives, such as an inhibitor, an olefin resin, a silicone polymer, a liquid acrylic copolymer, and a phosphate ester type compound.

Examples of the tackifier used in the present invention include petroleum resins such as aliphatic copolymers, aromatic copolymers, aliphatic aromatic copolymers and alicyclic copolymers, coumarone-indene resins, and terpene resins. Generally used for an adhesive, such as rosin-type resins, such as a terpene- phenol-type resin and polymerization rosin, (alkyl) phenol type resin, xylene resin, or these hydrogenated substances, can be used without a restriction | limiting in particular. As for the softening point of a tackifier, it is more preferable to use what is 90-140 degreeC. These tackifiers may be used independently or may use 2 or more types together. Moreover, in order to improve peelability, weather resistance, etc., it is more preferable to use the tackifier of a hydrogenation system. Moreover, you may use the tackifier marketed as a blend with an olefin resin.

The tackifier in this invention means that it is compatible with the rubber layer which is a conjugated diene type in the aromatic alkenyl block copolymer, or its hydrogenated soft segment, and can control adhesive force.

In addition, "commercial" means the state in which the tan delta peak temperature of the compound obtained by mix | blending a tackifier with a copolymer composition becomes a value different from the tan delta peak temperature of a copolymer composition. In addition, in this specification, "tan-delta peak temperature" means the temperature which becomes the maximum of tan-delta.

A styrene block-like reinforcement is used in order to suppress the adhesion improvement of an adhesive layer.

As the styrene-based block reinforcing agent used in the present invention, for example, styrene and α-methylstyrene, p-methylstyrene, p-chlorostyrene, chloromethylstyrene, tert-butylstyrene, p-ethylstyrene, as monomer units, Styrene-type compounds, such as divinylbenzene, are mentioned. These can be used individually or in combination of 2 or more types. In short, a styrene-based block reinforcing agent can be obtained by polymerizing these monomers. In the case of the copolymer which consists of two or more types of monomers, a block copolymer may be sufficient and a random copolymer may be sufficient. Especially, it is preferable that a styrene-type block reinforcement agent has a softening point of about 100 degreeC or more, and 150 degreeC or more is more preferable. Specifically, Eastman Chemical Co., a brand name "ENDEX155" (softening point 155 degreeC), "ENDEX160" (softening point 160 degreeC), etc. are used preferably.

Softeners are usually effective for improving adhesion. As the softener, for example, a low molecular weight diene polymer, polyisobutylene, hydrogenated polyisoprene, hydrogenated polybutadiene, paraffinic process oil, naphthenic process oil, aromatic process oil, castor oil, tall oil, natural What is generally used for adhesives, such as oil, a liquid polyisobutylene resin, polybutene, or these hydrogenated substances, can be used without a restriction | limiting in particular. These softeners may be used independently or may use 2 or more types together.

It does not specifically limit as antioxidant, For example, what is normally used, such as a phenol type (monophenol type, bisphenol type, polymer type phenol type), sulfur type, phosphorus type, is mentioned.

A hindered amine compound is mentioned as an optical stabilizer.

It does not specifically limit as a ultraviolet absorber, For example, a salicylic acid type, a benzophenone type, a benzotriazole type, a cyanoacrylate type etc. are mentioned.

As a filler, calcium carbonate, magnesium carbonate, silica, zinc oxide, titanium oxide, etc. are mentioned, for example.

As an anti-adhesive agent, fatty acid amide, a long-chain alkyl grafted product of polyethyleneimine, a soybean oil modified alkyd resin (for example, Arakawa Chemical Industry Co., Ltd. brand name "Arachid 251", etc.), tall oil modified alkyd resin (for example Arakawa Chemical) Industrial company make, brand names "Arachid 6300", etc. are mentioned.

These additives may be used independently or may use 2 or more types together.

Although the thickness in particular of an adhesive layer is not restrict | limited, For example, it is about 0.5-50 micrometers normally, Preferably it is 1-40 micrometers, More preferably, it is 2-30 micrometers.

In one preferable aspect of the surface protection film of this invention,

The base layer is a polyolefin base layer,

The pressure-sensitive adhesive composition further contains a tackifier, and

The temperature which becomes the maximum of tan-delta obtained by measuring dynamic viscoelasticity at -50 degreeC-80 degreeC of the said adhesive layer is -10 degreeC-20 degreeC.

Here, what was illustrated above can be used as a tackifier.

It is suitable to use a tackifier in the quantity which can prevent the adhesive residue at the time of peeling a surface protection film from a to-be-adhered body. For example, when using as a surface protection film for prism sheets, the compounding ratio of a tackifier is a rubber-based resin component [the said polymer (i), and the said polymer (ii) (henceforth, it is named aromatic alkenyl block. It may be called a copolymer)] 5-50 weight part is preferable with respect to 100 weight part, More preferably, it is 10-40 weight part.

It is preferable that the tan-delta peak temperature obtained by measuring dynamic viscoelasticity at -50 degreeC-80 degreeC of an adhesive layer is a range of -10 degreeC-20 degreeC. This tan delta peak temperature adjusts or softens the rubber-based resin component in the pressure-sensitive adhesive layer, for example, the range of the aromatic alkenyl compound unit content in the random block of the aromatic alkenyl block copolymer, the blending ratio of the tackifier, or the like. In consideration of temperature, it can adjust to a preferable range by selecting the tackifier to be used.

Here, tan-delta means the loss tangent (= loss modulus / storage elastic modulus) in the dynamic-viscoelastic spectrum measured on the following conditions in the measurement temperature range of -50 degreeC-80 degreeC.

Viscoelastic spectrometer: Product name "DVA-200" (product made by Haiti measurement control company)

Sample size of the pressure-sensitive adhesive layer: thickness of about 1.5 mm × 5 mm × 10 mm

Set temperature increase rate: 6 ℃ / min

Measuring frequency: 10 ㎐

Measurement mode: shear

By setting the tanδ peak temperature measured in this manner to this range, the cohesion force of the pressure-sensitive adhesive layer can be improved together with the action of the tackifier. Thereby, even when an adhesive layer adheres to the back surface of the base material layer of a surface protection film, and it is set as a winding object, a surface protection film can be peeled easily from the back surface of a base material layer. In short, the winding body can be rewound without difficulty. Moreover, even when it applies to the to-be-adhered body which has an unevenness | corrugation on the surface, it can be harvested to the unevenness | corrugation and can ensure the surface protection of a to-be-adhered body.

In another preferable aspect of the surface protection film of this invention,

The base layer is a polyolefin base layer,

The pressure-sensitive adhesive composition further contains a tackifier and a styrenic block-shaped reinforcing agent, wherein the weight of the pressure-sensitive adhesive layer of the unit weight of the aromatic alkenyl compound in the polymer (iii) and the polymer (ii) and the styrene-based block-shaped reinforcing agent The ratio with respect to (aromatic alkenyl compound unit content rate) is 20-50 weight%. When the said ratio is less than 20 weight%, the adhesive force with time may become easy to improve, and when the said ratio exceeds 50 weight%, a high adhesive force may not be obtained.

Here, what was illustrated above can be used as a tackifier.

It is preferable to use a tackifier in the usage-amount which can prevent the adhesive residue at the time of peeling a surface protection film from a to-be-adhered body. For example, it is preferable to contain a tackifier about 5 weight part-50 weight part with respect to 100 weight part of rubber-based resin components (aromatic alkenyl block copolymer), More preferably, it is about 10 weight part-40 weight part. .

As the styrene-based block reinforcing agent, those exemplified above can be used.

It is preferable to mix | blend a styrene-type block reinforcement with about 40 weight part or less with respect to 100 weight part of aromatic alkenyl block copolymers, More preferably, it is about 30 weight part or less. Moreover, what is necessary is just to mix | blend more than 0 weight part, 1 weight part or more is preferable.

By using a styrene block-like reinforcing agent, it is compatible with styrene (St) in a styrene-type copolymer block, and can improve the cohesion force of an adhesive layer. Thereby, the surface protection film which adhered from the back surface of a polyolefin base material layer can be peeled easily, and a wound body can be rewound unreasonably. Moreover, the adhesive residue at the time of peeling a surface protection film from a to-be-adhered body can be prevented, and it can peel with a comparatively small force.

In the surface protection film of this invention, the storage elastic modulus (G ') at 70 degrees C of the said adhesive layer becomes like this. Preferably it is 4.5 * 10 <^5> Pa ~ 6.0 * 10 <^5> Pa.

When the storage modulus (G ′) is 4.5 × 10 ⁵ Pa or more, undesired adhesion improvement is suppressed even in a high temperature environment, while the appropriate adhesive force is obtained by the storage modulus (G ′) of 6.0 × 10 ⁵ Pa or less. Lose.

In order to adjust the storage elastic modulus (G ') of an adhesive, what is necessary is just to adjust the aromatic alkenyl compound unit content rate of the adhesive layer in the surface protection film of this invention, and to make cohesion force of the said aromatic alkenyl block copolymer into an appropriate range. . Adjusting the said content rate can be performed by using the aromatic alkenyl block copolymer which has a content rate of the component derived from a suitable aromatic alkenyl monomer, and / or adding a styrene-type block reinforcement agent to an adhesive layer. . Styrene-based block reinforcing agents are agents for reinforcing island-like islands formed by aromatic alkenyl block copolymers, and have a property of being compatible with domains composed of aromatic alkenyl block copolymers.

40 weight part or less is preferable with respect to 100 weight part of aromatic alkenyl block copolymers, and, as for the usage-amount of the said styrene-type block reinforcement agent, 30 weight part or less is more preferable. When the usage-amount is too large, adhesive force is insufficient, and when extrusion molding, there exists a possibility that fluidity may worsen. Although the minimum of the said usage-amount is not specifically limited, When it is not necessary to adjust the aromatic alkenyl compound unit content rate as mentioned above, addition is unnecessary, Preferably it is 1 weight part or more.

In another preferable aspect, when the surface protection film of this invention is for surface protection of the prism surface of a prism sheet, it is affixed on the said prism surface and when 0.3 N / cm <2> load is loaded for 24 hours in 70 degreeC atmosphere. The penetration depth to the adhesive layer of the prism vertex angle of the said prism surface of is 1% or more and less than 40% of the thickness of an adhesive layer.

The penetration depth is measured by the following method.

The surface protection film to be published is affixed at the speed | rate of 300 mm / min on the surface of a prism sheet using 2 kg of compression rubber rollers, respectively in the environment of 23 degreeC of room temperature, and 50% of a relative humidity. As a prism sheet, what is 50 micrometers of center distances of a prism, and 25 micrometers in height is used. Then, the pressure of 0.3 N / cm <2> is interposed between the prism sheet which affixed the surface protection film with the polycarbonate plate (thickness 2mm), and it is left still for 24 hours in 70 degreeC environment in that state. Thereafter, the surface protection film is peeled off at a peeling angle of 180 degrees, the surface of the pressure-sensitive adhesive layer is observed by a laser microscope, and the penetration depth of the pressure-sensitive adhesive layer of the lens portion (prism) vertex angle of the prism sheet is measured.

When the penetration depth is 1% or more and less than 40% of the thickness of the pressure-sensitive adhesive layer, adhesion improvement when placed in an environment of high temperature (eg 70 ° C) is suppressed without adversely affecting adhesive properties such as adhesive strength.

Setting the penetration depth to 1% or more and less than 40% of the pressure-sensitive adhesive layer is achieved by, for example, controlling the storage elastic modulus (G ′) at 70 ° C. of the pressure-sensitive adhesive layer in the preferred range.

In another preferable aspect, the surface protection film of this invention is affixed to the said prism surface for the protection of the prism surface of a prism sheet, and is a processus | protrusion of diameter 400micrometer and height 12micrometer on the surface on the opposite side to the said prism surface side. The penetration depth of the prism vertex angle of the prism face when the water is pressurized into the pressure-sensitive adhesive layer is 1% or more and less than 100% of the thickness of the pressure-sensitive adhesive layer.

Here, the conditions for pressurizing the projections are preferably 24 hours with a force of 0.8 N / cm 2 under an atmosphere of 50 ° C.

In addition, even when the said projection is 400 micrometers or less in diameter, and 12 micrometers or less in height, it is estimated that it is less than 100% of the thickness of an adhesive layer about the upper limit of the said penetration depth similarly.

Therefore, when the surface protection film of this invention is stuck to a prism sheet, another surface protection film is stuck to a smooth sheet surface, for example, when several dozen sheets of prism sheets are laminated | stacked and stored, the surface of a smooth sheet surface Even if projections such as FE and mixed foreign matter exist in the protective film, the aromatic alkenyl compound unit content of the pressure-sensitive adhesive in the pressure-sensitive adhesive layer of the surface protective film is set to an appropriate amount, so that the pressure-sensitive adhesive layer is hardened and the surface of the lens portion of the prism sheet Excessive penetration of the protective film into the pressure-sensitive adhesive layer is reliably suppressed. Therefore, damage of the lens part surface (prism surface) of a prism sheet hardly arises.

What makes the said penetration depth into 1% or more and less than 100% of an adhesive layer thickness is mainly achieved by the aromatic alkenyl compound unit content rate of 30-50 weight% of an aromatic alkenyl block copolymer. Since the cohesion force of an adhesive is low that this content rate is less than 30 weight%, the penetration depth to the adhesive layer of a prism lens may not be suppressed. On the contrary, when this content rate exceeds 50 weight%, since the cohesion force of an adhesive is too high, a prism lens may hardly penetrate into an adhesive layer, adhesive force may become low too much, and may not be used as a protective film.

The lens part of the prism sheet to which the surface protection film of this invention is applied has a prism shape which consists essentially of a triangular prism. In this specification, the surface which has such a prism-shaped lens part is called a prism surface. More specifically, as shown in FIG. 2, the prism sheet 1 has a structure in which a plurality of triangular prism-shaped lens portions 3 are integrated on one surface of the flat sheet 2. The lens portion 3 has a substantially triangular prism shape. The plurality of lens portions 3 are closely arranged so that the ridge lines of the triangular prism are parallel to each other. The outer surface of this prism-shaped lens part 3 is protected by the surface protection film of this invention.

For example, as shown in sectional drawing in FIG. 3, the 1st surface protection film 4 (surface protection film of this invention) is stuck to the part in which the lens part 3 of the prism sheet 1 is formed. . The 1st surface protection film 4 has the base material layer 5 and the adhesive layer 6 formed in one surface of the base material layer 5, The said of the prism sheet 1 from the adhesive layer 6 side. It is affixed on the side in which the some lens part 3 is formed. Therefore, the surface protection film of this invention is affixed so that it may contact the some top part 3a of the lens part 3 of a triangular prism shape. In addition, although the cross-sectional shape of the lens part 3 of this triangular prism is a triangle, this triangle is preferably an isosceles triangle with the side fixed to the sheet as the base.

On the other hand, the 2nd surface protection film 7 is affixed on the flat surface of the prism sheet 1 on the opposite side to the side in which the lens part 3 is formed, as desired. If projections such as fisheye (FE) or mixed foreign matter are present in the surface protective film 7, it may cause breakage of the top of the lens portion.

In addition, the side surface in the prism shape of a triangular prism shall mean three side surfaces extended in the longitudinal direction of a triangular prism.

In the preferred prism sheet to which the surface protection film of the present invention is applied, in the plurality of prisms substantially triangular prism, the distance between the prisms adjacent to each other, that is, the pitch of the prism is preferably about 10 to 1000 µm, more Although it is 10-500 micrometers preferably, the to-be-adhered body to which the surface protection film of this invention is applied is not limited to this.

<Manufacturing Method>

In the pressure-sensitive adhesive composition of the present invention, for example, copolymer (I) and copolymer (II) are synthesized by block polymerization, and blended at a predetermined mass ratio, respectively, and then hydrogenated as desired. It is produced by obtaining a mixture (I) or a hydrogenated product thereof and a copolymer (II) or a mixture of the hydrogenated product thereof and mixing the additives blended as desired in a conventional manner.

As the hydrogenation catalyst, a compound containing any one of elemental periodic tables Ib, IVb, Vb, VIb, VIIb, and VIII metals can be used. For example, the compound containing Ti, V, Co, Ni, Zr, Ru, Rh, Pd, Hf, Re, Pt atom is mentioned, More specifically, Ti, Zr, Hf, Co, Ni, Rh And a supported heterogeneous catalyst in which metals such as metallocene compounds such as and Ru, metals such as pd, Ni, Pt, Rh, and Ru are supported on a carrier such as carbon, silica, alumina, diatomaceous earth, and basic activated carbon.

Moreover, as a specific example of a metallocene type compound, the Kaminsky (Kaminsky) catalyst which has two ligands which substituted the hydrogen on the cyclopentadienyl ring (Cp ring) or Cp ring with an alkyl group, ansa (ansa) type metallocene A catalyst, an uncrosslinked half metallocene catalyst, a crosslinked half metallocene catalyst, etc. are mentioned.

As a specific example, Unexamined-Japanese-Patent No. 1-275605, Unexamined-Japanese-Patent No. 5-271326, Unexamined-Japanese-Patent No. 5-271325, Unexamined-Japanese-Patent No. 5-222115, Unexamined-Japanese-Patent No. 11-292924, Japanese Patent Laid-Open No. 2000-37632, Japanese Patent Laid-Open No. 59-133203, Japanese Patent Laid-Open No. 63-5401, Japanese Patent Laid-Open No. 62-218403, Japanese Patent Laid-Open No. 7 The catalyst of -90017, Unexamined-Japanese-Patent No. 43-19960, and Unexamined-Japanese-Patent No. 47-40473 is mentioned. These various catalysts may be used individually by 1 type, or may use 2 or more types together.

As another method, when copolymer (II) has a structure represented by the said general formula (AB) xY (the symbol in a formula represents the same meaning as the above), the adhesive composition of this invention is a method (coupling method) as follows. You may manufacture by. Since the coupling method can synthesize | combine copolymer (I) or its hydrogenated substance (polymer (i)), and copolymer (II) or its hydrogenated substance (polymer (ii)) in 1 port, a manufacturing process is simple, and it manufactures It is inexpensive and it is preferable at the point of being able to control the ratio of a polymer (i) and a polymer (ii) according to the kind and quantity of a coupling agent.

Coupling method,

1st process: The process of synthesize | combining the copolymer which has a structure of [A-B] by block polymerization,

2nd process: A part of copolymer which has the structure of said [AB] is coupling agent YZ _X (wherein "Y" is a coupling agent residue, "Z" is a leaving group, and "X" represents an integer of 2 or more). By coupling to synthesize a copolymer having a structure of {[AB] _X -Y};

In the case of obtaining a hydrogenated additive,

Third Step: Hydrogenation of the copolymer having the structure of [AB] and the copolymer having the structure of {[AB] _X -Y} to yield hydrogenated copolymer (I) and copolymer (II), respectively. The process of obtaining the copolymer composition which consists of is provided.

As a "coupling agent", for example, methyl dichlorosilane, dimethyl dichlorosilane, methyl trichlorosilane, butyl trichlorosilane, tetrachlorosilane, dibromoethane, tetrachloro tin, butyl trichloro tin, tetrachloro germanium, bis Halogen compounds such as (trichlorosilyl) ethane; Epoxy compounds such as epoxidized soybean oil; Carbonyl compounds such as diethyl adipic acid, dimethyl adipic acid, dimethyl terephthalic acid and diethyl terephthalic acid, and polyvinyl compounds such as divinylbenzene; Polyisocyanate etc. are mentioned. Especially, methyldichlorosilane, dimethyldichlorosilane, methyl trichlorosilane, and tetrachlorosilane are preferable because they are easy to obtain industrially and have high reactivity.

The surface protection film of this invention is a method of apply | coating or spraying the liquid which melt | dissolved or melt | dissolved the said adhesive composition to a base material sheet, or the inflation method after manufacturing a base material sheet (base material layer) by extrusion molding, for example. It can manufacture by the method of bonding together the base material sheet and adhesive sheet which were obtained by this, or the co-extrusion of a base material and the said adhesive composition using the T die provided with the multilayer manifold. Especially, since the multilayer sheet which the base material layer and the adhesive layer contacted is obtained, the manufacturing method by coextrusion is preferable. In addition, the liquid which melted or melt | dissolved the adhesive composition of this invention is also contained in the adhesive composition of this invention.

<Application>

Although the surface protection film of this invention can be used suitably for to-be-adhered bodies, such as an optical plate, a prism sheet, and a diffusion film, it is not limited to this, For example, it can also use for surface protection of the sheet | seat with a smooth surface. Can be.

Although it does not specifically limit as a material which comprises the sheet used as a to-be-adhered body, Resin which has translucency, for example, acrylic resin, polycarbonate, etc. are mentioned.

Example

Hereinafter, although the surface protection film of this invention is demonstrated in detail based on an Example, this invention is not limited to a following example.

Synthesis Example of Copolymer Composition

Polymer block A

Into a nitrogen-substituted reaction vessel, 500 parts by mass of degassed and dehydrated cyclohexane, 20 parts by mass of styrene, and 5 parts by mass of tetrahydrofuran were added, 0.13 parts by mass of n-butyllithium was added at 40 ° C, which is the polymerization start temperature, and the temperature rising polymerization was performed. Was carried out.

Polymer block B

After the polymerization conversion ratio of the polymer block A reached almost 100%, the reaction solution was cooled to 15 ° C, and then 70 parts by mass of 1,3-butadiene and 10 parts by mass of styrene were added, followed by further heating.

After the polymerization conversion ratio reached almost 100%, 0.06 parts by mass of methyldichlorosilane was added as the coupling agent to carry out the coupling reaction. After the coupling reaction was completed, it was left for 10 minutes while supplying hydrogen gas at a pressure of 0.4 MPa-Gauge. The polymer taken out partly was 64% of vinyl content, the weight average molecular weight about 110,000, and the coupling rate of 60%.

Then, 0.03 mass part of diethyl aluminum chloride and 0.06 mass part of bis (cyclopentadienyl) titanium furfuryl oxychloride were added and stirred in reaction container. The hydrogenated reaction is initiated at a hydrogen gas supply pressure of 0.7 MPa-Gauge and a reaction temperature of 80 ° C., and when the absorption of hydrogen is completed, the reaction solution is returned to normal temperature and normal pressure, and the polymer and the polymer are removed from the reaction vessel. The copolymer composition which consists of (ii) was obtained (synthesis example 1 of Table 1).

Hereinafter, it operated similarly and obtained the desired copolymer composition (Synthesis Examples 2-24 of Table 1). The properties of these copolymer compositions are shown in Table 1.

In addition, in Table 1, "St (A + B)", "St (B)", "St (A)", and "St (b)" represent the numerical values defined as follows, respectively. In the definition, the term "total polymer" means the entirety of the polymer (i) and the polymer (ii).

"St (A + B)" is an aromatic alkenyl compound unit content rate of all the polymers, and means the numerical value represented by following Formula. In addition, this is equivalent to the sum of following "St (B)" and following "St (A)".

Formula: St (A + B) = (Aromatic alkenyl compound unit weight in total polymer) / (Total monomer unit weight in total polymer) × 100 (wt%)

"St (B)" means the numerical value represented by a following formula.

Formula: St (B) = (Aromatic alkenyl compound unit weight in total polymer block B) / (Total monomer unit weight in total polymer) × 100 (wt%)

"St (A)" means the numerical value represented by a following formula.

Formula: St (A) = (Aromatic alkenyl compound unit weight in total polymer block A) / (Total monomer unit weight in total polymer) × 100 (wt%)

"St (b)" is an aromatic alkenyl compound unit content rate of the polymer block B, and means the numerical value represented by following Formula.

Formula: St (b) = (Aromatic alkenyl compound unit weight in total polymer block B) / (Total monomer unit weight in total polymer block B) x 100 (% by weight)

In addition, in Table 1, "A: B" shows the weight ratio of the total amount of polymer block A and the total amount of polymer block B. FIG.

In addition, in Table 1, "(i): (ii)" shows the weight ratio of polymer (i) and polymer (ii).

In addition, in Table 1, "conjugated diene content rate" shows the conjugated diene unit content rate of the polymer block B. FIG.

In addition, in Table 1, a "vinyl bond content rate" shows the content rate of the vinyl bond of the polymer block B.

(Examples 1-8, Comparative Examples 1-7)

To 100 parts by weight of each copolymer composition (Table 2) obtained by the above synthesis methods, 30 parts by weight of arcon P100 (manufactured by Arakawa Chemical Industry Co., Ltd.) as an tackifier and Irganox 1010 (manufactured by Chiba Specialty Chemicals) as an antioxidant ) 1 weight part was mix | blended and each adhesive composition was obtained. The composition is shown in Table 2 below.

By using polypropylene (J715M manufactured by Prime Polymer Co., Ltd.) as the substrate and co-extrusion molding the substrate and each pressure-sensitive adhesive composition by the T-die method, an example in which the 34-micrometer-thick substrate layer and the 6-micrometer-thick adhesive layer were laminated and integrated The surface protection film of 1-8 and Comparative Examples 1-7 was shape | molded, and the wound body wound up to the core of 3 inches of internal diameters was obtained.

(evaluation)

The following items were evaluated about each surface protection film obtained as mentioned above. The results are shown in Table 3.

(1) film formation

The external appearance of each surface protection film formed by co-extrusion as mentioned above was visually evaluated, and it was set as "(circle)" when there was no problem in an external appearance.

(2) initial adhesion

Each surface protection film was affixed so that the lens surface of the prism sheet which has an unevenness | corrugation may be covered. The prism sheet was made of an acrylic resin having a thickness of 130 μm, and prepared with a pitch of 50 μm and a height of 25 μm of the prism. The sticking conditions were affixed at a speed of 300 mm / min using a 2 kg pressurized rubber roller, respectively, under an environment of room temperature at 23 ° C. and a relative humidity of 50%, and allowed to stand for 30 minutes in that state, followed by JIS Z 0237. , 180 degree peeling strength in 25 mm width was measured at the speed of 300 mm / min. The peeling direction at this time was made into the ridgeline direction of a prism. Thus, the peeling strength measured was made into initial stage adhesive force.

(3) time-lapse adhesion

Each surface protective film is affixed on the surface of the prism sheet used for the initial stage adhesiveness evaluation of (2) in the environment of 23 degreeC of room temperature, and 50% of relative humidity at the speed of 300 mm / min using 2 kg of compression rubber rollers, respectively. It was. Then, the prism sheet which affixed the surface protection film with the polycarbonate plate (thickness 2mm) is sandwiched between, and the pressure of 6.0x10 <^-3> Mpa is applied, and it is 48 hours in the environment of 60 degreeC and 90% of a relative humidity in that state. It was left to stand. After leaving this at room temperature and leaving it to stand for 30 minutes, 180 degree peeling strength in 25 mm width was measured at the speed | rate of 300 mm / min based on JISZ0237.

The peeling strength measured in this way was made into time-lapse adhesive force, and the change rate (adhesion improvement rate) of time-lapse adhesive force was computed by the following formula from initial stage adhesive force.

Rate of Change (Adhesion Relief Rate) = (Time Adhesion / Initial Adhesion) × 100

(4) development force

Except having changed the rewinding speed of the 50-mm-wide wound body of each surface protection film of an Example and a comparative example, rewinding force was measured at the rewinding speed of 15 m / min, and it was set as development force in accordance with JIS Z 0237.

<Judge criteria>

Adhesion (initial)

○ (good): 0.1 N / 25 mm or more

× (defect): less than 0.1 N / 25 mm

Adhesion (rate of change)

◎ (excellent): less than 200%

○ (good): 200% or more and 500% or less

× (defective): more than 500%

Development

◎ (excellent): less than 2.0 N / 50 mm

○ (good): 2.0 N / 50 mm or more and 3.5 N / 50 mm or less

× (defect): more than 3.5 N / 50 mm

(Example 9)

18 parts by weight of arcon P100 (manufactured by Arakawa Chemical Industry Co., Ltd.) as an tackifier, and 1 part by weight of Irganox 1010 (manufactured by Chiba Specialty Chemicals) as an antioxidant, and 100 parts by weight of the copolymer composition of Synthesis Example 4 as an ultraviolet absorber. 0.5 weight part of Chinubin 326 (made by Chiba Specialty Chemicals) was mix | blended, and the adhesive composition was obtained by kneading.

The surface protection film which laminated | stacked and integrated the 34-micrometer-thick base material layer and the 6-micrometer-thick adhesive layer by coextrusion-molding a base material and an adhesive composition by T-die method using polypropylene (J715M by Prime Polymer Co., Ltd.) for the base material Was molded and the wound body wound up to the core of 3 inches of internal diameters was obtained.

(Examples 10, 11 and 13, Comparative Examples 8 to 10)

As shown in Table 4, the adhesive composition was mix | blended and the wound body of a surface protection film was obtained by the method similar to Example 9.

(Example 12)

The winding of the surface protection film in the same manner as in Example 9, except that the pressure-sensitive adhesive composition in which 40 parts by weight of CRYARON P125 (manufactured by Yashara Chemical Co., Ltd.) was added to 100 parts by weight of the copolymer composition of Synthesis Example 7 was used. A round was obtained.

(evaluation)

The following items were evaluated about each surface protection film obtained as mentioned above.

The results are shown in Table 5.

(1) tanδ peak temperature

The viscoelastic spectrum of the pressure-sensitive adhesive layer was measured in a range of -50 ° C. to 80 ° C. at a frequency of 10 Hz and a heating rate of 6 ° C./min by a dynamic viscoelastic spectrum measurement device (manufactured by Haiti Metrology Control, Inc., product number: DVA-200), and tanδ The maximum temperature (tanδ peak temperature) of was determined.

(2) initial adhesion

Each surface protection film of an Example and a comparative example was stuck so that the lens surface of the prism sheet which has an unevenness | corrugation may be covered. The prism sheet was made of an acrylic resin having a thickness of 130 μm, and prepared with a pitch of 50 μm and a height of 30 μm of the prism. The sticking conditions were affixed at a speed of 300 mm / min using a 2 kg pressurized rubber roller, respectively, under an environment of room temperature at 23 ° C. and a relative humidity of 50%, and allowed to stand for 30 minutes in that state, followed by JIS Z 0237. , 180 degree peeling strength in 25 mm width was measured at the speed of 300 mm / min. The peeling direction at this time was made into the ridgeline direction of a prism. Thus, the peeling strength measured was made into initial stage adhesive force.

(3) development force

Except having changed the rewinding speed of the 50-mm wide wound body of each surface protection film of an Example and a comparative example, it was made into the development force by measuring the high-speed rewinding force at the rewinding speed of 20 m / min.

<Judge criteria>

Initial adhesion

○ (good): 0.1 N / 25 mm or more

× (defect): less than 0.1 N / 25 mm

Development

◎ (excellent): 2.5 N / 50 mm or less

○ (good): 3.5 N / 50 mm or less

× (defect): more than 3.5 N / 50 mm

(Example 14)

Adhesive layer:

50 parts by weight of arcon P100 (manufactured by Arakawa Chemical Industry Co., Ltd.) as a tackifier, and 10 parts by weight of ENDEX155 (manufactured by Eastman Chemical Co., Ltd.) as antioxidants in 100 parts by weight of the copolymer composition of Synthesis Example 4 as an tackifier. 1 weight part of Irganox 1010 (made by Chiba Specialty Chemicals) was mix | blended, and the adhesive composition was obtained by kneading | mixing.

Base layer:

The surface protection by which the base material which consists of polypropylene (J715M by Prime Polymer Co., Ltd.), and the adhesive composition obtained above were coextruded by T-die method, and the 34-micrometer-thick polypropylene base material layer and the 6-micrometer-thick adhesive were laminated | stacked and integrated. The adhesive sheet was wound up to a core having an inner diameter of 3 inches to obtain a wound body.

(Examples 15-19, Comparative Examples 11-14)

As shown in following Table 6, the adhesive composition was mix | blended and the wound body of a surface protection film was obtained by the method similar to Example 14.

In addition, the "St / adhesive layer (weight%)" in Table 6 is the ratio of the total weight of the whole aromatic alkenyl compound unit of a copolymer composition and a styrene block type reinforcement with respect to the weight of an adhesive (aromatic egg Kenyl compound unit content rate) is shown. In addition, "St / adhesive layer (-TF) (weight%)" is the total weight of the whole aromatic alkenyl unit of a copolymer composition and a styrene-type block type reinforcing agent with respect to the total weight of a copolymer composition and a styrene type block type reinforcing agent. Represents the ratio of.

(evaluation)

The following items were evaluated about each surface protection film obtained by making it above. The results are shown in Table 7.

(1) tanδ peak temperature

The viscoelastic spectrum of the pressure-sensitive adhesive layer was measured in a range of -50 ° C. to 80 ° C. at a frequency of 10 Hz and a heating rate of 6 ° C./min by a dynamic viscoelastic spectrum measurement device (manufactured by Haiti Metrology Control, Inc., product number: DVA-200), and tanδ The maximum temperature of was obtained.

(2) initial adhesion

Each surface protection film of an Example and a comparative example was stuck so that the lens surface of the prism sheet which has an unevenness | corrugation may be covered. The prism sheet was made of an acrylic resin having a thickness of 130 μm, and prepared with a pitch of 50 μm and a height of 30 μm of the prism. The sticking conditions were affixed at a speed of 300 mm / min using a 2 kg pressurized rubber roller, respectively, under an environment of room temperature at 23 ° C. and a relative humidity of 50%, and allowed to stand for 30 minutes in that state, followed by JIS Z 0237. , 180 degree peeling strength in 25 mm width was measured at the speed of 300 mm / min. The peeling direction at this time was made into the ridgeline direction of a prism. Thus, the peeling strength measured was made into initial stage adhesive force.

(3) time-lapse adhesion

Each surface protective film is affixed on the surface of the prism sheet used for the initial stage adhesiveness evaluation of (2) in the environment of 23 degreeC of room temperature, and 50% of relative humidity at the speed of 300 mm / min using 2 kg of compression rubber rollers, respectively. It was. Then, the prism sheet which affixed the surface protection film with the polycarbonate plate (thickness 2mm) is sandwiched between, and the pressure of 6.0x10 <^-3> Mpa is applied, and it is 48 hours in the environment of 60 degreeC and 90% of a relative humidity in that state. It was left to stand. After leaving this at room temperature and leaving it to stand for 30 minutes, 180 degree peeling strength in 25 mm width was measured at the speed | rate of 300 mm / min based on JISZ0237.

The peeling strength measured in this way was made into time-lapse adhesive force, and the change rate (adhesion improvement rate) of time-lapse adhesive force was computed by the following formula from initial stage adhesive force.

Rate of Change (Adhesion Relief Rate) = (Time Adhesion / Initial Adhesion) × 100

(4) development force

Except having changed the rewinding speed of the 50-mm wide wound body of each surface protection film of an Example and a comparative example, it was made into the development force by measuring the high-speed rewinding force at the rewinding speed of 20 m / min.

<Judge criteria>

Adhesion (initial)

○ (good): 0.1 N / 25 mm or more

△ (possible): 0.05 N / 25 mm or more and less than 0.1 N / 25 mm

× (not possible): less than 0.05 N / 25 mm

Adhesion (rate of change)

◎ (excellent): less than 200%

○ (good): 200% or more and 500% or less

× (defective): more than 500%

Development

○ (good): 3.5 N / 50 mm or less

× (defect): more than 3.5 N / 50 mm

(Example 20)

By co-extrusion by the T-die method, the surface protection film for prism sheets (700 mm in width) of a base material layer (thickness 34 micrometers) / adhesive layer (thickness 6 micrometers) was formed into a film, and the winding body of 100 m of winding lengths was obtained. . In the material for forming the pressure-sensitive adhesive layer, 30 parts by weight of an alicyclic saturated petroleum resin Arcon P125 (manufactured by Arakawa Chemical Industry Co., Ltd.) having a softening point of 125 ° C. as a tackifier and 100 parts by weight of the copolymer composition of Synthesis Example 13, and a styrene block-shaped reinforcing agent 20 parts by weight of ENDEX155 (manufactured by Eastman Chemical), 1 part by weight of Irganox 1010 (manufactured by Chiba Specialty Chemicals) as an antioxidant, 0.5 part by weight of Chinuvin 326 (manufactured by Chiba Specialty Chemicals) as an ultraviolet absorber, It knead | mixed with the twin screw extruder and used the pelletized thing. The material for forming the base layer includes 100 parts by weight of a block PP, a film (100 parts by weight of a block polypropylene (block PP) as a base material), and 100 parts by weight of a copolymer composition of Synthesis Example 13 as an adhesive, and a tackifier. 30 parts by weight of Arcon P125 (manufactured by Arakawa Chemical Industry Co., Ltd.), 20 parts by weight of ENDEX155 (manufactured by Eastman Chemical Co., Ltd.) as a styrene-based block reinforcing agent, and 1 part by weight of Irganox 1010 (manufactured by Chiba Specialty Chemicals) as an antioxidant It contains 0.5 parts by weight of Chinubin 326 (manufactured by Chiba Specialty Chemicals Co., Ltd.) as an absorbent. After molding, 10 parts by weight of the trimmed portions of both ends of the film were mixed in order to trim the roll shape during molding. Kneaded and pelletized were used.

(Examples 21 to 25)

As shown in Table 8 below, for the prism sheet in the same manner as in Example 20, except that the amount of the tackifier and the amount of the styrene block-like reinforcing agent (which may be abbreviated as St-based block reinforcing agent in the present specification) were changed. The winding object of a surface protection film was obtained.

In addition, "St / adhesive (weight%)" in Table 8 is the ratio of the total weight of the whole aromatic alkenyl unit of a copolymer composition and a styrene block type reinforcement with respect to the weight of an adhesive (aromatic alkenyl compound Unit content rate).

(evaluation)

About the item of following (1)-(4), the surface protection film of Examples 20-25 was evaluated. The results are shown in Table 9.

(1) initial adhesion

Each surface protection film of an Example and a comparative example was stuck so that the lens surface of the prism sheet which has an unevenness | corrugation may be covered. As a prism sheet, what consists of acrylic resin of 130 micrometers in thickness, and used the thing of pitch 50micrometer and height 30micrometer of prism. The sticking conditions were affixed at a speed of 300 mm / min using a 2 kg pressurized rubber roller, respectively, under an environment of room temperature at 23 ° C. and a relative humidity of 50%, and after standing for 1 hour in that state, in accordance with JIS Z 0237. , 180 degree peeling strength in 25 mm width was measured at the speed of 300 mm / min. Thus, the peeling strength measured was made into initial stage adhesive force.

(2) time-lapse adhesion

Each surface protective film of an Example and a comparative example was 300 mm / using the pressurized rubber roller of 2 kg each on the surface of the prism sheet used for initial stage adhesive evaluation of (1) in the environment of 23 degreeC of room temperature, and 50% of relative humidity. It stuck at the speed of minutes. Thereafter, a pressure of 0.3 N / cm 2 was interposed between a prism sheet affixing a surface protective film with a polycarbonate plate (thickness 2 mm), and left standing for 24 hours in an environment of 70 ° C in that state. Then, after leaving 1 hour in the environment of 23 degreeC of room temperature, and 50% of the relative humidity, 180 degree peeling strength in 25 mm width was measured at the speed | rate of 300 mm / min based on JISZ0237. The peeling strength measured in this way was made into time-lapse adhesive force, and the change rate (adhesion improvement rate) of time-lapse adhesive force was computed by the following formula from initial stage adhesive force.

Rate of Change (Adhesion Relief Rate) = (Time Adhesion / Initial Adhesion) × 100

(3) storage modulus (G ')

The storage elastic modulus of the pressure-sensitive adhesive layer was measured in a range of -50 ° C to + 150 ° C at a frequency of 1 Hz and a heating rate of 3 ° C / min by a dynamic viscoelastic spectrum measurement device (manufactured by IT Measurement Control, Inc., DVA200) to 70 ° C. The storage elastic modulus (G ') in was calculated | required.

(4) penetration

The surface protection film was affixed at the speed | rate of 300 mm / min on the surface of a prism sheet using 2 kg of compression rubber rollers, respectively in the environment of 23 degreeC of room temperature, and 50% of a relative humidity. As a prism sheet, the thing of pitch 50micrometer and height 30micrometer of a prism was used. Thereafter, a pressure of 0.3 N / cm 2 was interposed between a prism sheet affixing a surface protective film with a polycarbonate plate (thickness 2 mm), and left standing for 24 hours in an environment of 70 ° C in that state. Then, the surface protection film was peeled off at 180 degree peeling angle, the surface of the adhesive layer was observed with the laser microscope, and the penetration depth to the adhesive layer of the lens part of a prism sheet was measured.

The penetration amount was calculated by the following formula.

Penetration amount (%)

= (Penetration depth of the prism sheet into the pressure-sensitive adhesive layer) / (adhesive layer thickness: 6 µm) × 100

<Judge criteria>

Penetration

○ (excellent): 1% or more but less than 40%

△ (good): 40% or more but less than 80%

× (defective): 80% or more

Adhesion (rate of change)

◎ (excellent): less than 150%

○ (good): 150% or more and 300% or less

(Example 26)

As shown in following Table 10, 30 weight part of arcon P-125 (made by Arakawa Chemical Industry Co., Ltd.) which is an alicyclic saturated petroleum resin was added to 100 weight part of copolymer compositions of the synthesis example 14 as a tackifier, and the adhesive composition was obtained.

On the other hand, the base material which consists of the adhesive layer which consists of the said adhesive composition, the resin composition containing 75 weight part of block polypropylenes (block PP) shown in Table 10, and 25 weight part of low density polyethylene (LDPE) is coextruded by T-die method. The surface protection film which laminated | stacked and integrated the 40-micrometer-thick polypropylene base material and the 6-micrometer-thick adhesive layer was produced.

(Examples 27-28, and Comparative Examples 15-19)

A surface protective film was produced and evaluated in the same manner as in Example 25, except that the composition and thickness of the pressure-sensitive adhesive layer were changed as shown in Table 10 below. All the tackifiers were made into Arcon P-125.

In addition, Comparative Example 18 was poor in film formability.

(evaluation)

About these surface protection films,

1) A projection having a diameter of 400 µm and a height of 12 µm was applied to a pressure-sensitive adhesive layer of the lens portion of the prism sheet when the projection was pressed for 24 hours with a force of 0.8 N / cm 2 under a 50 ° C. atmosphere on a prism sheet having a surface protective film. About penetration,

2) initial adhesion (antiprism face), and

3) Initial adhesive force (large flat surface)

Was measured and evaluated in the following way.

In addition, at the time of evaluating the lens part penetration of the prism sheet of 1),

4) prism scratches,

5) Time-lapse adhesive force (antiprism face)

6) Adhesive residue

Was measured and evaluated in the following way.

Also,

7) deployment force

Was measured and evaluated in the following way.

The results are shown in Table 11 below.

1) Penetration

The surface protection film obtained above was affixed so that the adhesive layer surface might contact the lens surface of a prism sheet, and the test piece was produced. As a prism sheet, the lens part consisted of acrylic resin, the sheet | seat consists of polyethylene terephthalate of 150 micrometers in thickness, and the pitch of a prism is 50 micrometers and 23 micrometers in height (BEF, Sumitomo 3M) was prepared. At the time of sticking, a pressure of 5.9 × 10 ⁵ Pa was applied from the outer side of the surface protection film (that is, the side opposite to the pressure-sensitive adhesive layer surface) and affixed at a speed of 2 m / min. The following laminator was used for the sticking, and the sticking pressure was measured using the presscal ultra low pressure for Fujifilm Business Supply Co., Ltd. product.

Laminator

Manufacturer: MCK Co., Ltd.

Type: MRK-600

Roll: Heat Resistant Silicone Rubber Roll

Roll Diameter: Φ80

The obtained test piece was cut into the size of 3 cm x 8 cm, and the sample piece was produced.

In addition, in order to prepare the projection used for an evaluation test, the nylon fiber of diameter 0.2mm is cut into 11-13 micrometers in length by the cryomicrotome, the cut piece obtained on the slide glass is fixed, and the said from above The cut piece was fixed between the slide glass and a surface protection film by affixing the surface protection film obtained in the slide glass with a 2 kg roller. The convex shape (namely, protrusion) formed as a result was observed with the laser microscope, and the diameter and height were calculated | required.

The diameter and height of the convex shape used for evaluation are shown below.

Diameter: 400 μm

Height: 12 ㎛

On the sample piece, the slide glass with a surface protection film which has the said convex shape is set so that a sample piece and the surface protection film which has the said convex shape may contact | connect, and put 200 g of weights on the slide glass (0.8 N / Cm 2) and left in an oven at 50 ° C. for 24 hours. The sample piece was taken out after 24 hours, the cross section was cut out, the cross section was observed with the scanning electron microscope (SEM), and the penetration depth (micrometer) with respect to the adhesive layer of the lens part of a prism sheet was measured.

The penetration amount (%) was computed by the following formula | equation from the measured penetration depth (micrometer).

Penetration amount (%) = (penetration depth to the adhesive layer of the lens part of a prism sheet) / (adhesive layer thickness: 6 micrometers) x 100

2) Initial adhesive force (high prism face)

The surface protection film obtained above was stuck so that the lens surface of the said prism sheet might be covered. At the time of sticking, in the same manner as in 1), a pressure of 5.9 × 10 ⁵ Pa was applied from the outside of the surface protective film, affixed at a speed of 2 m / min, and left in a room of 23 ° C ± 2 ° C for 30 minutes.

After this, based on JIS Z 0237, 180 degree peeling strength (unit: N) in 25 mm is respectively measured by peeling speed 300 mm / min and 30 m / min in the direction parallel to the ridge of a prism, Initial adhesive force (large prism) was used.

3) Initial adhesive force (large flat surface)

The surface protection film obtained above was affixed on the flat acrylic resin board similarly to 1) on the conditions of pressure 5.9x10 <^5> Pa and the speed of 2m / min, and left to stand in the room of 23 degreeC +/- 2 degreeC for 30 minutes, and then JIS Based on Z 0237, 180 degree peeling strength (unit: N) in 25 mm width was measured on condition of the peeling speed of 30 m / min, and it was set as initial stage adhesive force (large flat surface).

4) Evaluation of Prism Scratches

At the time of the test in 1), the surface protection film taken out of the oven was peeled off from the prism sheet, and the presence or absence of bright spots caused by scratches on the lens surface of the prism sheet was visually observed.

In the following Table 10, x mark was attached | subjected to the sample with many scratches observed, (triangle | delta) mark was attached | subjected when it observed a little and (circle) mark was attached when it was not observed at all.

5) Time-lapse adhesive force (antiprism face)

The obtained surface protection film is affixed on the surface of the prism sheet used for initial stage adhesive evaluation of 2) on the conditions of pressure 5.9x10 <^5> Pa and the speed of 2m / min similarly to 1), and the atmosphere of 60 degreeC +/- 2 degreeC After standing for one week under the following, the peel strength of 180 degrees in 25 mm width was measured at a peel rate of 300 mm / min in accordance with JIS Z 0237. The peeling strength measured in this way was made into time-lapse adhesive force, and the change rate (adhesion improvement rate) of time-lapse adhesive force was computed from the initial stage adhesive force (large prism surface, peeling rate 300mm / min) by the following formula.

Rate of Change (Adhesion Reduction Rate) = (Time Adhesion / Initial Adhesion (Large Prism Surface, Peeling Rate 300 mm / min)) × 100

6) Adhesive residue

In the test in 5), the presence or absence of the adhesive residue on the lens surface of the prism sheet after peeling was observed visually in addition to the measurement of peeling strength. In the case where an adhesive residue is observed on the lens surface, a x mark is attached. When no adhesive residue is observed, a o mark is attached. The results are shown in Table 11 below.

7) deployment force

Except having changed the rewinding speed of the 50-mm wide wound body of each surface protection film of an Example and a comparative example, it was made into the development force by measuring the high-speed rewinding force at the rewinding speed of 20 m / min.

<Judge criteria>

Penetration

○ (good): 1% or more but less than 100%

× (defect): less than 1%, 100%

Initial adhesive force (large prism face) Peeling speed: 300 mm / min

○ (good): 0.05 N / 25 mm or more

× (defect): less than 0.05 N / 25 mm

Adhesive force (change rate, large prism face)

◎ (excellent): less than 200%

○ (good): 200% or more and 500% or less

× (defective): more than 500%

Prism Scratches Rating

○: no scratches visible with the naked eye

×: Scratches can be seen with the naked eye

Adhesive residue evaluation

○: Visually unable to confirm the occurrence of adhesive residue

×: Visually, the occurrence of adhesive residue can be confirmed

Development

○ (good): 3.5 N / 50 mm or less

× (defect): more than 3.5 N / 50 mm

(Example 29)

By co-extrusion by the T-die method, the surface protection film for prism sheets (700 mm in width) of a base material layer (thickness 34 micrometers) / adhesive layer (thickness 6 micrometers) was formed into a film, and the winding body of 100 m of winding lengths was obtained. .

In the material for forming the pressure-sensitive adhesive layer, 30 parts by weight of an alicyclic saturated petroleum resin arcon P125 (manufactured by Arakawa Chemical Industry Co., Ltd.) at a softening point of 125 ° C. as a tackifier, in 100 parts by weight of the copolymer composition of Synthesis Example 13, a styrene block-shaped reinforcing agent 10 parts by weight of ENDEX155 (manufactured by Eastman Chemical Co., Ltd.), 1 part by weight of Irganox 1010 (manufactured by Chiba Specialty Chemicals, Inc.) as an antioxidant, and 0.5 parts by weight of Chinuvin 326 (manufactured by Chiba Specialty Chemicals) as an ultraviolet absorber, 2 It knead | mixed with the screw extruder and the pelletized thing was used.

The material for forming the base layer includes 75 parts by weight of the block PP, 25 parts by weight of low density polyethylene (LDPR), and trimmed portions of both ends of the film for trimming the roll shape during film forming (block polypropylene (base) 100 parts by weight of the block PP) and 100 parts by weight of the copolymer composition of Synthesis Example 13 as an adhesive, and 30 parts by weight of Arcon P125 (manufactured by Arakawa Chemical Industry Co., Ltd.) as a tackifier, and ENDEX155 (as a styrene block-like reinforcing agent). 20 parts by weight of Eastman Chemical Co., Ltd., 1 part by weight of Irganox 1010 (manufactured by Chiba Specialty Chemicals) as an antioxidant, and 0.5 parts by weight of Chinuvin 326 (manufactured by Chiba Specialty Chemicals) as an ultraviolet absorber) 10 parts by weight After mixing, the resultant was kneaded with a twin screw extruder and pelletized was used.

In addition, "St / adhesive (weight%)" in Table 12 is the ratio of the total weight of the aromatic alkenyl compound units of the copolymer composition and the styrene block-like reinforcing agent to the weight of the pressure-sensitive adhesive (aromatic alkenyl compound unit Content rate).

(Examples 30-31, Comparative Examples 20-22)

As shown in Table 12 below, except that the amount and type of polyolefin blended in the base layer, the pressure-sensitive adhesive layer, the copolymer composition, the styrene content, the amount of the tackifier, and the amount of the styrene block reinforcing agent (that is, the St type block reinforcing agent) were changed, In the same manner as in Example 29, a wound body of the surface protective film for a prism sheet was obtained.

(evaluation)

About the item described in following (1)-(6), the surface protection film of Examples 29-31 and Comparative Examples 20-22 was evaluated. The results are shown in Table 13.

(1) It measured by the following measurement conditions using surface roughness Ra (post test SJ-301, the Mitsutoyo company make).

(Measuring conditions)

Measuring length: 7.2 mm

λc: 0.8 mm

λs: 2.5 μm

Measuring speed: 0.5 mm / s

Moreover, according to JIS B 0601: 2001, the relief motif average height and relief motif average length were calculated from the profile measured on the said measurement conditions.

(2) adhesion

Each surface protection film of an Example and a comparative example was stuck so that the lens surface of the prism sheet which has an unevenness | corrugation may be covered. As a prism sheet, what consists of acrylic resin of 130 micrometers in thickness, and used the thing of pitch 50micrometer and height 30micrometer of prism. The sticking conditions were affixed at a speed of 300 mm / min using a 2 kg pressurized rubber roller, respectively, under an environment of room temperature at 23 ° C. and a relative humidity of 50%, and after standing for 1 hour in that state, in accordance with JIS Z 0237. , 180 degree peeling strength in 25 mm width was measured at the speed of 300 mm / min. The peeling strength measured in this way was made into adhesive force.

(3) initial development force

The initial development force measured the high speed rewinding force in 15 m / min of rewind speed | rate in accordance with JIS Z 0237 except having changed the rewinding speed of the 50 mm width winding body of each surface protection film. The fast rewinding force thus measured was taken as the initial development force.

(4) time-lapse development

The time-lapse development force is that the 50 mm wide wound body of each surface protective film is cured for 1 week in a room at 40 ° C. ± 2 ° C., and then the rewind speed is 15 m / min except that the rewind speed is changed. The fast rewind force in was measured. The fast rewinding force thus measured was taken as the time course development force. In the table, when the time elapsed development force was 3 N / 50 mm or less, the drawability was evaluated to be good, and a mark was attached.

(5) Prism scratches evaluation

Each surface protection film of an Example and a comparative example was affixed so that the lens surface of the prism sheet which has an unevenness | corrugation may be covered and the test piece was produced. As a prism sheet, the same thing used for evaluation of adhesive force of (2) was used. At the time of sticking, a pressure of 5.9 × 10 ⁵ Pa was applied from the outside of the surface protective film, and the patch was stuck at a speed of 2 m / min. The test piece was cut into 3 cm x 8 cm size, and the sample piece was prepared.

Furthermore, a nylon fiber having a diameter of 0.2 mm was cut to a length of 8 to 10 µm by a cryomicrotome, the cut pieces were fixed on the slide glass, and the obtained surface protection film was affixed on the slide glass with a 2 kg roller and the sample pieces were It fixed between the slide glass and a surface protection film, and produced the convex sample of 400 micrometers in diameter, and 10 micrometers in height.

On the sample piece which covered the lens part with the surface protection film, the said convex-shaped sample was set so that it may overlap with the surface protection film which covers the lens part, 140 g of weights are put on the slide glass, and it is 24 hours in 50 degreeC oven. I was stationed. After 24 hours, the test piece was taken out, and the surface protection film was peeled from the prism sheet, and the presence or absence of the bright spot which generate | occur | produces by the damage to the lens surface of a prism sheet was visually observed. In the following Table 13, a (defective) table | surface and a (good) table when it was observed a little, and (circle) (excellent) table | surface were attached to the sample in which a lot of scratches are observed.

(Examples 32-38, Comparative Examples 23-29)

To 100 parts by weight of the copolymer composition obtained by the above synthesis method, 5 parts by weight of Arcon P125 (manufactured by Arakawa Chemical Industry Co., Ltd.) as a tackifier and 1 part by weight of Irganox 1010 (manufactured by Chiba Specialty Chemicals) as an antioxidant And the adhesive composition were obtained.

The surface protection film which laminated | stacked and integrated the 34-micrometer-thick base material layer and the 6-micrometer-thick adhesive layer by coextrusion-molding a base material and an adhesive composition by T-die method using polypropylene (J715M by Prime Polymer Co., Ltd.) for the base material Was molded and the wound body wound up to the core of 3 inches of internal diameters was obtained.

(evaluation)

The following items were evaluated about each surface protection film obtained as mentioned above. The results are shown in Table 15.

(evaluation)

The following items were evaluated about each surface protection film obtained as mentioned above. The results are shown in Table 15.

(1) film formation

The external appearance of the surface protection film formed into a film by co-extrusion was visually evaluated, and it was set as "(circle)" when there was no problem in appearance.

(2) initial adhesion

Each surface protection film of an Example and a comparative example was stuck so that the lens surface of a diffusion film (3M company make, DBEF) may be covered. The sticking conditions were affixed at a speed of 300 mm / min using a 2 kg pressurized rubber roller, respectively, under an environment of room temperature at 23 ° C. and a relative humidity of 50%, and allowed to stand for 30 minutes in that state, followed by JIS Z 0237. , 180 degree peeling strength in 25 mm width was measured at the speed of 300 mm / min. The peeling direction at this time was made into the MD (machine direction) direction of a surface protection film. Thus, the peeling strength measured was made into initial stage adhesive force.

(3) time-lapse adhesion

Each surface protective film of an Example and a comparative example was 300 mm / using the pressurized rubber roller of 2 kg each on the surface of the diffusion film used for initial stage adhesive evaluation of (1) in the environment of 23 degreeC of room temperature, and 50% of a relative humidity. It stuck at the speed of minutes. Thereafter, a pressure of 6.0 × 10 ⁻³ MPa was applied between the diffusion films affixing the surface protection film with a polycarbonate plate (thickness 2 mm), and a pressure of 6.0 × 10 ⁻³ MPa was applied thereto under conditions of 60 ° C. and 90% relative humidity for 48 hours. It was left to stand. After leaving this at room temperature and leaving it to stand for 30 minutes, 180 degree peeling strength in 25 mm width was measured at the speed | rate of 300 mm / min based on JISZ0237.

The peel strength measured in this way was made into time-lapse adhesive force, and the adhesion improvement rate of time-lapse adhesive force was calculated from the initial stage adhesive force by the following formula.

Rate of Change (Adhesion Relief Rate) = (Time Adhesion / Initial Adhesion) × 100

(4) development force

Except for changing the rewinding speed of the 50 mm wide wound body of each surface protective film of the Examples and Comparative Examples, the rewinding force was measured at a rewinding speed of 5 m / min and 15 m / min in accordance with JIS Z 0237. It was made.

<Judge criteria>

Adhesion (initial)

○ (good): 0.05 N / 25 mm or more and less than 0.35 N / 25 mm

× (defect): less than 0.05 N / 25 mm or 0.35 N / 25 mm or more

Adhesion (rate of change)

◎ (excellent): less than 200%

○ (good): 200% or more and 500% or less

× (defective): more than 500%

Development

◎ (excellent): less than 2.0 N / 50 mm

○ (good): 2.0 N / 50 mm or more and 3.5 N / 50 mm or less

× (defect): more than 3.5 N / 50 mm

Industrial availability

The adhesive composition of this invention is used suitably for the adhesive layer of surface protection films, such as a prism sheet and a diffusion film.

The surface protection film of this invention is used suitably for surface protection of a prism sheet, a diffusion film, etc.

1 prism sheet
2 sheets
3 lenses (prism)
3a Top of Lens Section (Prism Vertex Angle)
4 first surface protection film
5 base material layer
6 adhesive layer
7 second surface protective film

Claims (9)

Polymer (iii): The following polymer block A and the following polymer block B are contained, General formula [AB] n (In formula, A is a polymer block A, B is a polymer block B, n is an integer of 1-3. Copolymer (I) or its hydrogenated substance having a structure represented by
Polymer (ii): The following polymer block A and the following polymer block B are contained, General formula ABA (The symbol in a formula represents the same meaning as the above), or General formula (AB) xY (In formula, x represents an integer of 1 or more. Y represents a coupling agent residue, the other symbol represents the same meaning as the above), and contains the copolymer (II) or its hydrogenated substance which has a structure,
The aromatic alkenyl compound unit content rate (St (A + B)) of the said polymer (iii) and the said whole polymer (ii) is 30-50 weight%,
The weight ratio (A: B) of the total amount of the polymer block A and the total amount of the polymer block B contained in the said polymer (iii) and the said polymer (ii), respectively, exists in the range of 5: 95-25: 75. .
Polymer Block A:
Aromatic alkenyl compound units are continuous and the polymer block mainly having an aromatic alkenyl compound unit
Polymer block B:
An aromatic alkenyl-conjugated diene copolymer block containing a conjugated diene unit and an aromatic alkenyl compound unit randomly, wherein the polymer block has an aromatic alkenyl compound unit content (St (b)) of 10 to 35% by weight. The surface protection film which has a base material layer and the adhesive layer which consists of an adhesive composition of Claim 1. The method of claim 2,
The base layer is a polyolefin base layer,
The pressure-sensitive adhesive composition further contains a tackifier, and
The temperature which becomes the maximum of tan-delta obtained by measuring dynamic viscoelasticity at -50 degreeC-80 degreeC of the said adhesive layer is -10 degreeC-20 degreeC, The surface protection film characterized by the above-mentioned. The method of claim 2,
The base layer is a polyolefin base layer,
The pressure-sensitive adhesive composition further contains a tackifier and a styrene-based block phase reinforcing agent,
The ratio (aromatic alkenyl compound unit content rate) with respect to the weight of the said adhesive layer of the unit weight of the aromatic alkenyl compound in the said polymer (iii), the said polymer (ii), and a styrene-type block reinforcement agent is 20-50 weight% Surface protection film characterized by. 5. The method according to any one of claims 2 to 4,
The storage elastic modulus (G ') at 70 degrees C of the said adhesive layer is 4.5 * 10 <^5> Pa ~ 6.0 * 10 <^5> Pa, The surface protection film characterized by the above-mentioned. The method of claim 5, wherein
As the surface protection of the prism surface of the prism sheet, the penetration depth of the prism surface of the prism vertex angle to the pressure-sensitive adhesive layer of the prism surface when affixed to the prism surface and loaded with 0.3 N / cm 2 load in a 70 ° C. atmosphere for 24 hours. It is 1% or more and less than 40% of a layer thickness, The surface protection film characterized by the above-mentioned. 5. The method according to any one of claims 2 to 4,
For protecting the prism face of the prism sheet,
The depth of penetration into the pressure-sensitive adhesive layer of the prism vertex angle of the prism face when the projection having a diameter of 400 μm and the height of 12 μm is pressed on the surface opposite to the prism face side and the prism face side is the pressure-sensitive adhesive layer thickness It is 1% or more of less than 100% of the surface protection film characterized by the above-mentioned. 5. The method according to any one of claims 2 to 4,
For protecting the prism face of the prism sheet, the outer surface of the substrate layer has a surface roughness (Ra) of 0.7 to 2.0 μm, an average height of relief motifs of 3 μm or more, and an average length of relief motifs of 350 μm or more and 600 μm or less. Surface protection film characterized by. 5. The method according to any one of claims 2 to 4,
Surface protection film for surface protection of diffusion film.

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