KR20190113807A - Adhesive resin composition and laminated film comprising same - Google Patents

Abstract

An object of the present invention is to provide a pressure-sensitive adhesive composition which, when affixed to an adherend having fine surface irregularities, has a sufficient adhesive force and hardly improves the adhesive force even when exposed to a high temperature during transportation or storage thereof.
In order to solve the said subject, the adhesive resin composition of this invention is characterized by containing the following block copolymers.
The block copolymer is a block copolymer comprising polymer block A and polymer block B below.
Polymer block A: A polymer block in which aromatic alkenyl compound units are continuous and mainly consist of aromatic alkenyl compound units.
Polymer block B: The aromatic alkenyl-conjugated diene copolymer block which contains a conjugated diene unit and an aromatic alkenyl compound unit randomly

Description

Adhesive resin composition and laminated | multilayer film which consist of it {ADHESIVE RESIN COMPOSITION AND LAMINATED FILM COMPRISING SAME}

This invention relates to the laminated | multilayer film which has an adhesive composition and the adhesive layer which consists of it. Specifically, it is related with the adhesive composition excellent in the adhesive force and peelability with a to-be-adhered body, and the laminated | multilayer film which has the adhesion layer which consists of it.

Background Art Conventionally, protective films are stacked, stored, transported, or bent on members such as prism sheets used for optical applications, synthetic resin plates, stainless steel plates, aluminum plates, decorative plywood plates, steel sheets, and glass plates used for building materials. It has been used to protect against scratches during secondary processing such as machining or press working. It has also been used to protect home appliances, precision machinery and automobile bodies from scratches during transportation in the manufacturing process.

Such a protective film must have good adhesiveness and, after use, can be easily peeled off without contaminating the surface of the adherend with an adhesive.

In recent years, the adherend has been diversified, and many of the adherends have a smooth coating surface to have surface irregularities.

The back surface of the prism sheet is smoother than the prism surface having large surface irregularities, but a white surface having fine surface irregularities is formed to uniformly diffuse the light of the backlight, and to prevent interference or scratches by contact with other members. A function such as making the problem of appearance difficult to stand out is provided.

For this reason, when the back surface of a prism sheet is piled up and stored or transported, it is protected by the protective film.

However, when time passed after affixing a protective film on a to-be-adhered body, the problem of raise of adhesive force (so-called adhesion elevation) arises, and there existed a problem that it became difficult to peel. It is known that the product which affixed the surface protection film becomes more remarkable by exposing it to high temperature, during its transportation, storage, etc. This problem is particularly likely to occur when the surface of the product (adhered body) has an uneven shape.

A protective film for use in an adherend having fine surface irregularities, wherein the aromatic alkenyl compound units are continuous, and randomly contain a polymer block, a conjugated diene (butadiene) unit, and an aromatic alkenyl compound unit mainly composed of an aromatic alkenyl compound unit. It is known that a copolymer made of an aromatic alkenyl-conjugated diene copolymer block having a content of 35 to 55% by mass of an aromatic alkenyl compound unit in an adhesive layer is known (for example, Patent Document 1). It did not make it easy to peel off over time.

Japanese Patent Publication No. 2014-169347

An object of the present invention has sufficient adhesive strength when affixed to an adherend having fine surface irregularities, such as the back surface of a prism sheet, and it is difficult to improve the adhesive strength even when exposed to high temperatures during transportation and storage thereof. Since it is easy to peel off, an adhesive residue does not generate | occur | produce on an adherend even after peeling off a protective film.

This invention is a sticky resin composition containing a block copolymer and satisfy | filling the conditions of the following (1), (2), (3), (4) and (5).

(1) The block copolymer is

Block copolymer comprising polymer block A below and polymer block B below.

Polymer block A: A polymer block in which aromatic alkenyl compound units are continuous and mainly consist of aromatic alkenyl compound units.

Polymer block B: The aromatic alkenyl-conjugated diene copolymer block which contains a conjugated diene unit and an aromatic alkenyl compound unit randomly

(2) Content in the block copolymer of an aromatic alkenyl compound unit is 50 mass% or more.

(3) Content in the block copolymer of polymer block A is 15 mass% or more.

(4) The hydrogenation rate of the double bond derived from the said conjugated diene unit in the said polymer block B is 90 mol% or more.

(5) The mass average molecular weight (Mw) of the block copolymer is 180,000 or less.

In this case, it is preferable that the said block copolymer consists of the following copolymer (I) and / or copolymer (II).

 Copolymer (I): It contains the below polymer block A and the below polymer block B, and is a general formula [AB] n (wherein A is a polymer block A, B is a polymer block B, n is an integer of 1-3) It consists of the hydrogenated substance of the copolymer which has a structure represented by the following.

Copolymer (II): It consists of the hydrogenated substance of the copolymer which contains the following polymer block A and the following polymer block B, and has a structure represented by general formula A-B-A (wherein a symbol shows the same meaning as the above.).

Polymer block A: A polymer block in which aromatic alkenyl compound units are continuous and mainly consist of aromatic alkenyl compound units.

Polymer block B: The aromatic alkenyl-conjugated diene copolymer block which contains a conjugated diene unit and an aromatic alkenyl compound unit randomly

In this case, it is preferable that content in the adhesive resin composition of an adhesive adjuvant is 1-50 mass%.

In addition, in this case, it is preferable that the said adhesion | attachment adjuvant is hydrogenated terpene phenol resin.

Furthermore, in this case, it is preferable that content in the adhesive resin composition of an organic lubricant is 0.1-2 mass%.

Furthermore, in this case, it is preferable that the organic lubricant is ethylenebisstearic acid amide and / or calcium stearate.

Moreover, in this case, the laminated film which has the base material layer mainly comprised by polypropylene resin and the adhesive layer which consists of said adhesive resin composition on one side is preferable.

Furthermore, in this case, a laminated film having a base material layer mainly composed of polypropylene resin, an adhesive layer made of the adhesive resin composition on one side thereof, and a release layer on the opposite side to the adhesive layer is preferable. Do.

Furthermore, in this case, it is preferable that the laminated film is used for protecting the prism sheet back surface.

The adhesive resin composition of this invention has sufficient adhesive force when affixed to a to-be-adhered body which has a fine surface unevenness | corrugation like the back surface of a prism sheet, and even if it is exposed to high temperature during transport and storage, etc., adhesive force improves. Since it is difficult and easy to peel off from a to-be-adhered body, even after peeling off a protective film, an adhesive residue does not generate | occur | produce, and the function can be maintained.

(Block copolymer)

The block copolymer in this invention is a block copolymer containing the following polymer block A and the below polymer block B.

Polymer block A: A polymer block in which aromatic alkenyl compound units are continuous and mainly consist of aromatic alkenyl compound units.

Polymer block B: The aromatic alkenyl-conjugated diene copolymer block which contains a conjugated diene unit and an aromatic alkenyl compound unit randomly

Here, in "random" is interpreted in a broad sense, in which the chain distribution of the conjugated diene unit and the aromatic alkenyl compound unit conforms to a certain statistical law obtained by simultaneously polymerizing the mixed conjugated diene and the aromatic alkenyl compound. It means to be.

It is necessary that the content rate (St (A + B)) of the aromatic alkenyl compound unit in a block copolymer is 50 mass% or more. When content of an aromatic alkenyl compound unit is less than 50 mass%, initial stage adhesive force may be too strong, or adhesive force may become easy to improve. On the other hand, as for content of an aromatic alkenyl compound unit, 80 mass% or less is preferable. When it exceeds 80 mass%, initial stage adhesive force may not be confirmed. More preferably, it is 55 mass% or more, More preferably, it is 60 mass% or more.

The content rate (St (A + B)) of the aromatic alkenyl compound unit in a block copolymer shows the numerical value defined by the following formula.

The aromatic alkenyl compound unit content is determined by 1 H-NMR. In addition, such aromatic alkenyl compound unit content can also be determined by an infrared spectrum method, and the value substantially equivalent to 1H-NMR is obtained.

St (A + B)

[(Mass of unit derived from aromatic alkenyl compound monomer unit in block copolymer)

/ (Mass of all monomer-derived units in the block copolymer)] x 100 (wt%)

Content of the polymer block A in a block copolymer needs to be 15 mass% or more. When content of the polymer block A is less than 25 mass%, initial stage adhesive force may become strong too much, and a remnant may generate | occur | produce, and adhesive force may become easy to improve. More preferably, it is 30 mass% or more.

On the other hand, as for content of the polymer block A, 50 mass% or less is preferable. When it exceeds 50 mass%, initial stage adhesive force may not be confirmed. More preferably, it is 45 mass% or less, More preferably, it is 40 mass% or less.

Since the hydrogenated substance of the block copolymer B in the present invention has excellent heat resistance and weather resistance, 90% or more, preferably 95% or more, more preferably 98% or more of the double bond derived from the conjugated diene monomer unit It is preferable that it is the hydrogenated substance in which an unsaturated bond became a saturated bond by this hydrogenation. If it is less than 90%, not only the adhesive force to the to-be-adhered body which has fine unevenness | corrugation can be obtained, but heat resistance and weather resistance are concerned.

It is preferable that the weight average molecular weights of a block copolymer are 30,000-180,000. 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, which may make industrial production difficult. On the other hand, when the weight average molecular weight exceeds 180,000, not only the adhesive force to the adherend having fine surface irregularities is obtained, but also the solubility and heat meltability in the solvent are deteriorated, and also due to industrial processing and pellet extrusion into pellets Film manufacture may also become difficult. More preferably, it is 60,000-180,000, More preferably, it is 100,000-180,000, Especially preferably, it is 150,000-180,000.

It is preferable that it is in the range of 0.1-20 g / min, and, as for the melt flow index (MFR) value of a block copolymer, it is more preferable that it is 1-15 g / min. By setting the melt flow index value in the range of 0.1 to 20 g / min, not only the industrial production of the aromatic vinyl block copolymer can be facilitated, but also excellent workability can be provided even at the time of film forming. If the melt flow index value is less than 0.1 g / min, the solubility in the solvent at the time of polymerization worsens, the heat meltability may fall, and it may become difficult to take out a polymer from a manufacturing facility. This difficulty becomes a problem that can be recurred even at the time of film forming.

On the other hand, when the melt flow index value is larger than 20 g / min, the polymer adheres to and remains inside the manufacturing facility in the step of desolventing and drying the polymer, which makes it difficult to take out the polymer. This difficulty becomes a problem that can be recurred even at the time of film forming.

It is preferable that the block copolymer of this invention consists of the following copolymer (I) and / or copolymer (II).

Copolymer (I): It contains the below polymer block A and the below polymer block B, and is a general formula [AB] n (wherein A is a polymer block A, B is a polymer block B, n is an integer of 1-3) Indicates.)

It consists of the hydrogenated substance of the copolymer which has a structure represented by the following.

Copolymer (II): It consists of the hydrogenated substance of the copolymer which contains the following polymer block A and the following polymer block B, and has a structure represented by general formula A-B-A (wherein a symbol shows the same meaning as the above.).

Polymer block A: A polymer block in which aromatic alkenyl compound units are continuous and mainly consist of aromatic alkenyl compound units.

Polymer block B: The aromatic alkenyl-conjugated diene copolymer block which contains a conjugated diene unit and an aromatic alkenyl compound unit randomly

(Polymer block A)

The polymer block A in the present invention is a polymer block in which aromatic alkenyl compound units are continuous and mainly consist of aromatic alkenyl compound units.

Although it does not specifically limit as an aromatic alkenyl compound unit, For example, styrene, tert- butyl styrene, (alpha) -methylstyrene, p-methylstyrene, p-ethyl styrene, divinylbenzene, 1, 1- diphenyl ethylene, vinyl naphthalene And aromatic vinyl monomer units such as vinylanthracene, N, N-dimethyl-p-aminoethylstyrene, N, N-diethyl-p-aminoethylstyrene, and vinylpyridine. Among them, the "aromatic vinyl monomer unit" is preferably a styrene unit.

Repeating units other than an aromatic alkenyl monomeric unit can mention the repeating unit derived from the compound copolymerizable with an aromatic alkenyl monomeric unit, for example, a repeating unit derived from a conjugated diene compound or a (meth) acrylic acid ester compound. Among them, 1,3-butadiene and isoprene are preferable because of their high copolymerizability with aromatic alkenyl monomer units.

Polymer block A needs to be comprised using the aromatic alkenyl monomeric unit as a main repeating unit. Specifically, the content of the aromatic alkenyl monomer unit is preferably 80% by mass or more, more preferably 90% by mass or more. By carrying out the content rate of an aromatic alkenyl monomeric unit in this range, adhesive force, track | trackability with a to-be-adhered body surface unevenness, and extractability from a roll state can be improved more.

(Polymer block B)

The polymer block B in the present invention is an aromatic alkenyl-conjugated diene copolymer block which contains a conjugated diene unit and an aromatic alkenyl compound unit at random. By randomly containing the unit derived from a conjugated diene unit and the unit derived from an aromatic alkenyl compound unit, after attaching the protective film using the adhesive resin composition of this invention to the to-be-adhered body which has a fine surface unevenness, Even when exposed to high temperatures during storage, sticking is unlikely to occur.

The conjugated diene monomeric unit constituting the polymer block B in the present invention is a repeating unit derived from the conjugated diene monomer. Although it does not specifically limit as a conjugated diene monomeric unit, For example, 1, 3- butadiene, 1,2-butadiene, isoprene, 2, 3- dimethyl- butadiene, 1, 3- pentadiene, 2-methyl-1, 3- Butadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 1,3-cyclohexadiene, 4,5-diethyl-1,3-octadiene, 3-butyl-1,3- Octadiene, myrcene, chloroprene, etc. are mentioned. Especially, it is preferable that they are 1 or more types of repeating units chosen from the 1, 3- butadiene unit or the isoprene unit which are high in polymerization reactivity, and excellent in adhesiveness and weather resistance. Moreover, it is more preferable to select 1,3-butadiene units in order to obtain high mechanical strength.

In addition to this, the polymer block B is preferably an aromatic vinyl-conjugated diene copolymer block in which the conjugated diene monomer unit and the aromatic vinyl monomer unit are randomly included.

Since the hydrogenated substance of the block copolymer B in the present invention has excellent heat resistance and weather resistance, 90% or more, preferably 95% or more, more preferably 98% or more of the double bond derived from the conjugated diene monomer unit It is preferable that it is the hydrogenated substance in which an unsaturated bond became a saturated bond by this hydrogenation. If it is less than 90%, not only the adhesive force to the to-be-adhered body which has fine unevenness | corrugation can be obtained, but heat resistance and weather resistance are concerned.

(Adhesive Resin Composition)

The adhesive resin composition of this invention contains the block copolymer which satisfy | fills the conditions of the following (1), (2), (3), (4) and (5).

(1) The block copolymer is a block copolymer comprising the polymer block A below and the polymer block B below.

Polymer block A: A polymer block in which aromatic alkenyl compound units are continuous and mainly consist of aromatic alkenyl compound units.

Polymer block B: The aromatic alkenyl-conjugated diene copolymer block which contains a conjugated diene (butadiene) unit and an aromatic alkenyl compound unit randomly

(2) Content in the block copolymer of an aromatic alkenyl compound unit is 50 mass% or more.

(3) Content in the block copolymer of polymer block A is 25 mass% or more.

(4) The hydrogenation rate of the double bond derived from the said conjugated diene unit in the said polymer block B is 90 mol% or more.

(5) The mass average molecular weight (Mw) of the block copolymer is 180,000 or less.

The pressure-sensitive adhesive resin composition of the present invention, in addition to the block copolymer, if necessary, pressure-sensitive adhesives, organic lubricants, antioxidants, light stabilizers, ultraviolet absorbers, fillers, pigments, styrene block-like reinforcing agents, softeners, anti-tackiness inhibitors, olefin resins You may contain well-known additives, such as silicone resin, a liquid acrylic copolymer, and a phosphate ester type compound suitably.

(Adhesion aid)

In the present invention, an adhesive aid may be added for the purpose of increasing the adhesive force of the adhesive resin composition. As an adhesion | attachment adjuvant, For example, petroleum resins, such as an aliphatic copolymer, an aromatic copolymer, an aliphatic and aromatic copolymer, and an alicyclic copolymer; Coumarone- indene resin; Terpene resin; Terpene phenol resin; Rosin-based resins such as polymerized rosin; phenol-based resins, xylene-based resins, and the like, and those commonly used in pressure-sensitive adhesives such as hydrogenated substances thereof can be used without particular limitation.

It is preferable that the glass transition temperature of an adhesion | attachment adjuvant uses what is 30 degreeC or more. If it is less than 30 degreeC, the exudation at room temperature is feared and handleability is inferior. The glass transition temperature of the pressure sensitive adhesive is preferably 65 ° C. or higher in consideration of high temperature improvement.

Among the pressure sensitive adhesives, terpene phenol resins are preferred, and hydrogenated terpene phenol is particularly preferable. If a phenol group exists in an adhesion | attachment adjuvant, electrical affinity with a to-be-adhered body will act and the improvement of the adhesive force which does not depend on temperature more is expected. Furthermore, the addition of hydrogen can reduce the risk of discoloration due to high temperature and time.

The said adhesive adjuvant may be used independently and may use 2 or more types together. When the said adhesive adjuvant is hydrogenated resin, peelability, weather resistance, etc. become further higher. It is preferable that the adhesion | attachment adjuvant in the said adhesive layer is resin in which hydrogenation was carried out.

It is preferable that the content rate in the adhesive resin composition of an adhesive adjuvant is 1-50 mass%. An adhesive adjuvant can expect improvement of adhesive force and sensibility by the effect which plasticizes an adhesive resin composition, and the effect which inhibits the molecular motion of an adhesive. When the content rate of an adhesive adjuvant exceeds 50 mass%, compatibility with an adhesive resin composition may worsen, and the fall of initial stage adhesive force may be seen. More preferably, it is 40 mass% or less, More preferably, it is 30 mass% or less.

(Organic lubricant)

The organic lubricant used in the present invention is preferably saturated fatty acid bisamide or fatty acid metal salt in view of excessive exudation at room temperature or high temperature. Specifically, ethylene bis stearate bisamide, stearic acid metal salt, etc. are mentioned. These may be used independently and may use 2 or more types together.

It is preferable that the content rate in the adhesive resin composition of an organic lubricant is 0.1-2 mass%. An organic lubricant can expect the effect of suppressing the improvement of adhesive force. However, when the organic lubricant exceeds 2% by mass with respect to the adhesive resin composition, the degree of bleeding out at high temperature and time is severe and there is a fear of contaminating the adherend.

The organic lubricant used in the present invention is preferably a high melting point in view of bleeding out at high temperatures and over time, and specific examples thereof include ethylenebisstearic acid amide and calcium stearate.

(Antioxidant)

Antioxidant used by this invention is not specifically limited, For example, what is normally used, such as a phenol type (monophenol type, bisphenol type, a polymeric phenol type), sulfur type, phosphorus type, etc. is mentioned.

(Light stabilizer)

As a light stabilizer used by this invention, a hindered amine compound is mentioned.

(UV absorber)

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

(Softener)

In this invention, a softener can be added in order to lower the hardness of an adhesive resin composition. Softeners are also effective for improving adhesion. As the softener, for example, a low molecular weight diene polymer, polyisobutylene, hydrogenated polyisobutylene, hydrogenated polybutadiene, paraffinic process oil, naphthenic process oil, aromatic process oil, castor oil, tall oil, Natural oils, liquid polyisobutylene resins, polybutenes, or hydrogenated substances thereof, such as those generally used for pressure-sensitive adhesives, can be used without particular limitation. These softeners may be used independently and may use 2 or more types together.

(Filler)

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

(Laminated film)

The laminated | multilayer film of this invention is obtained by laminating | stacking the adhesion layer which consists of said adhesive resin composition on a base material layer. Moreover, you may have a release layer in the base material layer opposite to an adhesion layer.

It demonstrates in detail below.

(Adhesive layer)

The adhesive layer in this invention consists of the adhesive composition mentioned above, and thickness is about 1-30 micrometers normally, Preferably it is 2-10 micrometers.

It is preferable that the initial stage adhesive force of the laminated | multilayer film of this invention is 2 cN / 25mm or more and 20 cN / 25mm or less. If it is 2 cN / 25 mm or more, it does not come off or lifts off at the time of handling or transportation, and if it is 20 cN / 25 mm or less, it does not require excessive force when peeling. More preferably, they are 3 cN / 25mm or more and 15 cN / 25mm or less. More preferably, they are 3 cN / 25 mm or more and 10 cN / 25 mm or less. Especially preferably, they are 3 cN / 25 mm or more and 8 cN / 25 mm or less.

Initial adhesive force was measured as follows.

In an environment of 23 ± 2 ° C. and relative humidity of 50 ± 5% RH so that the surface of the adhesive layer of the laminated film is in contact with the back surface of the prism sheet, a linear pressure of 15 kN / m is applied from the opposite side to the adhesive layer surface of the laminated film by 2 m. It affixed at the rate of / min.

After leaving the obtained test piece for 30 minutes in a room of 23 ± 2 ° C and a relative humidity of 50 ± 5% RH, the peeling strength (unit: cN) in a 25 mm width in accordance with JIS Z0237 is 300 mm / It measured on the conditions of minutes and made initial stage adhesive force.

It is preferable that the time-lapse adhesive force of the laminated | multilayer film of this invention is 2 cN / 25mm or more and 80 cN / 25mm or less. If it is 2 cN / 25 mm or more, it does not come off or lifts off at the time of handling or transportation, and if it is 80 cN / 25 mm or less, it does not require excessive force when peeling. More preferably, they are 3 cN / 25 mm or more and 70 cN / 25 mm or less. More preferably, they are 3 cN / 25 mm or more and 60 cN / 25 mm or less. Especially preferably, they are 3 cN / 25 mm or more and 45 cN / 25 mm or less.

The tack over time was measured as follows.

The test piece was produced on the same conditions as the prism sheet used for the measurement of initial stage adhesive force. After standing for one week in an atmosphere of 65 ° C. ± 2 ° C. and a load of 6 kg / 400 cm 2, 180-degree peel strength in 25 mm width was measured at a peel rate of 300 mm / min in accordance with JIS Z0237 to obtain a tack over time. It was.

It is preferable that the adhesion improvement rate of the laminated | multilayer film of this invention is 1,000% or less. When the adhesion improvement rate is 1,000% or less, the working conditions when peeling the film from the adherend become more constant, and the work efficiency is improved. More preferably, it is 800% or less, More preferably, it is 600% or less, Especially preferably, it is 500% or less.

The adhesion improvement rate was calculated by the following equation using the initial adhesive force and the time-sensitive adhesive force.

Adhesion improvement rate = (time-sensitive adhesiveness / initial adhesive strength) × 100 (%)

The peeling force of the surface of the adhesion layer of this invention and the surface of the adhesion layer opposite surface is preferable in the range of 200 cN / 25mm or less in 23 degreeC from the viewpoint of the extractability of the film at the time of making laminated | multilayer film into a roll form. When the peeling force exceeds 200 cN / 25 mm, problems such as partial elongation or deformation of the film occur in the extraction of the film when the laminated film is in roll form. In addition, the minimum of peeling force with respect to the surface of the adhesion layer of a laminated | multilayer film, and the surface of the adhesion layer opposite surface is about 1 cN / 25mm, Furthermore, it is about 5 cN / 25mm as a realistic value. More preferably, it is 2-100 cN / 25mm, More preferably, it is 3-50 cN / 25mm.

(Base layer)

The base material layer in this invention can be formed with polyolefin resin. Polyolefin resin is a polymer using olefin monomers, such as ethylene, propylene, and (alpha) -olefin, and means that the ratio which the olefin monomer in all the monomers which comprise a polyolefin resin occupies is 70 mol% or more. As polyolefin resin contained in a base material, polyethylene type, such as an ethylene homopolymer, an ethylene-alpha-olefin copolymer, an ethylene- (meth) acrylic acid copolymer, an ethylene- (meth) acrylic acid ester copolymer, and an ethylene-vinyl acetate copolymer Polypropylene resins such as resins; propylene homopolymers, propylene-α-olefin copolymers, and propylene-ethylene copolymers; butene homopolymers; homopolymers or copolymers of conjugated dienes such as butadiene and isoprene. Moreover, as said polyethylene-type resin, a high density polyethylene, a medium density polyethylene, a low density polyethylene, etc. are mentioned. The form of copolymerization may be random, a block may be sufficient, and the form of a ternary copolymer may be sufficient. The said polyolefin resin may be used independently and may use 2 or more types together.

The said polyethylene-type resin is obtained using ethylene as a main component. The ratio of the structural unit derived from ethylene in 100 mass% of all the structural units of the said polyethylene-type resin becomes like this. Preferably it is 50 mass% or more, More preferably, it is 70 mass% or more, More preferably, it is 90 mass% or more.

The said polypropylene resin is obtained using propylene as a main component. Preferably the ratio of the structural unit derived from propylene in 100 mass% of all the structural units of the said polypropylene resin is 50 mass% or more, More preferably, it is 70 mass% or more, More preferably, it is 90 mass% or more.

It is preferable that the base material layer of this invention mainly consists of polypropylene resin from a viewpoint of heat resistance, weather resistance, or adhesiveness with an adhesion layer.

The thickness of the base material layer in this invention becomes like this. Preferably it is 10 micrometers or more, More preferably, it is 100 micrometers or less. If the thickness of the said base material is 10 micrometers or more and 100 micrometers or less, the handleability of a laminated | multilayer film will become still higher.

When the laminated | multilayer film of this invention consists only of the adhesion layer which consists of a base material layer and the said adhesive composition, in order to suppress the surface peeling force of the base material layer surface and the adhesion layer surface, surface unevenness is given and the contact area with an adhesion layer is made small. It is desirable to.

In this case, considering the resin composition of the adhesion layer of this invention, it is preferable to make average surface roughness SRa of the base material layer surface into 0.40 micrometer or more. The average surface roughness of the surface is more preferably 0.850 µm or less in SRa, more preferably 0.500 µm or more and 0.700 µm or less.

By setting average surface roughness SRa of the base material layer surface to 0.40 micrometer or more, the protective performance and peeling force of a to-be-adhered body can be improved. When the surface roughness of the base material layer is lower than 0.40 µm, the extractability of the film when the film is in roll form is deteriorated. When the surface roughness of a base material layer is made higher than 0.850 micrometer, the surface asperity of a base material layer may be transferred to the adhesion layer surface, and adhesive force may fall remarkably.

In order to make average surface roughness SRa 0.40 micrometer or more, incompatible resin can be added to homopropylene and random polypropylene, and a propylene ethylene block copolymer can be used suitably as resin used for a base material layer. have. When the propylene-ethylene block copolymer is used, it is difficult to change the uneven state according to the change of the production vessel support or melt kneading conditions during film formation, thereby enabling stable production.

Average surface roughness SRa can be enlarged by increasing the molecular weight of ethylene-propylene rubber in a propylene ethylene block copolymer, or increasing the quantity of ethylene. Moreover, average surface roughness SRa can be made larger by mixing incompatible resin with a propylene ethylene block copolymer.

In addition, in the extrusion process mentioned later, average surface roughness SRa can be made larger also by lowering the shear rate which resin takes, or lengthening residence time.

On the other hand, in order to make average surface roughness SRa small, it is effective to mix a homopolypropylene resin with a propylene ethylene block copolymer.

As the incompatible resin for the propylene-ethylene block copolymer, 4-methylpentene-1 polymer or 4-methyl-1-pentene-α-olefin copolymer can be preferably used. Moreover, as said (alpha) -olefin, if it is copolymerizable with ethylene, propylene, 4-methyl-1- pentene, it will not specifically limit, For example, ethylene, propylene, 1-butene, 1-hexene, 4-methyl-1- pentene And 1-octene, 1-pentene and 1-heptene.

In addition, low density polyethylene, high density polyethylene, the copolymer of ethylene and a small amount of (alpha) -olefin, the copolymer of ethylene and vinyl acetate, a polystyrene, an alicyclic olefin resin, polyester resin, polyamide resin, etc. are mentioned. In particular, the 4-methylpentene-1 polymer or 4-methyl-1-pentene-α-olefin copolymer not only roughens the surface in the form of a mat, but also lowers the peel force by further reducing the surface free energy of the film surface. It is preferable because it can be done.

The compounding quantity of 4-methylpentene-1 polymer or 4-methyl-1- pentene-alpha-olefin copolymer of 4 or more carbon atoms in a base material layer (resin component which comprises a base material layer) is 0 mass% or more and 35 mass% or less. . When the compounding quantity of a C4 or more alpha-olefin (co) polymer exceeds 35 mass%, when it attempts to laminate | stack the raw material of a base material layer and an adhesion layer by coextrusion using T die etc., the film forming property of a base material layer will worsen.

(Release layer)

The release layer in this invention is provided in the base material layer opposite to an adhesion layer. Thereby, it can respond to a wider use by disperse | distributing a function to each of a base material layer and a release layer.

In this case, in order to suppress the peeling force of the surface of a mold release layer and the surface of an adhesion layer, it is preferable to provide surface unevenness, and to make contact area with an adhesion layer small.

In view of the resin composition of the pressure-sensitive adhesive layer of the present invention, the average surface roughness SRa of the surface of the release layer is preferably 0.40 µm or more. The average surface roughness of the surface is more preferably 0.850 µm or less in SRa, more preferably 0.500 µm or more and 0.700 µm or less.

By making average surface roughness SRa of a release layer surface into 0.40 micrometer or more, the protective performance and peeling force of a to-be-adhered body can be improved. When the surface roughness of a release layer is lower than 0.40 micrometer, the feedability of the film at the time of making a film into a roll will worsen. When the surface roughness of a mold release layer is made higher than 0.850 micrometer, the surface asperity of a mold release layer may be transferred to the surface of an adhesion layer, and adhesive force may fall remarkably.

In order to make average surface roughness SRa 0.40 micrometer or more, incompatible resin is added to homopropylene and random polypropylene as a resin used for a release layer, and a propylene ethylene block copolymer can be used preferably. When the propylene-ethylene block copolymer is used, it is difficult to change the uneven state according to the change of the production vessel support or melt kneading conditions during film formation, thereby enabling stable production.

Average surface roughness SRa can be enlarged by increasing the molecular weight of ethylene-propylene rubber in a propylene ethylene block copolymer, or increasing the quantity of ethylene. Moreover, average surface roughness SRa can be made larger by mixing incompatible resin with a propylene ethylene block copolymer.

In addition, in the extrusion process mentioned later, average surface roughness SRa can be made larger also by lowering the shear rate which resin takes, or lengthening residence time.

On the other hand, in order to make average surface roughness SRa small, it is effective to mix a homopolypropylene resin with a propylene ethylene block copolymer.

As a resin which is incompatible with a propylene ethylene block copolymer, C4 or more alpha-olefin (co) polymers, such as a 4-methylpentene- 1 type | system | group (co) polymer, can be used preferably. In addition, low density polyethylene, high density polyethylene, the copolymer of ethylene and a small amount of (alpha) -olefin, the copolymer of ethylene and vinyl acetate, a polystyrene, polyester resin, a polyamide resin, etc. are mentioned. In particular, the 4-methylpentene- 1-based (co) polymer is preferable because not only the surface is roughened in a mat shape, but also the surface free energy of the film surface is lowered to further reduce the peeling force.

The compounding quantity of a C4 or more alpha-olefin (co) polymer in a mold release layer (resin component which comprises a mold release layer) is 0 mass% or more and 35 mass% or less. When the compounding quantity of a C4 or more alpha-olefin (co) polymer exceeds 35 mass%, when it is going to laminate | stack a base material layer and an adhesion layer by coextrusion, the film forming property of a base material layer will worsen.

The thickness of the release layer is not particularly limited. The thickness of the release layer is preferably 2 µm or more, preferably 10 µm or less. When the thickness of the release layer is 2 µm or more and 10 µm or less, the handleability of the laminated film is further enhanced.

The method of manufacturing the laminated | multilayer film of this invention contains the adhesive composition and the polyolefin resin for base material layers, the polyolefin resin for release layers as needed, melt | dissolution, and co-extruded from a T die by lamination | stacking to each extruder, Or a method of laminating other layers by a lamination method such as extrusion lamination or extrusion coating on a layer obtained by inflation molding, a method of laminating each layer independently to a film, and then laminating each obtained film by dry lamination. Etc., but from the viewpoint of productivity, coextrusion molding for supplying and molding each material of the release layer, the substrate layer, and the pressure-sensitive adhesive layer to a multilayer extruder is preferable, and T die molding is more preferable in terms of thickness precision. Do.

The surface protection film of this invention is used in order to protect the surface of the to-be-adhered body whose surface is smooth or fine unevenness | corrugation, It is especially effective when surface roughness is about 0.1-0.3 micrometer.

Example

Although an Example is given to the following and this invention is demonstrated in detail, this invention is not limited only to these Examples.

The measurement method is shown below.

(1) initial adhesion

The surface protection film obtained above was affixed so that the adhesive layer surface might contact the back surface of a prism sheet, and the test piece was produced. The patch is applied at a rate of 2 m / min by applying a linear pressure of 15 kN / m on the outside of the surface protective film (ie, opposite to the pressure-sensitive adhesive layer surface) under an environment of 23 ± 2 ° C. and a relative humidity of 50 ± 5% RH. It was affixed. The laminator below was used for the patch.

Laminator

Manufacturer: Tester Industry Co., Ltd.

Model ： SA-1010-S

role ： Heat resistant silicone rubber roll

Roll diameter: Φ 200

The obtained test piece was allowed to stand in a room of 23 ± 2 ° C. and a relative humidity of 50 ± 5% RH for 30 minutes, and then, according to JIS Z0237, 180 ° peel strength (unit: cN) at 25 mm width was measured at 300 mm / It measured on the conditions of minutes and made initial stage adhesive force.

(2) adhesion over time

The obtained surface protection film was affixed on the same conditions as the prism sheet used for the initial stage adhesiveness evaluation of (1), and left to stand for one week in the atmosphere of 65 degreeC +/- 2 degreeC and a load of 6 kg / 400 cm <2>, and it was 25 based on JISZ0237. The 180 degree peeling strength in mm width was measured at the peeling speed of 300 mm / min, and it was set as the adhesive force over time.

(3) adhesion improvement rate

Using the initial adhesive force and the time-dependent adhesive force obtained in said (1) and (2), the change rate (adhesion improvement rate) from initial stage adhesive force to time-dependent adhesive force was calculated by the following formula.

Change rate (adhesion improvement rate) = (time-sensitive adhesive force / initial adhesive force) * 100

(4) peeling force

Two films are piled up so that the obtained surface protection film faces the adhesion layer of one film, and the peeling layer of the other film is 110 mm (winding direction at the time of film manufacture) x 40 mm (orthogonal to the winding direction at the time of film manufacture) It cut out to size, and used it as the test piece, sandwiched the upper and lower sides between copy papers, put 60 kg on it, and let it stand in a room of 40 degreeC for 72 hours. Thereafter, it was left to stand for 1 hr in a room of 23 ± 2 ° C. and a relative humidity of 50 ± 5% RH, and 300 mm / min using "Autograph (trademark)" (AGS-J) manufactured by Shimadzu Corporation. The resistance value at the time of peeling 180 degree | times at the speed of was made into peeling force [cN / 25mm].

At the time of measurement, a polyester sheet having a thickness of 190 μm and a size of 40 mm × 170 mm was prepared as a holding portion of the measurement sample, and the end of the test piece of 110 mm × 40 mm was affixed with a cellophane tape at a width of 15 mm of the glued portion. It was made into the catch of the city. The measurement was performed three times for one sample, and the average value was taken as the peel force of the sample.

(5) surface roughness

Evaluation of the adhesive layer of the obtained laminated | multilayer film and the opposite surface roughness was carried out using the three-dimensional roughness meter (made by Kosaka laboratory company, model number ET-30HK), measuring length 1mm of X direction at 20 micrometers of needle pressure, and 100 micrometers / feeding speeds. Second, the number of lines, the number of lines in the height direction, 20,000 times, and the cutoff of 80 µm were measured at a feeding pitch of 2 µm in the Y direction, and the calculation was performed in accordance with the definition of arithmetic mean roughness described in JISB 0601 (1994).

Arithmetic mean roughness (SRa) was performed 3 times, respectively, and the average value was evaluated.

(6) Content in block copolymer of aromatic alkenyl compound unit

Each raw material resin and mixed resin sample were dissolved in CDCl ₃ , and 1 H-NMR was measured under the following conditions.

Apparatus: Fourier Transform Nuclear Magnetic Resonance Device (Bruker Biospin AVANCE500)

Measuring solution: 10-30 mg of samples were dissolved in 0.6 ml of deuterated chloroform.

5-10 vol% of trifluoroacetic acid was added there.

¹ H resonance frequency: 500.13 MHz

Flip angle of detection pulse: 45 °

Data acquisition time: 4.0 seconds

Delay time: 1.0 second

Accumulation frequency: 20-100 times

Measurement temperature: 25-40 degrees Celsius

(7) Content in the block copolymer of polymer block A

The content of the polymer block A was calculated by comparing the spectrum of homopolystyrene with the infrared spectrum of each raw material resin and mixed resin sample.

(8) weight average molecular weight

Each raw material resin and mixed resin sample were dissolved in tetrahydrofuran (sample concentration: 0.05% by mass). It filtered with the membrane filter of 0.20 micrometer, and GPC analysis of the obtained sample solution was performed on condition of the following. The molecular weight was calculated in terms of standard polystyrene.

GPC device conditions

Equipment: High speed liquid chromatograph HLC-8220 (TOSOH)

Column: TSKgel SuperHZM-H + SuperHZM-H + SuperHZ2000 (TOSOH)

Solvent: THF (tetrahydrofuran)

Flow rate: 0.35 mL / min

Injection amount: 10 μL

Temperature: 40 degrees Celsius

Detector: RI

Data processing: GPC data processing system (TOSOH)

The raw material resin used by the following example and the comparative example is shown below.

1) S1605: Brand name "S1605", hydrogenated product of styrene-butadiene copolymer, Asahi Kasei Co., Ltd., MFR = 3.5 g / 10 minutes, hydrogenation rate of the double bond derived from the conjugated diene unit of polymer block B = 100%, The weight average molecular weight = 180,700, the density = 1.00 g / cc, the content of the aromatic alkenyl compound unit = 66 mass%, the content of the polymer block A = 31 mass%, a mixture of the copolymer of the structural formula ABA and the structural AB.

2) L613: Brand name "L613", hydrogenated substance of styrene-butadiene copolymer, Asahi Kasei Co., Ltd., MFR = 5.0 g / 10min, hydrogenation rate of the double bond derived from the conjugated diene unit of polymer block B = 100%, The weight average molecular weight = 138,200, the density = 1.00 g / cc, the content of the aromatic alkenyl compound unit = 32 mass%, the content of the polymer block A = 35 mass%, a mixture of the copolymer of the structural formula ABA and the structural AB.

3) S1606: Brand name "S1606", hydrogenated product of styrene-butadiene copolymer, Asahi Kasei Co., Ltd., MFR = 4.0, hydrogenation rate of the double bond derived from the conjugated diene unit of polymer block B = 100%, weight average molecular weight = 169,900, density = 0.96 g / cc, content of aromatic alkenyl compound unit = 50 mass%, content of polymer block A = 25 mass%, copolymer of structural formula ABA.

4) H1221: Brand name "H1221", the hydrogenated substance of a styrene-butadiene copolymer, the Asahi Kasei Co., Ltd. make, MFR = 4.5 / 10min, hydrogenation rate of the double bond derived from the conjugated diene unit of polymer block B = 100%, weight A copolymer having an average molecular weight of 147,600, a density of 0.99 g / cc, a content of an aromatic alkenyl compound unit of 12 mass%, a content of polymer block A = 12 mass%, and a polymer block B.

5) UH115: Brand name "UH115", hydrogenated terpene phenol resin, Yashara Chemical Corporation make, glass transition point temperature = 65 degreeC

6) TH130: Brand name "TH130", terpene phenol resin, Yashara Chemical company make, glass transition point temperature = 80 degreeC

7) EB-P (brand name "EB-P", ethylene bis stearate amide, Gao Corporation make)

(Example 1)

S1606 Polyolefin resin (trade name "WF836DG3", a propylene ethylene random copolymer, the prime polymer company make, MFR = 4.5 / 10 minutes, melting | fusing point = 164 degreeC, ethylene copolymerization quantity = 0.3 as a raw material of 100 weight part of adhesive compositions and a base material layer) Mass%) and polyolefin resin (brand name "BC3HF", a polypropylene ethylene block copolymer, the prime polymer company make, melting | fusing point = 171 degreeC, ethylene content = 9 mass%) as a raw material of a release layer, With a discharge amount of 6 kg / hour with a 40 mmφ single screw extruder, the resin of the base material layer with a discharge amount of 30 kg / hour with a 90 mmφ single screw extruder, and the resin of a release layer with a discharge amount of 4 kg / hour with a 60 mmφ single screw extruder Using a three-layer T die (lip width 850 mm, lip gap 1 mm), each was coextruded and cooled with a cooling roll, and the thicknesses of the adhesive layer, the substrate layer, and the release layer were 6 µm, 30 µm, and 4 µm, respectively. The laminated film whose length of a direction is 650 mm was obtained. The results are shown in Table 1.

(Examples 2-8, Comparative Examples 1-3)

A laminated | multilayer film was obtained like Example 1 except having changed content of the raw material resin of an adhesion layer, and an additive, and thickness and content of an adhesion layer as shown in Table 1. The results are shown in Table 1.

When the laminated | multilayer film of Examples 1-8 were affixed on the back surface of a prism sheet, even if one week passed under high humidity, adhesive force was hard to improve and the blocking with a peeling layer was also small.

On the other hand, the laminated | multilayer film of Comparative Examples 1 and 2 was too strong adhesive force with a back surface, and it was hard to peel from a back surface.

When 1 week passed under high humidity, the laminated | multilayer film of the comparative example 3 became adhesive force with a white surface, and was difficult to peel from a white surface.

Industrial availability

The adhesive composition of this invention is used suitably for surface protections, such as a prism sheet, especially these back surfaces, and is industrially useful.

Claims (9)

It contains a block copolymer and satisfy | fills the conditions of the following (1), (2), (3), (4) and (5), The adhesive resin composition characterized by the above-mentioned.
(1) The block copolymer is a block copolymer comprising the polymer block A below and the polymer block B below.
Polymer block A: A polymer block in which aromatic alkenyl compound units are continuous and mainly consist of aromatic alkenyl compound units.
Polymer block B: The aromatic alkenyl-conjugated diene copolymer block which contains a conjugated diene unit and an aromatic alkenyl compound unit randomly
(2) Content in the block copolymer of an aromatic alkenyl compound unit is 50 mass% or more.
(3) Content in the block copolymer of polymer block A is 25 mass% or more.
(4) The hydrogenation rate of the double bond derived from the said conjugated diene unit in the said polymer block B is 90 mol% or more.
(5) The mass average molecular weight (Mw) of the block copolymer mixture is 180,000 or less. The method of claim 1,
Adhesive resin composition in which a block copolymer consists of the following copolymer (I) and / or copolymer (II).
Copolymer (I): It contains the below polymer block A and the below polymer block B, and is a general formula [AB] n (wherein A is a polymer block A, B is a polymer block B, n is an integer of 1-3) Indicates.)
It consists of the hydrogenated substance of the copolymer which has a structure represented by the following.
Copolymer (II): It consists of the hydrogenated substance of the copolymer which contains the following polymer block A and the following polymer block B, and has a structure represented by general formula ABA (wherein a symbol shows the same meaning as the above.).
Polymer block A: A polymer block in which aromatic alkenyl compound units are continuous and mainly consist of aromatic alkenyl compound units.
Polymer block B: The aromatic alkenyl-conjugated diene copolymer block which contains a conjugated diene unit and an aromatic alkenyl compound unit randomly The method according to claim 1 or 2,
Adhesive resin composition whose content in adhesive resin composition of an adhesive adjuvant is 1-50 mass%. The method of claim 3, wherein
The adhesive resin composition whose adhesion aid is hydrogenated terpene phenol resin. The method according to any one of claims 1 to 4,
Adhesive resin composition whose content in adhesive resin composition of an organic lubricant is 0.1-2 mass%. The method of claim 5,
The adhesive resin composition whose organic lubricant is ethylene bis stearate amide and / or calcium stearate. The laminated | multilayer film which has the base material layer comprised mainly from polypropylene resin, and the adhesive layer which consists of an adhesive resin composition in any one of Claims 1-6 on the one surface. It has a base material layer comprised mainly from polypropylene resin, the adhesive layer which consists of the adhesive resin composition of any one of Claims 1-6 on one surface, and has a release layer on the opposite surface to an adhesive layer. Laminated film. The method according to claim 7 or 8,
Laminated film used to protect the prism sheet back.