TWI723013B - Surface protective film and propylene copolymer composition for surface protective film - Google Patents

Abstract

The subject of the present invention is to obtain a surface protective film with less fish eyes, excellent extractability (roll-out properties, blocking resistance), and sufficient transparency, and a propylene copolymer suitable for obtaining the surface protective film. The composite composition, the present invention relates to a surface protective film, which is characterized in that it contains a propylene-ethylene block copolymer (A) that meets specific requirements: 75 to 97% by weight and an ethylene system that meets specific requirements. Elastomer (B): 3-25% by weight (wherein, (A)+(B)=100% by weight) film as the surface layer.

Description

Surface protective film and propylene copolymer composition for surface protective film

The present invention relates to a surface protective film and a propylene copolymer composition for the surface protective film. In detail, the present invention relates to a propylene copolymer composition suitable for the surface layer of a surface protective film and a surface protective film containing the composition.

The surface protection film is usually a laminated film with an adhesive layer on one side of the surface layer, and the adhesive layer is attached to the adherend for use. The surface protective film has applications such as building materials and optical components. For example, there are cases where a surface protection film is attached to various optical films (for example, diffusion films, polarizing films, retardation films, etc.) embedded in liquid crystal displays or plasma displays, and stored. Moreover, if it is a transparent surface protection film, it may also be attached to the display surface of the display.

Generally speaking, the laminated film is produced by co-extrusion molding, or coating on one side of the film that becomes the surface layer to form an adhesive layer. According to co-extrusion molding, generally, a laminated film can be produced at low cost. The laminated film produced by co-extrusion molding is usually wound into a roll for storage, and when the film is used, the film is wound out from the roll on which the film is wound and used.

However, if the surface protection film with the adhesive layer and the surface layer is wound into a roll shape, the surface layer and the adhesive layer of the film may be adhered, that is, adhesion occurs. If sticking occurs, the film cannot be unrolled from the roll, or the performance of the unrolled film deteriorates. Therefore, the surface protection film is usually wound into a roll in a state where the release film is superimposed on the adhesive layer. However, there is a roller with a surface protection film overlapped with a release film. When attached to the adherend, the peeled release film becomes a problem of a large amount of waste.

In order to solve this problem, the industry has proposed a surface protection film that does not stick to the surface layer of the surface protection film even if it is rolled into a roll without overlapping the release film on the adhesive layer (refer to the patent Literature 1).

In addition, when a surface protective film is used for an adherend such as an optical member, if there are fish eyes on the surface protective film, or if there is a paste residue on the surface of the adherend when the surface protective film is peeled off, it will exist as an adherend In the case of defects in the optical components, the industry expects a surface protective film with less paste residue or less fish eyes.

Patent Document 2 discloses a surface protection film mainly composed of a polyethylene component. However, although the method based on the publication can be applied to some parts of the application, the adhesion is low, and the transparency is not sufficient, and the application of the adherend is limited.

Patent Document 3 proposes a surface protective film containing a specific propylene-based random block copolymer obtained by a metallocene catalyst system.

In Patent Document 4, a surface protective film having a propylene copolymer composition containing a specific propylene-ethylene block copolymer (A) and a specific ethylene elastomer (B) as a surface layer is provided as a surface protective film, and suitable The above-mentioned propylene copolymer composition for the production of the surface protective film is proposed to have less fisheyes, less damage to the adherend, sufficient transparency, excellent functionality as a surface protective film, and even if it is not It is also excellent in blocking resistance when using a release film to be wound into a roll for storage, and it is a surface protective film with a surface layer that has excellent extractability when the wound film is used.

In recent years, the large-scale and high-performance display screens have been continuously promoted. In order to prevent the fisheyes on the surface protective film from being transferred to the adherend and becoming a defect, the requirements for low fisheyes of the surface protective film are increasing. . Moreover, in addition to the increase in the size of the adherend, the thinning of the surface protection film is also continuously promoted in accordance with the requirements of cost reduction. In addition, the expectation for a surface protective film with a surface layer that has excellent extractability during use of the wound film has also been increasing.

[Prior Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 2008-81709

Patent Document 2: Japanese Patent Laid-Open No. 2006-116769

Patent Document 3: Japanese Patent Laid-Open No. 2009-83110

Patent Document 4: International Publication of Publication WO2014/030594 Publication

The subject of the present invention is to provide a surface protective film with less fish eyes and excellent extractability (roll-out property, blocking resistance) of the roll-up film.

The applicant found that by using a polypropylene resin composition having a wide molecular weight distribution, especially a high molecular weight component, fish eyes were greatly reduced, and thus completed the present invention.

That is, the present invention relates to a surface protective film characterized by containing a propylene-ethylene block copolymer (A) that satisfies the following requirements (A1) to (A5): 75 to 97% by weight and satisfies the following requirements The ethylene elastomer (B) of the necessary conditions (B1)~(B2): 3-25% by weight (wherein, (A)+(B)=100% by weight) The film of the propylene copolymer composition is used as the surface layer .

(A1) The weight-average molecular weight Mw and number based on gel permeation chromatography (GPC, gel permeation chromatography) of the component (Dinsol) that is insoluble in n-decane at room temperature The ratio of the weight average molecular weight Mn (Mw/Mn) is 5.0 or more.

(A2) The GPC-based ratio of Z average molecular weight Mz to weight average molecular weight (Mz/Mw) of the component (Dinsol) insoluble in n-decane at room temperature (Dinsol) is 3.5 or more.

(A3) The limiting viscosity [η]insol of the component insoluble in n-decane at room temperature (Dinsol) in decalin at 135°C is 1.5~2.5dl/g.

(A4) The limiting viscosity [η]sol of the component (Dsol) soluble in n-decane at room temperature in decalin at 135°C is 3.0~5.5dl/g.

(A5) The content of the component (Dsol) soluble in n-decane at room temperature, derived from the ethylene skeleton, is 35-50% by weight.

(B1) The melt flow rate (MFR) measured by the method of ASTM D1238 at 190°C and a load of 2.16kg is 0.3~1.0g/10 minutes.

(B2) The density measured according to JIS K6922 is 860~900kg/m ³ .

The surface protection film of the present invention has less fish eyes and less damage to the adherend, and has excellent functionality as a surface protection film, and even when it is wound into a roll for storage without using a release film It also has excellent blocking resistance, and is a surface protective film that has excellent extractability when the film is used.

Hereinafter, the present invention will be explained in detail.

<Propylene-ethylene block copolymer (A)>

As a component contained in the propylene copolymer composition for surface protection of the present invention One of the propylene-ethylene block copolymers (A) is formed of a portion that is insoluble in n-decane at room temperature (Dinsol) and a portion that is soluble in n-decane at room temperature (Dsol).

As long as the propylene-ethylene block copolymer (A) of the present invention satisfies the following requirements (A1) to (A5), the polymerization catalyst or polymerization conditions used in its production are not particularly limited. In addition, the propylene-ethylene block copolymer (A) of the present invention may be used alone or in combination of two or more.

(A1) The weight average molecular weight (Mw) and quantity calculated from the measured value of gel permeation chromatography (GPC) of the propylene-ethylene block copolymer (A) insoluble in n-decane at room temperature (Dinsol) The ratio of average molecular weight (Mn), that is, Mw/Mn, is 5.0 or more, preferably in the range of 5.0 to 12.0, and more preferably in the range of 7.0 to 10.0. Mw/Mn is an index of molecular weight distribution. If the value is small, the molecular weight distribution is narrower. If the molecular weight distribution is smaller than the above range, it may cause fish eyes on the film. In order to expand the molecular weight distribution, multi-stage polymerization can be carried out.

(A2) Z average molecular weight (Mz) and weight calculated based on the measured value of gel permeation chromatography (GPC) of the propylene-ethylene block copolymer (A) insoluble in n-decane at room temperature (Dinsol) The ratio of average molecular weight (Mw), ie, Mz/Mw, is 3.5 or more, preferably in the range of 3.5 to 6.0, and more preferably in the range of 4.0 to 5.0. When there are polymer components that deviate from the molecular weight distribution represented by Mw/Mn, the value of Mz/Mw becomes larger. If the value becomes larger, the fisheye may increase. Sometimes it is difficult to increase the value by polymerization, and in this case, the catalyst described later can be used to obtain the value.

It is found that the propylene-ethylene block copolymer (A) of the present invention has a Mz/Mw of 3.5 or more, which is the larger part (Dinsol), which is insoluble in n-decane at room temperature. Although there are many high molecular weight components, the combination The propylene-ethylene block copolymerization Body (A) and the ethylene-based elastomer (B) of the present invention described later to obtain a surface protective film with less (reduced) fish eyes.

(A3) The propylene-ethylene block copolymer (A) insoluble in n-decane at room temperature (Dinsol) has an ultimate viscosity [η]insol in the range of 1.5~2.5dl/g in decalin at 135°C. The lower limit of the limiting viscosity [η] insol is preferably 1.7 dl/g, more preferably 1.9 dl/g, and the upper limit of the limiting viscosity [η] insol is preferably 2.4 dl/g, more preferably 2.3 dl/g.

When using a propylene-ethylene block copolymer whose limiting viscosity [η]insol deviates from the above range, the obtained propylene copolymer composition for a surface protective film tends to have poor film formability. In addition, in the case of using a propylene-ethylene block copolymer below this range, the fish eyes of the obtained film may increase, and in the case of using a propylene-ethylene block copolymer exceeding this range, there may be The surface roughness of the obtained film is reduced.

As a method for controlling the propylene-ethylene block copolymer (A) within the range that satisfies the above-mentioned requirement (1), as described in the section of the propylene-ethylene block copolymer (A) production method below, the use of The first polymerization step polymerizes the part (Dinsol) which is mainly composed of homopolypropylene or propylene-ethylene random copolymer which is insoluble in n-decane at room temperature, and the second polymerization step is used to make propylene-ethylene random copolymer elastomer as the main component. When the part (Dsol) of the components soluble in n-decane at room temperature is polymerized, by controlling the amount of hydrogen supplied in the first polymerization step, etc., the part insoluble in n-decane at room temperature (Dinsol) can be placed in decalin at 135°C. The ultimate viscosity [η]insol is controlled within the above range.

(A4) The propylene-ethylene block copolymer (A) soluble in n-decane at room temperature (Dsol) has an ultimate viscosity [η]sol in the range of 3.0~5.5dl/g in decalin at 135°C. The lower limit of the limiting viscosity [η]sol is preferably 3.2 dl/g, more preferably 3.5 dl/g, and the upper limit of the limiting viscosity [η] sol is preferably 5.2 dl/g, more preferably 5.0 dl/g.

If it is more than the above lower limit value, the obtained surface protective film has excellent blocking resistance; if it is less than the upper limit value, the production of fish eyes of the obtained surface protective film can be sufficiently suppressed.

As a method of controlling the propylene-ethylene block copolymer (A) within the range that satisfies the above-mentioned requirement (A4), as described below, in the first polymerization step, homopolypropylene or propylene-ethylene random copolymer Polymerization of the part (Dinsol) insoluble in n-decane at room temperature as the main component, and polymerization of the part (Dsol) soluble in n-decane at room temperature with propylene-ethylene random copolymer elastomer as the main component in the second polymerization step At this time, by controlling the hydrogen supply amount in the second polymerization step, etc., the limiting viscosity [η]sol of the portion soluble in n-decane at room temperature (Dsol) in decalin at 135°C can be controlled within the above range.

(A5) The content of the ethylene-derived skeleton in the room temperature n-decane-soluble part (Dsol) of the propylene-ethylene block copolymer (A) is in the range of 35-50% by weight. The lower limit of the content of the ethylene-derived skeleton of the portion (Dsol) soluble in n-decane at room temperature is preferably 37% by weight, more preferably 40% by weight.

If the content of the ethylene-derived skeleton in the room-temperature n-decane-soluble part (Dsol) is above the above lower limit, a surface protective film with excellent blocking resistance is obtained. If the room-temperature n-decane-soluble part (Dsol) If the content of the ethylene-derived skeleton of) is below the upper limit, a surface protective film with less fish eyes can be obtained.

As a method for controlling the propylene-ethylene block copolymer (A) within the range that satisfies the above-mentioned requirement (A5), as described in the section of the polymerization method of the propylene-ethylene block copolymer (A) below, it is used The first polymerization step polymerizes the part (Dinsol) which is mainly composed of homopolypropylene or propylene-ethylene random copolymer, which is insoluble in n-decane at room temperature, and uses the second polymerization step to use propylene-ethylene random copolymer elastomer as Master In the case of polymerization of the portion soluble in n-decane (Dsol) at room temperature, by controlling the amount of ethylene supplied in the second polymerization step, the portion (Dsol) soluble in n-decane at room temperature can be derived from ethylene The content of the skeleton is controlled within the above range.

The propylene-ethylene block copolymer (A) of the present invention preferably satisfies the following requirements (A6) and (A7) in addition to the aforementioned requirements (A1) to (A5).

(A6) The weight fraction of the propylene-ethylene block copolymer (A) soluble in n-decane at room temperature (Dsol) is in the range of 5-40% by weight. The lower limit of the amount of the portion (Dsol) soluble in n-decane at room temperature is more preferably 10% by weight, and the upper limit of the amount of the portion (Dsol) soluble in n-decane at room temperature is more preferably 30% by weight.

If the amount of the portion soluble in n-decane at room temperature (Dsol) is above the above lower limit, the obtained surface protective film will obtain sufficient surface roughness; if the amount of the portion soluble in n-decane at room temperature (Dsol) is Below the upper limit value, the obtained surface protective film has excellent rigidity and blocking resistance.

As a method of controlling the propylene-ethylene block copolymer (A) within the range that satisfies the above-mentioned requirement (A6), as described in the section of the propylene-ethylene block copolymer (A) production method below, use the The first polymerization step polymerizes the part (Dinsol) whose main component is homopolypropylene or propylene-ethylene random copolymer which is insoluble in n-decane at room temperature, and the second polymerization step uses propylene-ethylene random copolymer elastomer as its main component. When the room temperature n-decane-soluble part (Dsol) is polymerized, by controlling the ratio of the polymerization amount between the first polymerization step and the second polymerization step, the room-temperature n-decane-soluble part (Dinsol) can be combined with the The mass fraction of the portion (Dsol) of n-decane at room temperature is controlled within the above range.

(A7) The content of the ethylene-derived skeleton in the part (Dinsol) insoluble in n-decane at room temperature of the propylene-ethylene block copolymer (A) is in the range of 0-10% by weight Surrounding. More preferably, it is in the range of 0 to 8% by weight.

As a method of controlling the propylene-ethylene block copolymer (A) within the range that satisfies the above-mentioned requirement (A7), by adjusting the type of solid catalyst or electron-supplying compound used, it can be insoluble in the room The content of the ethylene-derived skeleton in the warm n-decane portion (Dinsol) is controlled within the above range.

The propylene-ethylene block copolymer (A) of the present invention can be produced by the following method, for example.

<Production method of propylene-ethylene block copolymer (A)>

For the propylene-ethylene block copolymer (A) of the present invention, the polymerization catalyst or polymerization conditions used in the production as described above are not particularly limited, and the known Ziegler catalyst or metallocene catalyst is preferred. In the presence of propylene, the first polymerization step ([Step 1]) is used to produce homopolypropylene or a propylene-ethylene random copolymer containing propylene and a small amount of ethylene, and then the second polymerization step ([Step 2]) is used to make propylene It is obtained by copolymerizing more ethylene with a larger amount than the first step to produce a propylene-ethylene copolymer elastomer.

"Polymerization Catalyst"

The propylene-ethylene block copolymer (A) of the present invention is preferably an organic compound containing a solid titanium catalyst component (I) and a metal atom selected from the group 1, 2, and 13 of the periodic table. It is obtained by polymerization in the presence of a metal compound (II) and an electron donor (III) as a catalyst for olefin polymerization as needed.

Specifically, those described in International Publication No. 2010/032793 can be exemplified.

The above solid titanium catalyst component (I) includes titanium, magnesium, halogen and cyclic ester Compound (a) and cyclic ester compound (b).

Among them, the cyclic ester compound (a) and the cyclic ester compound (b) that are considered to contribute to the wide molecular weight distribution of the propylene-based block copolymer used in this technology are listed below. The best compound. In addition, the respective components of titanium, magnesium, and halogen are obtained by known methods including the above-mentioned publications.

<Cyclic Ester Compound (a)>

Specific examples of the cyclic ester compound (a) of the present invention include 3,6-dimethylcyclohexane-1,2-dicarboxylic acid diisobutyl ester and 3,6-dimethylcyclohexane -Di-n-hexyl 1,2-dicarboxylate, 3,6-Dimethylcyclohexane-Di-n-octyl 1,2-dicarboxylate, 3-methyl-6-ethylcyclohexane-1, Diisobutyl 2-dicarboxylate, 3-methyl-6-ethylcyclohexane-1,2-dicarboxylate di-n-hexyl, 3-methyl-6-ethylcyclohexane-1,2 -Di-n-octyl dicarboxylate, 3-methyl-6-n-propylcyclohexane-1,2-diisobutyl dicarboxylate, 3-methyl-6-n-propylcyclohexane-1 ,2-Dicarboxylic acid di-n-hexyl ester, 3-methyl-6-n-propylcyclohexane-1,2-dicarboxylic acid di-n-octyl ester, 3,6-diethylcyclohexane-1,2 -Diisobutyl dicarboxylic acid, 3,6-diethylcyclohexane-1,2-dicarboxylic acid di-n-hexyl ester, and 3,6-diethylcyclohexane-1,2-dicarboxylic acid Di-n-octyl ester is a preferred example. These compounds can be produced by Diels Alder reaction.

For example, in the cyclic ester compound (a) having a diester structure, there are isomers such as cis and trans. Any structure has the same effect as the purpose of this technology, but if the content of trans is higher , It not only has the effect of expanding the molecular weight distribution, but also has a tendency to have higher activity or the stereoregularity of the obtained polymer, so it is particularly preferred. The ratio of the trans body in the cis body and the trans body is preferably 51% or more. More preferably, the lower limit is 55%, more preferably 60%, and particularly preferably 65%. On the other hand, the upper limit is preferably 100%, more preferably 90%, still more preferably 85%, and particularly preferably 79%.

<Cyclic Ester Compound (b)>

Specific examples of the cyclic ester compound (b) of the present invention include cyclohexane-1,2-dicarboxylic acid diisobutyl ester, cyclohexane-1,2-dicarboxylic acid dihexyl ester, and cyclohexane Alkyl-1,2-dicarboxylic acid diheptyl ester, cyclohexane-1,2-dicarboxylic acid dioctyl ester, and cyclohexane-1,2-dicarboxylic acid di-2-ethylhexyl ester, etc. as A better example. The reason is not only the performance of the catalyst, but also that the Diels Alder reaction can be used to produce these compounds more economically.

The cyclic ester compounds (a) and (b) of the present invention may be used alone, or two or more of them may be used in combination.

更佳為85莫耳%，尤佳為80莫耳%。 The molar ratio of the combination of cyclic ester compound (a) and cyclic ester compound (b) (cyclic ester compound (a)/(cyclic ester compound (a) + cyclic ester compound (b)) × 100 (mol Ear%)) is preferably 10 mol% or more. More preferably, it is 30 mol% or more, more preferably 40 mol% or more, and especially more preferably 50 mol%. Preferably the upper limit is 99 mol%, preferably 90 mol% ,

More preferably, it is 85 mol%, and particularly preferably, it is 80 mol%.

In the preparation of the solid titanium catalyst component (I) used in the present invention, the above-mentioned cyclic ester compounds (a) and (b), as well as magnesium compounds and titanium compounds are used. Moreover, as long as the purpose of the present invention is not impaired, the catalyst component (d) described later may be used in combination. As the magnesium compound of the present invention, it is particularly preferable to use magnesium chloride.

<Titanium Compound>

As the titanium compound used for the preparation of the solid titanium catalyst component (I), specifically, titanium tetrahalide is preferred, and titanium tetrachloride is particularly preferred.

As the above-mentioned magnesium compound and titanium compound, for example, Japanese Patent Laid-Open No. 5-17043, Japanese Patent Laid-Open No. 3-7703, etc. The compound described in detail in.

The preparation of the solid titanium catalyst component (I) uses cyclic ester compounds (a) and (b), and known methods can be used without limitation. Specifically, for example, the method described in detail in International Publication No. 2010/032793 can be used.

<Aromatic carboxylic acid ester and/or compound having 2 or more ether bonds via several carbon atoms>

The solid titanium catalyst component (I) may further include aromatic carboxylic acid esters and/or compounds having two or more ether bonds via several carbon atoms (hereinafter also referred to as "catalyst component (d)" ). If the solid titanium catalyst component (I) contains the catalyst component (d), there are cases in which the catalyst activity can be improved, the stereoregularity can be improved, or the molecular weight distribution can be further expanded.

As the catalyst component (d), known aromatic carboxylic acid esters or polyether compounds preferably used in conventional catalysts for olefin polymerization can be used without limitation, for example, Japanese Patent Laid-Open No. 5-17084 or A compound described in Japanese Patent Laid-Open No. 2001-354714, etc.

As aromatic carboxylic acid ester, aromatic polyvalent carboxylic acid ester is preferable, and phthalic acid ester is more preferable. The phthalate esters are preferably ethyl phthalate, n-butyl phthalate, isobutyl phthalate, hexyl phthalate, heptyl phthalate, etc. Alkyl phthalate, particularly preferably diisobutyl phthalate.

2,2-二環己基-1,3-二甲氧基丙烷、及2,2-雙(環己基甲基)1,3-二甲氧基丙烷。 In addition, as specific compounds of the above-mentioned polyether compounds, 1,3-diethers are preferred, and 2-isopropyl-2-isobutyl-1,3-dimethoxypropane, 2,2 -Diisobutyl-1,3-dimethoxypropane, 2-isopropyl-2-isopentyl-1,3-dimethoxypropane,

2,2-Dicyclohexyl-1,3-dimethoxypropane, and 2,2-bis(cyclohexylmethyl)1,3-dimethoxypropane.

These compounds may be used individually by 1 type, and may be used in combination of 2 or more types.

In the solid titanium catalyst component (I), the halogen/titanium (atomic ratio) (ie, the number of moles of halogen atoms/the number of moles of titanium atoms) is preferably 2 to 100, preferably 4 to 90, cyclic Ester compound (a)/titanium (mole ratio) (i.e. cyclic ester compound (a) mol number/titanium atom mol number) and cyclic ester compound (b)/titanium (mole ratio) (i.e. The number of moles of the cyclic ester compound (b)/the number of moles of titanium atoms) is preferably 0.01-100, preferably 0.2-10.

Here, as a preferable ratio of the cyclic ester compound (a) to the cyclic ester compound (b), 100×cyclic ester compound (a)/(cyclic ester compound (a) + cyclic ester compound (b) The lower limit of the value (mole%) of) is 5 mol%, preferably 25 mol%, more preferably 40 mol%, especially more preferably 50 mol%. The upper limit is 99 mol%, preferably 90 mol%, more preferably 85 mol%, and particularly preferably 80 mol%.

The magnesium/titanium (atomic ratio) (ie, the molar number of magnesium atom/the molar number of titanium atom) is preferably 2-100, preferably 4-50.

In addition, components that may be included in addition to the cyclic ester compounds (a) and (b), for example, the content of the catalyst component (c) and the catalyst component (d) is preferably relative to the cyclic ester compound (a) And (b) 100% by weight is 20% by weight or less, more preferably 10% by weight or less.

As more detailed preparation conditions of the solid titanium catalyst component (I), in addition to the use of cyclic ester compounds (a) and (b), for example, EP585869A1 (European Patent Application Publication No. 0585869 Specification) can be preferably used. Or the conditions described in Japanese Patent Laid-Open No. Hei 3-7703, etc.

<Organic metal compound catalyst component (II)>

As the catalyst component (II) of the organometallic compound, examples include those selected from the periodic table Organometallic compounds of Group 1, Group 2 and Group 13 metal atoms. Specifically, compounds containing Group 13 metals, such as organoaluminum compounds, alkylated complexes of Group 1 metals and aluminum, and organometallic compounds of Group 2 metals, can be used. Among them, an organoaluminum compound is preferred.

As the organometallic compound catalyst component (II), specifically, the organometallic compound catalyst component described in known documents such as the above-mentioned EP585869A1 can be cited as a preferable example.

<Electronic Donor (III)>

In addition, the olefin polymerization catalyst contains the above-mentioned organometallic compound catalyst component (II) and at the same time, optionally contains an electron donor (III). As the electron donor (III), preferably, an organosilicon compound can be cited. As the organosilicon compound, vinyl triethoxysilane, diphenyldimethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, and bicyclic Pentyl dimethoxysilane.

In addition, the alkoxysilane compound described in International Publication No. 2004/016662 is also a preferable example of the above-mentioned organosilicon compound. Specific examples of alkoxysilane compounds include dimethylaminotriethoxysilane, diethylaminotriethoxysilane, dimethylaminotrimethoxysilane, diethylaminotrimethoxysilane, Diethylaminotri-n-propoxysilane, di-n-propylaminotriethoxysilane, methyl n-propylaminotriethoxysilane, tertiary butylaminotriethoxysilane, ethyl n-propyl Triethoxysilane, ethylisopropylaminotriethoxysilane, and methylethylaminotriethoxysilane.

In addition, as other examples of the above-mentioned organosilicon compounds, specific examples include (perhydroquinoline) triethoxysilane, (perhydroisoquinoline) triethoxysilane, (1,2,3,4- Tetrahydroquinoline) triethoxysilane, (1,2,3,4-tetrahydroisoquinoline) triethoxysilane, and octamethyleneiminotriethoxysilane, etc.

These organosilicon compounds can also be used in combination of two or more kinds.

In addition, as other compounds that can be used for the electron donor (III), the aromatic carboxylic acid ester defined as the above-mentioned catalyst component (d) and/or the ether bond having two or more via several carbon atoms can also be cited The compound (polyether compound) as a preferred example.

In addition, the catalyst for olefin polymerization may optionally contain other components useful for olefin polymerization in addition to the above-mentioned components. Examples of other components include carriers such as silica, antistatic agents, particle flocculants, storage stabilizers, and the like. When particles are produced using, for example, magnesium chloride and ethanol as a particle aggregating agent, sorbitan distearate or the like is used as a preferable compound.

<Polymerization method of propylene-ethylene block copolymer (A)>

The propylene-ethylene block copolymer (A) of the present invention is preferably obtained by continuously implementing the following two steps ([Step 1] and [Step 2]) by using a polymerization device in which two or more reaction devices are connected in series. obtain.

[Step 1] Under the polymerization temperature of 0~100℃ and the polymerization pressure of normal pressure~5MPa gauge pressure, propylene is polymerized alone, or propylene and ethylene are copolymerized. In [Step 1], by setting the supply amount of ethylene to a small amount relative to propylene, the polypropylene or propylene-ethylene random copolymer produced in [Step 1] becomes a propylene-ethylene block copolymer (A) It is the main component of the part (Dinsol) that is insoluble in n-decane at room temperature.

[Step 2] Copolymerize propylene and ethylene at a polymerization temperature of 0-100°C and a polymerization pressure of normal pressure to 5MPa gauge pressure. In [Step 2], by increasing the supply amount of ethylene relative to propylene compared to that in [Step 1], the prepared in [Step 2] The produced propylene-ethylene copolymer elastomer becomes the main component of the propylene-ethylene block copolymer (A) which is soluble in n-decane at room temperature (Dsol).

Thus, the necessary conditions (A1)~(A3) and (A7) of Dinsol can be satisfied by the adjustment of the polymerization conditions in [Step 1], and Dsol can be satisfied by the adjustment of the polymerization conditions in [Step 2] The necessary conditions (A4) and (A5). In addition, the composition ratio of the propylene-ethylene block copolymer (A) insoluble in room temperature n-decane (Dinsol) and the propylene-ethylene block copolymer (A) in the room temperature n-decane-soluble portion (Dsol) The necessary condition (A6) can be controlled by adjusting the amount ratio of the polymer produced in [Step 1] and [Step 2].

The essential condition (A3) of the propylene-ethylene block copolymer (A), the part insoluble in n-decane at room temperature (Dinsol) in decalin at 135°C, the limiting viscosity [η] insol can be determined by [Step 1] The supply amount of molecular weight regulators such as hydrogen is adjusted.

The limiting viscosity [η]sol of Dsol in the required condition (A4) at 135°C decalin can be adjusted by the supply amount of molecular weight regulators such as hydrogen in [Step 2].

The content of the ethylene-derived skeleton in the propylene-ethylene block copolymer (A) soluble in n-decane at room temperature (Dsol) of the necessary condition (A7) can be determined by the amount of ethylene supplied in [Step 2] Wait and adjust.

The composition of the necessary condition (A6) of the ethylene block copolymer (A) that is insoluble in room temperature n-decane (Dinsol) and the propylene-ethylene block copolymer (A) that is soluble in room temperature n-decane (Dsol) The ratio and the melt flow rate of the propylene-ethylene block copolymer (A) can be appropriately adjusted by adjusting the ratio of the amount of the polymer produced in [Step 1] and [Step 2].

The content of the ethylene-derived skeleton in the ethylene block copolymer (A) insoluble in n-decane at room temperature (Dinsol) of the necessary condition (A5) can also be adjusted by adjusting the solid catalyst or electron-supplying compound used The type is adjusted. Moreover, it can also be adjusted by the supply amount of ethylene in [Step 1], etc.

In addition, the propylene-ethylene block copolymer (A) used in the present invention can also be used in the presence of a polymerization catalyst to separately produce the propylene-ethylene random copolymer produced in [Step 1] of the above method and the above After the propylene-ethylene random copolymer elastomer produced in [Step 2] of the method, it is produced by blending using these physical means.

<Ethylene Elastomer (B)>

The ethylene elastomer (B), which is one of the components contained in the propylene copolymer composition for surface protection of the present invention, is ethylene that satisfies the following requirements (B1) to (B2) and α of carbon number 3-20 -Random copolymers of olefins.

As long as the ethylene-based elastomer (B) of the present invention satisfies the following requirements, the polymerization catalyst or polymerization conditions used are not particularly limited. In addition, the ethylene-based elastomer (B) may be used singly or in two or more types.

(B1) The melt flow rate (MFR) at 190°C under a load of 2.16kg is in the range of 0.3~1.0g/10 minutes. The lower limit of MFR is preferably 0.4 g/10 minutes, more preferably 0.5 g/10 minutes, and the upper limit of MFR is preferably 0.9 g/10 minutes, more preferably 0.8 g/10 minutes.

丙烯共聚合體組成物之擠出特性及所獲得之表面保護膜之魚眼較少，耐黏連性優異，若乙烯系彈性體(B)之MFR為上限值以下，則所獲得之表面保護膜之魚眼較少，表面粗糙度優異。 If the MFR of the ethylene elastomer (B) is above the above lower limit, then

The extrusion characteristics of the propylene copolymer composition and the obtained surface protective film have fewer fish eyes and excellent blocking resistance. If the MFR of the ethylene elastomer (B) is below the upper limit, the obtained surface protection The film has fewer fish eyes and excellent surface roughness.

As a method of controlling the MFR of the ethylene-based elastomer (B) within the above-mentioned range, a known method can be suitably adopted. In addition, for example, it can be controlled within the above-mentioned range by selecting a suitable one from commercially available ethylene-based elastomers.

(B2) The density is in the range ^{of 860~900kg/m 3.} The lower limit of the density of the ethylene elastomer (B) is preferably 870 kg/m ³ , more preferably 875 kg/m ³ , and the upper limit of the density of the ethylene elastomer (B) is preferably 895 kg/m ³ , more preferably 890 kg /m ³ , more preferably 889 kg/m ³ , most preferably 888 kg/m ³ .

If the density of the ethylene-based elastomer (B) is within the above range, fish eyes of the obtained surface protective film can be appropriately suppressed.

As a method of controlling the density of the ethylene-based elastomer (B) within the above-mentioned range, a known method can be suitably adopted. In addition, for example, it can be controlled within the above-mentioned range by selecting a suitable one from commercially available ethylene-based elastomers.

That is, the surface layer of the surface protective film of the present invention exhibits the average surface roughness as described later, is excellent in blocking resistance, and the reason for suppressing fish eyes is not clear. The copolymer (A) is blended with a relatively high-viscosity ethylene elastomer (B) that does not become the nucleus of fish eyes, and the area where the ethylene elastomer (B) component of the propylene copolymer composition for surface protective films is blended The size (dispersed particle size) becomes larger, and the surface roughness of the film becomes coarse by forming it, and the blocking resistance is significantly improved.

<Propylene copolymer composition for surface protective film>

The propylene copolymer composition for a surface protective film of the present invention [hereinafter, sometimes referred to as "propylene copolymer composition"] is a composition suitable for forming the surface layer of a surface protective film, and contains the above-mentioned propylene-ethylene block copolymer The combined body (A) is 75 to 97% by weight, and the above-mentioned ethylene elastomer (B) is 3 to 25% by weight [wherein, (A)+(B)=100% by weight].

The lower limit of the content of the propylene-ethylene block copolymer (A) contained in the propylene copolymer composition of the present invention is preferably 76% by weight, more preferably 77% by weight, and the upper limit is preferably 96% by weight, more preferably It is 95% by weight, more preferably 93% by weight. In addition, the lower limit of the content of the ethylene-based elastomer (B) is preferably 4% by weight, more preferably 5% by weight, still more preferably 7% by weight, and the upper limit is preferably 24% by weight, more preferably 23% by weight.

If the blending amount of the ethylene-based elastomer (B) is more than the above lower limit value, the obtained surface protective film will have excellent surface roughness and suppress fish eyes, and if it is less than the above upper limit value, the film formability will be excellent.

)較佳為處於0.5~50g/10分鐘之範圍，下限更佳為3g/10分鐘，上限更佳為6g/10分鐘。若MFR

為上述範圍，則膜成形性優異，故而較佳。 In addition, the propylene copolymer composition of the present invention usually has a melt flow rate (MFR) at 230°C and a load of 2.16 kg

) Is preferably in the range of 0.5-50 g/10 minutes, the lower limit is more preferably 3 g/10 minutes, and the upper limit is more preferably 6 g/10 minutes. If MFR

The above range is preferable because it has excellent film formability.

For the purpose of further imparting impact resistance, transparency, dimensional stability, and imparting high-speed extrusion sheet formability to the obtained surface protective film, the propylene copolymer composition of the present invention may also be used without impairing the present invention. The polyethylene resin (C) or other thermoplastic resins are blended as necessary within the scope of the purpose of the invention.

For example, when the propylene copolymer composition of the present invention is a composition containing a propylene-ethylene block copolymer (A), an ethylene elastomer (B) and a polyethylene resin (C), the polyethylene resin (C) The amount of) is usually 0 to 30 parts by mass, preferably 1 to 20 parts by mass relative to 100 parts by mass of the propylene-ethylene block copolymer (A). In addition, the ratio of the ethylene-based elastomer (B) to the polyethylene resin (C) can be arbitrarily adjusted depending on the purpose.

The propylene copolymer composition of the present invention may also contain vitamins, antioxidants, heat-resistant stabilizers, weather-resistant stabilizers, lubricating agents, anti-blocking agents, mineral oil, etc., as needed, within the scope of not impairing the purpose of the present invention. Additives. That is, the surface layer of the surface protective film of the present invention may optionally contain the various additives described above within a range that does not impair the purpose of the present invention.

<Production of propylene copolymer composition for surface protective film>

The propylene copolymer composition for a surface protective film of the present invention can be produced by melt-kneading the above-mentioned propylene-ethylene block copolymer (A) and ethylene elastomer (B), or it can also be produced by mixing p-propylene- The pellets of the ethylene block copolymer (A) are granulated and the pellets of the ethylene elastomer (B) are dry blended to produce. Preferably, a method of manufacturing by melt kneading can be used. In this case, a continuous extruder or a closed kneader can be used. For example, devices such as a single-screw extruder, a twin-screw extruder, a mixing roll, a Banbury mixer, and a kneader can be cited. Among these, it is preferable to use a single-screw extruder and/or a twin-screw extruder from the viewpoints of economy, processing efficiency, and the like.

The propylene copolymer composition for a surface protective film of the present invention can be preferably used as a composition for forming a surface layer of a surface protective film having a surface layer and an adhesive layer.

<Surface Protection Film>

The surface protective film of the present invention has a film formed of the above-mentioned propylene copolymer composition for a surface protective film as a surface layer. The surface protection film of the present invention may be formed in a single layer, or may be a laminated film of at least two layers having an adhesive layer on one side of the surface layer.

<Surface layer>

The surface layer of the surface protective film of the present invention is formed of the above-mentioned propylene copolymer composition for surface protective film.

<Adhesive layer>

As the material for forming the adhesive layer of the surface protection film of the present invention, there is no particular limitation as long as the surface protection film can be attached to the adherend. For example, ethylene vinyl acetate (EVA, Ethylene Vinyl Acetate) series, Styrene-butadiene rubber (SBR, Styrene Butadiene Rubber) series, styrene-isoprene-styrene (SIS, Styrene Isoprene Styrene) series, styrene-butadiene-styrene (SBS, Styrene-Butadiene) -Styrene) series, Styrene-Ethylene-Butylene-Styrene (SEBS, Styrene-Ethylene-Butylene-Styrene) series, butyl elastic system, natural elastic system, and acrylic adhesives.

As a material for forming the adhesive layer, linear low-density polyethylene (LLDPE) ^{with a density of 0.900 kg/m 3 or less can also be used.}

In addition, as a material for forming the above-mentioned adhesive layer, a propylene-based random block copolymer described in Japanese Patent Laid-Open No. 2009-185239, which is polymerized by a metallocene catalyst system, can also be used.

When the adhesive is formed into a film by co-extrusion using a T-die co-extrusion molding method, EVA-based, SEBS-based, and linear low-density polyethylene (LLDPE) can be preferably used. In addition, when the adhesive is applied to the base film, an acrylic adhesive can be preferably used.

The adhesive layer in the surface protective film of the present invention may optionally contain additives such as vitamins, antioxidants, heat-resistant stabilizers, weather-resistant stabilizers, mineral oil, etc., within the scope of not impairing the purpose of the present invention.

The surface protection film of the present invention has a film formed of the above-mentioned propylene copolymer composition for surface protection film as a surface layer, and optionally an adhesive layer, but as long as it has a layer formed of the above-mentioned propylene copolymer composition for surface protection film as a surface layer The surface layer can also have an intermediate layer on the other side or between the adhesive layer. The middle layer can be Single layer or more than two layers.

<Middle layer>

The intermediate layer of the surface protective film of the present invention can also be provided for the purpose of controlling the mechanical strength or transparency of the surface protective film. In addition, when the adhesion with the surface layer and the adhesive layer is insufficient, it can also contain polyolefin resin Or adhesive resin or adhesive layer with adhesive.

As the intermediate layer, as long as it does not interfere with the functions of the surface layer and the adhesive layer, there are no particular restrictions. Generally speaking, crystalline polyolefins such as polypropylene or polyethylene with a melting point of 100°C or higher, polyesters, polyamides, etc. can be used. Polyolefin-based elastomers, etc.

When it is desired to impart adhesiveness to the intermediate layer, modified polyolefin or polyolefin elastomer, styrene elastomer, polyester elastomer, etc. can be used.

Among them, it is preferable to use polypropylene or polyolefin elastomer as the intermediate layer in terms of productivity and transparency.

The thickness of the surface protection film of the present invention may be appropriately determined depending on the purpose, and may be set to 10 to 200 μm, for example. The thickness of the surface layer can be set to 8~150μm, and the thickness of the adhesion layer can be set to 2~50μm.

Since the surface layer of the surface protective film of the present invention is formed using the above-mentioned propylene copolymer composition for surface protective film, it can effectively suppress fish eyes. In addition, the surface protective film of the present invention with such a surface layer is not easy to adhere to the contact adhesive layer when the surface protective film is wound into a roll shape, and has excellent anti-blocking properties. Rolling out of the roll film Excellent performance.

The surface where the surface layer that becomes the surface of the surface protective film is exposed, that is, the surface opposite to the adhesive layer side is preferably formed with fixed concavities and convexities, and more preferably as a display The average surface roughness Ra (arithmetic average roughness) of the parameter of the surface condition is preferably 0.5 μm or more, more preferably 0.6 μm or more. When the surface on the surface layer side of the surface protection film of the present invention has such an average surface roughness Ra, it has fixed unevenness, whereby when the surface protection film is wound into a roll, the overlapped film and The contact of the adhesive layer becomes a point contact, the contact area is reduced, so the adhesion with the adhesive layer is suppressed, and the surface protection film has excellent blocking resistance and excellent roll-out properties of the roll film.

The surface layer having such an average surface roughness can be easily obtained when the above-mentioned propylene-ethylene block copolymer of the present invention is formed into a film by a common method.

The surface layer of the surface protective film of the present invention exhibits such an average surface roughness, excellent blocking resistance, and the reason for suppressing fish eyes is not clear. The present inventor believes that by adding a propylene-ethylene block copolymer ( A) The area size (dispersion) of the ethylene-based elastomer (B) with a higher viscosity that does not become the nucleus of the fish eye, and the ethylene-based elastomer (B) component in the propylene copolymer composition for surface protective film is formulated The particle size) becomes larger, and the surface roughness of the film becomes coarse by forming it, and the blocking resistance is significantly improved.

Furthermore, it can be considered that the fish-eye core is caused by the high viscosity component of the elastomer component present in the propylene-ethylene block copolymer (A), especially the high molecular weight. Here, the unevenness of the surface of the film that improves the blocking resistance is in the order of several μm, for example, about 1 to 3 μm, while the FE core is in the order of tens of μm, for example, about 10 to 50 μm, and the size levels are different.

<Manufacturing method of surface protective film>

The surface protection film of the present invention can adopt various known methods. For example, by combining the above-mentioned propylene copolymer composition for surface protection film with a polymer that forms an intermediate layer if necessary. Combine the single-layer/multi-layer surface protection film from the method of T-molded film into film shape and the method of round-shaped molded film into tube shape. In addition, the surface protection film formed by the film formed by these methods and other films may be laminated in multiple layers by a dry lamination method or an extrusion lamination method.

In addition, the surface film formed by the above-mentioned method can be appropriately extended and used.

The adhesive layer of the surface protection film of the present invention is formed by various known methods. For example, a method of coating the adhesive on a substrate including a surface layer using a coater, a co-extrusion method of forming a multilayer film with the substrate and the adhesive using a T-die or a circular die, and the like can be cited.

[Example]

Hereinafter, the present invention will be explained more specifically based on examples, but the present invention is not limited to these examples.

The measuring methods of physical properties in the examples and comparative examples are as follows.

(1) MFR (melt flow rate): g/10 minutes

MFR is measured in accordance with ASTM D1238 (230°C or 190°C, load 2.16kg).

(2) Room temperature n-decane soluble part (Dsol)

200 ml of n-decane was added to 5 g of a sample of the final product [ie, propylene-ethylene block copolymer (A)], and the mixture was heated and dissolved at 145°C for 30 minutes. It takes about 3 hours to cool to 20°C and let it stand for 30 minutes. After that, the precipitate (hereinafter referred to as n-decane insoluble portion: Dinsol) was separated by filtration. The filtrate was poured into approximately 3 times the amount of acetone, and the components dissolved in n-decane were analyzed (precipitate (A)). The precipitate (A) is separated from acetone by filtration, and the precipitate is dried. In addition, even if the filtrate side was concentrated and dried, no residue was confirmed.

The amount of n-decane soluble part at room temperature is calculated by the following formula.

The soluble part of n-decane at room temperature (wt%)=[weight of precipitate (A)/weight of sample]×100

(3) The content of the skeleton derived from ethylene

In order to determine the concentration of the ethylene-derived skeleton in the propylene-ethylene block copolymer (A) insoluble in n-decane at room temperature (Dinsol) and in the n-decane soluble part (Dsol) at room temperature, 20-30 mg of the sample was dissolved After in 0.6ml of 1,2,4-trichlorobenzene/deuterobenzene (2:1) solution, carbon nuclear magnetic resonance analysis ( ¹³ C-NMR) was performed. The quantifications of propylene, ethylene, and α-olefins are determined based on the binary linkage distribution.

For example, in the case of propylene-ethylene copolymer, PP=Sαα, EP=Sαγ+Sαβ, EE=1/2(Sβδ+Sδδ)+1/4Sγδ, by the following calculation formula (Eq-1) and (Eq-2) Find it out.

Propylene (mol%)=(PP+1/2EP)×100/[(PP+1/2EP)+(1/2EP+EE)]…(Eq-1)

Ethylene (mol%)=(1/2EP+EE)×100/[(PP+1/2EP)+(1/2EP+EE)]…(Eq-2)

(4) Ultimate viscosity [η]

Using decalin solvent, the measurement was performed at 135°C. About 20 mg of the sample was dissolved in 15 ml of decalin, and the specific viscosity ηsp was measured in an oil bath at 135°C. After adding 5 ml of decalin solvent to the decalin solution for dilution, the specific viscosity ηsp was measured in the same manner. This dilution operation is further repeated twice, and the concentration (C) is obtained by extrapolating the value of ηsp/C to 0 as the limiting viscosity.

[η]=lim(ηsp/C)(C→0)

(5) Haze (HAZE)

It is measured according to JIS K-7105.

(6) Average surface roughness (Ra)

According to JIS-B0601:2001, use a surface roughness measuring machine to measure the average surface roughness Ra of the MD direction of the surface layer of the surface protective film at a measuring speed of 0.15mm/min and n=3, and calculate the arithmetic average.

(7) Fisheye (FE)

Use the FE counter to count the number of FEs (pieces/m ² ) above 100 μm in size.

[Production example 1 (A-1) of propylene-ethylene block copolymer (A)] (1) Preparation of solid titanium catalyst components

After the high-speed stirring device (manufactured by Special Machinery Industry (TK emulsifier M type)) with an internal volume of 2 liters is fully replaced with nitrogen, 700ml of refined decane, 10g of commercially available magnesium chloride, 24.2g of ethanol and products are added to the device 3 g of RHEODOL SP-S20 (Sorbitan Distearate manufactured by Kao Co., Ltd.), the temperature of the system was raised while stirring the suspension, and the suspension was stirred at 120°C and 800 rpm for 30 minutes. Secondly, while stirring the suspension at high speed so as not to produce any sediment, transfer the suspension to 1 liter of refined product that has been cooled to -10°C in advance using a tube made of Teflon (registered trademark) with an inner diameter of 5 mm. Decane in a 2 liter glass flask (with a stirrer). The solid produced by pipetting was filtered and thoroughly washed with purified n-heptane to obtain a solid adduct with 2.8 mol of ethanol coordinated to 1 mol of magnesium chloride.

The solid adduct was made into a suspension with decane, and the solid adduct, converted to 23 millimoles of magnesium atom, was introduced with stirring to 100 ml of titanium tetrachloride kept at -20°C. Obtain a mixed solution. It took 5 hours to raise the temperature of the mixed solution to 80°C. After reaching 80°C, 3,6-dimethylcyclohexane was added in an amount of 0.085 mol relative to 1 mol of magnesium atom of the solid adduct. -Diisobutyl 1,2-dicarboxylic acid (a mixture of cis and trans isomers), the temperature is increased to 110°C in 40 minutes. After reaching 110°C, cyclohexane- 1,2-dicarboxylic acid diisobutyl ester (cis isomer, trans isomer) was added in an amount of 0.0625 mol relative to 1 mol of magnesium atom of the solid adduct. Formula body mixture), keep the temperature while stirring at 110°C for 90 minutes, thereby allowing the reaction.

After the 90-minute reaction, the solid part was collected by hot filtration, the solid part was resuspended with 100 ml of titanium tetrachloride, and then the temperature was raised. After reaching 110°C, the temperature was maintained while stirring for 45 minutes. The reaction. After the 45-minute reaction, the solid part was collected by hot filtration again, and washed thoroughly with decane and heptane at 100°C until the free titanium compound was not detected in the washing solution.

The solid titanium catalyst component (α-1) prepared by the above operation is stored as a decane suspension, and a part of it is dried for the purpose of investigating the composition of the catalyst.

The composition of the solid titanium catalyst component (α-1) thus obtained is 3.2% by mass of titanium, 17% by mass of magnesium, 57% by mass of chlorine, 3,6-dimethylcyclohexane-1,2-dicarboxylate 10.6% by mass of diisobutyl acid, 8.9% by mass of diisobutyl cyclohexane- 1,2-dicarboxylate, and 0.6% by mass of ethanol residue.

(2) Manufacturing of pre-polymerized catalyst

Insert 230g of solid catalyst component, 67mL of triethylaluminum, and 115L of heptane into a polymerization tank with a stirrer with an inner volume of 200L, keep the internal temperature at 15-20°C, insert 2300g of propylene, and stir for 60 minutes. reaction. After the polymerization is completed, the solid content is precipitated, and the unreacted propylene is replaced with nitrogen to obtain a prepolymerization catalyst.

(3) Formal aggregation

To a circulating tubular polymerizer with a jacket with an inner volume of 58L, propylene was continuously supplied at 43kg/hour, hydrogen was continuously supplied at 124NL/hour, and the catalyst slurry produced in (2) was used as solid at 0.69g/hour The catalyst component is continuously supplied, triethylaluminum is continuously supplied at 2.3ml/hour, and dicyclopentyldimethoxysilane is continuously supplied at 2.4ml/hour, and the polymerization is carried out in a state where there is no gas phase full of liquid. The temperature of the tubular polymerizer is 70°C and the pressure is 3.34MPa/G.

The obtained slurry was sent to a bowl-shaped polymerizer with a stirrer with an inner volume of 100 L, and then polymerized. To the polymerizer, propylene was supplied at 45 kg/hour, and hydrogen was supplied so that the hydrogen concentration in the gas phase became 4.0 mol%. The polymerization was carried out at a polymerization temperature of 70°C and a pressure of 3.14 MPa/G.

The obtained slurry was transferred to a 2.4L pipette, and the slurry was vaporized to perform gas-solid separation. At this time, in order to adjust the reaction amount, Atmer 163 (manufactured by Croda Japan Co., Ltd.) was continuously supplied at 5.9 g/hour and brought into contact with polypropylene homopolymer powder. After that, the powder was sent to a gas phase polymerizer with an inner volume of 480 L to perform block copolymerization of ethylene/propylene. Propylene, ethylene, and hydrogen are continuously supplied in such a way that the gas composition in the gas phase polymerizer becomes ethylene/(ethylene+propylene)=0.52 (molar ratio) and hydrogen/ethylene=0.048 (molar ratio). The polymerization was carried out at a polymerization temperature of 70°C and a pressure of 1.10 MPa/G.

The obtained propylene-ethylene block copolymer (A-1) was vacuum dried at 80°C.

[Production example 2 (A-2) of propylene-ethylene block copolymer (A)]

(1) Preparation of solid titanium catalyst component and (2) Preparation of prepolymerized catalyst were performed in the same manner as in Manufacturing Example 1, and (3) Main polymerization was performed by the following method.

(3) Formal aggregation

To a circulating tubular polymerizer with a jacket with an inner volume of 58L, propylene was continuously supplied at 43kg/hour, hydrogen was continuously supplied at 123NL/hour, and the catalyst slurry produced in (2) was used at 0.56g/hour. The solid catalyst component is continuously supplied, with 2.3ml/hour of triethylaluminum and 2.4ml/hour of dicyclopentyldimethoxysilane, and polymerization is carried out in a state where there is no gas phase full of liquid. The temperature of the tubular polymerizer is 70°C and the pressure is 3.34MPa/G.

The obtained slurry was sent to a bowl-shaped polymerizer with a stirrer with an inner volume of 100 L, and then polymerized. To the polymerizer, propylene was supplied at 45 kg/hour, and hydrogen was supplied so that the hydrogen concentration in the gas phase became 4.0 mol%. The polymerization was carried out at a polymerization temperature of 70°C and a pressure of 3.14 MPa/G.

The obtained slurry was transferred to a 2.4L pipette, and the slurry was vaporized to perform gas-solid separation. At this time, in order to adjust the reaction amount, Atmer 163 (manufactured by Croda Japan Co., Ltd.) was continuously supplied at 1.4 g/hour and brought into contact with polypropylene homopolymer powder. After that, the powder was sent to a gas phase polymerizer with an inner volume of 480 L to perform block copolymerization of ethylene/propylene. Propylene, ethylene, and hydrogen are continuously supplied in such a way that the gas composition in the gas phase polymerizer becomes ethylene/(ethylene+propylene)=0.52 (molar ratio) and hydrogen/ethylene=0.048 (molar ratio). The polymerization was carried out at a polymerization temperature of 70°C and a pressure of 1.10 MPa/G.

To the obtained propylene-ethylene block copolymer (A-2) at 80°C Carry out vacuum drying.

[Production example 3 (A-3) of propylene-ethylene block copolymer (A)]

(1) Preparation of solid titanium catalyst component and (2) Preparation of prepolymerized catalyst were performed in the same manner as in Manufacturing Example 1, and (3) Main polymerization was performed by the following method.

(3) Formal aggregation

To a circulating tubular polymerizer with a jacket with an inner volume of 58L, propylene was continuously supplied at 43kg/hour, hydrogen was continuously supplied at 123NL/hour, and the catalyst slurry produced in (2) was used at 0.58g/hour. The solid catalyst component is continuously supplied, with 2.3ml/hour of triethylaluminum and 2.4ml/hour of dicyclopentyldimethoxysilane, and polymerization is carried out in a state where there is no gas phase full of liquid. The temperature of the tubular polymerizer is 70°C and the pressure is 3.36 MPa/G.

The obtained slurry was sent to a bowl-shaped polymerizer with a stirrer with an inner volume of 100 L, and then polymerized. To the polymerizer, propylene was supplied at 45 kg/hour, and hydrogen was supplied so that the hydrogen concentration in the gas phase became 4.2 mol%. The polymerization was carried out at a polymerization temperature of 70°C and a pressure of 3.14 MPa/G.

The obtained slurry was transferred to a 2.4L pipette, and the slurry was vaporized to perform gas-solid separation. At this time, in order to adjust the reaction amount, Atmer 163 (manufactured by Croda Japan) was continuously supplied at 5.0 g/hour to contact the polypropylene homopolymer powder. After that, the powder was sent to a gas phase polymerizer with an inner volume of 480 L to perform block copolymerization of ethylene/propylene. Propylene, ethylene, and hydrogen are continuously supplied in such a way that the gas composition in the gas phase polymerizer becomes ethylene/(ethylene+propylene)=0.58 (mole ratio) and hydrogen/ethylene=0.048 (mole ratio). Carry out at polymerization temperature 70℃ and pressure 1.10MPa/G polymerization.

The obtained propylene-ethylene block copolymer (A-3) was vacuum dried at 80°C.

[Production example 4 (A-4) of propylene-ethylene block copolymer (A)]

(1) Preparation of solid titanium catalyst component and (2) Preparation of prepolymerized catalyst were performed in the same manner as in Manufacturing Example 1, and (3) Main polymerization was performed by the following method.

(3) Formal aggregation

To a circulating tubular polymerizer with a jacket with an inner volume of 58L, propylene was continuously supplied at 43kg/hour, hydrogen was continuously supplied at 123NL/hour, and the catalyst slurry produced in (2) was used at 0.55g/hour. The solid catalyst component is continuously supplied, with 2.3ml/hour of triethylaluminum and 2.4ml/hour of dicyclopentyldimethoxysilane, and polymerization is carried out in a state where there is no gas phase full of liquid. The temperature of the tubular polymerizer is 70°C and the pressure is 3.35 MPa/G.

The obtained slurry was sent to a bowl-shaped polymerizer with a stirrer with an inner volume of 100 L, and then polymerized. To the polymerizer, propylene was supplied at 45 kg/hour, and hydrogen was supplied so that the hydrogen concentration in the gas phase became 4.0 mol%. The polymerization was carried out at a polymerization temperature of 70°C and a pressure of 3.15 MPa/G.

The obtained slurry was transferred to a 2.4L pipette, and the slurry was vaporized to perform gas-solid separation. At this time, in order to adjust the reaction amount, Atmer 163 (manufactured by Croda Japan) was continuously supplied at 5.0 g/hour to contact the polypropylene homopolymer powder. After that, the powder was sent to a gas phase polymerizer with an inner volume of 480 L to perform block copolymerization of ethylene/propylene. The gas composition in the gas phase polymerizer becomes ethylene /(Ethylene+propylene)=0.52 (molar ratio), hydrogen/ethylene=0.022 (molar ratio), propylene, ethylene, and hydrogen are continuously supplied. The polymerization was carried out at a polymerization temperature of 70°C and a pressure of 1.10 MPa/G.

The obtained propylene-ethylene block copolymer (A-4) was vacuum dried at 80°C.

[Production example 5 of propylene-ethylene block copolymer (E) (E-5)] (1) Preparation of magnesium compounds

The reaction tank (inner volume of 500 liters) with a stirrer was fully replaced with nitrogen, 97.2 kg of ethanol, 640 g of iodine, and 6.4 kg of magnesium metal were added, and the reaction was carried out under reflux conditions while stirring until no hydrogen was generated in the system. A solid reaction product was obtained. The target magnesium compound (carrier of solid catalyst) is obtained by drying the reaction liquid containing the solid reaction product under reduced pressure.

(2) Preparation of solid catalyst components

To a reaction tank (inner volume 500 liters) with a stirrer fully replaced with nitrogen, 30 kg of the above-mentioned magnesium compound (not crushed), 95 liters of purified heptane (n-heptane), 4.4 liters of silicon tetrachloride, and adjacent 6.0 liters of dibutyl phthalate. The system was kept at 90°C, and 144 liters of titanium tetrachloride was added while stirring, and after reacting at 110°C for 2 hours, the solid content was separated and washed with purified heptane at 90°C. Furthermore, 228 liters of titanium tetrachloride was added, and it was made to react at 110 degreeC for 2 hours, It wash|cleaned fully with the purified heptane, and obtained the solid catalyst component.

(3) Preparation of pre-polymerized catalyst

Put 230 liters of refined heptane into a reaction tank with a stirrer with an internal volume of 500 liters, and supply 25 kg of the above-mentioned solid catalyst component, and supply triethyl aluminum at 1.0 mol/mol relative to the titanium atom in the solid catalyst component. The ratio of 1.8 mol/mol supplies dicyclopentyl dimethoxysilane. After that, propylene was introduced until the propylene partial pressure became 0.3 kg/cm ² G, and the reaction was carried out at 25° C. for 4 hours. After the completion of the reaction, the solid catalyst component was washed several times with purified heptane, and carbon dioxide was further supplied and stirred for 24 hours.

(4) Formal aggregation

The block polymerization is carried out using two-tank polymerization tanks connected in series.

As the first stage, a polymerization tank with a stirring blade (homogeneous polymerization tank) with an inner volume of 200 liters was supplied with propylene at 45 kg/h and hydrogen at 380 NL/h to conduct homogeneous polymerization. Supply the solid catalyst component that has completed the pre-polymerization treatment at a polymerization rate of 30 kg/hour, and supply triethyl aluminum and dicyclopentyl dimethoxy at 120 millimoles/hour and 12 millimoles/hour, respectively Silane was reacted at a polymerization temperature of 83°C and a polymerization tank pressure of 3.0 MPa (Gauge). At this time, use hydrogen to adjust so as to have a predetermined molecular weight. Next, the powder is continuously discharged from the polymerization tank at the front stage and transferred to the rear stage (block polymerization tank).

In the subsequent polymerization tank (block polymerization tank), propylene, ethylene, and hydrogen were supplied at a polymerization temperature of 60°C at 9.9 kg/h, 15.5 kg/h, and 400 NL/h, respectively. In addition, the catalyst activity control agent ethanol supplied from the upper part of the reactor was supplied at 4.4 g/h. The powder was continuously discharged from the subsequent polymerization tank to obtain propylene-ethylene block copolymer powder (PP-A).

The propylene-ethylene block copolymers (A-1) to (A-4) obtained in Production Examples 1 to 4 and the propylene-ethylene block copolymers (E-5) obtained in Production Example 5 The physical properties are shown in Table 1.

[Examples 1 to 8, Reference Example 1, and Comparative Examples 1 and 2]

As the propylene-ethylene block copolymer (abbreviated as "block copolymer" in Table 2) and ethylene elastomer (B) (abbreviated as "elastomer" in Table 2) produced in Production Examples 1 to 5, The trade name Tafmer-A-0585X manufactured by Mitsui Chemicals Co., Ltd.: MFR (190°C) = 0.5 g/10 min, density = 885 kg/m ^{3 is} set as the blending amount described in Examples 1 to 8, but Reference Example 1 does not The ethylene elastomer (B) (only propylene-ethylene block copolymer) is blended.

With respect to these 100 parts by weight, the heat stabilizer IRGANOX1010: 0.1 parts by weight, IRGAFOS168: 0.1 parts by weight, and 0.1 parts by weight of calcium stearate were mixed with a roller, and then a twin-shaft kneader made by Kobe Steel (screw diameter 30mm) was used to Melt and knead at 230°C to prepare a granular propylene copolymer composition.

A 25mm single-screw extruder installed on a single-layer T-die forming machine with a mold width of 250mm is used as a film forming machine to form a single-layer film with a thickness of 50μm.

Measure the haze, tensile modulus of elasticity and surface roughness of the obtained film Degree, linear expansion coefficient. In addition, the number of fisheyes was measured by an online fisheye counter (manufactured by HUTECH Corporation) during film formation.

The results are shown in Table 2.

[Discussion of Examples]

As shown in Table 2, the propylene-ethylene block copolymers (A-1) to (A-4) produced in Production Examples 1 to 4 were used to obtain the surface protective films shown in Examples 1 to 8 and each In comparison with the case where the ethylene-based elastomer (B) is not added (Reference Example 1), although the surface roughness of the film becomes larger, the number of fisheyes is reduced, and the fisheye grade is good.

As shown in Comparative Examples 1 and 2, it has been difficult to obtain a surface protective film of a propylene-ethylene block copolymer with the opposite properties of having a larger surface roughness and less fish eyes at the same time, such as the above-mentioned Examples 1-8. As shown, the surface protection film with more excellent balance can be obtained by the present invention.

(Industrial availability)

The surface protective film of the present invention can be used without limitation for various applications where the surface protective film is used, and because it exhibits sufficient transparency, it can be suitably used for the purpose of protecting the surface of optical films, optical components, electrical materials, etc. .

Claims (5)

A surface protective film characterized by having a film containing a propylene copolymer composition as a surface layer, the propylene copolymer composition containing a propylene-ethylene block copolymer meeting the following requirements (A1) to (A5) (A): 75~97% by weight and ethylene elastomer (B) satisfying the following requirements (B1)~(B2): 3~25% by weight (where (A)+(B)=100% by weight ), (A1) The ratio of the GPC-based weight average molecular weight Mw to the number average molecular weight Mn (Mw/Mn) of the component insoluble in n-decane at room temperature (Dinsol) is 5.0 or more; (A2) the component insoluble in n-decane at room temperature ( The ratio of GPC-based Z average molecular weight Mz to weight average molecular weight (Mz/Mw) of Dinsol) is 3.5 or more; (A3) the limiting viscosity of the component (Dinsol) insoluble in n-decane at room temperature in decalin at 135°C [η ]insol is 1.5~2.5dl/g; (A4) the component that is soluble in n-decane at room temperature (Dsol) has an ultimate viscosity [η]sol of 3.0~5.5dl/g in decalin at 135℃; (A5) can The content of the ethylene-derived skeleton of the component (Dsol) soluble in n-decane at room temperature is 35-50% by weight; (B1) Melt flow rate (MFR) measured by ASTM D1238 at 190°C under a load of 2.16 kg It is 0.3~1.0g/10 minutes; (B2) The density measured according to JIS K6922 is 860~900kg/m ³ . Such as the surface protective film of claim 1, wherein the propylene-ethylene block copolymer (A) has a room temperature n-decane-insoluble component amount of 70 to 90% by weight, and room temperature n-decane-soluble component amount of 10~ 30% by weight. Such as the surface protection film of claim 1 or 2, which has an adhesive layer on one side of the surface layer. A surface protecting film of copolymer composition with propylene, wherein: comprising satisfies the following requirement (A1) ~ (A5) of the propylene - ethylene block of copolymer (A): 75 ~ 97 wt% and satisfy the following necessary Conditions (B1) ~ (B2) of the ethylene elastomer (B): 3-25% by weight (wherein, (A) + (B) = 100% by weight), (A1) insoluble in room temperature n-decane component (Dinsol ) The ratio of GPC-based weight average molecular weight Mw to number average molecular weight Mn (Mw/Mn) is 5.0 or more; (A2) GPC-based Z average molecular weight Mz and weight average molecular weight of the component (Dinsol) insoluble in n-decane at room temperature The ratio (Mz/Mw) is 3.5 or more; (A3) the limiting viscosity of the component (Dinsol) that is insoluble in n-decane at room temperature in decalin at 135°C [η]insol is 1.5~2.5dl/g; (A4) can The limiting viscosity [η]sol of the component soluble in n-decane at room temperature (Dsol) in decalin at 135°C is 3.0~5.5dl/g; (A5) the component soluble in n-decane at room temperature (Dsol) is derived from ethylene The content of the skeleton is 35-50% by weight; (B1) The melt flow rate (MFR) measured by ASTM D1238 at 190°C and a load of 2.16kg is 0.3~1.0g/10 minutes; (B2) According to JIS The density measured by K6922 is 860~900kg/m ³ . Acrylic for surface protection film as in claim 4

Total polymer composition, wherein the propylene - weight component ethylene block of copolymer (A) of insoluble decane at room temperature of 70 to 90% by weight, soluble in room-temperature n component decane of 10 to 30 wt% .