JPH0362839A - Peelable protection film and composition therefor - Google Patents

Abstract

PURPOSE:To obtain a composition giving a protection film exhibiting moderate adhesivity and peelability to an adherend by compounding a specific propylene.1- butene random copolymer with a specific propylene.ethylene.alpha-olefin copolymer. CONSTITUTION:The objective peelable protection film is produced from a composition composed of (A) 100 pts.wt. of a propylene.1-butene random copolymer having a melt index of 0.1-100g/10min, a propylene content of 60-85mol% and a heat of crystal melting of 20-80Joule/g by DSC and (B) 6-50 pts.wt. of a propylene.ethylene.alpha-olefin copolymer having a propylene content of 50-80mol%, an ethylene content of 3-25 mol%, a 4-10C alpha-olefin content of 10-40mol% (the sum of the contents is 100mol%), an intrinsic viscosity of 0.1-3dl/g (in decalin at 135 deg.C) and a crystallinity of 5-40% determined by X-ray diffraction.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is used to prevent scratches, contamination, corrosion, etc. that occur during processing, transportation, or storage of metal products, plastic products, rubber products, etc. The present invention also relates to a polyolefin-based releasable protective film and a composition thereof, which can be temporarily coated on a surface and can be easily and integrally peeled off after the above objective has been achieved.

[Conventional technology]

Conventional removable protective films include, for example, ethylene,
Vinyl acetate copolymers (hereinafter referred to as EVA) and those containing low crystallinity ethylene/α-olefin as main components are used. Although these have good initial adhesion, they have the disadvantage that during long-term storage, especially when placed at high temperatures, the adhesive strength increases due to their lack of heat resistance, and the releasability deteriorates significantly. There is.

Japanese Patent Publication No. 58-45914 proposes a polyolefin-based releasable protective film with improved heat resistance of an EVA-based film.

However, although this film has improved heat resistance, when it is stored for a long time, the adhesive strength of the film increases due to changes over time, or when it is peeled off from the adherend, the adhesive strength of the film increases. There were some problems, such as remaining.

[Problem to be solved by the invention]

The purpose of the present invention is to solve the above problems by providing flexibility,
The film has excellent transparency, scratch resistance, and heat resistance, as well as moderate initial adhesion and peelability to adherends, as well as excellent cold workability during adhesion. It is an object of the present invention to provide a releasable protective film and a composition thereof that have little change over time and do not leave any bleed matter on the surface of an adherend even when peeled off.

[Means to solve the problem]

The present invention provides the following releasable protective film and its assembly. It is an acid.

(]) (A) Melt index (ASTM D123
8-65T.

230°C) is 0.1 to OOg/10min, the propylene content is 60 to 85 mol%, and the heat of crystal fusion measured by DSC method is 20 to 80 Joul.
e/g propylene/1-butene random copolymer 10
0 parts by weight, and (B) a propylene (a) content of 50 to 80 mol%, an ethylene (b) content of 3 to 25 mol%, and an α-olefin (C) having 4 to 10 carbon atoms. ill! content is 10 to 40 mol% and a + b + c = 100 mol% at 1:15'C in decalin solvent! A propylene/ethylene/α-olefin random copolymer having an ocular viscosity [η] of 0.1 to 3 clQ/g and a crystallinity of 5 to 40% as measured by X-ray diffraction method. A composition for a releasable protective film comprising parts by weight.

(2) A peelable protective film that is a single-layer or multilayer film, in which at least one layer located on the outermost surface is made of the composition described in (1) above.

As the propylene/1-butene random copolymer (A) in the present invention, one having the above characteristics (1) is used. That is, from null 1 to index (230°C) is 0.
．． 1-100g/10mln, propylene content 60
-85 mol%, crystal fusion heat of 20 to 80 Jou],
The e/g propylene/1-butene random copolymer is
It has excellent flexibility, transparency, scratch resistance, heat resistance, etc. By using such a copolymer as a base resin, the heat resistance of the film can be improved and the adhesive properties can be prevented from changing over time during storage. can do.

Such propylene/1-butene random J (polymer (A) is a catalyst formed from a solid titanium catalyst fraction and an organometallic compound component, or a catalyst formed from both of these components and an electron donor. The solid titanium catalyst component may be titanium trichloride or a titanium trichloride composition produced by various methods, or magnesila 11, a halogen, or an electron donor. , preferably contains an aromatic carboxylic acid ester or an alkyl group ether and titanium as essential components, and preferably has a specific surface area of 00rr
It is a titanium catalyst component with a support of r/g or more. Particularly suitable is one produced using the latter supported catalyst component.

As the organometallic compound component, organoaluminum compounds are suitable, such as trialkylaluminum, dialkylaluminum halide, alkyl aluminum sesquihalide, alkyl aluminum civalide, etc., and the suitable ones differ depending on the type of titanium catalyst component. . Suitable examples of electron donors include organic compounds containing nitrogen, phosphorus, sulfur, oxygen, silicon, boron, etc., such as esters and ethers.

In the present invention, the propylene/ethylene/α -Olefin random copolymer (B
). This propylene/ethylene/α-olefin random comonomer (B) has a propylene (a) content of 50-50-8O% and an ethylene (b) content of 3-2O%.
5 mol%, and the content of α-olefin (C) having 4 to 10 carbon atoms is 10 to 40 mol% (a + b +
c = 100 mol%) propylene ethylene α
- It is an olefin random terpolymer. Here, the α-olefin having 4 to 10 carbon atoms includes butene-1, pentene-1, hexene-1,4-methylpentene-1,3-methylpentene-1, heptene-1, octene-1, nonene-1, decene-1, dodecene-1,
Examples include tetradecene-1 and octadecene-1.

In addition, propylene, ethylene, α-
The intrinsic viscosity [η] of the olefin random copolymer (B) measured in decalin at 135°C is 0.1 to 3 dl.
,/g, crystallinity measured by X-ray diffraction method is 5
~40%, and by using such a low molecular weight and low crystallinity propylene/ethylene/α-olefin random copolymer (B), the initial adhesive strength with the adherend can be moderately increased. Make it something.

This propylene/ethylene/α-olefin terpolymer (B) is a solid titanium catalyst or organometallic compound catalyst similar to that used in the production of the propylene/1-butene random copolymer (A). It is produced by copolymerizing three components using a catalyst formed from, for example, an electron donor.

The polyolefin-based releasable protective film composition of the present invention comprises the propylene/1-butene random copolymer (A
) and 5 to 50 parts by weight of propylene/ethylene/α-olefin random copolymer (B). By using such a blending ratio,
Appropriate adhesive strength is obtained, transparency is good, there is little change over time, and removability after adhesion is ensured, and there is no blocking or residual bleed material after peeling.

The composition for a releasable protective film of the present invention may contain other resin components such as polyethylene resin within a range that does not contradict the purpose of the present invention, and may also contain antioxidants, ultraviolet absorbers, lubricants, nucleating agents, etc. , '41F antistatic agents, flame retardants, pigments, dyes, inorganic or organic fillers, and other various additives may be added.

To prepare the composition for a peelable protective film of the present invention,
Any known method can be used, such as a V-type blender,
A method of mixing with a mixing machine such as a ribbon blender, tumbler blender, Hengeno, Remixer, and/or
Or extruder, mixing roll, Banbury mixer
A method of kneading with a kneader such as a kneader or the like can be adopted.

The removable protective film of the present invention uses a film made of the above composition. As the removable protective film of the present invention, a single layer film made of the above composition can be used as it is.

A film laminated with other '14 fat films can also be used. When using a laminated film with other films, the film made of the composition of the present invention is laminated as an adhesive layer so as to be located on at least one outermost surface.

in this case! ! As other resin films serving as No. 4, polyolefin films such as polyethylene, polypropylene, poly-1-butene, etc., which have good adhesion with the composition of the present invention are preferred, but polyolefin films such as polyamide-1, polyester, etc. can be used via another adhesive layer. films may be laminated.

The releasable protective film of the present invention is produced by extrusion molding the composition as a single layer or as a layer with another resin film using a film molding machine such as a T-die molding machine.

The peelable protective film produced in this way can be used to coat the surfaces of articles such as metal products, plastic products, and rubber products with the layer made of the composition of the present invention as an adhesive layer, and can be used during processing, transportation, and storage of the above-mentioned articles. Prevents scratches, contamination, corrosion, etc.

In this case, since the adhesive layer made of the composition of the present invention has appropriate adhesive properties, it is easy to cover and peel with adhesive, and since it has heat resistance, there is little change in adhesive strength over time, and the adhesive layer maintains adhesiveness for a long period of time. and long-lasting peelability. Furthermore, the above film has excellent scratch resistance and does not cause any blocking phenomenon, so it is easy to process in a coated state, and coated articles are protected from scratches, contamination, etc.

〔Effect of the invention〕

As described in "2" below, according to the present invention, specific propylene 1
- Butene random copolymer with propylene, ethylene, α
- Contains Olefin Lander 11 polymer, which has excellent flexibility, transparency, scratch resistance, and heat resistance, and also has moderate adhesion and peelability to adherends, and cold workability during adhesion. It is possible to obtain a removable protective film that has excellent properties, shows little change over time when stored for a long period of time, and does not leave any bleat on the surface of the adherend even when peeled off.

〔Example〕

Examples of the present invention will be described below.

Example 1.2 (Production of propylene/1-butene random copolymer) In a stainless steel 20Q polymerization vessel equipped with a stirring blade, 200 g of anhydrous magnesium chloride (11.46 m) was added as a catalyst component.
Q of ethyl benzoate and 30 mQ of methylpolysiloxane were ball milled in a nitrogen atmosphere.

Next, the suspension was suspended in titanium tetrachloride and filtered to give a titanium concentration of 0.0]m+nol #1. What happens is that the concentration of 1-ethylaluminum in the polymerization vessel is 1. Ommol
, /11, and the concentration of p~methyl toluate as an electron donor in the polymerization vessel was 0.33 mmol. /Q, using n-hebutane as the polymerization solvent, a mixed gas of propylene and 1-butene (propylene 68 mo)
%, 1-butene 32 mol%) per hour. The copolymerization reaction was carried out at 70° C. by feeding at a rate of KQ. The propylene/1-butene random copolymer (hereinafter abbreviated as PBC) thus obtained has a propylene content I ratio of 7] as measured by nuclear magnetic resonance spectrum.
Omo]%, melting point 110°C, heat of fusion 50 Jou]e/
g, melt index (230℃) 7.0g/]O
It was mjn.

(Manufacture of propylene/ethylene/1-butene copolymer) The titanium concentration was reduced to 0.
023 mmol#l, triisobutylaluminum]
, ]5 mmol #, triphenyltrimethoxysilane is O,]4 mmo], /(l, ethylene is]00 g/h, propylene is 640 g/h, 1
- Butene was supplied at 740 g/h and hydrogen was supplied so that the gas phase concentration in the polymerizer was 46 mo]%, and the polymerization temperature was 70°C.
Copolymerization was carried out under a polymerization pressure of 6 kg/ant2. Four propylene/ethylene/1-butene base types (hereinafter referred to as PE
The physical properties of 6), abbreviated as BC, are that the propylene content is 64 m
oJ%, ethylene content 15 mol%, 1 butene content 2], mol%, intrinsic viscosity [7+) = 0.48d
Q/lx and crystallinity were 16%.

(Preparation of #l porcelain and film) PBC and r'EBC obtained by the above method were mixed for 2 minutes in a tumbler blender at the mixing ratio shown in Table 1, and a
The composition was made into UR by melt-mixing in a 0 mm extruder (set temperature = 230°C).

Next, this composition was molded into a T-die molding machine (set temperature = 230°C).
) was used to form an 11-layer film with a thickness of 50 μm.

! The physical properties of the composition and film were measured using the following methods.

A film formed by the above method on a base material made of polycarbonate I or acrylic resin preheated to 55°C was rolled with a pinch roll at a linear pressure of 3.6 kg/cm. Paste (=JJru.

After that, it was left in an air oven at 50°C for a predetermined time, and then peeled at 180°C (tensile speed: 300mm/mj-n
) The adhesive strength was measured.

L East-Li 1 block- It was measured according to the method of ASTM-1)-1003.

[Table - Box] A press sheet with a thickness of 2 cm of the composition described above was prepared (200
℃-quenching method) and measured by the method of AS1'M-1)-2240.

The surface of the adherend was visually observed after the film was peeled off according to the above adhesive force measurement, and evaluated according to the following criteria: 60: No stain △: Slight stain ×: Stain Comparative Example 1 Instead of the composition used in Example j, P shown in Example]
The same procedure as in Example 5 J was carried out except that BC was used in a rhythmic manner.

Comparative Example 2 Comparative Example 1 was carried out in the same manner as in Comparative Example 1, except that instead of the PBC used in Comparative Example 1, a composition prepared in a proportion of PBC and PEBC as shown in Table 1 was used.

Comparative Example 3 Instead of the PBC used in Comparative Example, a mixture of ethylene and dobutene was polymerized at 50°C in the presence of hydrogen in a hexane/8 medium using vanadium oxytrichloride and ethylene aluminum sesquichloride as catalysts. In addition, an ethylene/1-butene random copolymer (hereinafter abbreviated as EBC) having an ethylene content of 90IIIO1%, a density of 0.889 g/cnt, and a melt index (190 ° C.) of 3.5 g/]0 mL was used. was carried out in the same manner as in Comparative Example 1. Comparative Example 4 Instead of the PBC used in Comparative Example 1, null l-index (190°C) 2 g/10 m1n, vinyl acetate content 25 tvt%, density 0.95 g/ cn? Ethylene/vinyl acetate” (polymer (EVA) rP-25
05J (Mitsui DuPont Polychemical Co., Ltd. lie!)
The same procedure as in Comparative Example 1 was carried out except that the product (trade name) was used.

5 The following results are shown in Table ↓.

6

Claims (2)

[Claims] (1) (A) Melt index (ASTMD1238
-65T, 230℃) is 0.1 to 100g/10m
in, propylene content 60 to 85 mol%, D
The heat of crystal fusion measured by SC method is 20 to 80
Joule/g of 100 parts by weight of a propylene/1-butene random copolymer, (B) a propylene (a) content of 50 to 80 mol%, an ethylene (b) content of 3 to 25 mol%, and carbon atoms. number 4 to 10
The content of α-olefin (c) is 10 to 40 mo
1% and a + b + c = 100 mol%, the intrinsic viscosity [η] measured at 135 ° C. in decalin solvent is 0.1 to 3 dl/g, and the crystallinity measured by X-ray diffraction method is 5 to 40%. A composition for a peelable protective film comprising 5 to 50 parts by weight of a propylene/ethylene/α-olefin random copolymer. (2) A peelable protective film that is a single-layer or multilayer film, in which at least one layer located on the outermost surface is made of the composition according to claim (1).