JPH0362838A - Peelable protection film and composition therefor - Google Patents

Abstract

PURPOSE:To obtain a protection film having excellent flexibility, transparency, heat-resistance, etc., and exhibiting moderate adhesivity and peelability to an adherend by compounding a specific propylene.1-butene random copolymer with a specific amount of a tackifier. CONSTITUTION:The objective composition is produced by compounding (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 produced by using a catalyst composed of a solid titanium catalyst and an organic metal compound, etc., with (B) 0.5-20 pts.wt. of one or more kinds of tackifiers selected from aliphatic hydrocarbon resins, low-molecular weight styrene resins, rosin-based hydrocarbon resins, etc. The objective peelable protection film is a monolayered or multilayered film wherein at least one of the outermost surface layers is composed of the above composition.

Description

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

[Conventional technology]

Conventional removable protective films include, for example, ethylene,
Vinyl acetate copolymers (hereinafter referred to as EVA) and those whose main components are low-crystalline ethylene/α-olefin 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.

In Japanese Patent Publication No. 58-45974, EvA system fi/l
/t.

A polyolefin-based releasable protective film with improved heat resistance has been proposed.

However, although this film has improved heat resistance, when 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, bleed remains on the surface of the adherend. There were problems such as:

[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, 1Iij scratchability, and heat resistance, as well as moderate adhesion and peelability to the adherend, and excellent cold workability when applied. It is an object of the present invention to provide a releasable protective film and a composition thereof that undergo little change and do not leave any bleat on the surface of an adherend even when peeled off.

[Means to solve the problem]

The present invention relates to the following removable protective film and its composite acid product.

(1) Null 1 to index (AS'l'M 1112
:18-651', 2:F"c) is 0.1 to 10
0g/]Om]n, propylene content 60 to 8
5 mo]%, and a propylene/1-butene random copolymer (A) having a heat of crystal fusion of 20 to 80 Joule/H as measured by the DSC method, for 100 parts by weight,
A composition for a releasable protective film containing 0.5 to 20 parts by weight of a tackifier (n).

(2) The tackifier (B) is an aliphatic hydrocarbon resin, an aromatic hydrocarbon resin, an aliphatic/aromatic copolymerized hydrocarbon resin, an alicyclic hydrocarbon resin, a synthetic terpene hydrocarbon resin, One or more selected from terpene-based hydrocarbon resins, coumaron-indene-based hydrocarbon resins, low molecular weight styrene-based resins, and rosin-based hydrocarbon resins." (1)
The releasable protective film composition described above.

(3) A removable protective film comprising a single-layer or multi-layer film 11, in which at least one outermost layer of the film is made from the composition described in item (1) or (2). .

As the propylene/1-butene random copolymer (A) in the present invention, one having the above characteristics (1) is used.

That is, the melt index (230°C) is 0.1-
100g/10mjn, propylene content 60-85
mol%, heat of crystal fusion is 20 to 80 Jou1. e/g
The propylene/1-butene random copolymer has excellent flexibility, transparency, scratch resistance, heat resistance, etc., and by using such a copolymer as a base resin, the heat resistance of the film can be improved. This can prevent changes in adhesive properties over time during storage.

Such a propylene/1-butene random copolymer (
A) uses a catalyst formed from a solid titanium catalyst component and an organometallic compound component, or a catalyst formed from these same components and an electron donor,
- It can be produced by copolymerizing butene. As a solid titanium catalyst component, titanium trichloride or a titanium trichloride composition produced by various methods, or magnesium, a halogen, an electron donor, preferably an aromatic carboxylic acid ester or an alkyl group-containing ether, and titanium are essential components. The catalyst component is a supported titanium catalyst component with a specific surface area of preferably 100ml/g or more. The latter carrier (one prepared using a -1 catalyst acid content) is particularly suitable.

As the organometallic compound component, suitable aluminum compounds are suitable, such as 1-realkylaluminum,
Dialkyl aluminum halides (~, alkylaluminum sesquihalides, alkylaluminum cybarides, etc.) are suitable, and the suitability of these differs depending on the type of titanium catalyst component.As electron donors, nitrogen, phosphorus, sulfur, oxygen, silicon, and boron are used. Preferred examples include esters and ethers.

In the present invention, the tackifier (B ). This tackifier (B) is a solid, non-toxic polymer and is commonly used as a tackifying agent in adhesive tapes, paints, and photosensitive adhesives!・These resins are used in the field of adhesives and the like, and the following resins can be listed depending on the monomer source to be polymerized. For example, C4 fractions, C5 fractions, mixtures thereof, or any fractions thereof obtained by cracking petroleum, naphtha, etc., such as aliphatic products whose main raw materials are isoprene and 1,3-pentadiene in the C7 fraction. Hydrocarbon resin;
Aromatic hydrocarbon resin whose main raw materials are styrene derivatives and indenes in the C3 fraction obtained by cracking stone sludge, naphtha, etc.; copolymerization of any fraction of the C4 and C5 fractions with the C9 fraction aliphatic/aromatic copolymerized hydrocarbon resin; alicyclic hydrocarbon resin obtained by hydrogenating aromatic hydrocarbon resin; synthetic terpene hydrocarbon resin with a structure containing aliphatic, alicyclic, and aromatic groups. ; Terpene hydrocarbon resin made from α,β-pinene in turpentine oil; Coumarone indene hydrocarbon resin made from indene and styrene in coal tar naphtha; Low molecular weight styrenic resin; and rosin These include hydrocarbon resins.

Among these tackifiers (B), alicyclic hydrocarbon resins obtained by hydrogenating aliphatic hydrocarbon resins and aromatic hydrocarbon resins are preferable because they have good compatibility with component (A), and further soften Particularly preferred are alicyclic hydrocarbon resins having a temperature (ring and ball method) of 70 to 150°C, preferably 80 to 140°C, and a hydrogenation rate of aromatic nuclei of 80% or more, preferably 85% or more.

The polyolefin-based releasable protective film 11 composition of the present invention comprises the propylene/1-butene random copolymer (
A) 100 parts by weight of the above tackifier (B) 0
．． The composition contains 5 to 20 parts by weight. By using such a blending ratio, appropriate adhesive strength can be obtained, and removability after adhesion is ensured, and there is no blocking or residual bleed material after peeling. .

The composition for the removable protective film 11 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, core Various additives such as antistatic agents, antistatic agents, flame retardants, pigments, dyes, and inorganic or organic fillers can be added.

In order to prepare the composition for the peelable protective film 11 of the present invention, any known method can be adopted, such as a method of mixing with a mixer such as a V-type blender, a ribbon blender, a tumbler blender, a Henschel mixer, and/or Or extruder, mixing roll, Banbury mixer,
A method of kneading using a mixer such as a kneader 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 is, but a film WtMed with another resin film 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, the other resin film serving as the base layer is preferably a polyolefin film such as polyethylene, polypropylene, poly-1-butene, etc., which has good adhesiveness with the composition of the present invention, but polyamide, polyester, etc. 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 GOL Prevents damage, contamination, corrosion, etc. during storage.

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 above, according to the present invention, specific propylene 1-
Since a tackifier is added to the butene random copolymer,
It has excellent flexibility, transparency, scratch resistance, and heat resistance, as well as moderate adhesion and peelability to adherends, excellent cold workability during adhesion, and no change over time when stored for a long period of time. It is possible to obtain a removable protective film that has a small amount of bleed and leaves no bleed matter on the surface of the adherend even when it is 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 and 46 mf were added as a catalyst component.
1 of ethyl benzoate and 30 mQ of methylpolysiloxane were ball milled in a nitrogen atmosphere.

Next, 111ml of titanium tetrachloride was suspended and filtered until the titanium concentration was 0. O]mmol. /n so that
The concentration of 1-ethylaluminum in the polymerization vessel is 1.0 m
mol/Q, and p-l as an electron donor.
-The concentration of methyl ruylate in the polymerization vessel is 0.33 mmol
/R, and using n-hebutane as the polymerization solvent, a mixed gas of propylene and 1-butene (propylene 68 mol%
, 1-butene (32 mol%) per hour. The copolymerization reaction was carried out at 70° C. by feeding at a rate of KQ. The propylene/l-butene random copolymer thus obtained has a propylene content of 7], Omol%, melting point of 110°C, heat of fusion of 50 Joule/g, and melt index as measured by nuclear magnetic resonance spectroscopy. (230
℃) 7.0 g/]0 m1n.

(Preparation of composition and film) The propylene/1-butene random copolymer (hereinafter abbreviated as PBC) obtained by the above method was added to the alicyclic hydrocarbon resin "Alcon P" 25J (Arayo Kagaku Co., Ltd.). Co., Ltd., product name) for 2 minutes using a tumbler blender at the compounding ratio shown in the table, and then using an extruder with a diameter of 40 mm (temperature set at 230°C).
) to prepare the composition.

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

The physical properties of the composition and film produced by vJ were as follows: It was measured by the method.

Adhesive strength to adherend: A film shaped using the above method is placed on a base material made of polycarbonate or acrylic resin that has been preheated to 55°C, at a linear pressure of 3.
．． Attach with a 6kg/cm pinch roll.

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/m1n).
The adhesion strength was measured.

Kumibinpi Measured by the method of ASTM-D-1003.

A press sheet with a thickness of 2 mm was prepared from the above composition (200
°C-quenching method) and measured by the method of ASTM-D-2240.

After the film was peeled off, the surface of the adherend was visually observed and evaluated according to the following criteria.

○: No stain △: Slight stain ×: Stain Comparative Example 1 The same procedure as Example 1 was carried out except that instead of the composition used in Example 1, PBC shown in Example 1 was used alone. Ta.

Comparative Example 2 The same procedure as in Comparative Example 2 was carried out, except that instead of the PBC used in Comparative Example 1, a composition prepared with a blending ratio of PBC and Alcon P125 as shown in Table 1 was used. went.

Comparative Example 3 Instead of PBC used in Comparative Example 1, a mixture of ethylene and 1-butene was polymerized at 50°C in the presence of hydrogen in a hexane solvent using vanadium oxytrichloride and ethylene aluminum sesquichloride 1- as catalysts. The obtained ethylene content was 90 mol%, density was 0, and 889 g/aI? , melt index (190°C) 3.5g/]0mln ethylene/1-butene random copolymer (hereinafter referred to as EBC)
It is abbreviated as ) was used in the same manner as in Comparative Example 1.

Comparative Example 4 Instead of the PBC used in Comparative Example 1, an ethylene/vinyl acetate copolymer (melt index (190°C) 2 g/10n1j, n, vinyl acetate content 25tyt%, density 0.95 g/c+&) was used. EVA) rP-250
5J (manufactured by DuPont Mitsui Polychemicals Co., Ltd., product name)
The same procedure as in Comparative Example 1 was carried out except that .

The following results are shown in Table 1.

Claims (3)

[Claims] (1) Melt index (ASTMD1238-65
T, 230°C) is 0.1 to 100g/10min,
Propylene content is 60 to 85 mol%, and DS
The heat of crystal fusion measured by C method is 20 to 80 J
ole/g of propylene/1-butene random copolymer (A), 0 parts by weight of tackifier (B).
．． A composition for a peelable protective film containing 5 to 20 parts by weight. (2) The tackifier (B) is an aliphatic hydrocarbon resin, an aromatic hydrocarbon resin, an aliphatic/aromatic copolymerized hydrocarbon resin, an alicyclic hydrocarbon resin, a synthetic terpene hydrocarbon resin, Claim (1) The resin is one or more selected from terpene-based hydrocarbon resins, coumaron-indene-based hydrocarbon resins, low molecular weight styrene-based resins, and rosin-based hydrocarbon resins.
The releasable protective film composition described above. (3) A peelable protective film that is a single-layer or multilayer film, in which at least one outermost layer of the film is composed of the composition according to claim (1) or (2).