CA2144396C - Paint film-protective sheet - Google Patents

Paint film-protective sheet Download PDF

Info

Publication number
CA2144396C
CA2144396C CA002144396A CA2144396A CA2144396C CA 2144396 C CA2144396 C CA 2144396C CA 002144396 A CA002144396 A CA 002144396A CA 2144396 A CA2144396 A CA 2144396A CA 2144396 C CA2144396 C CA 2144396C
Authority
CA
Canada
Prior art keywords
paint film
protective sheet
sensitive adhesive
glycerol ester
acid glycerol
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CA002144396A
Other languages
French (fr)
Other versions
CA2144396A1 (en
Inventor
Komaharu Matsui
Mitsuo Wakimoto
Takeshi Eda
Tadayoshi Tatsuno
Tsuyoshi Inoue
Kenichi Shibata
Yutaka Kuwabara
Tatsuo Wada
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kansai Paint Co Ltd
Nitto Denko Corp
Original Assignee
Kansai Paint Co Ltd
Nitto Denko Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kansai Paint Co Ltd, Nitto Denko Corp filed Critical Kansai Paint Co Ltd
Priority to CA002144396A priority Critical patent/CA2144396C/en
Publication of CA2144396A1 publication Critical patent/CA2144396A1/en
Application granted granted Critical
Publication of CA2144396C publication Critical patent/CA2144396C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C09DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09JADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00Adhesives in the form of films or foils
    • C09J7/20Adhesives in the form of films or foils characterised by their carriers

Abstract

A paint film-protective sheet comprising a supporting substrate having formed thereon a rubber-based pressure- sensitive adhesive layer compounded with a fatty acid glycerol ester.

Description

PAINT FILM-PROTECTIVE SHEET
FIELD OF THE INVENTION
The present invention relates to a paint film protective sheet which is hard to cause a paint film deformation and suitable for the surface protection of automobile bodies and parts, coated steel plates, etc.
BACKGROLiND OF THE INVENTION
In the case of loading trucks or ships with coated automobiles, the parts thereof, etc., and transporting those to remote places such as overseas, an effective means is desired to prevent the paint films of the automobiles, etc., from being damaged, dulled, discolored, etc., by various suspended matters such as dusts or rains, or impinging matters.
Hitherto, a method of applying a coating material comprising a wax as the main component at a thickness of from 5 to 40 um has been known as such a prevention means.
However, this method has various problems such that it is difficult to form the wax coating at a uniform thickness, whereby a uniform protection of the paint film is not obtained;
the coated layer is liable to be stained and has a poor resistance to acidic rain; the wax and the like penetrate into the paint film to cause discloration or other defects; the -formation and the removal of the wax coating require much labors; and the use of a solvent, the treatment of waste liquids, etc., are liable to cause environmental problems.
2~4439~
On the other hand, various surface protective sheets comprising a substrate having formed thereon a pressure-sensitive adhesive layer are known, and a surface protective sheet comprising a substrate having formed thereon a radiation-curable pressure-sensitive adhesive layer having a lowered glass transition point (Tg) is proposed for use on adherends having a paint film as disclosed in JP-A-2-199184 (the term "JP-A" as used herein means an "unexamined published Japanese patent application"). Such a sheet system can overcome the problems described above.
However, where such a surface protective sheet is adhered to the surface of the paint film of an automobile or the like, low molecular weight components contained in the paint film, such as a fatty acid glycerol ester, migrate into the surface protective sheet side due to a temperature rise in the outdoor transportation, whereby a step mark phenomenon occurs in the paint film to cause a problem that the adhesive marks of the protective sheet clearly appear on the surfaces of the paint film. In particular, in a low Tg type paint film, the adhered traces having a depth of from about 0.1 to 0.5 Pm usually occur during the adhesion of the protective sheet for about 10 hours under 50°C.
The present inventors have previously proposed a surface protective sheet in which a rubber-based polymer such as a polyisobutylene is used as a pressure-sensitive adhesive (EP 0 519 278 A2). This sheet is hard to cause the deformation _ 2 21443J~
of a paint film and does not have a problem on adhesive remaining. Thus, this sheet is a practical surface protective sheet. However, this sheet has in some cases a problem that the adhesive marks may not completely be eliminated where the paint film contains a fatty acid glycerol ester.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a paint film-protective sheet which can prevent the occurrence of the step marks as illustrated in the Figure onto a paint film by the migration of the low molecular weight components contained in the paint film into the paint film-protective sheet even in the case of being accompanied by the temperature rise in the outdoor transportion of automobiles, etc., whereby the adhesive marks of the protective sheet are not formed on the surface of the paint film, and is excellent in the protective property for paint films and in the releasing property without leaving the pressure-sensitive adhesive which becomes a staining material.
According to the present invention, there is provided a paint film-protective sheet comprising a supporting substrate having formed thereon a rubber-based pressure-sensitive adhesive layer compounded with a fatty acid glycerol ester.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a view showing a state that a paint film-protective film 1 comprising a supporting substrate 11 and a pressure-sensitive adhesive layer 12 is adhered on a paint film
- 3 -2;
Figure 2 is a view showing a state that low molecular weight components contained in a paint film 2 have migrated into a pressure-sensitive adhesive layer 12 of a paint film-s protective sheet 1; and Figure 3 is a view showing a state that a step mark 3 is formed on a paint film 2 after removing a paint film-protective sheet 1.

The present invention is described in detail below.
In the present invention, by using the rubber-based pressure-sensitive adhesive compounded with a fatty acid glycerol ester, the migration of the low molecular weight components in a paint film into the protective sheet can be prevented even in the case of involving the temperature rise in an outdoor transportation of automobiles, etc., and the step mark phenomenon of the paint film does not occur, whereby the adhesive marks of the protective sheet are not formed on the surface of the paint film. Further, the paint film-protective sheet of the present invention is excellent in the protective property for the paint film in the state that the protective sheet is adhered thereon, and also can be easily released from the paint film without leaving the pressure-sensitive adhesive which becomes a staining material on the paint film.
The paint film-protective sheet of the present invention has on a supporting substrate a rubber-based
- 4 -pressure-sensitive adhesive layer compounded with a fatty acid glycerol ester.
The supporting substrate used in the present invention can be any appropriate material, and examples thereof are plastic films, porous films, papers, nonwoven fabrics, etc.
The thickness of the supporting substrate is generally 300 um or less, and preferably from 10 to 100 um, although the invention is not limited to the thickness.
The pressure-sensitive adhesive layer can be formed by using an appropriate rubber-based pressure-sensitive adhesive comprising one or more kinds of rubber-based polymers such as natural rubber, polyisobutylene, an A-B-A type block polymer, etc., as the main components and, if necessary, a tackifier or a softener. Further, the pressure-sensitive adhesive layer may contain appropriate additives such as a filler, a pigment, an antioxidant, a stabilizer, etc.
Examples of the more preferred rubber-based polymer from the point of the stability of the performance of the paint film-protective sheet over a long period of time are a non-curable polyisobutylene-based polymer and an A-B-A type block polymer comprising a polystyrene block, an ethylene-butylene copolymer block, and a polystyrene block. Further, the polyisobutylene-based polymer which is preferably used is a mixture of a high molecular weight type polymer having a viscosity average molecular weight of at least 100,000 and a low molecular weight type polymer having a viscosity average
- 5 -2~4439~
molecular weight of less than 100,000 at a weight ratio of 95 to 80 : 20.
The tackifier or the softener which may be contained in the rubber-based pressure-sensitive adhesive can be any 5 appropriate material, but the tackifier or the softener having a good compatibility with the rubber-based polymer is preferred. In general, Examples of the tackifier are hydrocarbon resins, alkylphenol resins, and terpene resins.
Examples of the softener generally used are a polyisobutylene having a low molecular weight when the rubber- _ based polymer is a polyisobutylene, and a paraffin oil when the rubber-based polymer is the A-B-A type block polymer.
Examples of the fatty acid glycerol ester to be compounded with the rubber-based pressure-sensitive adhesive layer in the present invention are a (mono, di, or tri)capric acid glycerol ester, a (mono, di, or tri)lauric acid glycerol ester, a (mono, di, or tri)myristic acid glycerol ester, and coconut oil. Of those, coconut oil is preferably used.
The fatty acid glycerol ester is used in the state that it is compounded with the rubber-based pressure-sensitive adhesive, and the compounding amount thereof is appropriately determined by the thickness of the pressure-sensitive adhesive layer formed. When the pressure-sensitive adhesive layer having a thickness of 15 ~m is a standard, the compounding amount of the fatty acid glycerol ester is from 0.5 to 20 parts by weight, and preferably from 3 to 10 parts by weight, per 100
- 6 -parts by weight of the rubber-based pressure-sensitive adhesive. If the compounding amount is over 20 parts by weight, it sometimes happens that the fatty acid glycerol ester bleeds on the surface of the pressure-sensitive adhesive layer to stain the surface of the paint film. On the other hand, if the compounding amount of the fatty acid glycerol ester is less than 0.5 part by weight, the addition effect thereof is poor and the adhesive marks are liable to form.
The paint film-protective sheet of the present invention can be formed according to a conventional method of forming an adhesive sheet, such as a method of coating a supporting substrate with a solution of the rubber-based pressure-sensitive adhesive compounded with the fatty acid glycerol ester or a hot-melt liquid of the rubber-fatty acid glycerol ester, or a method of transferring the pressure-sensitive adhesive layer formed on a separator onto a supporting substrate, etc.
The thickness of the pressure-sensitive adhesive layer formed may be appropriately determined, but is generally 200 ~m or less, and preferably from 5 to 50 um. The pressure sensitive adhesive layer is, if necessary, protected by pre-fixing thereto a separator, etc., before use.
The paint film-protective sheet of the present invention is advantageously used to protect the surfaces of adherends having a paint film, such as bodies and parts of automobiles coated with a paint film such as a melamine-alkyd _ 7 _ 21~439~
type, melamine-acryl type or urethane type paint film, or metal plates (such as steel plates) or the shaped articles thereof coated with the paint film, from impinging of fine matters, chemicals, etc. In particular, the paint film-protective sheet of the present invention can be advantageously used in the case which involves the temperature rise as in the case of the outdoor transporting of the automobiles, etc., or in the case that the paint film-protective sheet is adhered to paint films of automobiles, etc., over a long period of time.
The present invention is described below in more detail by reference to the following examples and comparative examples, but it should be understood that the invention is not construed as being limited thereto. Unless otherwise indicated, all percents, parts, ratio and the like or by weight.

To a toluene solution of a rubber-based pressure- -sensitive adhesive composed of a mixture of 75 parts of a polyisobutylene having a viscosity average molecular weight of 1,000,000 and 25 parts of a polyisobutylene having a viscosity average molecular weight of 80,000 was added 5 parts of coconut oil followed by compounding. The resulting liquid was coated on a film having a thickness of 40 um composed of polypropylene and polyethylene (9/1 by weight ratio), and dried at 80°C for 2 minutes to obtain a paint film-protective sheet having a pressure-sensitive adhesive layer having a thickness of 15 Vim.
_ g A paint film-protective sheet was obtained in the same manner as in Example 1 except that the compounding amount of coconut oil was changed to 10 parts.

A paint film-protective sheet was obtained in the same manner as in Example 1 except that the compounding amount of coconut oil was changed to 20 parts.
A paint film-protective sheet was obtained in the same manner as in Example 1 except that trilauric acid glycerol ester was used in place of coconut oil.

A paint film-protective sheet was obtained in the same manner as in Example 1 except that a mixture of 100 parts of an A-B-A type block polymer comprising a polystyrene block, an ethylene-butylene copolymer block, and a polystyrene block (KratonTM G-1657, made by Shell Chemical Co. ) and 40 parts of a hydrogenated petroleum resin (ArconTM, made by Arakawa Chemical Industries, Ltd.) was used as the rubber-based pressure-sensitive adhesive.

A paint film-protective sheet was obtained in the same manner as in Example 1 except that coconut oil was not compounded.
_ g -A paint film-protective sheet was obtained in the same manner as in Example 1 except that the compounding amount of coconut oil was changed to 30 parts.
Evaluation Tests Each of the paint film-protective sheets obtained in the examples and the comparative examples was subjected to the following tests.
Adhesive Remaining:
The paint film-protective sheet was adhered at room temperature to a plate having an alkyd-melamine paint film having a glass transition point of 60°C and containing the fatty acid glycerol ester. The resulting plate was placed in an atmosphere of 80°C for 24 hours, taken out therefrom, and then allowed to stand at room temperature for 3 hours.
Thereafter, the paint film-protective sheet was stripped off, and the presence of the pressure-sensitive adhesive remained on the paint film of the plate, in particular, the presence of the pressure-sensitive adhesive remained on the portion of the paint film of the plate corresponding to the peripheral portion of the paint film-protective sheet was examined.
Adhesive Mark:
The alkyd-melamine paint film after the above adhesive remaining test was observed, and the presence of the adhesive marks in the paint film, in particular, the presence of the adhesive marks in the portion corresponding to the peripheral ~144~9~
portion of the paint film to which the paint film-protective sheet had been adhered was visually examined. In this test, when the adhesive mark (concaved portion) of the paint film caused by the migration of the fatty acid glycerol ester contained in the alkyl-melamine paint film into the paint film-protective sheet was not observed, the case was evaluated as "none" and when such an adhesive mark was observed, the case was evaluated as "found".
The results obtained are shown in the table below.
TABLE
Comparative Example example Adhesive Hone None None None None None None Remaining Adhesive None None None None None Found Found Mark According to the paint film-protective sheet of the present invention, even in the case that the glass transition point of a paint film is low and a temperature of the paint film rises, the migration of the low molecular weight components in the paint film into the paint film-protective sheet adhered onto the paint film can be prevented, whereby the occurrence of the step mark phenomenon of the paint film can be prevented and the adhesive marks of the protective sheet are not formed on the surface of the paint film. Further, the paint film-protective sheet of the present invention is excellent in the paint film-protecting property in the adhered state and can be easily released from the paint film without leaving thereon the pressure-sensitive adhesive which becomes a staining material.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. -

Claims (5)

WHAT IS CLAIMED IS:
1. A paint film-protective sheet comprising a supporting substrate having formed thereon a rubber-based pressure-sensitive adhesive layer compounded with a fatty acid glycerol ester, wherein the fatty acid glycerol ester is compounded in an amount of from 0.5 to 20 parts by weight per 100 parts by weight of the rubber-based pressure-sensitive adhesive.
2. A paint film-protective sheet as claimed in claim 1, wherein the fatty acid glycerol ester is compounded in an amount of from 3 to 10 parts by weight per 100 parts by weight of the rubber-based pressure-sensitive adhesive.
3. A paint film-protective sheet as claimed in claim 1, wherein the fatty acid glycerol ester is selected from the group consisting of a (mono, di or tri)capric acid glycerol ester, a (mono, di or tri)lauric acid glycerol ester, a (mono, di or tri)myristic acid glycerol ester, and coconut oil.
4. A paint film-protective sheet as claimed in claim 1, wherein the fatty acid glycerol ester is coconut oil.
5. A paint film-protective sheet as claimed in claim 1, wherein the rubber-based pressure-sensitive adhesive comprises, as a main component of the pressure-sensitive adhesive, (a) a non-curable polyisobutylene polymer, or (b) an A-B-A type block polymer comprising a polystyrene block, an ethylene-butylene copolymer block, and a polystyrene block.
CA002144396A 1995-03-10 1995-03-10 Paint film-protective sheet Expired - Fee Related CA2144396C (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CA002144396A CA2144396C (en) 1995-03-10 1995-03-10 Paint film-protective sheet

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CA002144396A CA2144396C (en) 1995-03-10 1995-03-10 Paint film-protective sheet

Publications (2)

Publication Number Publication Date
CA2144396A1 CA2144396A1 (en) 1996-09-11
CA2144396C true CA2144396C (en) 2002-07-16

Family

ID=4155402

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002144396A Expired - Fee Related CA2144396C (en) 1995-03-10 1995-03-10 Paint film-protective sheet

Country Status (1)

Country Link
CA (1) CA2144396C (en)

Also Published As

Publication number Publication date
CA2144396A1 (en) 1996-09-11

Similar Documents

Publication Publication Date Title
EP0519278B1 (en) Use of a sheet for protecting the surface of an automobile paint film
EP0106559B1 (en) Storable, crosslinkable, pressure-sensitive adhesive tape
CA2160204C (en) Paint film-protective sheet
KR100476797B1 (en) Equipment for painting masking tape and painting masking tape
KR100485280B1 (en) Adhesive protective film
CA2218275C (en) Sheet for protecting paint film
EP0768354B1 (en) Sheet for protecting paint films of automobiles
US3565750A (en) Pressure-sensitive adhesive article with dry-strippable liner
US5810960A (en) Paint film-protective sheet
KR100311669B1 (en) Coating protection sheet
USRE40723E1 (en) Automobile paint film-protective sheet
CA2144396C (en) Paint film-protective sheet
EP0731152A1 (en) Paint film-protective sheet
KR100317099B1 (en) Coating protection sheet
JP2756905B2 (en) Paint film protection sheet
JPH04183768A (en) Pressure-sensitve adhesive tape for protecting colored rubber surface in rubber tire
JPH10140113A (en) Sheet for protecting coating film
JPH09241596A (en) Surface protective sheet
JPH07117195A (en) Surface protective film
JPH1112547A (en) Sheet for protecting coating film
EP1164177A1 (en) Sheet for protecting paint film
JPH0812948A (en) Adhesive film or tape
JPH1112548A (en) Sheet for protecting coating film
JP2003206456A (en) Protecting sheet for automobile coating film
JPH07216323A (en) Automotive surface protective film

Legal Events

Date Code Title Description
EEER Examination request
MKLA Lapsed