JPH09254328A - Biodegradable automobile coating film protecting sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automobile coating film protecting sheet likely not to demolish a biological system in soil without destructing natural environment even though disposed in the soil while the coating film can be cleanly peeled off without remaining of paste after service. SOLUTION: This biodegradable automobile coating film protecting sheet is composed of a biodegradable base material film 1 and a pressure sensitive adhesive layer 2 formed on its one side surface. A pigment 4 is applied to a surface of the base material film 1 or the pigment is blended in the base material film 1 and/or the pressure sensitive layer 2. Transmittance of visible radiation at 780-380nm wave-length is 10% or under, and transmittance of ultraviolet at 380-300nm wavelength is 5% or under. The pressure sensitive adhesive layer 2 is preferably composed of a biodegradable pressure sensitive adhesive. A release agent layer 3 may be formed on the other side surface of the base material film 1, and the formed release agent layer 3 is preferably composed of a biodegradable release agent layer.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a sheet for protecting automobile coating films, and more specifically, it can be peeled off without leaving an adhesive residue after use, and is decomposed by microorganisms when buried in soil and disposed of. The present invention relates to a biodegradable adhesive label that does not adversely affect the natural environment.

[0002]

BACKGROUND OF THE INVENTION Conventionally, when a new car (painted car) is transported or stored before it reaches consumers, rain or dust,
In order to prevent dirt due to dust or corrosion due to sea breeze or the like, an automobile coating film protective sheet having a base film made of polyethylene, polypropylene or the like and having an adhesive layer provided on one side thereof is widely used.

After protecting the surfaces of automobile bodies and parts, such automobile coating sheet-protecting sheets are almost always peeled off, incinerated, or disposed of in the soil. .

[0004] However, these processes have the following problems. (1) Problems when incinerating an automobile coating film protection sheet Energy is required when incinerating an automobile coating film protection sheet having a base film of polyethylene, polypropylene or the like. In addition, carbon dioxide generated when the substrate film is incinerated may cause global warming. Especially when the substrate film is vinyl chloride, hydrogen chloride gas is generated when the sheet is incinerated, which causes acid rain.

(2) Problems in Disposing Automotive Coating Film Protecting Sheets in Soil In recent years, there has been a dramatic increase in the number of cases in which used automotive coating film protecting sheets are buried in the soil and disposed of. It has become difficult to secure land for disposal. In addition, the base film such as polyethylene and polypropylene dumped in the soil
They can persist for long periods of time, destroying the natural environment or destroying soil ecosystems.

In order to solve the problems associated with such waste treatment, a biodegradable pressure-sensitive adhesive film using a film obtained from a lactic acid-based polymer as a base film has been proposed (for example, JP-A-6-33001). No.). However, even in such a biodegradable adhesive film,
There are the following problems in practical use.

(3) Problems due to deterioration with time of the adhesive The transportation and storage of automobiles are often performed outdoors. In particular, when exported by ship, automobiles and sheets for protecting automobile coating films are exposed to strong light rays (especially ultraviolet rays) at sea. Such a strong light ray has a bad influence such as fading and chalking of the coating film of the automobile, and also decomposes the pressure-sensitive adhesive used in the protective sheet to deteriorate the adhesive property over time. Therefore, when the protective sheet is peeled off, a part of the adhesive may remain on the surface of the automobile coating film (paste residue).

[0008]

SUMMARY OF THE INVENTION The present invention is intended to solve the problems associated with the prior art as described above, and after use, it can be peeled off neatly without leaving an adhesive residue, and even if it is discarded in the soil. The purpose of the present invention is to provide a sheet for protecting automobile coating films that does not disturb the natural environment and does not disturb the ecosystem in the soil.

[0009]

SUMMARY OF THE INVENTION A biodegradable automobile coating film protective sheet according to the present invention comprises a biodegradable base film and an adhesive formed on one side thereof, and a pigment is applied to the surface of the base film. Or a pigment is added to the base film and / or the pressure-sensitive adhesive layer, the transmittance of visible light at a wavelength of 780 to 380 nm is 10% or less, and the transmission of ultraviolet light at a wavelength of 380 to 300 nm. The feature is that the rate is 5% or less.

In the present invention, it is particularly preferable that the pressure-sensitive adhesive layer is formed of a biodegradable pressure-sensitive adhesive. Further, it is preferable that a release agent layer is formed on the other surface of the base film.

Particularly, in the present invention, it is preferable that the release agent layer is composed of a biodegradable release agent layer.

[0012]

DETAILED DESCRIPTION OF THE INVENTION The biodegradable automobile coating film-protecting sheet according to the present invention will be described below more specifically with reference to the drawings.

As shown in FIGS. 1 to 3, a biodegradable automobile coating film-protecting sheet 10 according to the present invention comprises a biodegradable substrate film 1, an adhesive layer 2 formed on one side thereof, and a substrate. The release agent layer 3 is formed on the other surface of the material film 1 if necessary, and the base material film 1 contains a pigment (see FIG. 1) or the adhesive layer 2 contains a pigment. (See FIG. 2) or the surface of the base film 1 is coated with a pigment (see FIG. 3).

In the present invention, the base film 1
The pigment may be blended in both the adhesive layer 2 and the adhesive layer 2, and at this time, the pigment may be applied to the surface of the base film 1.

Biodegradable Substrate Film The biodegradable substrate film is formed from a biodegradable polymer that can be degraded by microorganisms and enzymes in the natural environment. In the present invention, various biodegradable polymers can be used without any particular limitation. Specific examples of such a biodegradable polymer are shown below.

A) Linear polyester of 3-hydroxybutyric acid and 3-hydroxyvaleric acid (trade name: Biopol, manufactured by Zeneca) Incidentally, this linear polyester (Biopol) is Al
Obtained by sugar fermentation with caligenes Europhus.

B) Lactic acid-based biodegradable polymer produced by polymerizing lactic acid obtained by fermenting glucose c) Biodegradable polymer produced from natural polymer such as starch, polysaccharide and chitin [ For example, pullulan (trade name, manufactured by Hayashibara Research Institute, etc.) d) Biodegradable polycaprolactone obtained by ring-opening polymerization of ε-caprolactone e) Polyvinyl alcohol or a biodegradable polymer which is a modified product thereof (trade name Vitex, (Manufactured by US Air Products and Chemicals, Inc.) f) Polyether, polyacrylic acid, ethylene / carbon monoxide copolymer, aliphatic polyester / polyamide copolymer, aliphatic polyester / polyolefin copolymer, aliphatic polyester / aromatic Production of polyester copolymers, aliphatic polyester / polyether copolymers, etc. Degradable polymer g) Biodegradable polymer such as polylactic acid, polybutyric acid, polyglycolide or derivatives thereof h) Polymer alloy of starch and modified polyvinyl alcohol (trade name: Matterby, manufactured by Novamont, USA), etc.

I) Polymer alloy of starch and polyethylene (trade name: Polygrade II, manufactured by Ampacet; trade name: Polyclean, manufactured by Arcer Daniel Midland Co., USA) j) Composition of silane starch and polyethylene (trade name: Eco Star, manufactured by St. Lawrence Starch) k) Polymer alloy of polycaprolactone and polyethylene (trade name: Biomicron, manufactured by JSP; trade name: Tone, manufactured by Union Carbide Co., USA) Such a biodegradable substrate film 1 in soil When it is discarded, the microorganisms in the soil decompose it into carbon dioxide and water.

The thickness of the above biodegradable base film 1 is
Usually, it is 5 to 200 μm, preferably 10 to 100
μm. Such a biodegradable substrate film 1 is formed by film-forming a mixture of the above-mentioned biodegradable polymer, for example, starch and modified polyvinyl alcohol by an inflation method or a T-die casting method, and then stretching it if necessary. It is obtained by processing and adjusting to a desired film thickness.

When the pigment 4 which will be described later is added to the base film 1, the biodegradable polymer and the pigment may be mixed prior to film processing. When the pigment 4 is applied to the surface of the base film, coating,
It may be applied by printing, spraying or the like.

In addition to the above, the substrate film may further contain an ultraviolet absorber, a light stabilizer, an antioxidant, a heat stabilizer, if necessary.
There is no problem even if other additives such as a lubricant are blended. Adhesive Layer An adhesive layer 2 is formed on one surface of the biodegradable substrate film 1. Adhesives that can form such an adhesive layer 2 include silicone-based, acrylic-based, urethane-based adhesives,
Adhesives such as natural rubber are included.

As the silicone-based pressure-sensitive adhesive, a rubber component composed of a high degree of polymerization polyorganosiloxane and [(CH ₃ ) ₃
And a resin component which is a copolymer of [SiO _1/2 ] units and [SiO ₂ ] units.

Examples of the acrylic pressure-sensitive adhesives include acrylic copolymers of methacrylic acid alkyl ester and / or C2-C14 acrylic acid alkyl ester and ethylenically unsaturated carboxylic acid.

Examples of natural rubber adhesives include rosin and its derivatives (hydrogenated rosin, disproportionated rosin, polymerized rosin,
Rosin esters), terpenes and their derivatives (α
-Pinene resin, β-pinene resin, dipentene resin and hydrogenated products thereof), and a pressure-sensitive adhesive composed of a mixture of one or more tackifier resins and natural rubber. Among them, the natural rubber may be solid or latex. In the adhesive, 1 to 150 parts by weight of a tackifying resin may be blended with 100 parts by weight of natural rubber.

Of these, biodegradable natural rubber adhesives are preferred. Use of such a biodegradable adhesive can further reduce adverse effects on the natural environment.

The adhesive amount of the adhesive layer 2 is usually 5 to 1
The amount is 00 g / m ² , and preferably 10 to 50 g / m ² . Such a pressure-sensitive adhesive layer 2 is obtained by a method of applying a solution in which the above-mentioned pressure-sensitive adhesive is dissolved to one surface of the base film 1 and drying at a temperature of 50 to 160 ° C. When the pigment is mixed in the pressure-sensitive adhesive layer, the pigment may be mixed with the pressure-sensitive adhesive coating solution before the pressure-sensitive adhesive coating solution is applied.

As the solvent for the above-mentioned pressure-sensitive adhesive coating liquid, for example, toluene, xylene, ethyl acetate, water or the like is used. The pigment applied to the surface of the pigment base film 1 or the pigment contained in the base film 1 and / or the pressure-sensitive adhesive layer 2 is
There is no particular limitation as long as it is generally used as a pigment. Mainly, organic pigments, natural pigments and inorganic pigments are used.

Examples of the organic pigment include legal pigments defined by Ordinance No. 37 of the Ministry of Health and Welfare, mainly tar pigments. For example, Red No. 202 (Resor Rubin BCA), Red No. 203 (Rake Red C), Red 20
No. 4 (Rake Red CBA), Red No. 205 (Resole Red), Red No. 206 (Resole Red CA), Red No. 207 (Resole Red BA), Red No. 208 (Resole Red SR), Red No. 219 (Brilliant Lake Red) R), Red No. 220 (Deep Maroon), Red No. 221 (Toluidine Red), Red No. 228 (Permaton Red), Daidai No. 203 (Permanent Orange), Daidai No. 204 (Pentidine Orange G), Yellow 205 (Pentidine Yellow G), red 404
No. (Brilliant Fast Scarlet), Red 405
No. (Permanent Red F5R), Daidai No. 401 (Hanza Orange), Yellow No. 401 (Hanza Yellow),
Blue No. 404 (phthalocyanine blue) and the like can be mentioned.

Specific examples of natural pigments include carotenoids such as β-carotene, β-apo-8-carotinal, capsanthin, lycopene, bixin, crocin, canthaxanthin, and anato, and flavonoids such as shisonine, raphanin, Anthocyanidins such as enocyanine, chalcones such as safrole yellow and safflower, flavonols such as rutin and quercetin, flavones such as cacao pigments, flavins, riboflavin, quinone, laccaine, etc. Anthraquinones such as acids, carminic acid (cotinyl), quermesic acid, alizarin, etc., naphthoquinones such as shikonin, alkanine, echinochrome, etc., porphyrins, chlorophyll, hemoglobin, etc.
Curcumin (turmeric) is used for the diketone type, and betanin is used for the betacyanidine type.

As the inorganic pigment, silicic acid anhydride, magnesium silicate, talc, kaolin, bentonite, mica, titanium mica, bismuth oxychloride, zirconium oxide, magnesium oxide, zinc oxide, titanium oxide, light calcium carbonate, heavy carbonic acid. Examples thereof include calcium, light magnesium carbonate, heavy magnesium carbonate, yellow iron oxide, red iron oxide, black iron oxide, sunflower, chromium oxide, chromium hydroxide, carbon black and calamine.

The pigment may be applied to the surface of the base material film, or may be added to the base material film 1, or may be added to the pressure-sensitive adhesive layer 2. The coating amount and the blending amount of the pigment are not particularly limited, but are appropriately set according to the type of the pigment, the adhesive performance described below, the visible light transmittance and the ultraviolet transmittance.

[0032] The release agent layer aforementioned substrate film 1 surface (surface not to form an adhesive layer) may be formed a release agent layer 3 if necessary.

As the release agent that can form the release agent layer 3,
Examples include natural compounds such as shellac, natural wax, casein and starch, polyvinyl alcohol and its derivatives, and synthetic release agents such as silicone.

These may be used alone or in combination of two or more. Among these release agents, in the present invention, it is particularly preferable to use a release agent exhibiting biodegradability. Examples of the biodegradable release agent include a release agent composed of a natural compound and a polyvinyl alcohol-based synthetic release agent.

The thickness of the release agent layer 3 is usually 0.01
˜1 μm, preferably 0.05 to 0.5 μm. Such a release agent layer 3 is formed by applying the above-described release agent to the surface of the base film 1 (the surface on which the adhesive is not formed) by a roll coater or the like.

Sheet for Protecting Automotive Coating Film The sheet 10 for protecting automobile coating film according to the present invention comprises the above-mentioned base film 1, adhesive agent 2 and release agent 3 which is optionally formed. The light transmittance of the sheet 10 is reduced to a specific value or less by applying a pigment to the surface of the sheet or by blending the pigment into the base film 1 and / or the adhesive layer 2.

That is, the automobile coating film-protecting sheet 10 according to the present invention has a visible light transmittance of 10% or less, preferably 5% or less at a wavelength of 780 to 380 nm, and an ultraviolet ray at a wavelength of 380 to 300 nm. Has a transmittance of 5% or less, preferably (3% or less, particularly preferably 2% or less).

The visible light is usually 780 to 380n.
It means a light beam having a wavelength of m, and various methods of measuring its transmittance are known. The visible light transmittance in the present invention is
The transmittance of visible light at a wavelength of 780 to 380 nm is determined by measuring with a spectrophotometer.

The ultraviolet ray means a wavelength of usually 380 to 1 nm which is shorter than the visible ray, and various measuring methods of its transmittance are known. The ultraviolet transmittance in the present invention is determined by measuring the ultraviolet transmittance at a wavelength of 380 to 300 nm with a spectrophotometer.

As described above, in the sheet 10 for protecting an automobile coating film of the present invention, since the light transmittance is reduced to a specific value or less, the amount of light rays exposed to the coating film during storage / transportation of an automobile is reduced. It is possible to lower the color and prevent discoloration and chalking of the coating film. Further, since light rays (especially ultraviolet rays) that adversely affect the adhesive property are blocked, deterioration of the adhesive layer 2 with time is prevented, and the sheet 10 does not leave an adhesive on the surface of the coating film.
Can be peeled off.

[0041]

As described above, according to the present invention, since the automobile coating film-protecting sheet is mainly formed of a biodegradable substance, even if it is discarded in the soil after use, it will be in a natural environment. It does not destroy the soil or significantly disturb the soil ecosystem.

Further, by coating or blending a pigment, the light transmittance for protecting the automobile coating film is reduced, so that even if it is exposed to sunlight for a long period of time, the adhesive physical properties are not deteriorated and the conventional automobile coating is applied. It has the same adhesiveness and peelability as the film protection sheet.

[0043]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

In the following Examples and Comparative Examples, the visible light transmittance, the ultraviolet transmittance, the adhesive force and the decomposition rate were evaluated by the following methods. Visible Light Transmittance Sample Preparation: Cut the film into 10 mm x 50 mm.

Measuring device: spectrophotometer (Shimadzu Corporation)
UV-VIS-NIR Scanning Spectrometer UV-3101
P) Measurement wavelength: 780 to 380 nm Evaluation method: The maximum value of the transmittance measured at the above wavelength is defined as the visible light transmittance.

Ultraviolet transmittance sample preparation: The film is cut into 10 mm × 50 mm. Measuring device: Spectrophotometer (UV-VIS-NIR, Shimadzu Corporation)
Scanning spectrometer UV-3101P) Measurement wavelength: 380 to 300 nm Evaluation method: The maximum value of the transmittance measured at the above wavelength is defined as the ultraviolet transmittance.

Adhesive Strength The biodegradable automobile coating film-protecting sheets obtained in the following Examples or Comparative Examples were cut into a width of 25 mm, and the adhesive layer contacted the melamine coated steel sheet SPCC-SB (Japan test Adhesive to Panel Industry Co., Ltd., then 23 ° C. 6
Under an atmosphere of 5% RH, the adhesive tape was peeled from the SPCC-SB surface at a peeling rate of 300 mm / min and a peeling angle of 180 °, and the adhesive force of the biodegradable adhesive label was evaluated from the peeling force at this time.

Biodegradation rate The biodegradable automobile coating film protective sheet obtained by the above method obtained in the following Examples or Comparative Examples was 100 mm x 10
Cut to a size of 0 mm and obtain a sample with a depth of 10 cm.
Of the biodegradable automobile coating film-protecting sheet was evaluated by the following formula.

[0049]

[Equation 1]

[0050]

Example 1 On one side of a polymer alloy base film (“Matterby”, Novamont (Italy)) of starch and modified polyvinyl alcohol having a thickness of 50 μm, shellac (Gifu shellac Co., Ltd.) was used as a release agent. (Manufactured by Seisakusho) is applied so that the thickness of the release agent layer is 0.05 μm. Then, an emulsion solution of a mixture of natural rubber and a terpene resin as a pressure-sensitive adhesive is applied to the other surface of the base film by a coater to form a pressure-sensitive adhesive layer having an adhesion amount of 30 g / m ² .

As a pigment, titanium oxide was used in an amount of 1 for the adhesive.
Disperse in the above emulsion solution so as to be 0% by weight. The visible light transmittance and the ultraviolet transmittance, the adhesive strength and the biodegradability of the biodegradable automobile coating film-protecting sheet thus obtained were evaluated.

The above results are shown in Table 1.

[0053]

Example 2 3-hydroxybutyric acid having a thickness of 50 μm and 3-
A biodegradable automobile coating film-protecting sheet was prepared in the same manner as in Example 1 except that a base film (“Biopol”, manufactured by ICI, UK) composed of a copolymer with hydroxysuccinic acid was used. Then, the visible light transmittance, the ultraviolet light transmittance, the adhesive force and the biodegradation rate of the obtained sheet were evaluated.

The above results are shown in Table 1.

[0055]

[Comparative Example] The same as Example 1 except that a polypropylene film having a thickness of 50 μm (trade name: Alfan SY101, manufactured by Honshu Paper Co., Ltd.) was used as a base film, and titanium oxide was not mixed in the adhesive layer. Then, a sheet for protecting automobile coating film was prepared, and the visible light transmittance and the ultraviolet transmittance, the adhesive force and the decomposition rate of the obtained sheet were evaluated.

The above results are shown in Table 1.

[0057]

[Table 1]

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a biodegradable automobile coating film-protecting sheet according to the present invention.

FIG. 2 is a schematic cross-sectional view of a biodegradable automobile coating film-protecting sheet according to the present invention.

FIG. 3 is a schematic cross-sectional view of a biodegradable automobile coating film-protecting sheet according to the present invention.

[Explanation of symbols]

 1 ... Biodegradable substrate film 2 ... Adhesive layer 3 ... Release agent layer 4 ... Pigment 10 ... Automotive coating film protective sheet

Claims (4)

[Claims] 1. A biodegradable automobile coating film protective sheet comprising a biodegradable base film and an adhesive layer formed on one side thereof, wherein the surface of the base film is coated with a pigment. Alternatively, a base film and / or a pressure-sensitive adhesive layer is blended with a pigment, the visible light transmittance at a wavelength of 780 to 380 nm is 10% or less, and the ultraviolet transmittance at a wavelength of 380 to 300 nm. Is 5% or less, a biodegradable sheet for protecting an automobile coating film. 2. The biodegradable automobile coating film protective sheet according to claim 1, wherein the pressure-sensitive adhesive layer comprises a biodegradable pressure-sensitive adhesive. 3. The biodegradable automobile coating film protective sheet according to claim 1, wherein a release agent layer is formed on the other surface of the base film. 4. The biodegradable automobile coating film-protecting sheet according to claim 3, wherein the release agent layer comprises a biodegradable release agent layer.