JP2010018640A - Peelable film-forming composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a peelable film-forming composition effective for temporarily protecting the surface of a coated material such as a coated surface of an automobile exterior plate, etc. <P>SOLUTION: This repeelable film-forming composition is provided by containing an emulsion obtained by using (A) a biodegradable resin and (B) a redispersible emulsion resin. By applying the peelable film-forming composition on a coated article such as the coated film surface of the automobile exterior plate, etc., to form the peelable film, the surface of the coated article such as the coated surface of the automobile exterior plate, etc., is temporarily protected. As the biodegradable resin (A), a lactic acid-based polymer (C) having a ≥50 kg/cm<SP>2</SP>tensile strength at 20°C and a ≥50,000 weight-average molecular weight is suitable. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a peelable film-forming composition useful for temporarily protecting the surface of an automobile outer plate, such as a coated surface or other coated articles.

Vehicles such as automobiles are covered with stones, sand dust, dust, iron powder while being stored in the outdoor stockyard or transported by rail, trailer, ship, etc. before being delivered to the user as a painted product. , Salt, soot, birds and other feces, insect body fluids and carcasses, sun rays, wind and rain (especially acid rain), etc., resulting in coating damage, gloss change, discoloration, etc. Since there is a problem, the coating film is temporarily protected until it reaches the user's hand.
As a method for this, a protective film capable of being peeled off after being dried is used to temporarily protect the automobile outer panel coating film. However, after using these, the protective film and the peeled coating film have been discarded.

  A polyolefin film generally used as a protective film has an advantage that it is flexible and easily follows the shape of an object having a somewhat complicated shape. However, this film is affixed to the surface of an automobile coating film using an adhesive or a pressure-sensitive adhesive. The adhesive or pressure-sensitive adhesive is applied to one side of the film and the adhesive or pressure-sensitive adhesive is applied to the other side of the film. When it is buried in the soil because it cannot be recycled after use because it is coated with a silicone or other release agent to prevent it from sticking to the part, and it cannot be recycled under natural conditions. It will remain in the soil semipermanently. In addition, when incinerated, the incineration itself requires a lot of energy, and there are problems such as generation of a large amount of toxic gas and carbon dioxide.

  On the other hand, although a method using an acrylic resin emulsion containing (meth) acrylonitrile as an aqueous temporary protective agent is known, this is excellent in film strength and peelability, but contains (meth) acrylonitrile, It is difficult to dispose of the release coating. Under the natural environment, it hardly decomposes, and when buried in the soil, there is a possibility of water pollution, and when incinerated, there is a problem that toxic gas is generated.

In order to avoid such environmental pollution, there is a method using an acrylic emulsion or a protective agent for polyurethane composition as the peelable coating composition (for example, Patent Documents 1 and 2). It can be used and has excellent workability, but any of the above-mentioned peelable coatings may remain after being used and disposed of by landfill, or the landscape may be damaged if discarded. When treated, there is a problem that the incinerator may be damaged because of the high calorific value at the time of incineration.
In addition, a method using a film-like biodegradable resin has been proposed (for example, Patent Documents 3 and 4). Since the film itself is biodegradable, there is no environmental problem, but it is not only costly to produce the film, but the work process of attaching is inevitably manual, which increases the work cost. There is a problem.

JP-A-11-302590 JP 2003-261664 A JP 2003-231216 A JP 2004-322624 A

  The object of the present invention is biodegradable and does not adversely affect the natural environment even after use, but can be easily peeled off, and can be applied to the surface of a coating film such as an automobile or a vehicle or other coatings. Another object of the present invention is to provide a strippable film-forming composition useful for temporarily protecting the surface of an article or the like.

  The present invention relates to a peelable film-forming composition comprising an emulsion using a biodegradable resin (A) and a redispersible emulsion resin (B), and the peelable film-forming composition. The present invention relates to a temporary protection method characterized by applying a composition to a substrate surface.

  The strippable film-forming composition of the present invention can be quickly applied to the surface of an automobile outer plate or other coated article, and can be easily peeled off. Since the coating film is biodegradable, it is very useful from the viewpoint of environmental protection.

  In the present invention, the emulsion using the biodegradable resin (A) is blended as a film-forming component. Examples of the biodegradable resin (A) include lactic acid polymers, lactone polymers, polyester polymers, Cellulose polymer, vinyl alcohol polymer, amino acid polymer, peptide polymer, glycolic acid polymer, etc. are mentioned, especially lactic acid based on relatively low glass transition temperature, good peelability and fast biodegradability. Polymer (C) is preferred. As the lactic acid-based polymer (C), any conventionally known one can be used without particular limitation as long as it is a biodegradable resin mainly composed of lactic acid. For example, polylactic acid, lactic acid and other hydroxycarboxylic acids are copolymerized. Suitable aliphatic polyesters can be exemplified, and these can be used alone or in combination.

  Examples of other hydroxycarboxylic acids copolymerizable with lactic acid include glycolic acid; 2-hydroxycaproic acid, 6-hydroxycarboxylic acid, 2-hydroxy-2-methylcaproic acid, and 2-hydroxy-2-ethylcaproic acid. 2-hydroxybutyric acid, 2-hydroxy-2-methylbutyric acid, 2-hydroxy-2-ethylbutyric acid, 4-hydroxybutyric acid, 2-hydroxyvaleric acid, 5-hydroxyvaleric acid, 2-hydroxyheptanoic acid, 2-hydroxy -2-ethylheptanoic acid, 2-hydroxyoctanoic acid, 7-hydroxyheptanoic acid, 2-hydroxy-2-methyloctanoic acid, 2-hydroxy-2-methylpropionic acid, 3-hydroxypropionic acid, and the like. Can be used alone or in combination of two or more. Of these, glycolic acid and hydroxycaproic acid derivatives are particularly preferred from the viewpoint of finishing the formed film and imparting flexibility.

  The lactic acid-based polymer (C) has a storage stability and a film-forming property in which L-form and D-form are present as lactic acid monomers in the constituent components within a range of 75/25 to 98/2 by weight ratio. Desirable from the viewpoint of sex. Further, it is desirable from the viewpoint of the strength of the formed film that the lactic acid monomer is used in the constituent components in an amount of 60% by mass or more, preferably 80% by mass or more.

The lactic acid-based polymer (C) has a tensile strength of 50 kg / cm ² or more, preferably 70 kg / cm ² or more from the viewpoint of ease of peeling. Here, the tensile strength is a polypropylene plate coated with an emulsion of a lactic acid polymer (C) with an applicator so as to have a dry film thickness of 50 μm, and left for 7 days under conditions of an air temperature of 20 ° C. and a relative humidity of 60%. Then, using the obtained coating film as an apparatus for measuring the tensile strength, an Instron type tensile tester (Autograph AG2000B type, manufactured by Shimadzu Corporation) was used to cut the coating film into a width of 5 mm and a length of 20 mm, and the tensile speed It is a value measured at 20 mm / min and a weight of 5 kg.

  The lactic acid polymer (C) has a weight average molecular weight of 50,000 or more, preferably 70,000 to 300,000 in view of the strength and peelability of the formed film. Here, the weight average molecular weight is measured using gel permeation chromatography (hereinafter referred to as GPC) at a flow rate of 1.0 ml / min and a measurement temperature of 40 ° C., based on the weight average molecular weight of polystyrene, using tetrahydrofuran as a solvent. This is the value when converted. “HLC8120GPC” (trade name, manufactured by Tosoh Corporation) can be used for the GPC apparatus, and columns used for GPC as a solvent include “TSKgel G-2500H × L”, “TSKgel G-3000H × L”, “ Four pieces of “TSKgel G-2500H × L” and “TSKgel G-2000H × L” (both manufactured by Tosoh Corporation) are used.

  The biodegradable resin (A) can be blended with a hydrolysis inhibitor as necessary in order to suppress hydrolysis during storage or the like. Examples of the hydrolysis inhibitor include compounds having reactivity with carboxylic acid or hydroxyl group, which are terminal functional groups of lactic acid polymers, and more specifically, carbodiimide compounds, isocyanate compounds, oxazoline compounds, and the like. Can be mentioned. Among these, a carbodiimide compound capable of effectively suppressing the hydrolyzability by adding a small amount can be preferably used.

  The carbodiimide compound may be a conventionally known one without particular limitation as long as it has one or more carbodiimide groups in the molecule, and may be oil-soluble or water-soluble. Examples of the carbodiimide compound include monocarbodiimides such as dicyclohexylcarbodiimide, diisopropylcarbodiimide, dimethylcarbodiimide, dioctylcarbodiimide, diphenylcarbodiimide, and the like, and carbodiimide compounds having two or more carbodiimide groups in the molecular chain include aromatic compounds. Examples thereof include modified polycarbodiimide compounds in which an isocyanate group which is a polymerization terminal of a polycarbodiimide compound using an organic diisocyanate compound such as an aliphatic diisocyanate, an aliphatic diisocyanate, and an alicyclic diisocyanate as a synthesis raw material is end-capped with an active hydrogen compound.

  The blending amount of the hydrolysis inhibitor is preferably within a range of 0.1 to 3% by mass with respect to the solid content of the biodegradable resin (A) from the viewpoint of hydrolysis inhibiting ability and gelation prevention. .

  The biodegradable resin (A) can be dispersed in water by a conventionally known method. Usually, an organic solvent solution of the biodegradable resin (A) is mixed with an anionic surfactant, a cationic surfactant, or a nonion. An aqueous surfactant, a water-soluble polymer such as polyvinyl alcohol, and the like are dispersed in water using a dispersion stabilizer, and then the organic solvent is removed to prepare an emulsion.

  In the present invention, the redispersible emulsion resin (B) refers to a resin that can be easily redispersed by adding it to water, and is exemplified by JIS A 6203 (polymer dispersion for cement admixture and re-emulsified powder resin). A powdery resin mainly composed of acrylic, vinyl acetate, ethylene-vinyl acetate, vinyl acetate-vinyl versatate, acrylic-styrene, or the like can be used. These resins can be used alone or in combination.

  The redispersible emulsion resin (B) is produced by any production method such as a dry method (dry blend method, melt kneading method) or a wet method (spray dry method, belt dry method, thin film distillation method, vacuum distillation method). There is no particular limitation.

  The redispersible emulsion resin (B) may be blended in a powder state or dissolved in water or a solvent.

  Content of the said redispersible emulsion resin (B) is 0.01-10 mass parts with respect to 100 mass parts of solid content of the said biodegradable resin (A), Preferably it is the range of 0.05-8 mass parts. It is desirable from the viewpoint of peelability.

  The composition of the present invention contains the components (A) and (B) as essential components, and can further contain a fibrous substance (D) as necessary.

The fibrous substance (D) is used for speeding up drying of the coating film and improving the coating film strength of the peelable coating film, and from the viewpoint of coating workability and peelability, the fiber diameter is 0.01 to 10 μm. It is preferable that the fiber length is 1 to 3000 μm. The fiber warp represents the diameter of the cross section of the fibrous substance. The material of the fibrous material is not particularly limited. For example, natural cellulose fibers such as cotton, hemp, sawdust, cocoon, regenerated cellulose fibers such as viscose silk and cupra silk, and cellulose-based artificial materials such as rayon and acetate. Examples thereof include synthetic fibers such as fibers, polyamide, polyester, and acrylic, natural fibers such as grass charcoal, wool, chitin / chitosan, and coconut shell fibers, and pulp.
Among these, cellulose fiber is preferable from the viewpoint of easy availability, cost, and naturally-derived components that are naturally friendly.

  The content of the fibrous substance (D) is 0.1 to 10 parts by mass, preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the total resin solid content. From the viewpoint of the strength and elongation of the coating, it is preferable. When the content exceeds 10 parts by mass, the biodegradability is deteriorated.

  The fibrous substance (D) may be as it is or may be suspended in water or a solvent, and the blending method of the biodegradable resin (A) in the aqueous dispersion is not particularly limited. The aqueous emulsion can be formed by a method such as mechanical dispersion or dispersion using an emulsifier.

  Furthermore, the composition of the present invention preferably contains a peeling aid (E) from the viewpoint of imparting appropriate adhesion to the surface to be coated and enabling easy peeling even after long-term use. As the peeling aid (E), at least one compound selected from wax, silicone, fluorine and the like can be suitably used. Any of those dissolved or dispersed in water or powdered can be used. Of these, polyether-modified silicone oil can be preferably used.

  The content of the peeling aid (E) is suitably 0.01 to 10 parts by mass, preferably 0.01 to 5 parts by mass, with respect to 100 parts by mass of the total resin solid content in the composition.

  The composition of the present invention also contains at least one weathering aid (F) selected from an ultraviolet absorber and a light stabilizer from the viewpoint of improving durability of the formed coating when used outdoors for a long period of time. It is desirable.

  A conventionally well-known thing can be used as a ultraviolet absorber. Specific examples thereof include salicylic acid derivatives such as phenyl salicylate, p-octylphenyl salicylate, 4-tert-butylphenyl salicylate; 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2′-dihydroxy- 4-methoxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone trihydrate, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, sodium 2,2'-dihydroxy-4,4'-dimethoxy-5-sulfobenzophenone, 2,2 ', 4,4' -Tet Lahydroxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 5-chloro-2-hydroxybenzophenone, resorcinol monobenzoate, 2,4-dibenzoylresorcinol, 4,6-dibenzoylresorcinol, hydroxydodecylbenzophenone, 2,2 ′ Benzophenone series such as -dihydroxy-4 (3-methacryloxy-2-hydroxypropoxy) benzophenone; benzotriazole series such as 2- (2'-hydroxy-5'-methylphenyl) benzotriazole and others (oxalide anilide, cyano) Acrylate etc.) and the like.

  Conventionally known light stabilizers can be used. Although mainly hindered amine derivatives, specifically, bis- (2,2 ′, 6,6′-tetramethyl-4-piperidinyl) sebacate, 4-benzoyloxy-2,2 ′, 6,6′-tetramethyl Piperidine and the like are preferred.

  The ultraviolet absorber and the light stabilizer can be used alone or in combination.

  Although the compounding quantity of the said weather resistance adjuvant (F) can be arbitrarily selected according to the objective, 0.1-10 mass parts of ultraviolet absorbers with respect to 100 mass parts of resin solid content in a composition, Preferably 0.5 to 5 parts by mass and 0.1 to 5 parts by mass, preferably 0.3 to 3 parts by mass of the light stabilizer are appropriate.

  Further, the composition of the present invention preferably contains a pigment (G). Examples of the pigment (G) include coloring pigments such as titanium white, carbon black, phthalocyanine blue, and phthalocyanine green, and extender pigments such as talc, calcium carbonate, silica, barium sulfate, clay, and mica. More than one species can be used in combination. Of these, titanium white is particularly preferred.

  The compounding quantity of a pigment (G) is 3-50 mass parts with respect to 100 mass parts of resin solid content in a composition, Preferably it is 10-30 mass parts. If it is less than 3 parts by mass, the barrier effect against ultraviolet rays, heat, etc. is small, and the stress relaxation ability is extremely small. Also, if it exceeds 50 parts by mass, the elongation of the film is reduced, it is easy to peel off when peeled, the water absorption of the film is increased, and it is not preferable because the film tends to bulge when exposed to rain. .

  As a pigment (G), a white coating is obtained by blending it with the composition of the present invention, especially after making titanium white as an aqueous dispersion, and when whitened, the barrier effect against ultraviolet rays, heat, etc. is enhanced. The peelability with time can be improved. In addition, by adding the titanium white, the shrinkage stress generated in the film can be relieved. This is because, particularly in winter, when the film is absorbed by rain or snow and exposed to low temperature, a large stress is generated in the film. This is effective because it prevents floating and peeling of the coated film on the end face, which causes the film to peel off naturally due to strong winds.

  The peeling aid (E), weathering aid (F), and pigment (G) are mixed in an emulsion using the biodegradable resin (A) after preliminarily forming an aqueous emulsion as necessary. Is desirable. In order to make these components into an aqueous emulsion, methods such as mechanical dispersion and dispersion with an emulsifier can be carried out.

  Further, the composition of the present invention preferably contains a plasticizer (H). In the present invention, the plasticizer (H) is blended in order to improve the film forming property by the biodegradable resin (A) component, and the viscosity at 25 ° C. is 25 mPa · s or more, preferably 27 to 1000 mPa · s. It is a compound of s, and a compound having biodegradation is particularly desirable. If the viscosity is less than 25 mPa · s, the plasticizing effect is poor and the film forming property is lowered, which is not preferable. Here, the viscosity of the plasticizer (H) is a value measured using a Brookfield B-type rotational viscometer at a shear rate (number of revolutions) of 60 rpm and 25 ° C.

  Examples of the plasticizer (H) include citric acid derivatives such as triethyl citrate, tributyl citrate, triethyl citrate, and tributyl acetyl citrate; diethylene glycol diacetate, triethylene glycol diacetate, triethylene glycol dipropionate, and the like. Ether ester derivatives of glycerol; glycerol derivatives such as glycerol diacetomonolaurate, glycerol triacetate, glycerol tripropionate, glycerol tributyrate; ethyl phthalyl ethyl glycolate, ethyl phthalyl butyl glycolate, butyl phthalyl butyl glycolate, etc. Phthalic acid derivatives; adipic acid derivatives such as condensates of adipic acid and 1,4-butanediol; polyhydroxys such as polycaprolactone and polypropiolactone Such carboxylic acid and the like, which may be used alone or in combination of two or more. Of these, glycerin derivatives and adipic acid derivatives are particularly preferred because of their high effect of improving film-forming properties.

  Content of the said plasticizer (H) is 1-50 mass parts with respect to 100 mass parts of solid content of the said biodegradable resin (A), Preferably it exists in the range of 5-45 mass parts. If the content is less than 1 part by mass, the film-forming property is lowered and the flexibility of the formed film is poor. On the other hand, if it exceeds 50 parts by mass, the plasticizer may bleed out from the formed film, which is not preferable.

  Depending on the type of the plasticizer (H), it is desirable that the plasticizer (H) is mixed with an aqueous dispersion of the biodegradable resin (A) after previously forming an aqueous emulsion as necessary. The aqueous emulsion can be formed by a method such as mechanical dispersion or dispersion using an emulsifier.

  In the composition of the present invention, if necessary, polymer particles, pigment dispersant, surfactant, surface conditioner, anti-settling agent, antistatic agent, softener, antibacterial agent, perfume, curing catalyst, dispersant, Defoaming agent, thickener, film-forming aid, preservative, antifungal agent, antifreezing agent, pH adjuster, humidity control agent, layered viscosity mineral, powdered or fine particle activated carbon, photocatalytic titanium oxide etc. as appropriate Can be blended.

  In the present invention, the peelable film-forming composition of the present invention can be applied to the substrate surface and dried to form a peelable film, thereby temporarily protecting the substrate surface. Can do.

  As the base material surface, automobile outer panels; surfaces of motorcycles, railway vehicles, airplanes, steel furniture, building materials, home appliances, kitchen equipment, and other industrial products; building outer walls, piers, tunnel inner surfaces, guardrails, utility poles, telephone boxes The surface of an outdoor structure such as

  As a coating method, for example, a conventionally known method such as spray, roller, brush, etc. can be employed without any particular limitation. The coating film may be dried by heat drying, forced drying, or room temperature drying. In this specification, the drying conditions of less than 40 ° C. are room temperature drying, the drying conditions of 40 ° C. or more and less than 80 ° C. are forced drying, and the drying conditions of 80 ° C. or more are heat drying. Usually, forced drying below about 80 ° C. is desirable.

  The film thickness of the peelable film is preferably 20 to 200 μm, preferably 50 to 100 μm in terms of dry film thickness, from the viewpoints of securing protection, ease of peeling, and coating workability.

  In the present invention, the peelable film-forming composition of the present invention is applied to the substrate surface, dried to form a peelable film, and then the dirt caused by dust and birds on the film is peeled off. Can be easily removed together with the protective coating. Moreover, in this invention, a coating-film surface can be protected from a sunlight ray, a wind and rain, etc.

  Hereinafter, the present invention will be described in more detail with reference to examples. “Part” and “%” indicate “part by mass” and “% by mass” unless otherwise specified.

Production of compositions for forming a peelable film Examples 1-7 and Comparative Examples 1-2
According to the composition shown in Table 1, mixing and stirring were performed to obtain each of the peelable film forming compositions A to I. In Table 1, (Note 1) to (Note 12) are as follows.

(Note 1) Biodegradable resin (lactic acid polymer) emulsion: Polylactic acid resin (L-form / D-form = 80/20 (weight ratio), weight average molecular weight 140,000, glass transition temperature 52 ° C.) 50 parts toluene 200 20 parts of “Newcol 707SF” (trade name, manufactured by Nippon Emulsifier Co., Ltd., an anionic emulsifier having a polyoxyethylene chain, active ingredient 30%) was added to the solution dissolved in part, and the mixture was stirred and mixed. Thereafter, 55 parts of water was gradually added and emulsified with stirring with a homodisper, and then toluene was removed under reduced pressure. An emulsion of a polylactic acid resin having a tensile strength of 70 kg / cm ² , a solid content of 50% and a particle size of 870 nm. Got.
Here, the glass transition temperature was measured by a differential scanning calorimetry (DSC) according to JIS K 7121 (plastic transition temperature measuring method).

(Note 2) “Primal AC-264”: trade name, manufactured by Rohm and Haas, acrylic emulsion with a solid content of 60.5%, glass transition temperature of 18 ° C.
(Note 3) Redispersible emulsion resin: Trade name “Mobilis Powder DM2072P”, manufactured by Clariant Polymer Co., Ltd. (resin powder with vinyl acetate / vinyl versatic acid / acrylic acid ester)

  (Note 4) Microfiber slurry: Product name “Serisch FD100G”, manufactured by Daicel Chemical Industries, Ltd., a slurry product of microfibers having a cellulose fiber content of 10 mass%, an average fiber diameter of 0.1 μm, and an average fiber length of 500 μm.

  (Note 5) “Riquemar PL-019”: trade name, manufactured by Riken Vitamin Co., Ltd., glycerin diacetomonolaurate, plasticizer.

  (Note 6) Peeling aid: 30 parts of modified silicone oil “TSF4445” (manufactured by Toshiba Silicone Co., polyether-modified silicone oil), 2 parts of polyoxyethylene sorbitan monooleate and 68 parts of water are added and stirred well to obtain a solid content. An aqueous dispersion of 30% silicone oil was obtained.

  (Note 7) Ultraviolet absorber: “Tinubin 1130” (manufactured by Ciba Specialty Chemicals Co., Ltd., benzotriazole derivative) is added with 5 parts of polyoxyethylene sorbitan monooleate and 65 parts of water and stirred well, and the solid content is 30%. An aqueous dispersion of an ultraviolet absorber was obtained.

  (Note 8) Light stabilizer: 5 parts of polyoxyethylene sorbitan monooleate and 45 parts of water are added to 50 parts of “Sanol LS-292” (manufactured by Sankyo Co., Ltd., hindered amine derivative), and the mixture is stirred well. An aqueous dispersion of stabilizer was obtained.

  (Note 9) Titanium white paste: Titanium oxide (trade name “Titanium CR-95”, manufactured by Ishihara Sangyo Co., Ltd.) 560 parts, 12 parts of a 40% aqueous solution of polycarboxylic acid sodium salt and 160 parts of water were added and stirred well. Dispersed to a particle size of 10 μm or less with a sand mill disperser to obtain a titanium white paste.

(Note 10) “SN Deformer 380”: trade name, manufactured by San Nopco, defoaming agent (Note 11) “Suraoff 72N”: trade name, manufactured by Takeda Pharmaceutical Company Limited, preservative (Note 12) “Adecanol UH-438” : Product name, manufactured by Asahi Denka Kogyo Co., Ltd., thickener

Evaluation test The above-described compositions for forming a peelable film A to I were evaluated according to the following criteria. The results are shown in Table 2.

(* 1) Appearance of coating film: Each peelable film-forming composition was coated on a glass plate using a 6 mil doctor blade so that the dry film thickness was 30 to 40 μm, and the temperature was 20 ° C. and the relative humidity was 60%. Each test coated plate was obtained by drying under the conditions described above. The appearance of the coating film was visually evaluated after 1 day.
◎: Good and excellent in feeling of meat ○: Good △: Slightly poor ×: Defects such as cracks and chijimi

(* 2) Peelability (initial): Amino alkyd resin paint on mild steel plate (thickness 0.7 mm) surface-treated with “Palbond 3050” (trade name, zinc phosphate surface treatment agent, manufactured by Nihon Parkerizing Co., Ltd.) Each peelable film-forming composition has a dry film thickness of about 80 μm on a coated plate that has been baked at 140 ° C. for 30 minutes so that the dry film thickness is about 20 μm. Spray coating was performed and dried at 70 ° C. for 10 minutes to obtain each test coated plate. Then, it was left for one day under conditions of an air temperature of 20 ° C. and a relative humidity of 60%. Under the same conditions, the obtained film was cut with a width of 30 mm with a cutter, and the film was peeled off at a speed of 1 m / 30 seconds.
◎: Easy to peel ○: There is a sense of resistance, but it can be peeled Δ: Although it can be peeled, the coating is broken along the way ×: Cannot be peeled

(* 3) Peelability (accelerated weather resistance): Each test coated plate was produced in the same manner as (* 2) above. Next, the obtained test coated plate was subjected to an accelerated weather resistance test of 7-7 of JIS K 5600 (General coating test method-Part 7: Long-term durability of coating film-Section 7: Accelerated weather resistance (xenon lamp method)). Similarly, after irradiation for 150 hours, the peelability was evaluated by the same method as (* 2) under the condition of an air temperature of 20 ° C.
A: Easy peeling
○: Although there is a sense of resistance, the film can be peeled.

(* 4, * 5) Strength and elongation of the coating: A polypropylene plate coated with an applicator so as to have a dry film thickness of 50 μm was left for 7 days under conditions of an air temperature of 20 ° C. and a relative humidity of 60%. The coating film was cut into a width of 5 mm and a length of 20 mm, and measured at a temperature of 0 ° C. and 20 ° C. under a pulling speed of 20 mm / min and a load of 5 kg. An Instron type tensile tester (manufactured by Shimadzu Corporation, Autograph AG2000B type) was used as a tensile strength measuring device.
Strength of coating ◎: 100 kgf / cm ² or more ○: 50 to 100 kgf / cm ²
Δ: 30-50 kgf / cm ²
×: 30 kgf / cm ² or less

Elongation of coating ◎: 100% or more ○: 50-100%
Δ: 30-50%
×: 30% or less

(* 6) Biodegradability: Each composition for forming a peelable film was coated on a polypropylene plate with a doctor blade so that the dry film thickness was about 100 μm, and the temperature was 20 ° C. and the relative humidity was 60. After being left for 7 days in a% atmosphere, the coating was peeled off from the plate to obtain each test piece (coating). The obtained test piece was sandwiched between two polypropylene nets, buried in soil of a site depth of 50 cm in Kansai Paint Co., Ltd. in Hiratsuka City, Kanagawa Prefecture, and evaluated visually after 6 months.
A: 80 to 100% of the test piece has disappeared O: 60 to 80% of the test piece has disappeared Δ: 20 to 60% of the test piece has disappeared x: 0 to 20 of the test piece % Disappeared

Claims (11)

A peelable film-forming composition comprising an emulsion using a biodegradable resin (A) and a redispersible emulsion resin (B). The peelable material according to claim 1, wherein the biodegradable resin (A) is a lactic acid polymer (C) having a tensile strength at 20 ° C of 50 kg / cm ² or more and a weight average molecular weight of 50,000 or more. Film-forming composition. The peelable film forming composition according to claim 2, wherein the lactic acid polymer (C) is polylactic acid. The composition for forming a peelable film according to claim 2, wherein the lactic acid polymer (C) is an aliphatic polyester obtained by copolymerizing lactic acid and another hydroxycarboxylic acid. The content of the redispersible emulsion resin (B) is 0.01 to 10 parts by mass with respect to 100 parts by mass of the solid content of the biodegradable resin (A). A composition for forming a peelable film. Furthermore, the peelable film according to any one of claims 1 to 5, wherein the fibrous substance (D) is contained in an amount of 0.1 to 10 parts by mass with respect to 100 parts by mass of the total resin solid content in the composition. Forming composition. The peelable coating according to any one of claims 1 to 6, further comprising 0.01 to 10 parts by mass of a peeling aid (E) with respect to 100 parts by mass of the total resin solid content in the composition. Forming composition. Furthermore, the composition for peelable film formation of any one of the Claims 1 thru | or 7 containing the at least 1 sort (s) of weathering adjuvant (F) chosen from a ultraviolet absorber and a light stabilizer. Furthermore, the composition for peelable film formation of any one of Claims 1 thru | or 8 containing a pigment (G). Furthermore, the composition for peelable film formation of any one of Claim 1 thru | or 9 containing a plasticizer (H). The temporary protection method characterized by apply | coating the composition for peelable film formation of any one of Claim 1 thru | or 10 to a base-material surface.