JP2012224788A - Composition for forming coated film and molded article for piping - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition for forming a coated film which enables a coated film to be formed on a molded article for piping made of vinyl chloride based resin, enables the molded article for piping to be adhered and joined to a coupling via an adhesive for vinyl chloride based resin even after drying the coated film and enables the ultraviolet deterioration of the molded article for piping to be suppressed over a long time, and to provide the molded article for piping on the surface layer of which the coated film is formed.SOLUTION: The composition for forming a coated film includes: an organic solvent having an SP value of 8.0 or more and less than 11.0; a synthetic resin which can be dissolved in the organic solvent; 5 to 200 pts.wt. of an ultraviolet absorber with respect to 100 pts.wt. of the synthetic resin; and 5 to 50 pts.wt. of a light stabilizer with respect to 100 pts.wt. of the synthetic resin. The molded article for piping has the coated film obtained by applying the composition for forming a coated film on the surface layer of the molded article for piping and, thereafter, removing the organic solvent contained in the composition for forming a coated film.

Description

  The present invention relates to a composition for forming a film for forming a film on a molded article for piping made of a vinyl chloride resin and a molded article for piping in which a film is formed on the surface layer.

  Vinyl chloride resins are excellent in mechanical strength and chemical resistance, and have been used for various applications such as piping materials and building materials. It is known that when a molded article using such a vinyl chloride resin is used outdoors for a long period of time, the resin deteriorates due to ultraviolet rays, causing discoloration and deterioration of physical properties. Therefore, it is required to suppress the deterioration of the vinyl chloride resin molded product due to ultraviolet rays.

  In the following Patent Document 1, 0.5 to 4 parts by weight of a stabilizer, 0.1 to 5 parts by weight of an ultraviolet absorber, and 0.5 to 10 parts by weight with respect to 100 parts by weight of a vinyl chloride resin. A vinyl chloride resin composition and a vinyl chloride resin rain gutter product containing aluminum hydroxide are disclosed. Further, in Patent Document 2 below, 1 to 6 parts by weight of stabilizer and 0.1 to 0.7 parts by weight of ultraviolet light are added to the surface layer of the vinyl chloride resin base material with respect to 100 parts by weight of vinyl chloride resin. A rain gutter is disclosed in which a weather-resistant vinyl chloride resin composition layer for surface layer to which an absorbent or the like is added is laminated.

  Patent Document 3 below discloses a two-component aqueous coating composition in which a coating is cured by adding a cross-linking agent to a base coating composed mainly of a copolymer emulsion containing an ultraviolet absorber and / or a light stabilizer. Is disclosed. The weather resistance of the vinyl chloride resin molded article can be enhanced by coating the two-component aqueous coating composition of Patent Document 3 on the vinyl chloride resin molded article.

  On the other hand, pipes made of vinyl chloride resin are known as molded articles made of vinyl chloride resin. When connecting the plurality of pipes using joints, it is necessary to bond the pipes and the joints with a high adhesive force so as to withstand the high pressure of the fluid flowing in the pipes. Therefore, there is also a need for a pipe made of vinyl chloride resin having an increased adhesive strength with a joint.

JP 2003-105148 A JP 2008-150933 A JP 2001-262056 A

  Patent Document 1 describes that when an ultraviolet absorber is added in an amount exceeding 5 parts by weight with respect to 100 parts by weight of a vinyl chloride resin, the ultraviolet absorber itself tends to come out on the surface and the appearance and weather resistance deteriorate. ing. Therefore, many ultraviolet absorbers cannot be added and there is a problem that weather resistance cannot be sufficiently improved. Furthermore, since expensive ultraviolet absorbers and stabilizers are added to the entire vinyl chloride resin, there is a problem that the cost is remarkably increased.

  In Patent Document 2, there is a description that when the ultraviolet absorber exceeds 0.7 parts by weight with respect to 100 parts by weight of the vinyl chloride resin, the effect of improving weather resistance may be dull. Therefore, many ultraviolet absorbers cannot be added and there is a problem that weather resistance cannot be sufficiently improved. Furthermore, since the rain gutter is manufactured by laminating a vinyl chloride resin base material and a vinyl chloride resin composition layer for surface layer by coextrusion, a complicated molded product having a shape like a joint is obtained. There was also a problem that it was not possible.

  In the two-component water-based paint composition of Patent Document 3, after the base paint is applied to a vinyl chloride resin molded article, the coating film is cured by adding a crosslinking agent. Once the coating film is cured, it does not melt and adhere to the adhesive component for vinyl chloride resin. Therefore, when painting pipes made of vinyl chloride resin that need to be joined at the time of use, it is necessary to paint the exposed part after joining the pipes, and it is not possible to coat vinyl chloride resin molded products at the factory shipment stage. There was a problem. Furthermore, in order to improve the adhesion between the two-component water-based paint composition and the vinyl chloride resin molded product, it is necessary to perform a surface treatment on the surface of the vinyl chloride resin molded product before the base paint is applied. Therefore, there are problems that extra time and cost are generated in the coating film, and mechanical performance of the conventional vinyl chloride resin product may be lowered.

  The object of the present invention is to form a film on a molded product for piping made of vinyl chloride resin, and to bond the molded product for piping and the joint through an adhesive for vinyl chloride resin even after the coating is dried. An object of the present invention is to provide a film-forming composition capable of bonding and suppressing ultraviolet deterioration of the above-mentioned molded article for piping over a long period of time, and a molded article for piping in which the above-mentioned film is formed on the surface layer.

  The film-forming composition of the present invention comprises an organic solvent having an SP value of 8.0 or more and less than 11.0, a synthetic resin soluble in the organic solvent, and 5 to 100 parts by weight of the synthetic resin. 200 parts by weight of an ultraviolet absorber and 5 to 50 parts by weight of a light stabilizer with respect to 100 parts by weight of the synthetic resin.

  On the specific situation with the film forming composition of this invention, the said ultraviolet absorber is an organic type ultraviolet absorber.

  In another specific aspect of the film-forming composition of the present invention, the light stabilizer is a hindered amine light stabilizer.

  The molded article for piping of the present invention includes a molded article for piping made of a polyvinyl chloride resin and / or a chlorinated polyvinyl chloride resin, and a coating formed on the surface layer of the molded article for piping. The coating is obtained by removing the organic solvent contained in the coating forming composition after applying the coating forming composition of the present invention onto the surface layer of the molded article for piping.

  Since the composition for forming a film of the present invention contains an organic solvent having an SP value of 8.0 or more and less than 11.0, a film can be reliably formed on a vinyl chloride resin molded article. In addition, since the film forming composition of the present invention contains a synthetic resin that can be dissolved in the organic solvent, the vinyl chloride resin molded article on which the film is formed is provided with an adhesive for vinyl chloride resin. Thus, it can be bonded to other vinyl chloride resin molded bodies and securely bonded. Furthermore, since the film forming composition of the present invention contains a sufficient amount of an ultraviolet absorber and a light stabilizer, the weather resistance of the vinyl chloride resin molded article on which the film is formed can be further enhanced. it can.

  Further, in the molded product for piping of the present invention, since the coating film of the coating film-forming composition of the present invention is formed on the surface layer, the molded product for piping of the present invention and the joint made of vinyl chloride resin are used as a vinyl chloride resin. It is possible to perform adhesive bonding via the adhesive, and to improve the weather resistance of the molded product for piping of the present invention.

  Hereinafter, the present invention will be clarified by describing specific embodiments of the present invention.

  The film forming composition of the present invention comprises an organic solvent having an SP value of 8.0 or more and less than 11.0, a synthetic resin soluble in the organic solvent, and 5 to 100 parts by weight of the synthetic resin. It contains 200 parts by weight of an ultraviolet absorber and 5 to 50 parts by weight of a light stabilizer with respect to 100 parts by weight of the synthetic resin. The film-forming composition of the present invention can be obtained by mixing the organic solvent, the synthetic resin, the ultraviolet absorber, and the light stabilizer in any order and method.

(Organic solvent)
The film forming composition of the present invention contains an organic solvent having an SP value of 8.0 or more and less than 11.0. Desirably, the SP value of the organic solvent is 9.0 or more and less than 10.0. By setting the SP value of the organic solvent in the above range, the SP values of the organic solvent and the vinyl chloride resin are close. Therefore, when the film of the film forming composition is formed on the vinyl chloride resin molded article, the adhesion between the film and the vinyl chloride resin molded article can be enhanced.

  When the SP value of the organic solvent is less than 8.0 or 11.0 or more, when the film forming composition is applied on the surface layer of the vinyl chloride resin molded article, the film forming composition and the vinyl chloride type are used. Adhesiveness with a resin molding becomes low. Therefore, in the molded article in which the film obtained from the film forming composition is formed on the surface layer, the film is easily peeled off.

  Examples of the organic solvent include diethylamine, cyclohexane, s-butyl acetate, dichlorofluoromethane, isopropyl acetate, dipentene, 2-heptanone, carbon tetrachloride, propylbenzene, pentylamine, xylene, p-chlorotoluene, butyraldehyde, Ethyl acetate, tetrahydrofuran, benzene, styrene, methyl ethyl ketone, benzaldehyde, chlorobenzene, ethylene glycol monobutyl ether, 2-ethyl-1-hexanol, methyl acetate, dichloroethyl ether, 1,2-dichloroethane, acetone, cyclohexanone, 1,4-dioxane , Isopentyl alcohol, o-dichlorobenzene, acetic acid, m-cresol, aniline, 1-octanol, cyclopentanone, ethylene glycol monoethyl Ether, t- butyl alcohol, pyridine, propionitrile, N, N- dimethylacetamide, 1-pentanol, and the like. Preferably, the organic solvent is butyraldehyde, ethyl acetate, tetrahydrofuran, benzene, styrene, methyl ethyl ketone, benzaldehyde, chlorobenzene, ethylene glycol monobutyl ether, 2-ethyl-1-hexanol, methyl acetate, dichloroethyl ether, 1,2- Dichloroethane, acetone, cyclohexanone. The said organic solvent may be used independently and may use 2 or more types together.

  The boiling point of the organic solvent is desirably 100 ° C. or lower. In that case, when the composition for film formation is applied to the vinyl chloride resin molded article and the organic solvent contained in the composition for film formation is removed, the time necessary for evaporating the organic solvent is set. Can be shortened.

  The amount of the organic solvent is not particularly limited, but is preferably 2 to 50 times the weight of the synthetic resin, and more preferably 5 to 30 times the weight. If the weight of the organic solvent is less than twice the weight of the synthetic resin, the resin component may be difficult to dissolve. Therefore, it may be difficult to apply the film-forming composition to the polyvinyl chloride pipe. When the weight of the organic solvent exceeds 50 times the weight of the synthetic resin, the thickness of the solid content after the coating film-forming composition is applied and dried may be reduced. In addition, since the amount of the organic solvent used is large, the cost may increase.

(Synthetic resin)
The film forming composition of the present invention contains a synthetic resin that is soluble in the organic solvent. In the present invention, that the synthetic resin can be dissolved in an organic solvent means that 10 g of the synthetic resin is completely dissolved in the organic solvent in 1 liter under the condition of 23 ° C. The fact that the synthetic resin is completely dissolved in the organic solvent means that no gel-like composition remains in the organic solvent after the synthetic resin is added to the organic solvent and stirred. If it cannot be visually confirmed that no gel-like composition remains, it is confirmed by using filter paper or the like. In the film forming composition of the present invention, it is preferable that the synthetic resin is completely dissolved in the organic solvent.

  As described above, the organic solvent has an SP value close to that of a vinyl chloride resin. That is, the SP value of the synthetic resin that can be dissolved in the organic solvent is close to that of the vinyl chloride resin. Therefore, the synthetic resin that can be dissolved in the organic solvent can be melted with the adhesive for vinyl chloride resin. Thereby, the molded article in which the film obtained from the said film formation composition was formed on the surface layer can be adhere | attached with another vinyl chloride resin molded object through the adhesive agent for vinyl chloride resins. Specifically, when the molded product is a molded product for piping, the molded product for piping and a joint made of vinyl chloride resin can be adhesively bonded.

  In the present invention, the fact that the molded product for piping and the joint can be bonded and bonded means that the molded product for piping in which a coating film is formed by the construction method described in the Eslon Pipe General Catalog for Building Piping (Revised 25th Edition) P38. And the joint are bonded via a vinyl chloride resin adhesive, and the instantaneous breaking water pressure after complete drying bonds the molded body for piping and the joint with no adhesive film with an adhesive. It means that it is equivalent to the instantaneous breaking water pressure after complete drying. The instantaneous breaking water pressure is measured by the method described in JIS S3200-1.

  Examples of the synthetic resin include polyvinyl chloride resin, chlorinated polyvinyl chloride resin, acrylic graft polyvinyl chloride resin, polyvinyl chloride resin containing a vinyl acetate component as a copolymer component, and acrylic resin. Examples thereof include resins, ABS resins, AES resins, MBS resins, EVA resins, TPU resins, and TPEE resins. The said synthetic resin may be used independently and may use 2 or more types together.

  The average degree of polymerization of the synthetic resin is not particularly limited, but is preferably 600 to 3000, and more preferably 600 to 1300. When the average polymerization degree of the synthetic resin is less than 600, the chemical resistance performance of the film formed by the film forming composition may be deteriorated. When the average polymerization degree of the synthetic resin exceeds 3000, the synthetic resin may be difficult to dissolve in an organic solvent.

(UV absorber)
The film forming composition of the present invention contains an ultraviolet absorber. The said ultraviolet absorber absorbs the ultraviolet-ray which causes deterioration of a vinyl chloride resin molded product. Therefore, even if the vinyl chloride resin molded article on which the film is formed by the film forming composition is used outdoors for a long time, deterioration due to ultraviolet rays is suppressed. Therefore, the weather resistance of the vinyl chloride resin molded product can be improved.

  It does not specifically limit as said ultraviolet absorber, A well-known ultraviolet absorber can be used. The ultraviolet absorber may be either organic or inorganic, but an organic ultraviolet absorber is preferably used. Examples of the organic ultraviolet absorber include benzotriazole-based, triazine-based, benzophenone-based, and benzoate-based ultraviolet absorbers. Examples of the inorganic ultraviolet absorber include titanium oxide, zinc oxide, cerium oxide, iron oxide, and barium sulfate fine particles. The said ultraviolet absorber may be used independently and may use 2 or more types together. Moreover, as said ultraviolet absorber, you may use together an organic type ultraviolet absorber and an inorganic type ultraviolet absorber. The said organic type ultraviolet absorber may be used independently, and may use 2 or more types together.

  Examples of the benzotriazole-based ultraviolet absorber include 2- (2-hydroxy-5-tert-butylphenyl) -2H-benzotriazole, 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2 -[2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) benzotriazole, 2- (3-t-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-t-amyl-2-hydroxyphenyl) benzotriazole, 2- (2′-hydroxy-5′-octylphenyl) Examples thereof include benzotriazole, and mixtures, modified products, polymers, and derivatives thereof.

  Examples of the triazine-based ultraviolet absorber include 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol, 2- [4 -[(2-hydroxy-3-dodecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [4- [ (2-Hydroxy-3-tridecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2,4-bis (2 , 4-Dimethylphenyl) -6- (2-hydroxy-4-iso-octyloxyphenyl) -s-triazine, mixtures thereof, modified products, polymers, derivatives and the like.

  Examples of the benzophenone-based ultraviolet absorber include 2-hydroxy-4-methoxybenzophenone and 2-hydroxy-4-n-octyloxybenzophenone.

  Examples of the benzoate-based ultraviolet absorber include phenyl salicylate, 4-t-butylphenyl salicylate, 2,5-t-butyl-4-hydroxybenzoic acid n-hexadecyl ester, 2,4 -Di-t-butylphenyl-3 ', 5-di-t-butyl-4'-hydroxybenzoate and the like.

  The amount of the ultraviolet absorber is 5 to 200 parts by weight with respect to 100 parts by weight of the synthetic resin. When the amount of the ultraviolet absorber is less than 5 parts by weight, the effect of suppressing discoloration due to weather resistance deterioration and mechanical performance is lowered. If the amount of the UV absorber exceeds 200 parts by weight, bleeding of the UV absorber or the like may easily occur.

(Light stabilizer)
The film-forming composition of the present invention contains a light stabilizer in order to suppress deterioration of the film-forming composition due to light, heat, water, or the like. As the light stabilizer, a hindered amine light stabilizer is preferably used. Examples of the hindered amine light stabilizer include bis (1,2,2,6,6-pentamethyl-4-piperidinyl) [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl]. Methyl] butyl malonate, bis (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, methyl (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, bis-decanedioic acid bis Examples include [2,2,6,6-tetramethyl-1-octyloxy) -4-piperidinyl] ester, and mixtures, modified products, polymers, and derivatives thereof. The said light stabilizer may be used independently and may use 2 or more types together.

  The amount of the light stabilizer is 5 to 50 parts by weight with respect to 100 parts by weight of the synthetic resin. When the amount of the light stabilizer is 5 parts by weight or less, the effect of preventing deterioration of the synthetic resin is lowered. When the amount of the light stabilizer exceeds 50 parts by weight, bleeding of the light stabilizer or the like may easily occur.

(Other ingredients)
The film-forming composition of the present invention may contain appropriate amounts of various additives as necessary within the range not impairing the object of the present invention, in addition to the above-described components. Examples of the additive include an organic stabilizer, an inorganic stabilizer, a film forming aid, a dispersant, a thickener, an antifoaming agent, an antioxidant, a fine agent, an antiseptic, a freezing stabilizer, and an antistatic agent. And various stabilizers such as extender pigments, colored pigments, rust preventive pigments, and the like.

(Molded product for piping)
The molded article for piping of the present invention includes a molded article for piping made of a polyvinyl chloride resin and / or a chlorinated polyvinyl chloride resin, and a film formed on the surface layer of the molded article for piping. The film is obtained by removing the organic solvent contained in the film-forming composition after applying the film-forming composition of the present invention onto the surface layer of the molded article for piping. Therefore, in the molded product for piping according to the present invention in which the coating film is formed, the molded product for piping according to the present invention and the joint made of vinyl chloride resin can be bonded and bonded via the adhesive for vinyl chloride resin. And the weather resistance of the molded article for piping of this invention can be improved.

  The thickness of the film is not particularly limited, and is appropriately adjusted according to the concentration of the ultraviolet absorber or the light stabilizer used. Preferably, the thickness of the coating is 1 μm or more. When the thickness of the film is less than 1 μm, the deterioration of the molded product for piping may not be effectively suppressed.

  As a method for applying the film-forming composition onto the surface layer of the molded article for piping, a generally known method such as brush coating, dip coating, gravure coating, spray coating or the like can be used.

  The method for removing the organic solvent contained in the film-forming composition is not particularly limited. For example, the organic solvent can be evaporated by allowing the film to stand, air-drying, heating or decompressing.

  The polyvinyl chloride resin and / or chlorinated polyvinyl chloride resin may contain other components other than polyvinyl chloride and / or chlorinated polyvinyl chloride.

  Hereinafter, the present invention will be clarified by giving specific examples and comparative examples of the present invention. The present invention is not limited to the following examples.

The materials used in the examples and comparative examples of the present invention are as follows.
Polyvinyl chloride: Tokuyama Sekisui Industry Co., Ltd., TS-800E, polymerization degree 800
Polyvinyl chloride: Tokuyama Sekisui Industry Co., Ltd., TS-640M, polymerization degree 640
Polyvinyl chloride: manufactured by Shin-Etsu Chemical Co., Ltd., TK-2500P, polymerization degree 3000
・ Ultraviolet absorber: BASF Japan Co., Ltd., TINUVIN 326, benzotriazole series ・ Light stabilizer: BASF Japan Co., Ltd., TINUVIN 770DF, hindered amine series Vinyl resin-based paints / commercially available paints: Dainippon Paint Co., Ltd., Vinylose, vinyl chloride resin-based paints / commercially available paints: Nihon Paint Co., Ltd., Terraval AE, acrylic resin-based paints

(Manufacture of composition for film formation)
Using the organic solvent and synthetic resin described in Table 1, compositions for film formation of Examples 1 to 11 and Comparative Examples 1 to 10 were prepared by the following method.

  500 g of the organic solvent was charged at room temperature into a glass container with a lid of 1000 cc. Next, the synthetic resin was gradually added while stirring the organic solvent, and the synthetic resin was dissolved in the organic solvent. As a result, a resin solution was obtained in which the amount of the organic solvent relative to the amount of the synthetic resin was the magnification described in Table 1. Subsequently, an ultraviolet absorber and a light stabilizer were added while stirring the resin solution, and dissolved in the resin solution. Thereby, the composition for film formation in which the quantity of the said ultraviolet absorber and the said light stabilizer was contained in the weight part of Table 1 with respect to 100 weight part of the said synthetic resins was obtained.

(Preparation of sample with coating)
-Production of plate sample The above-mentioned composition for forming a film obtained by the above production method was applied on a hard vinyl chloride resin press plate of 17 cm x 17 cm x 0.2 cm using a bar-shaped bar coater. did. This obtained the said press plate by which the said film forming composition liquid of the thickness of Table 1 was apply | coated to the upper surface. Thereafter, the organic solvent contained in the film-forming composition is evaporated by leaving the press plate coated with the film-forming composition in an atmosphere at 20 ° C. for 1 hour. A plate-like sample having a film having a thickness of 5 mm on the upper surface was obtained.

-Preparation of pipe-shaped sample The following predetermined amount of the organic solvent described in Table 1 was further added to the film-forming composition obtained by the above-described production method, to obtain a dipping solution. A pipe made of hard vinyl chloride resin (made by Sekisui Chemical Co., Ltd., trade name “Plant VP pipe”, nominal diameter 20) sealed at the end of the pipe with the above dipping solution, with the pipe end facing downward. Dipped vertically. Next, the pipe made of hard vinyl chloride resin was pulled up from the dipping liquid at a pulling rate of 15 cm / s. This obtained the said pipe | tube made from the hard vinyl chloride resin by which the said dipping liquid of the thickness of Table 1 was apply | coated on the surface layer. Then, the hard vinyl chloride resin pipe coated with the dipping liquid on the surface layer is left in a 20 ° C. atmosphere for 1 hour to evaporate the organic solvent contained in the dipping liquid. A pipe-like sample in which a film having the described thickness was formed on the surface layer was obtained.

  In addition, the thickness of the film of the pipe-shaped sample was adjusted to the thickness shown in Table 1 by the amount of the organic solvent added to the dipping solution. In Examples 1 to 10 and Comparative Examples 1 to 10, the amount of the organic solvent further added during the preparation of the dipping solution was 2400 parts by weight with respect to 100 parts by weight of the synthetic resin in the film forming composition. Yes, in Example 11, it was 9200 parts by weight.

(Performance test method)
About the sample in which the composition for film formation in Examples 1-11 and Comparative Examples 1-10 and the film in which the film was formed were evaluated with the following method.

-Solubility of synthetic resin in organic solvent In the step of preparing the film-forming composition, the solubility of the synthetic resin in the organic solvent was determined. Soluble in the criteria indicates that no gel-like composition remains in the organic solvent after the synthetic resin is added to the organic solvent and stirred. When it was not possible to visually confirm that no gel-like composition remained, it was confirmed by using filter paper or the like. The determination results are shown in Table 1.

-Adhesive performance The pipe-shaped sample produced by the above method was cut to prepare two pipe-shaped samples having a length of 30 cm. The above two pipe-shaped samples and a joint made of hard vinyl chloride resin having a nominal diameter of 20 are bonded via a general vinyl chloride resin adhesive (Sekisui Chemical Co., Ltd., NO.73 adhesive). The two pipe samples were connected. Subsequently, the adhesive was dried by leaving the connected pipe-shaped sample in a 23 ° C. atmosphere for 24 hours. Thereafter, water was allowed to flow inside the connected pipe sample, and water pressure was applied to the pipe sample. At this time, the load pressure of the connected pipe-like sample when the tube was broken or the pipe was inserted and broken was measured.

The hard vinyl chloride resin pipe before forming the coating was also cut and connected in the same manner as described above to apply a water pressure, and the load pressure was measured. The load pressure of the pipe-shaped sample was compared with the load pressure of the rigid polyvinyl chloride resin pipe, and the following criteria were used for evaluation. The evaluation results are shown in Table 1.
(Double-circle): 100% or more of a state without a film.
○: 90% or more of the state without a film.
(Triangle | delta): 80% or more of the state without a film.
X: Less than 80% of the state without a film.

-Adhesion performance with base material Using the plate-like sample prepared by the above method, a hard vinyl chloride resin as a base material by an adhesion test (cross cut method-100 mass) described in JIS K5600-5-6 Adhesion between the press plate and the film formed on the plate sample was evaluated according to the following criteria. The evaluation results are shown in Table 1.
A: No peeling at all.
○: The peeled surface is less than 5% of the whole.
(Triangle | delta): A peeling surface is less than 15% of the whole.
X: The peeled surface is less than 30% of the whole.

・ Weather resistance test (color change)
The plate-like sample produced by the above method was placed on a metal weather (Daipura Wintes Co., Ltd., trade name “Daipura Metal Weather”). Next, by operating the metal weather in the following operation mode, the following L, D and shower conditions were repeated, and the plate sample was irradiated with ultraviolet rays for 120 hours. Thereafter, the color difference ΔE value of the surface state of the plate-like sample was calculated by a color difference meter (trade name “Color Analyzer” manufactured by Tokyo Denshoku Co., Ltd.) and evaluated. The evaluation results are shown in Table 1.

Operation mode: L (light) + D (du)
L: Black panel temperature 65 ° C., humidity 50%, UV irradiation intensity 80 mW / mm ² , 4 hours D: Black panel temperature 30 ° C., humidity 98%, 4 hours Shower: The above plate shape over 30 seconds before and after D hour Show the sample with water.
A: ΔE is less than 0.5.
○: ΔE is less than 1.0.
Δ: ΔE is less than 3.0.
X: ΔE is 3.0 or more.

・ Weather resistance test (decrease in physical properties)
The pipe-shaped sample produced by the above method was irradiated with ultraviolet rays for 120 hours in the same manner as described above using the above metal weather. Thereafter, the impact reduction rate was measured according to the general rules for the falling weight impact test method for hard plastics described in JIS K7211.

  The impact reduction rate was measured in the same manner as above for the pipe made of the hard vinyl chloride resin before the coating was formed. The impact reduction rate of the pipe-shaped sample and the impact reduction rate of the hard vinyl chloride resin pipe were compared and evaluated according to the following criteria. The evaluation results are shown in Table 1.

In addition, about the weight shape and weight of the hard plastic used for the said evaluation, the conditions by the 20A pipe as described in JIS K6741 were used.
(Double-circle): The impact reduction rate from the said pipe | tube made from a hard vinyl chloride resin before forming a film is less than 10%.
○: Impact reduction rate from the hard vinyl chloride resin pipe before forming the coating is less than 30%.
(Triangle | delta): The impact reduction rate from the said pipe | tube made from the hard vinyl chloride resin before forming a film is less than 50%.
X: The impact reduction rate from the said hard vinyl chloride resin pipe before forming a film is 50% or more.

(Examples 1-3 and Comparative Examples 1-2)
About the organic solvent contained in the composition for film formation, THF (SP value = 9.1) in Example 1, cyclohexane (SP value = 8.2) in Example 2, and DMAc in Example 3 (SP value = 10) When .8) was used, good adhesion performance and weather resistance performance were obtained. On the other hand, when the dimethyl siloxane of Comparative Example 1 (SP value = 5.5) and the methanol of Comparative Example 2 (SP value = 14.5) were used, the synthetic resin was completely dissolved in the organic solvent. The film could not be formed.

(Example 4 and Comparative Example 3)
When the acrylic resin of Example 4 was used for the synthetic resin contained in the film forming composition, good adhesion performance and weather resistance performance were obtained. On the other hand, when the fluororesin of Comparative Example 3 was used, it was not dissolved in THF as an organic solvent. Therefore, the adhesive strength with a base material fell remarkably, and the adhesive performance and the weather resistance performance also deteriorated significantly.

(Examples 5-6)
As the synthetic resin contained in the film-forming composition, the polymerization degree of the polyvinyl chloride resin was changed. In both cases of Examples 5 and 6, good adhesion performance and weather resistance performance were obtained.

(Examples 7-8 and Comparative Examples 4-5)
In the case of 5 parts by weight of Example 7 with respect to the addition amount of the ultraviolet absorber contained in the film-forming composition, although the color tone and physical properties were slightly deteriorated in the weather resistance test, sufficient adhesion performance and weather resistance performance were obtained. Obtained. Even in the case of 200 parts by weight of Example 8, sufficient adhesion performance and weather resistance performance were obtained although the color tone was slightly deteriorated in the weather resistance test. On the other hand, in 1 part by weight of Comparative Example 4, the color tone and physical properties were remarkably inferior in the weather resistance test. In 300 parts by weight of Comparative Example 5, the ultraviolet absorber bleed occurred on the surface layer of the sample. Therefore, the remarkable deterioration of the color tone in the weather resistance test was observed.

(Examples 9 to 10 and Comparative Examples 6 to 7)
In the case of 5 parts by weight of Example 9 with respect to the addition amount of the light stabilizer contained in the film-forming composition, although the color tone and physical properties were slightly deteriorated in the weather resistance test, sufficient adhesion performance and weather resistance performance were obtained. Obtained. Also in the case of 50 parts by weight of Example 10, sufficient adhesion performance and weather resistance performance were obtained although the color tone was slightly deteriorated in the weather resistance test. On the other hand, in the case of 1 part by weight of Comparative Example 6, the color tone and physical properties were remarkably inferior in the weather resistance test. In the case of 100 parts by weight of Comparative Example 7, bleeding occurred on the surface layer of the sample. Therefore, the remarkable deterioration of the color tone change in the weather resistance performance was observed.

(Example 11)
The thickness of the film formed on the sample was 1 μm. In that case, although the color tone and physical properties were slightly deteriorated in the weather resistance test, sufficient adhesion performance and weather resistance performance were obtained.

(Comparative Examples 8 to 10)
Samples on which a film was formed by the same method as described above were prepared using the coating compositions shown in Table 1 that are generally commercially available, and various performance evaluations were performed. In that case, the adhesive strength with the joint was significantly reduced, and the physical properties in the weather resistance test were also significantly reduced.

Claims (4)

An organic solvent having an SP value of 8.0 or more and less than 11.0;
A synthetic resin soluble in the organic solvent;
5 to 200 parts by weight of an ultraviolet absorber with respect to 100 parts by weight of the synthetic resin;
A film-forming composition comprising 5 to 50 parts by weight of a light stabilizer with respect to 100 parts by weight of the synthetic resin.   The film forming composition according to claim 1, wherein the ultraviolet absorber is an organic ultraviolet absorber.   The film-forming composition according to claim 1, wherein the light stabilizer is a hindered amine light stabilizer. A molded article for piping comprising a polyvinyl chloride resin and / or a chlorinated polyvinyl chloride resin;
It is a molded article for piping comprising a coating formed on the surface layer of the molded article for piping,
The said coating film removes the said organic solvent contained in the said film formation composition, after providing the film formation composition of any one of Claims 1-3 on the surface layer of the said molded object for piping. A molded product for piping, which is a film obtained by doing.