JP6586250B1 - Rigid vinyl chloride resin tube - Google Patents

Abstract

The present invention provides a hard vinyl chloride resin tube having excellent heat shielding properties and color tone stability. A rigid polyvinyl chloride resin tube containing a polyvinyl chloride resin and two or more metal inorganic pigments and having a whiteness of 50 or more has excellent heat shielding properties and color tone stability. . Preferably, stearate is further included, and the content of the stearate is 10 to 54 parts by weight per 1 part by weight of the metallic inorganic pigment exhibiting the color, more preferably, calcium carbonate is further included, The content of the calcium carbonate is 5 parts by weight or more per 100 parts by weight of the polyvinyl chloride resin. [Selection figure] None

Description

  The present invention relates to a hard vinyl chloride resin tube having excellent heat shielding properties and color tone stability.

  Rigid vinyl chloride resin pipes are widely used for transporting general fluids such as water pipes and drain pipes, and are colored gray in JIS standards. Conventionally, carbon black is often used as a coloring pigment as a means for coloring a hard vinyl chloride resin tube gray.

  However, when carbon black is used as the color pigment, the solar panel has a low solar reflectance due to the high endothermic properties of carbon black, and outdoor sunlight is irradiated onto the hard vinyl chloride resin tube. When stored under certain conditions, the temperature rises particularly when exposed to sunlight. When such a temperature rise occurs, there is a large difference in the surface temperature between the surface exposed to sunlight and the surface not exposed to the surface of the hard vinyl chloride resin tube, and the tube itself is bent or warped due to thermal deformation. Invite you.

  As a technique for solving such a problem of thermal deformation, Patent Document 1 describes that an organic pigment having excellent infrared transmittance is used as a coloring pigment without using carbon black.

JP 2001-139698 A

  The molding process of the hard vinyl chloride resin tube is performed by heating and melting the material in an extruder to knead it into a fluid state and continuously extruding it from a die. Since the kneaded material has a high viscosity and receives a temperature difference generated due to a temperature setting of the apparatus through which the kneaded raw material passes, a difference in shape, and the like, there is a problem that the heat history is inevitably non-uniform. The present inventor has studied various types of hard vinyl chloride resin tubes using colored pigments. When an organic pigment is used as a colored pigment as in Patent Document 1, the organic pigment is affected by heat and deteriorated. The characteristic that is easy to perform and the non-uniformity of the thermal history as described above cause a variation in the color tone of the hard vinyl chloride resin tube that is a molded product, and the variation in the color tone is a hard vinyl chloride type In order to improve the heat shielding property of the resin tube, the present invention faced a particularly significant problem when it was colored in a bright color tone with a whiteness of 50 or more.

  Accordingly, an object of the present invention is to provide a hard vinyl chloride resin tube having excellent heat shielding properties (high solar reflectance) and color tone stability.

  As a result of intensive studies, the present inventor has achieved excellent thermal insulation (high solar reflectance) and color tone stability of the hard vinyl chloride resin tube by using two or more kinds of metal-based inorganic pigments as color pigments. Found to get. The present invention has been completed by further studies based on this finding.

That is, this invention provides the invention of the aspect hung up below.
Item 1. A rigid polyvinyl chloride resin tube comprising a polyvinyl chloride resin and two or more metal inorganic pigments and having a whiteness of 50 or more.
Item 2. Item 2. The rigid polyvinyl chloride resin tube according to Item 1, wherein the total content of the two or more metal inorganic pigments is 0.050 part by weight or more per 100 parts by weight of the polyvinyl chloride resin.
Item 3. Item 3. The hard polyvinyl chloride system according to Item 1 or 2, wherein the total content of the two or more metal inorganic pigments is 0.050 to 0.500 parts by weight per 100 parts by weight of the polyvinyl chloride resin. Resin tube.
Item 4. Item 4. The hard polyvinyl chloride resin tube according to any one of Items 1 to 3, wherein the two or more metal inorganic pigments are a mixture of a metal inorganic pigment exhibiting a color and a metal inorganic pigment exhibiting a white color.
Item 5. Item 5. The rigid polyvinyl chloride according to any one of Items 1 to 4, further comprising a stearate, wherein the content of the stearate is 10 to 54 parts by weight per part by weight of the metallic inorganic pigment exhibiting the color. Resin tube.
Item 6. Item 6. The rigid polyvinyl chloride resin tube according to any one of Items 1 to 5, further comprising calcium carbonate, wherein the content of the calcium carbonate is 5 parts by weight or more per 100 parts by weight of the polyvinyl chloride resin.
Item 7. Item 7. The rigid polyvinyl chloride according to any one of Items 1 to 6, wherein the content of the metallic inorganic pigment exhibiting the color is 0.025 to 0.06 parts by weight per 100 parts by weight of the polyvinyl chloride resin. Resin tube.
Item 8. Item 8. The rigid polyvinyl chloride resin tube according to any one of Items 1 to 7, wherein the colored inorganic metal pigment includes a chromium-containing compound.
Item 9. Item 9. The rigid polyvinyl chloride resin tube according to any one of Items 1 to 8, wherein the white inorganic metal pigment is titanium oxide.
Item 10. Item 10. The rigid polyvinyl chloride resin tube according to any one of Items 1 to 9, further comprising an organic pigment.
Item 11. Item 11. The rigid polyvinyl chloride resin tube according to Item 10, wherein the organic pigment is a phthalocyanine pigment.
Item 12. Item 12. The rigid polyvinyl chloride resin tube according to Item 10 or 11, wherein the content of the organic pigment is 0.0001 to 0.004 parts by weight per 100 parts by weight of the polyvinyl chloride resin.

  ADVANTAGE OF THE INVENTION According to this invention, the hard vinyl chloride-type resin tube which has the outstanding heat-shielding property (high solar reflectance) and color tone stability is provided.

  The rigid polyvinyl chloride resin tube of the present invention includes a polyvinyl chloride resin and two or more metal inorganic pigments, and has a whiteness of 50 or more. Hereinafter, the rigid polyvinyl chloride resin pipe of the present invention will be described in detail.

[Polyvinyl chloride resin]
Examples of the polyvinyl chloride resin include a polyvinyl chloride homopolymer and a composite polyvinyl chloride resin mainly composed of vinyl chloride. These may be used alone or in combination of two or more.

  The average degree of polymerization of the polyvinyl chloride resin is 600 to 3000, preferably 800 to 2000. An average polymerization degree of 600 or more is preferable from the viewpoint of obtaining good mechanical strength, and an average polymerization degree of 3000 or less is preferable from the viewpoint of ease of molding. The average degree of polymerization is obtained by dissolving a vinyl chloride homopolymer or a composite vinyl chloride resin in tetrahydrofuran (THF), removing insoluble components by filtration, and then removing THF in the filtrate by drying. It means an average degree of polymerization measured using a resin as a sample and measuring in accordance with “vinyl chloride resin test method” of Japanese Industrial Standard JIS K-6721.

  Examples of the composite polyvinyl chloride resin mainly composed of vinyl chloride include a vinyl chloride monomer and a copolymer of a monomer or a polymer copolymerizable with the vinyl chloride monomer.

  Examples of monomers copolymerizable with vinyl chloride monomer include α-olefins such as ethylene, propylene, and butylene; vinyl esters such as vinyl propionate; vinyl ethers such as ethyl vinyl ether and butyl vinyl ether; methyl (meth) acrylate. , (Meth) acrylates such as butyl (meth) acrylate and hydroxyethyl (meth) acrylate; aromatic vinyls such as styrene and α-methylstyrene; N-substituted maleimides such as N-phenylmaleimide and N-cyclohexylmaleimide Etc. These copolymerizable monomers may be used alone or in combination of two or more.

  Examples of the polymer copolymerizable with the vinyl chloride monomer include acrylic copolymers composed of alkyl (meth) acrylate monomers and the like. These copolymerizable polymers may be used alone or in combination of two or more. Here, (meth) acrylate means acrylate or methacrylate.

  When the vinyl chloride monomer is used in combination with the above copolymerizable monomer or polymer, the amount of the copolymerizable monomer or polymer used may be appropriately determined according to the performance and purpose of the obtained rigid vinyl chloride tube. There is no particular limitation.

  The polymerization method of the polyvinyl chloride homopolymer or the composite polyvinyl chloride resin mainly composed of vinyl chloride may be a conventionally known method, and examples thereof include suspension polymerization.

[Pigment]
The rigid polyvinyl chloride resin tube of the present invention contains two or more metal inorganic pigments as pigments. By including two or more kinds of metal-based inorganic pigments, it is possible to achieve both excellent heat shielding properties (high solar reflectance) and color tone stability.

  As the two or more kinds of metal-based inorganic pigments, any metal-based inorganic pigment can be used as long as it can be adjusted to a color tone having a whiteness of 50 or more. Preferably, a mixed pigment of a metallic inorganic pigment exhibiting color (non-white) and a metallic inorganic pigment exhibiting white is used. More preferably, the mixed pigment mixed so that it may be adjusted to the gray color tone prescribed | regulated to the "hard polyvinyl chloride pipe | tube" prescribed | regulated to JISK6741 is mentioned.

  As a metallic inorganic pigment exhibiting a color (non-white), one (single salt) or a plurality of metals selected from the group consisting of chromium, iron, cobalt, copper, manganese, magnesium, bismuth, yttrium, aluminum, and vanadium are used. Examples include compounds containing seeds (double salts). The compounds containing these metals may be used alone or in combination of two or more. Specific examples of the double salt include Fe—Co—Cr, Cu—Cr, Fe—Cr, Fe—Mn, Cu—Mn, Cu—Mg, Cu—Bi, Mn—Bi, Examples of the salt include Y—Mn, Co—Al, and Fe—Co—Al—Mg. Among these, a chromium-containing compound, preferably a Fe—Cr system is preferable because it has high infrared absorption suppression and excellent heat shielding properties.

  Examples of the metal-based inorganic pigment include oxides, hydroxides, sulfides, silicates, ferrocyanide salts of the above-described metals. These compounds may be used alone or in combination of two or more. Among these, an oxide is preferable in terms of excellent color tone stability.

More specifically, the metallic inorganic pigment exhibiting a color is preferably a pigment exhibiting a black color by combining one or a plurality of pigments from the above-described metallic inorganic pigment exhibiting a color. As pigments exhibiting black, mixed pigments of two or more pigments exhibiting complementary colors or colors close to complementary colors; metals constituting each of two or more pigments exhibiting colors complementary or complementary to each other And double salt pigments containing a plurality of ions; and mixtures thereof. From the viewpoint of better obtaining high solar reflectance and color tone stability, as a metallic inorganic pigment exhibiting a color, preferably, green chromium oxide (Cr ₂ O ₃ ) and a red pigment (for example, a complementary color thereof) Iron oxide) in combination as a mixed pigment, and a black-toned pigment; a composite oxide containing chromium oxide and iron oxide; and a mixture thereof, more preferably, chromium oxide and iron oxide. The composite oxide containing is mentioned.

  The content of the metallic inorganic pigment exhibiting color in the rigid polyvinyl chloride resin tube of the present invention is 100 wt% of polyvinyl chloride resin from the viewpoint of preferably suppressing non-uniformity in color tone due to non-uniform dispersion of the pigment. For example, 0.013 weight part or more is mentioned per part. Further, the content of the metallic inorganic pigment exhibiting a color may be 0.013 to 0.09 parts by weight in consideration of suppression of contamination of equipment in extrusion molding. From the viewpoint of obtaining these effects more favorably, the content of the colored metallic inorganic pigment is preferably 0.015 to 0.08 parts by weight, more preferably 0.025 to 0.08 parts by weight, Preferably it is 0.025-0.07 weight part, More preferably, 0.025-0.06 weight part is mentioned.

  Examples of the white inorganic inorganic pigment include metal oxides such as titanium dioxide, aluminum oxide, and zinc oxide. Among these, titanium dioxide is preferable because it has a high refractive index and high whiteness.

  The ratio of the metallic inorganic pigment exhibiting color to the metallic inorganic pigment exhibiting white is not particularly limited as long as the whiteness is 50 or more. For example, the total of two or more metallic inorganic pigments is 100. In the case of weight%, the content ratio of the metallic inorganic pigment exhibiting color is 18 to 58% by weight.

  The total content of the two or more types of metal inorganic pigments in the rigid polyvinyl chloride resin tube of the present invention is preferably a polyvinyl chloride resin from the viewpoint of preferably suppressing color non-uniformity due to pigment non-uniform dispersion. For example, 0.050 part by weight or more per 100 parts by weight. In addition, the total content of two or more kinds of metal-based inorganic pigments is 0.050 to 0.500 parts by weight in consideration of suppression of contamination of equipment in extrusion molding. From the viewpoint of obtaining these effects better, the total content of the two or more metal-based inorganic pigments is preferably 0.085 to 0.280 parts by weight, more preferably 0.085 to 0.230 parts by weight. More preferably, 0.087-0.0210 weight part is mentioned.

[Organic pigments]
The rigid polyvinyl chloride resin tube of the present invention can contain an organic pigment. Since the organic pigment has excellent dispersion characteristics, the rigid polyvinyl chloride resin tube can be more uniformly colored by combining with the inorganic pigment. The organic pigment is not particularly limited, and examples thereof include azo pigments, phthalocyanine pigments (such as phthalocyanine copper), selenium pigments, and dye lake pigments. These may be used alone or in combination of two or more. Among these organic pigments, a phthalocyanine pigment is preferable, and phthalocyanine copper is more preferable, from the viewpoint of obtaining excellent color tone stability of the hard vinyl chloride resin tube.

  When the organic pigment is included in the rigid polyvinyl chloride resin tube of the present invention, the content of the organic pigment is 100% by weight of the total content of the two or more metal inorganic pigments from the viewpoint of not impairing the color stability. 15 parts by weight or less per part, preferably 10 parts by weight or less, more preferably 6 parts by weight or less, more preferably 3 parts by weight or less. Moreover, as content of an organic pigment, 0.004 weight part or less is mentioned per 100 weight part of polyvinyl chloride-type resin from a viewpoint which does not impair color tone stability. More specifically, a preferable content of the organic pigment is 0.0001 to 0.004 parts by weight per 100 parts by weight of the polyvinyl chloride resin.

[Additive]
As long as the effects of the present invention are not impaired, the rigid polyvinyl chloride resin tube of the present invention is added with stabilizers, stabilizing aids, lubricants, processing aids, antioxidants, fillers, etc., as necessary. An agent may be included. Among these additives, a stabilizer and a filler are preferable.

  The stabilizer is not particularly limited. For example, dimethyltin mercapto, dibutyltin mercapto, dioctyltin mercapto, dibutyltin malate, dibutyltin malate polymer, dioctyltin malate, dioctyltin malate polymer, dibutyltin laurate, dibutyltin Organotin stabilizers such as laurate polymers; lead stabilizers such as lead stearate, dibasic lead phosphite, tribasic lead sulfate, calcium-zinc stabilizers, barium-zinc stabilizers, barium- Cadmium stabilizers: Stearate stabilizers (metal soaps) such as calcium stearate, zinc stearate, barium stearate, lead stearate; salicylate ester, benzophenone, benzotriazole, cyanoacrylate, etc. UV absorbers; hindered amine light stability Etc. The. These may be used alone or in combination of two or more.

  Among these stabilizers, stearates (stearic acid stabilizers) are preferable, and lead stearate is more preferable. When stearate is included in the hard polyvinyl chloride resin tube of the present invention, the content of stearate is polyvinyl chloride from the viewpoint of obtaining even better color tone stability of the hard vinyl chloride resin tube. 0.5 to 2 parts by weight, preferably 0.8 to 1.7 parts by weight, more preferably 1 to 1.5 parts by weight, and still more preferably 1.1 to 1.4 parts by weight, per 100 parts by weight of the resin. Can be mentioned. Further, the content of stearate is 10 to 54 parts by weight, preferably 1 to 54 parts by weight per 1 part by weight of a metallic inorganic pigment exhibiting color, from the viewpoint of obtaining even better color tone stability of the hard vinyl chloride resin tube. 15-53 weight part, More preferably, it is 20-52 weight part, More preferably, 22-52 weight part is mentioned.

  The stabilization aid is not particularly limited, and examples thereof include epoxidized soybean oil, epoxidized linseed bean oil, epoxidized tetrahydrophthalate, epoxidized polybutadiene, and phosphate ester. These may be used alone or in combination of two or more.

  Examples of the lubricant include an internal lubricant and an external lubricant. The internal lubricant is used for the purpose of lowering the flow viscosity of the molten resin during molding and preventing frictional heat generation. The internal lubricant is not particularly limited, and examples thereof include butyl stearate, lauryl alcohol, stearyl stearate, epoxidized soybean oil, glycerin monostearate, stearic acid, and bisamide. These may be used alone or in combination of two or more. The external lubricant is used for the purpose of increasing the sliding effect between the molten resin and the metal surface during the molding process. The external lubricant is not particularly limited, and examples thereof include montanic acid wax, paraffin wax, polyolefin wax, and ester wax. These may be used alone or in combination of two or more.

  The processing aid is not particularly limited, and examples thereof include acrylic processing aids that are alkyl acrylate / alkyl methacrylate copolymers having a weight average molecular weight of 100,000 to 2,000,000. Specific examples include n-butyl acrylate / Examples thereof include a methyl methacrylate copolymer and a 2-ethylhexyl acrylate / methyl methacrylate / butyl methacrylate copolymer. These may be used alone or in combination of two or more.

  It does not specifically limit as antioxidant, For example, a phenolic antioxidant etc. are mentioned. These may be used alone or in combination of two or more.

  The filler is not particularly limited, and examples thereof include calcium carbonate and talc. These may be used alone or in combination of two or more. Among these fillers, calcium carbonate is preferably used from the viewpoint of obtaining better color tone stability of the hard vinyl chloride resin tube. In addition, when calcium carbonate is included in the hard polyvinyl chloride resin tube of the present invention, the content of calcium carbonate is polyvinyl chloride from the viewpoint of obtaining even better color tone stability of the hard vinyl chloride resin tube. 5 parts by weight or more per 100 parts by weight of the resin. The upper limit of the content of calcium carbonate is not particularly limited, but may be, for example, 10 parts by weight or less, preferably 9 parts by weight or less, more preferably 8 parts by weight or less per 100 parts by weight of the polyvinyl chloride resin.

[Whiteness]
The rigid polyvinyl chloride resin tube of the present invention has a color tone with a whiteness of 50 or more. This makes it possible to obtain excellent heat shielding properties of the hard polyvinyl chloride resin tube. In addition, when a relatively bright color tone having a whiteness of 50 or more is colored, inherent variations in color tone (color tone instability) tend to occur. However, in the rigid polyvinyl chloride resin tube of the present invention, the above-described two types are used. By using the above metallic inorganic pigment as a color pigment, excellent color tone stability can be achieved. The upper limit of the whiteness range is not particularly limited, but is 70 or less, preferably 60 from the viewpoint of adapting to the gray color tone defined in “Hard Polyvinyl Chloride Tube” defined in JIS K6741. The following are mentioned. The whiteness can be adjusted by adjusting the content of the metallic inorganic pigment exhibiting a color and / or the content of the metallic inorganic pigment exhibiting a white color in the above-described two or more metallic inorganic pigments. . Whiteness refers to an L ^* value measured under a D65 light source based on the CIE 1976 L ^* a ^* b ^* colorimetric system.

[Solar reflectance]
Since the hard polyvinyl chloride resin pipe of the present invention has excellent heat shielding properties, it is possible to achieve a high solar reflectance of, for example, more than 28.5%. From the viewpoint of obtaining better heat shielding properties, the solar reflectance is preferably more than 29.5%, more preferably more than 30.5%, and even more preferably more than 31.5%. Although the upper limit of solar reflectance is not particularly limited, it is 70% or less, preferably 65% or less in consideration of the above-described whiteness. The solar reflectance is adjusted by adjusting the content of the above-described two or more kinds of metal-based inorganic pigments, adjusting the content of the organic pigment in the case of blending the organic pigment, and / or adjusting the above-described whiteness. be able to. The solar reflectance is a value measured according to JIS R3106-1998.

[Production method]
The method for producing a rigid polyvinyl chloride resin tube of the present invention comprises mixing the above-mentioned polyvinyl chloride resin and two or more kinds of metal inorganic pigments, and other components blended as required, to produce a polyvinyl chloride resin. The process 1 which prepares a resin compound, and the process 2 which shape | molds a polyvinyl chloride-type resin compound are included.

  In step 1, a polyvinyl chloride resin compound is prepared by mixing polyvinyl chloride resin with two or more kinds of metal inorganic pigments and other components blended as required. Examples of the mixing method include a hot blend method and a cold blend method. Among these mixing methods, in the case of using an organic pigment in the cold blending method, the compound is prepared under conditions where energy (heat, shearing force), which is an element necessary for the color development of the organic pigment, is not sufficiently applied. In the subsequent molding step, color unevenness due to the influence of unevenness of molding conditions (molding temperature, residence time, shearing force) becomes remarkable. In other words, the cold blend method is a mixing method that inherently tends to be unstable in color tone. However, since the rigid polyvinyl chloride resin tube of the present invention has excellent color tone stability, even when a compound is prepared by a cold blend method, which tends to be inherently unstable in color tone, the color tone is effectively stabilized. The effect can be demonstrated.

  In step 2, a polyvinyl chloride resin compound, preferably a cold blend compound of polyvinyl chloride resin, is formed. A conventionally known method is used as the molding method, and for example, an extrusion molding method is preferably used.

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

[Production of polyvinyl chloride resin compound]
The resin, pigment, and additive shown in Table 1 are stirred and mixed by a cold blend method using a super mixer (100 L, manufactured by Kawata) to obtain a polyvinyl chloride resin compound (a cold blend compound of a polyvinyl chloride resin). It was. In the numerical values shown in Table 1, for example, the description of “0.038-0.053” for titanium oxide means that titanium oxide was blended in an amount between 0.038 parts by weight and 0.053 parts by weight. Details of each component are as follows.

-Polyvinyl chloride resin: Polyvinyl chloride homopolymer (trade name “TS-1000R”, manufactured by Tokuyama Sekisui Industry Co., Ltd.)
-Lead stearate: trade name "SAK-NSBN", manufactured by San Ace,
-Calcium carbonate: trade name "Whiteon 305S", manufactured by Shiraishi Calcium Co., Ltd.-Pigment composition A: Inorganic pigment composition (including titanium oxide, chromium compound, copper phthalocyanine, dispersant. (This is a complex oxide with iron oxide.)
Pigment composition B: Carbon pigment composition (including titanium oxide, carbon black, copper phthalocyanine, and dispersant)
Pigment composition C: Organic pigment three-color composition (including titanium oxide, diketopyrrolopyrrole, monoazo yellow, copper phthalocyanine, and dispersant)
Pigment composition D: Organic pigment two-color composition (including titanium oxide, copper phthalocyanine, benzimidazoline, and dispersant)

[Production of rigid polyvinyl chloride resin moldings]
The polyvinyl chloride resin composition obtained above was supplied to a biaxial counter-rotating extruder (trade name “SLM-50”, manufactured by Nagata Seisakusho Co., Ltd.) having a diameter of 50 mm, and an outer diameter of 60 mm and a wall thickness of 4. A vinyl chloride resin tube having a length of 5 mm and a length of 1 m was obtained. Alternatively, the obtained hard polyvinyl chloride resin composition was molded by a hot press with two heated rolls to obtain a plate-shaped molded body having a thickness of 1.5 mm. The following measurements and evaluations were performed on the obtained tube or plate-shaped molded body.

[Measurement of whiteness]
Using a SPECTRO PHTO METER CM3600d apparatus (manufactured by Konica Minolta), the whiteness of the tube was measured as an L ^* value based on the CIE 1976 L ^* a ^* b ^* colorimetric system.

[Evaluation of thermal insulation (measurement of solar reflectance)]
The solar reflectance was measured in accordance with JIS R3106-1998. Specifically, the reflectance of the near-infrared wavelength region (300-2100 nm) was measured for the plate-shaped molded body, and the solar reflectance (%) was obtained based on the formula defined in JIS R3106-1998. The obtained solar reflectance was classified based on the following criteria.
-: 28.5% or less
+: More than 28.5% and 29.5% or less
++: more than 29.5% and less than 30.5% ++++: more than 30.5% and less than 31.5% ++++: more than 31.5% and less than 32.5% ++++++: more than 32.5%

[Evaluation of color stability]
From each of the polyvinyl chloride resin compositions (106.37 g) having the same composition, plate-like molded bodies of two kinds of hard polyvinyl chloride resins having different mixing conditions were obtained. The two mixing conditions are as follows. Due to the difference between these two kinds of mixing conditions, the resin composition obtained under the mixing condition (2) was prepared such that the degree of accumulation of thermal history was larger than that of the resin composition obtained under the mixing condition (1).

Mixing condition (1): The mixture was put into a 200 mL capacity cup and manually mixed at a speed of about 20 rotations per minute using a spatula.
Mixing condition (2): It put into the 200 mL capacity | capacitance cup, and stirred for 40 seconds with a household cooking mill (10,000 rpm).

About the plate-shaped molded products according to the mixing conditions (1) and (2), using SPECTRO PHTO METER CM3600d (manufactured by Konica Minolta), L ^* value based on CIE1976L ^* a ^* b ^* colorimetric system, a ^* value, and b ^* values were measured. The L ^* value, the a ^* value, and the b ^* value were all average values when 5 points were measured per n = 1. The color difference ΔE was derived from the amount of change in the Lab value of the plate-shaped molded product according to the mixing condition (2), using the Lab value of the plate-shaped molded product according to the mixing condition (1) as a reference. From ΔE, the degree of color stability was evaluated based on the following criteria.
A: ΔE <0.65
○: 0.65 ≦ ΔE <1.60
Δ: 1.60 ≦ ΔE <2.55
×: 2.55 ≦ ΔE

The results are shown in Table 1. When two or more kinds of metallic inorganic pigments are not included as the color pigment (Comparative Example 1), even if the whiteness is adjusted to 50 or more, the solar reflectance is only 1.5%, and the heat shielding property is extremely poor. It was. On the other hand, when organic pigments were used as the color pigments (Comparative Examples 2 to 4), when the whiteness was adjusted to 50 or more, the solar reflectance was good and there was no problem with heat shielding properties, but the color tone stability was extremely high. It was bad. If an organic pigment is used as the coloring pigment, if it is attempted to improve the color tone stability, the whiteness must be adjusted to a color tone greatly below 50, and the solar reflectance is reduced to 16.4%. The heat shielding property was impaired (Comparative Example 5). On the other hand, when 2 or more types of metallic inorganic pigments are included as the color pigments (Examples 1 to 5), high solar reflectance is achieved when the color is adjusted so that the whiteness is 50 or more. In addition, the color stability was excellent. For example, the polyvinyl chloride resin tube of Example 1 was irradiated with infrared rays (780 to 3000 nm) with an infrared lamp (IR100 / 110V / 250WRH manufactured by Iwasaki Electric Co., Ltd.) for 30 minutes in a 23 ° C. environment. (Accumulated light amount 2700000 mJ / cm ² ), a heat shielding test for measuring the surface (irradiated surface) temperature of the tube after completion of irradiation for 30 minutes was 58.2 ° C. Since this thermal insulation test can be evaluated as good thermal insulation if it is less than 60 ° C., the thermal insulation of the vinyl chloride resin molded bodies of Examples 1 to 5 is actually good. Admitted.

  Among Examples 1 to 5, when the content of stearate per 1 part by weight of a metallic inorganic pigment (that is, chromium compound) exhibiting a color is 10 to 54 parts by weight (Examples 2 to 5), the color tone It was observed that the stability was further significantly improved. Further, among Examples 2 to 5, when the content of calcium carbonate per 100 parts by weight of the polyvinyl chloride resin is 5 parts by weight or more (Examples 3 to 5), the solar reflectance is further remarkably improved. It was recognized that

  Examples 2 to 5 have excellent color stability as shown in Table 1. Here, specific values of ΔE (amount to be used as an evaluation criterion for color tone stability) in Examples 2, 3, 4, and 5 are 0.43, 0.35, 0.54, and 0.64, respectively. there were. That is, when compared in Examples 2 to 5, it was confirmed that the color tone stability tends to decrease as the amount of the pigment composition A increased with the peak at Example 3. And in order to obtain color tone stability at the most preferable level (that is, “◎” evaluation), it was confirmed that the amount used in Example 5 should be the upper limit as the addition amount of the pigment composition A. .

Claims (8)

A polyvinyl chloride resin, a colored metallic inorganic pigment, a white metallic inorganic pigment, and an organic pigment that is a phthalocyanine pigment ,
The whiteness is 50 or more,
The content of the metallic inorganic pigment exhibiting the color per 0.0100 parts by weight of the polyvinyl chloride resin is 0.025 to 0.06 parts by weight,
The polyvinyl chloride resin per 100 parts by weight, the content of the organic pigment, Ru 0.0001 to 0.004 parts by weight der, rigid polyvinyl chloride resin pipe.   The rigid polyvinyl chloride resin tube according to claim 1, wherein the total content of the two or more metal inorganic pigments is 0.050 part by weight or more per 100 parts by weight of the polyvinyl chloride resin.   The rigid polyvinyl chloride according to claim 1 or 2, wherein the total content of the two or more metal inorganic pigments is 0.050 to 0.500 parts by weight per 100 parts by weight of the polyvinyl chloride resin. Resin tube. The hard polychlorination according to any one of claims 1 to 3 , further comprising a stearate, wherein the content of the stearate is 10 to 54 parts by weight per part by weight of the metallic inorganic pigment exhibiting the color. Vinyl resin tube. The rigid polyvinyl chloride resin pipe according to any one of claims 1 to 4 , further comprising calcium carbonate, wherein the content of the calcium carbonate is 5 parts by weight or more per 100 parts by weight of the polyvinyl chloride resin. The rigid polyvinyl chloride resin tube according to any one of claims 1 to 5 , wherein the colored metallic inorganic pigment includes a chromium-containing compound. The rigid polyvinyl chloride resin tube according to any one of claims 1 to 6, wherein the colored metallic inorganic pigment includes a composite oxide containing chromium oxide and iron oxide . The rigid polyvinyl chloride resin tube according to any one of claims 1 to 7 , wherein the white inorganic metal pigment is titanium oxide.