JP2005105259A - Polyester composition for molding pipe and molded pipe product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a composition capable of giving a molded pipe product having excellent heat resistance and impact strength with good moldability at a low cost, by using a reclaimed polyester as a raw material, to provide a method for molding the product, and to provide a new method for accelerating crystallization of the molded pipe product, capable of producing the molded pipe product having the high heat resistance. <P>SOLUTION: The composition comprises the polyester (A), a high-viscosity polymer (B) having an MFR of ≤ 5g/10 min (at 280°C under a load of 2.16kg) and an HLMFR of ≥ 0.1g/10 min (at 280°C under a load of 21.6kg), and a compatibilizing agent (C). The molded pipe product is produced by subjecting the composition to melting, kneading, and extrusion molding. Further, the crystallization of the molded pipe product is accelerated by keeping the product at 100-200°C in such a state that the molded pipe product is fastened to a supporting material. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a polyester composition for extrusion molding of pipes, an extruded pipe molding obtained thereby, and a molding method thereof, and is particularly effective when recycled polyester is used as a raw material.

  In recent years, flaky materials crushed as containers and packaging fields, for example, recycled PET bottles, have begun to be used as recycled polyester resins, and in particular, reuse in the fiber and sheet fields has begun.

  However, in these fields, transparency and non-coloring properties are required, and mixed regenerated products such as colored bottles are difficult to use. The inventors have paid attention to civil engineering and building materials in which the addition of pigments is a general field that can be used even for recycled products containing such colored products, and mixing of colored products is not a problem. The use of extruded products, especially pipe products, has been studied. Recycled polyester has a low degree of polymerization of the original polyester itself, and is molecularly cut due to degradation such as hydrolysis in the regeneration process, etc., so the viscosity and melt tension at the time of melting are lowered, and it is extruded under normal conditions. Even if molding is performed, the extruded molten resin falls to the ground ("sagging") before performing cooling shaping, and there is a problem that stable extrusion cannot be performed. . Nevertheless, in the textile field, the molten resin could be prevented from falling by taking it at a high speed to form a thin thread. However, in the extrusion molding field, particularly in the pipe field where the diameter is large and the thickness distribution needs to be uniform, the recycled polyester could not be molded substantially.

As a method for solving the above-mentioned problems, a bis-cyclic imino ether compound (for example, see Patent Document 1), a specific epoxy compound and a binding reaction catalyst (for example, see Patent Document 2), a polyvalent carboxylic acid anhydride (for example, There is a method of obtaining an extrusion-molded product by increasing the melt viscosity of polyester by adding, for example, Patent Document 3. However, the molded bodies obtained by these have low heat resistance, and are particularly difficult to use for alternative uses for polyvinyl chloride drain pipes.
For the purpose of improving the heat resistance of the polyester pipe, a method of gradually cooling to promote crystallization is known. However, in the conventional polyester, when such crystallization promotion treatment is performed, the impact strength is remarkably lowered, and a satisfactory pipe molded body cannot be obtained. As another method for accelerating crystallization of polyester, a heat set method in which the obtained molded body is reheated for crystallization is known in PET bottle molding. However, when the obtained pipe molded body is heated and attempts to promote crystallization as it is, there is a problem that the roundness is deteriorated due to thermal deformation, and it cannot be inserted into the joint well.

  As a method for improving the impact strength, a method using a composition based on an epoxy group-containing polyolefin and polyester (see, for example, Patent Document 4 and Patent Document 5) can be mentioned. However, the viscosity of the composition obtained within the disclosed range does not have sufficient viscosity for pipe forming, the moldability is not good, and the heat resistance is low. Patent Document 5 discloses polyesters, epoxy group-containing polyolefins and polyolefin resins as compatibilizing agents, but did not focus on the melt viscosity and molecular weight of polyolefin resins as in the present invention.

As described above, a pipe molded article having a low molecular weight polyester (particularly recycled polyester) as a raw material, good moldability, good low-temperature impact strength, and excellent heat resistance has not been obtained.
JP-A-57-92046 International Publication No. 98/44019 Pamphlet JP 2002-219742 A Japanese Patent Publication No. 58-47419 Japanese Patent Laid-Open No. 2000-129099

  An object of the present invention is to develop a molding method and a composition for providing a pipe molded body having a low cost by using a recycled polyester as a raw material, which has excellent heat resistance and impact strength, and good moldability. An object of the present invention is to provide a novel crystallization promotion method for a pipe molded body for providing a high heat-resistant pipe molded body.

  The present inventors have used as a raw material a mixture comprising polyester (A), high viscosity polymer (B) and MFR ≦ 5 g / 10 min (280 ° C., 2.16 kg load) and compatibilizer (C). The present inventors have found that the above problems can be solved and have completed the present invention. That is, the present invention relates to the following [1] to [21].

  [1] Polyester (A), high-viscosity polymer (B) and phase having MFR ≦ 5 g / 10 min (280 ° C., 2.16 kg load) and HLMFR ≧ 0.1 g / 10 min (280 ° C., 21.6 kg load) A polyester composition for pipe molding comprising a solubilizer (C).

  [2] High viscosity polymer (B) with 100 parts by mass of polyester (A), MFR ≦ 5 g / 10 min (280 ° C., 2.16 kg load) and HLMFR ≧ 0.1 g / 10 min (280 ° C., 21.6 kg load) ) A polyester composition for pipe molding comprising 1 to 50 parts by mass and 1 to 40 parts by mass of a compatibilizer (C).

  [3] The pipe-forming polyester composition as described in [1] or [2] above, wherein the high-viscosity polymer (B) is polyethylene.

  [4] The pipe molding polyester composition as described in [3] above, wherein the compatibilizer (C) is polyethylene having an epoxy group.

  [5] The polyester composition for pipe forming as described in any one of [1] to [4] above, wherein the polyester (A) is a regenerated polyester.

  [6] A molded pipe obtained from the composition according to any one of [1] to [5].

  [7] Polyester (A), high-viscosity polymer (B) and phase having MFR ≦ 5 g / 10 min (280 ° C., 2.16 kg load) and HLMFR ≧ 0.1 g / 10 min (280 ° C., 21.6 kg load) A molded pipe obtained by melt-kneading a composition comprising the solubilizer (C) and extrusion molding.

  [8] Polyester (A), high-viscosity polymer (B) and phase having MFR ≦ 5 g / 10 min (280 ° C., 2.16 kg load) and HLMFR ≧ 0.1 g / 10 min (280 ° C., 21.6 kg load) A pipe molded body obtained by melt-kneading a mixture comprising the solubilizing agent (C) and extrusion molding.

  [9] The molded pipe according to [7] or [8], wherein the high-viscosity polymer (B) is polyethylene.

  [10] The molded pipe according to [9], wherein the compatibilizing agent (C) is polyethylene having an epoxy group.

  [11] The molded pipe according to any one of [7] to [10], wherein the polyester (A) is a recycled polyester.

  [12] Polyester (A), high-viscosity polymer (B) and phase having MFR ≦ 5 g / 10 min (280 ° C., 2.16 kg load) and HLMFR ≧ 0.1 g / 10 min (280 ° C., 21.6 kg load) A method for producing a molded pipe comprising melt-kneading a composition comprising a solubilizer (C) and extrusion-molding the composition.

  [13] Polyester (A), high-viscosity polymer (B) and phase having MFR ≦ 5 g / 10 min (280 ° C., 2.16 kg load) and HLMFR ≧ 0.1 g / 10 min (280 ° C., 21.6 kg load) A method for producing a pipe molded body, comprising melt-kneading a mixture comprising a solubilizer (C) and extrusion-molding the mixture.

  [14] The method for producing a molded pipe according to the above [12] or [13], wherein after the melt-kneading, the molded article is gradually cooled during extrusion molding.

  [15] The method for producing a molded pipe according to any one of [12] to [14], wherein the high-viscosity polymer (B) is polyethylene.

  [16] The method for producing a molded pipe according to [15], wherein the compatibilizer (C) is polyethylene having an epoxy group.

  [17] The method for producing a pipe molded body according to any one of the above [12] to [16], wherein the polyester (A) is a regenerated polyester.

  [18] A method for accelerating crystallization of a pipe molded body, wherein the pipe molded body according to [6] is maintained at 100 to 200 ° C. in a state where the pipe molded body is fixed with a support.

  [19] A molded pipe obtained by the crystallization promotion method of [18] above.

  [20] A two-layer pipe in which the molded pipe according to [6] is coated with mortar.

[21] containing 50% by mass or more of polyester (A),
Vicat softening temperature (1 kg load) ≧ 85 ° C. and Izod impact strength (−60 ° C.) ≧ 5 kg · cm / cm ²
A two-layer pipe obtained by mortar-covering the pipe molded body according to the above [6], in which no flame is blown to the non-heated side for more than 10 seconds in the section penetration portion performance test, and the non-heated surface A two-layer pipe covered with a mortar-coated pipe molded body, characterized in that there is no flame that continues for more than 10 seconds, and there is no damage such as cracks and gaps through which the flame passes.

  According to the polyester composition for pipe molding of the present invention, pipe moldability can be remarkably improved even when recycled polyester is used as a raw material, and it is possible to form a pipe with a large thickness and a uniform thickness distribution. In addition, the obtained molded pipe is not only excellent in heat resistance and impact strength, but can also be obtained by heat crystallization to obtain a highly heat-resistant polyester pipe molded body.

  The two-layer pipe in which this polyester pipe is covered with mortar exhibits thermal blockage in the fire resistance performance test and is effective in preventing the spread of fire.

  In general, a composition comprising polyester, another resin, or a specific compound added for the purpose of thickening is once melt-kneaded and pelletized to form a pellet of the composition. Then, the pellet is again applied to a molding machine to obtain a molded body having a predetermined shape. If the initial pelletization is omitted, it is difficult to control the uniformity of the thickening reaction, the extrusion molding is difficult to stabilize, or a special kneading device is required to stabilize the molded product, which has sufficient physical properties. Is often difficult to obtain. However, the composition of the present invention can obtain a molded product maintaining desired physical properties even if each component is put into an extruder (so-called dry blend), melt-kneaded and directly extruded.

  In pipe forming, a take-up machine is generally used. This take-up machine is generally a type that pulls while pinching the pipe, but if the impact strength of the pipe is low, cracking is likely to occur when pinching with a take-up machine, and if a crack occurs, the take-up machine cannot take it off Therefore, it is necessary to take up again to the take-up machine by human power, which is not stable as pipe forming. Since the pipe obtained by the present invention has high impact strength and is not easily broken, it does not cause a problem such as cracking when it is taken up by a take-up machine. Even when the pipe is taken up in the longitudinal direction, if the polyester composition obtained in the present invention is used, it can be said that it is suitable for pipe forming in that it is difficult to “sag” and can easily make the wall thickness distribution uniform.

Details of the present invention will be described below.
1. 1. Polyester composition for pipe molding 1-1 Component (A) Polyester The polyester (A) used for the pipe molding polyester composition of the present invention (sometimes simply referred to as a polyester composition) is, for example, dicarboxylic acid or its reaction. It can be synthesized from a functional derivative (such as ester) compound and a diol compound.

  Dicarboxylic acid compounds include terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl sulfone dicarboxylic acid, diphenoxyethane dicarboxylic acid, diphenyl ether dicarboxylic acid, methyl terephthalic acid, methyl isophthalic acid, succinic acid, adipic acid, sebacin Aromatic, aliphatic, and alicyclic dicarboxylic acids such as acid, decanedicarboxylic acid, dodecanedicarboxylic acid, and cyclohexanedicarboxylic acid. These can be used alone or in combination. Of these, terephthalic acid is preferred.

  Examples of the diol compound include ethylene glycol, triethylene glycol, tetramethylene glycol, butylene glycol, hexamethylene glycol, decamethylene glycol, neopentyl glycol, cyclohexane dimethanol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. These can be used alone or in combination. Of these, ethylene glycol is preferred.

  The polyester (A) of the present invention can be obtained by polycondensation of the above dicarboxylic acid compound and a diol compound. Most preferred for each component is terephthalic acid and ethylene glycol, but other components may be copolymerized.

  Specific examples of the polyester (A) of the present invention include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polycyclohexanediethylene terephthalate, polyneopentyl terephthalate, and two kinds thereof. The above mixture is mentioned. Among them, polyethylene terephthalate is preferable, and particularly, 80% by mole or more of the dicarboxylic acid component is terephthalic acid, and 80% by mole or more of the diol component is ethylene glycol. Specific examples of the polyethylene terephthalate resin include polyethylene terephthalate, polyethylene (isophthalate / terephthalate), polyethylene (adipate / terephthalate), polyethylene (decane dicarboxylate / terephthalate), poly (ethylene / butylene) terephthalate, and the like.

  In the present invention, a recycled product can be used as the polyester (A). In the case of recycled polyester, it is difficult to limit the type of polyester as a raw material, and a mixture of several types of polyester is often obtained. Further, in many cases, the molecular weight is lowered due to heat history and hydrolysis during the regeneration process. In the present invention, even such a polyester can be used without any problem. As the recycled polyester, commercially available flakes, or those having an arbitrary shape such as granules, powders, chips and melts can be used.

  The polyester (A) of the present invention preferably has a melt flow rate (hereinafter referred to as MFR) of 210 g / 10 min or less at a temperature of 280 ° C. and a load of 2.16 kg as defined in Condition S of Appendix A Table 1 of JIS K7210: 1999. MFR is more preferably about 130 g / 10 min or less. When the MFR exceeds 210 g / 10 min, it is difficult to sufficiently perform the modification of the present invention, and there is a possibility that the physical properties and moldability of the obtained product cannot be given.

  Although there is no restriction | limiting in particular about the upper limit of the intrinsic viscosity of the polyester (A) of this invention, It melt | dissolved in the 1,1,2,2-tetrachloroethane / phenol (1/1 weight ratio) mixed solvent, and measured at 25 degreeC. The intrinsic viscosity (IV value) is preferably 0.50 dl / g or more, and more preferably 0.60 dl / g or more. When the intrinsic viscosity is less than 0.50 dl / g, it is difficult to sufficiently perform the modification of the present invention, and physical properties and moldability of the obtained product may not be provided.

When the recycled polyester is a recycled product that has been mainly used as a PET bottle, the intrinsic viscosity is mainly 1.0 dl / g or less, but can be used without any problem in the present invention.
The content of the polyester (A) of the present invention contained in the polyester composition or the pipe molded body is preferably 50% by mass or more when used as a raw pipe of a fire-resistant two-layer pipe coated with mortar. This is because, in a test according to the performance test of the through-compartment section, if the content of polyethylene having high combustibility and low self-occlusion properties during combustion is too high, flames are generated, which is not so much as a fireproof two-layer pipe. It is because it is not preferable. A more preferable polyester content is 60% by mass or more, and particularly preferably 70% by mass or more.

(B) High-viscosity polymer The high-viscosity polymer (B) used in the present invention includes polyolefins such as high-density polyethylene, low-density polyethylene, linear low-density polyethylene, polypropylene, polybutene, and polyhexene, and α-olefins. A copolymer, a methacrylic resin represented by polymethacrylic acid, polyacetal, polycarbonate and the like can be used. Polyolefins are preferable, and polyethylene is more preferable. High-density polyethylene is more preferred, and particularly preferred is high-density polyethylene polymerized using a PHILLIPS-based catalyst, or a Cr-based catalyst capable of producing long-chain branching, a single-site catalyst, a special catalyst High-density polyethylene having a long chain branch obtained by polymerization with a Ziegler-based catalyst. Polyethylene having a long chain branch has a high melt tension and good draw-down property (difficult to sagging), and therefore is suitable for the pipe molding of the present invention.

The high-viscosity polymer (B) used in the present invention has a melt flow rate (MFR) of 5 g / 10 min at a temperature of 280 ° C. and a load of 2.16 kg as defined in the condition S of Appendix A Table 1 of JIS K7210: 1999. It is as follows. If the MFR is higher than this, the molten resin of the polyester composition for pipe molding tends to drip and the pipe moldability is not good. In particular, at the start of extrusion pipe molding, when the taken molten resin is guided to a sizer for cooling shaping, the molten resin tends to fall and workability becomes very poor. Getting worse. In addition, there is a problem that it is difficult to make the thickness distribution of the pipe product uniform. More preferable MFR is 2 g / 10 min or less, further preferable MFR is 0.5 g / 10 min or less, and particularly preferable MFR is 0.1 g / 10 min or less.
The high viscosity polymer (B) has an MFR of preferably 0.001 g / 10 min or more, and more preferably 0.005 g / 10 min or more. When it is less than 0.001 g / 10 min, it becomes difficult to melt-knead the pipe molding polyester composition of the present invention.
If the MFR is extremely small as described above, the measurement error tends to increase. Therefore, in the case of low MFR, instead of MFR, a high load melt flow rate (HLMFR, temperature 280 ° C., load 21.6 kg) is often used as an indicator of resin fluidity.
The high viscosity polymer (B) of the present invention preferably has an HLMFR of 0.1 g / 10 min or more, more preferably 1.0 g / 10 min or more. When it is less than 0.1 g / 10 min, it becomes difficult to melt-knead the polyester composition for pipe molding of the present invention.

  The high viscosity polymer (B) used in the present invention preferably has a high load melt flow rate (hereinafter, HLMFR) to MFR ratio (HLMFR / MFR) of 30 or more at a temperature of 280 ° C. and a load of 21.6 kg. If the HLMFR / MFR is 20 or less, the kneadability at the time of producing the composition or the pipe molded body is not good, and gels and blisters are likely to occur, and the surface skin on the side that is not cooled and shaped by the former of the pipe molded body (For example, when the outer surface of a pipe is cooled and shaped with a former, the surface of the pipe that is not in close contact with the former has poor surface skin even though the outer surface can be surface-smoothed by being in close contact with the farmer.) In addition, there is a problem that pipe formability is difficult to stabilize. More preferable HLMFR / MFR is 40 or more, and particularly preferable HLMFR / MFR is 80 or more.

  As for content of the high-viscosity polymer (B) used by this invention, 1-50 mass parts is preferable with respect to 100 mass parts of polyester (A). More preferably, it is 3-40 mass parts, Most preferably, it is 5-30 mass parts.

(C) Compatibilizer As the compatibilizer (C) used in the present invention, a polymer compound having the same type as the high-viscosity polymer (B) and having a functional group that reacts with polyester is preferable. Examples of the functional group include an epoxy group, an ester group, a carboxyl group, an acid anhydride group, and a hydroxyl group, and an epoxy group is particularly preferable.

  When the high viscosity polymer (B) is polyethylene, the compatibilizer (C) is preferably a polyethylene having a functional group, and particularly preferably a polyethylene having an epoxy group. In the present invention, the reason why the epoxy group-containing polyethylene is particularly preferable for increasing the viscosity is that the epoxy group reacts with the terminal of the polyester, and as a reaction product of PET and the epoxy group-containing polyethylene itself is more than the original polyester. In addition to being thickened, the polyethylene chain of the reactant and the high-viscosity polyethylene used as the polymer thickener are thought to contribute to significantly increasing the overall melt viscosity.

  As for content of the compatibilizing agent (C) used by this invention, 1-40 mass parts is preferable with respect to 100 mass parts of polyester (A). More preferably, it is 3-30 mass parts, Most preferably, it is 5-20 mass parts.

  The reason why the combination of recycled polyester, epoxy group-containing polyethylene and high-viscosity high-density polyethylene is particularly favorable in the present invention is that the epoxy-group-containing polyethylene is well compatible with low-viscosity polyester and high-viscosity polyethylene during the thickening reaction. In addition, the high-density polyethylene with high viscosity effectively scrapes the polyester that tends to adhere to the walls and screws in the molding machine, thereby preventing the polyester from being unevenly distributed and long-term residence in the extruder, thereby stabilizing the thickening reaction. This is thought to have created a synergistic effect. As a result, it was possible to realize stable direct pipe forming by dry blending of each raw material pellet without particularly pelletizing.

(D) Other components In the present invention, an impact strength improving auxiliary agent may be added to the polyester composition in addition to the high-viscosity polymer (B) and the compatibilizer (C). As the impact strength improving auxiliary agent, those containing an ethylene chain are preferable, and examples include an ethylene-α-olefin copolymer, an ethylene-polar monomer copolymer, a graft product of polyethylene and another polymer, and a low density polyethylene. Can do. Particularly preferred is low density polyethylene.

  The addition amount of the impact strength improving auxiliary agent is preferably 1 to 40 parts by mass with respect to 100 parts by mass of the polyester (A). More preferably, it is 3-30 mass parts, Most preferably, it is 5-20 mass parts.

  The polyester composition of the present invention includes talc, calcium carbonate, kaolin, alumina, etc. as fillers, glass fibers, carbon fibers, aramid fibers, whiskers, etc. as reinforcing materials, and carbon black, antimony oxide, niobium as pigments. Molybdenum sulfide, titanium oxide, etc. Other colorants, stabilizers, UV absorbers, antioxidants, antistatic agents, conductive agents, fluidity-imparting agents, mold release agents, other crosslinking agents, other resins are required You may mix according to.

  Antioxidants include hindered phenolic antioxidants such as pt-butylhydroxytoluene and pt-butylhydroxyanisole, and sulfur-based antioxidants such as distearyl thiodipropionate and dilaurylthiodipropionate. Agents, ultraviolet absorbers such as pt-butylphenyl salicylate, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2-carboxybenzophenone, 2,4,5-trihydroxybutyrophenone, etc. Examples of the inhibitor include N, N-bis (hydroxyethyl) alkylamine, alkylamine, alkylallylsulfonate, alkylsulfonate, and the like, and flame retardants such as hexabromocyclododecane and tris- (2,3-dichloropropyl). ) Phosphate, pentabromo It can be mentioned E sulfonyl allyl ether.

1-2 Production of Polyester Composition for Pipe Molding The polyester composition for pipe molding of the present invention is obtained by melting and kneading each of the above components with an extruder or the like. The reaction between the polyester (A) and the compatibilizer (C) proceeds during the melt kneading. The melt-kneaded resin is preferably pelletized once from the viewpoint of subsequent handling.

  It is preferable to dry the polyester raw material before the melt kneading. In particular, when using an extruder without a vacuum degassing device (abbreviated as a vent) with a vent mechanism for melt kneading, the polyester will hydrolyze if the residual water content is large, and the polyester with the desired viscosity will be used. It may not be possible to obtain a composition or a molded article having good moldability. When using a pressure-reducible extruder with a vent, undried polyester can be used because dehydration can be performed simultaneously by depressurizing from the vent during melt-kneading. The degree of vacuum for dehydration drying at this time is preferably 2600 Pa or less, particularly preferably 660 Pa or less. However, when it is difficult to keep the moisture content of the undried polyester constant, it is more preferable to use it after drying because it is easy to stabilize the MFR of the composition and the moldability of the molded body.

  The raw material components including the polyester (A), the high-viscosity polymer (B), and the compatibilizer (C) are desirably mixed in a predetermined formulation before being melt-kneaded with an extruder. Examples of the mixing method include a method of mixing with a Henschel mixer or the like, a method of using a side feeder or the like, and supplying the extruder at a predetermined ratio.

  The temperature for melt kneading is preferably not lower than the melting point of the polyester and not higher than 350 ° C. This is because when the temperature exceeds 350 ° C., discoloration and thermal decomposition of the polyester are more likely to occur. In particular, the melting point of the polyester is preferably 300 ° C.

  As an apparatus for melt-kneading, a single-screw extruder, a twin-screw extruder, a two-stage extruder in combination thereof, a kneader such as a kneader / ruder, or various extruders for simultaneously performing kneading and molding Can do.

  The screw length (L) / screw diameter (D) of the extruder used for melt kneading is preferably 10 or more, and particularly preferably 20 or more. As an upper limit, 100 or less is desirable from a viewpoint of economical efficiency, More preferably, it is 60 or less, Most preferably, it is 40 or less.

  The average residence time in the extruder necessary for kneading depends on the kneading performance of the apparatus, but is preferably 10 seconds to 20 minutes, more preferably 30 seconds to 10 minutes, and particularly preferably 1 minute to 6 minutes. . When the residence time is too short, the appearance of the molded article is deteriorated due to poor kneading, the reaction is insufficient, and the physical properties cannot be sufficiently exhibited. Further, if the residence time is unnecessarily too long, the productivity is deteriorated by that amount, which is not economical.

2. 2. Production of Pipe Molded Body 2-1 Shaping The pipe molded body is an extruder having a ring-shaped die 2 of the polyester composition pellets for pipe molding of the present invention, a former (also referred to as a shaping apparatus or sizer) 4, a cooling tank ( A pipe forming machine comprising a vacuum water tank 9 and a pipe take-up machine 5 can be used as a pipe 7. In the present invention, not a polyester composition once melt-mixed and pelletized, but a mixture of each component of the polyester composition is directly supplied to an extruder for forming a pipe, and each component is melt-kneaded and formed into a pipe in one step. It is also possible.

  When pipe molding is performed using the obtained polyester composition, it is preferable to dry the polyester composition so that the water content is 200 ppm (wt) or less. In particular, a general pipe forming machine often uses an extruder without a vent, and if there is a large amount of residual water, the polyester is hydrolyzed to obtain a molded body having good formability. I can't. A more preferable water content is 100 ppm or less, and particularly preferably 50 ppm or less.

  The method of extruding the polyester composition or mixture of the present invention into a pipe shape is essentially the same as a conventional thermoplastic resin pipe manufacturing apparatus, for example, a ring shape attached to the outlet of the extruder as shown in FIG. By extruding from the die 2, the molten resin 3 is extruded as a pipe. A gear pump or the like may be installed between the die 2 and the extruder outlet to stabilize the extrusion characteristics. The extruder is preferably a biaxial extruder with a vent in terms of moisture removal, kneadability, and reactivity.

  The shaping of the pipe 7 having a predetermined dimension is performed by extruding the polyester composition into a pipe shape and then bringing it into close contact with the outer surface or the inner surface of the cylindrical former 4 simultaneously with cooling (cooling shaping). In the case of guiding to the former 4, a molding method in which it is pulled in the horizontal direction is generally used, but at this time, the extruded molten resin 3 falls before being guided to the former 4 (between the die 2 and the former 4). If it does ("sagging"), it becomes difficult to form substantially. The polyester composition of the present invention is not “sagging” even when melted, has particularly good moldability, and is very suitable for pipe molding.

  As a method of forming by closely contacting the former, the so-called “vacuum sizing” in which the inner wall of the former is in a vacuum (reduced pressure) state, and the pipe-shaped molten resin before forming is brought into close contact with the former and shaped. Examples of such a method include a method that is called, and a method in which a pipe-shaped molten resin before being shaped is inflated by sending a gas such as air when the former enters the former and is closely attached to the former.

  After shaping with a former, it is solidified in a cooling tank and finally becomes a pipe molding.

  The diameter of the obtained molded pipe is not particularly limited. Not only can all types of bores used in commonly used resin pipes such as rigid vinyl chloride pipes and polyethylene pipes be manufactured, but the polyester composition of the present invention is thickened, so that the outer diameter is 48 mm or more. Large diameter pipes can also be molded.

2-2 Method for promoting crystallization (higher heat resistance) In order to obtain a pipe in which crystallization is promoted in the present invention, the obtained pipe is heated with the support fixed to promote crystallization. The method and the method of cooling gradually at the time of cooling shaping at the time of pipe forming are mentioned.

  As a method of promoting crystallization by heating a pipe obtained by water cooling or the like in a state where it is fixed by a support, a cylindrical or rod-like one is inserted into the pipe and placed in a 100 to 200 ° C. heating machine. And a method for promoting crystallization. The temperature of a preferable heater is 120 to 180 ° C, more preferably 130 to 170 ° C.

  The cylindrical or rod-like material to be inserted into the pipe is not particularly limited, but a material having high hardness, hardly causing thermal deformation, and having heat resistance of 200 ° C. or higher is used.

  Preferable materials include metal, mortar, wood, heat-resistant plastics, etc., more preferably metal or graphite. Examples of the metal include alloys such as stainless steel in addition to simple metals such as iron and tungsten.

  In addition to the method of inserting and fixing the inside of the pipe, there is a method of inserting and fixing the pipe to a cylindrical support. Further, as a combination, there is a method in which a pipe is inserted into a cylindrical support, and then a cylindrical or rod-shaped support is inserted and fixed.

  As the size of the support (in the present invention, the outer diameter of the support is indicated when inserted into a pipe, and the inner diameter of the support is indicated when inserted into a support), the crystallization is promoted. It is defined in consideration of the expansion coefficient so that the gap between the pipe and the support when the temperature is reached is 0 to 1 mm, preferably 0 to 0.5 mm.

  In addition, when a pipe is inserted into and fixed to a cylindrical support and the gap between the pipe and the support is taken at the crystallization promoting temperature, a support having a larger expansion coefficient than the pipe is used. It is preferable to insert the pipe after the support is heated to the crystallization temperature in advance. Further, a release agent generally used for plastics may be used for the support.

  As a method of gradually cooling the cooling at the time of pipe forming, the cooling can be performed by increasing the temperature of the cooling tank at the time of cooling forming, or the cooling time in the cooling tank can be shortened as much as possible. Thereafter, there is a method of slow cooling by air cooling.

  The temperature of the cooling tank when the temperature of the cooling tank is increased and gradually cooled is preferably 80 to 180 ° C, more preferably 90 to 160 ° C, and particularly preferably 100 to 140 ° C. In this case, it is preferable to use oil as the cooling medium.

  As the residence time in the cooling tank necessary for slow cooling when the cooling time in the cooling tank is as short as possible, the temperature of the cooling tank and the pipe wall thickness (preferably wall thickness in this method is 1 mm or more, more preferably 2 mm or more, particularly preferably 3 mm or more), but preferably within 10 seconds. More preferably, it is within 8 seconds, and particularly preferably within 5 seconds.

3. Mortar-coated two-layer pipe The method for forming a two-layer pipe by mortar-coating the pipe molded body obtained in the present invention is to form a mortar into a sheet and then wrap it around a rod to form into a pipe Or, injecting mortar into a pipe-shaped mold to shape the pipe-shaped mortar, inserting the obtained pipe molded body to obtain a two-layer pipe, or fitting the obtained pipe molded body into the mold, The method etc. which inject | pour mortar and obtain a two-layer pipe directly are mentioned.

According to a preferred embodiment of the present invention, the polyester (A) is contained in an amount of 50% by mass or more, and the Vicat softening temperature (1 kg load) ≧ 85 ° C. and the Izod impact strength (−60 ° C.) ≧ 5 kg · cm / cm ² . This is a two-layer pipe with a mortar-coated pipe molded body, and in the section penetration part performance test, there is no jet of flame that continues for more than 10 seconds to the non-heated side, and the emission that continues for more than 10 seconds on the non-heated surface. It is possible to obtain a two-layer pipe having a mortar-coated pipe molded body characterized in that there is no flame and damage such as a crack through which the flame passes and a gap are not generated.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.
Evaluation method of physical properties and preparation of measurement samples

○ Melt flow rate (MFR)
After the obtained pipe was crushed and passed through a sieve having a nominal size of 2.36 mm specified in JIS Z 8801, it was dried at 140 ° C. to a water content of 200 ppm or less, and then the JIS K7210: 1999, Annex A, Table 1 According to the condition S, the measurement was performed at a temperature of 280 ° C. and a load of 2.16 kg. The composition and raw material MFR were measured without crushing.

○ High load melt flow rate (HLMFR)
The load was changed to 21.6 kg by the same measurement method as that for the melt flow rate.

○ Moisture amount Using AQUATRAC AT type polymer moisture meter manufactured by Brabender Messtechnik (Germany), the sample is heated at 160 ° C., and the amount of hydrogen generated by reacting the generated water vapor with CaH ₂ is measured. The amount of water contained was determined from the total number of moles of hydrogen generated and divided by the weight of the sample to obtain the amount of water.

○ Izod (IZOD) impact strength In accordance with JIS K7110: 1999 appendix 1 Table 1 “Test specimen dimensions” No. 2 B, pipe thickness is set to pipe thickness (t). The sample cut from the pipe is JIS K7110 so that the circumferential direction is the width (b) direction of the Izod test piece and the width of both ends is 12.7 mm and the notch depth is 2.54 mm in a state of curvature. : Izod impact strength was measured according to 1999.

○ Vicat softening temperature The obtained pipe molded body is in accordance with JIS K7206: 1999 “5. A sample cut to have a side of 15 mm was measured under a load of 1.00 to 1.05 kg in accordance with A50 method of JIS K7206: 1999.

○ Performance test of section penetration section Construction performance of the Building Standards Law Article 115-2, Paragraph 1, Item 7, Item C, “Performance of pipes that penetrate fire prevention sections, etc.” designated by the Minister of Land, Infrastructure, Transport and Tourism This was performed according to the “Test and Evaluation Work Method”.

[Example 1] (Kneading-Pipe forming continuous system)
Recycled PET (polyethylene terephthalate, manufactured by Tokyo PET Bottle Recycle Co., Ltd., A rank flake: MFR 49 g / 10 min after drying) 40 kg, KBX44A (high density polyethylene: manufactured by Nippon Polyolefin Co., Ltd.) : MFR 0.05g / 10min, HLMFR 15g / 10min) 4kg and Lexpearl RA3150 (Epoxy group-containing polyethylene: manufactured by Nippon Polyolefin Co., Ltd.) 3kg mixed in the same direction biaxial extruder (Toshiba Machine Co., Ltd.) TEM-37BS, tandem screw, screw diameter 37 mm, screw length (L) / screw diameter (D) = 35), and melt kneaded at a screw speed of 60 rpm and 280 ° C. Furthermore, after being extruded into a cylindrical shape from a die having an outer diameter of 48 mm and an inner diameter of 42 mm and heated to 260 ° C. installed on the outlet side of this extruder, it is led to a vacuum water tank having a former with an inner diameter of 48 mm cooled to 20 ° C. Then, cooling shaping was performed to form a pipe having an outer diameter of 48 mm and a wall thickness of 3 mm.

  The molten resin while being led from the die to the former was extremely difficult to sag and the moldability was very good.

  According to the Izod impact strength measurement method and Vicat softening temperature measurement method, the obtained pipe was evaluated by cutting a sample with the same width in a state of curvature (the Izod specimen is curved in the width direction). Went. The Vicat softening temperature was measured in consideration of the curvature of the pipe with the bent side facing upward (with the inner surface of the pipe facing upward). The measurement results including MFR are shown in Table 1.

[Example 2] (Kneading-Pipe forming continuous system with LDPE)
Recycled PET (polyethylene terephthalate, manufactured by Tokyo PET Bottle Recycle Co., Ltd., A rank flake: MFR 49 g / 10 min after drying) 40 kg, KBX44A (high density polyethylene: manufactured by Nippon Polyolefin Co., Ltd.) : MFR 0.05 g / 10 min, HLMFR 15 g / 10 min) 4 kg, Lexpearl RA3150 (epoxy group-containing polyethylene: manufactured by Nippon Polyolefin Co., Ltd.), and JK311A (low density polyethylene: manufactured by Nippon Polyolefin Co., Ltd., MFR 7 g / 10 min) A mixture of 4 kg was extruded under the same conditions as in Example 1, cooled and shaped to form a pipe having an outer diameter of 48 mm and a wall thickness of 3 mm. The molten resin while being led from the die to the former was extremely difficult to sag and the moldability was very good. The measurement results are shown in Table 1.

[Example 3] (Kneading-pipe forming continuous system 2)
Recycled PET (polyethylene terephthalate, manufactured by Tokyo PET Bottle Recycling Co., Ltd., A rank flake: MFR 49 g / 10 min after drying), 40 kg, KL353A (high density polyethylene: manufactured by Nippon Polyolefin Co., Ltd.) : MFR 4 g / 10 min, HLMFR 180 g / 10 min) 4 kg and Lexpearl RA3150 (epoxy group-containing polyethylene: manufactured by Nippon Polyolefin Co., Ltd.) 3 kg were extruded under the same conditions as in Example 1, cooled and shaped, and the outside A pipe having a diameter of 48 mm and a wall thickness of 3 mm was formed. The molten resin while being led from the die to the former was hard to sag and the moldability was good. The measurement results are shown in Table 1.

[Example 4] (After kneading pelletization, pipe forming)
Recycled PET (polyethylene terephthalate, manufactured by Tokyo PET Bottle Recycle Co., Ltd., A rank flake: MFR 49 g / 10 min after drying) 40 kg, KBX44A (high density polyethylene: manufactured by Nippon Polyolefin Co., Ltd.) : MFR 0.05 g / 10 min, HLMFR 15 g / 10 min) 4 kg, Lexpearl RA3150 (epoxy group-containing polyethylene: manufactured by Nippon Polyolefin Co., Ltd.) 3 kg, and JK311A (low density polyethylene: manufactured by Nippon Polyolefin Co., Ltd.) 4 kg Was melted and kneaded at 280 ° C. at a screw speed of 60 rpm with a twin screw extruder in the same direction (the same as in Example 1), taken into a thread form through a water bath cooled to 20 ° C., and To obtain pellets of a pipe molding polyester composition is granulated. After drying the obtained pellets at 140 ° C. to a moisture content of 200 ppm or less, a single screw extruder (manufactured by Ikegai Co., Ltd., GS65-25, screw diameter 65 mm, full flight screw, screw length (L) / It was melted at 280 ° C. with a screw diameter (D) = 25), and was extruded at a cylindrical shape from a die set at the outlet of the extruder, having an outer diameter of 48 mm, an inner diameter of 42 mm, and heated to 260 ° C. The pipe was led to a cooled water tank having an inner diameter of 48 mm and cooled, and a pipe having an outer diameter of 48 mm and a wall thickness of 3 mm was formed. The molten resin while being led from the die to the former was extremely difficult to sag and the moldability was very good. The physical property measurement results are shown in Table 1.

[Comparative Example 1] (using low viscosity HDPE)
Recycled PET (polyethylene terephthalate, manufactured by Tokyo PET Bottle Recycling Co., Ltd., A rank flake: MFR 49 g / 10 min after drying) 40 kg, KV568Y (high-density polyethylene: manufactured by Nippon Polyolefin Co., Ltd.) previously dried at 140 ° C. to a water content of 200 ppm or less : MFR 14 g / 10 min) 4 kg and Lexpearl RA3150 (epoxy group-containing polyethylene: manufactured by Nippon Polyolefin Co., Ltd.) 3 kg were extruded under the same conditions as in Example 1, and cooling shaping was attempted. As a result, the molten resin dropped between the vacuum water tank and the die, and a good pipe molded body could not be obtained. The falling resin that was not obtained as a pipe molded body was crushed and passed through a sieve having a nominal size of 2.36 mm specified in JIS Z 8801, and dried at 140 ° C. to a water content of 200 ppm or less, and MFR was measured. The measurement results are shown in Table 1.

[Comparative Example 2] (No epoxy group-containing PE)
Recycled PET (Polyethylene terephthalate, manufactured by Tokyo PET Bottle Recycling Co., Ltd., A rank flake: MFR 49 g / 10 min after drying) 40 kg, and KBX44A (High Density Polyethylene: Nippon Polyolefin Co., Ltd.) dried in advance at 140 ° C. to a water content of 200 ppm or less. (Product: MFR 0.05 g / 10 min, HLMFR 15 g / 10 min) A mixture of 4 kg was extruded under the same conditions as in Example 1 to perform cooling shaping, but between the vacuum water tank having the former and the die The molten resin dropped and a good pipe molded body could not be obtained. MFR was measured in the same manner as in Comparative Example 1 for the dropped resin that was not obtained as a pipe molded body. The measurement results are shown in Table 1.

[Comparative Example 3] (Use medium viscosity HDPE)
Recycled PET (polyethylene terephthalate, manufactured by Tokyo PET Bottle Recycling Co., Ltd., A rank flake: MFR 49 g / 10 min after drying) 40 kg, KM458A (high-density polyethylene: manufactured by Nippon Polyolefin Co., Ltd.), which was previously dried at 140 ° C. to a water content of 200 ppm or less. : MFR 6 g / 10 min) 4 kg and Lexpearl RA3150 (epoxy group-containing polyethylene: manufactured by Nippon Polyolefin Co., Ltd.) 3 kg mixed, extruded under the same conditions as in Example 1, cooled and shaped, outer diameter 48 mm, A pipe having a wall thickness of 3 mm was formed. However, as compared with Examples 1 to 4, the molten resin while being led from the die to the former was easy to sag and the moldability was not good. The physical property measurement results are shown in Table 1.

[Example 5] (Slow-cooled pipe molded body and molding method)
Recycled PET (polyethylene terephthalate, manufactured by Tokyo PET Bottle Recycle Co., Ltd., A rank flake: MFR 49 g / 10 min after drying) 40 kg, KBX44A (high density polyethylene: manufactured by Nippon Polyolefin Co., Ltd.) : MFR 0.05 g / 10 min, HLMFR 15 g / 10 min) 4 kg, Lexpearl RA3150 (epoxy group-containing polyethylene: manufactured by Nippon Polyolefin Co., Ltd.), and JK311A (low density polyethylene: manufactured by Nippon Polyolefin Co., Ltd., MFR 7 g / 10 min) A mixture of 4 kg was melt kneaded at 280 ° C. at a screw rotation speed of 60 rpm using the same direction biaxial extruder (same as in Example 1). Furthermore, after being extruded into a cylindrical shape from a die having an outer diameter of 48 mm and an inner diameter of 42 mm and heated to 260 ° C. installed on the outlet side of this extruder, it is led to an oil tank having a 48 mm inner diameter former heated to 120 ° C. After the tip was sealed, it was inflated by applying internal pressure to make it closely contact with the former, and cooling shaping was performed to form a pipe having an outer diameter of 48 mm and a wall thickness of 3 mm. The measurement results are shown in Table 1. It can be seen that by virtue of slow cooling, the Vicat softening temperature is significantly increased as compared with the rapidly cooled Example 2.

[Example 6] (Method for promoting crystallization of water-cooled pipe)
An iron round bar having an outer diameter of 41.5 mm at 150 ° C. was inserted into the molded pipe obtained in Example 2, and crystallization was promoted in a 150 ° C. heating machine for 1 hour. The resulting pipe molded body had a Vicat softening temperature of 110 ° C. and an Izod impact strength at −60 ° C. of 5.3 kg · cm / cm ² .

[Example 7] (mortar coating and fire resistance test)
The pipe molded body obtained in Example 2 was cut into a length of 1.5 m, and a mortar pipe having an inner diameter of 49 mm and a wall thickness of 8 mm (manufactured by Niigata Showa Co., Ltd.) was cut into a length of 1.5 m. The mortar coating was performed. When the compartment penetration part performance test was carried out with the obtained two-layer tube, there was no jet of flame that continued for more than 10 seconds to the non-heated side, and there was no flame that continued for more than 10 seconds on the non-heated surface In addition, there was no damage such as cracks through which the flame passed and gaps. Furthermore, the surface temperature of the partition penetration part was 210 ° C. or less and (room temperature + 180 ° C.) or less, and no smoke was detected from the partition penetration part.

An example of the pipe molding machine used for manufacture of a pipe molded object is shown.

Explanation of symbols

2 Dies 3 Molten resin (pipe shape)
4 Former 5 Take-up machine 6 Pipe cutter 7 Pipe 8 Rasha seal 9 Vacuum water tank 10 Vacuum gauge

Claims (21)

  Polyester (A), high viscosity polymer (B) and compatibilizer (MFR ≦ 5 g / 10 min (280 ° C., 2.16 kg load) and HLMFR ≧ 0.1 g / 10 min (280 ° C., 21.6 kg load)) A polyester composition for pipe molding comprising C).   High viscosity polymer (B) 1 to 100 parts by mass of polyester (A), MFR ≦ 5 g / 10 min (280 ° C., 2.16 kg load) and HLMFR ≧ 0.1 g / 10 min (280 ° C., 21.6 kg load) A polyester composition for pipe molding comprising 50 parts by mass and 1 to 40 parts by mass of a compatibilizer (C).   The polyester composition for pipe forming according to claim 1 or 2, wherein the high-viscosity polymer (B) is polyethylene.   The polyester composition for pipe molding according to claim 3, wherein the compatibilizing agent (C) is polyethylene having an epoxy group.   The polyester composition for pipe forming according to any one of claims 1 to 4, wherein the polyester (A) is a regenerated polyester.   A molded pipe obtained from the composition according to claim 1.   Polyester (A), high viscosity polymer (B) and compatibilizer (MFR ≦ 5 g / 10 min (280 ° C., 2.16 kg load) and HLMFR ≧ 0.1 g / 10 min (280 ° C., 21.6 kg load)) A molded pipe obtained by melt-kneading the composition comprising C) and extrusion molding.   Polyester (A), high viscosity polymer (B) and compatibilizer (MFR ≦ 5 g / 10 min (280 ° C., 2.16 kg load) and HLMFR ≧ 0.1 g / 10 min (280 ° C., 21.6 kg load)) A pipe molded body obtained by melt-kneading the mixture comprising C) and extrusion molding.   The pipe molding according to claim 7 or 8, wherein the high viscosity polymer (B) is polyethylene.   The pipe forming body according to claim 9, wherein the compatibilizing agent (C) is polyethylene having an epoxy group.   The molded pipe according to any one of claims 7 to 10, wherein the polyester (A) is a recycled polyester.   Polyester (A), high viscosity polymer (B) and compatibilizer (MFR ≦ 5 g / 10 min (280 ° C., 2.16 kg load) and HLMFR ≧ 0.1 g / 10 min (280 ° C., 21.6 kg load)) A method for producing a pipe-molded product, comprising melt-kneading a composition comprising C) and extrusion-molding the composition.   Polyester (A), high viscosity polymer (B) and compatibilizer (MFR ≦ 5 g / 10 min (280 ° C., 2.16 kg load) and HLMFR ≧ 0.1 g / 10 min (280 ° C., 21.6 kg load)) A method for producing a pipe molded body, comprising melt-kneading a mixture of C) and extrusion molding.   The method for producing a pipe molded body according to claim 12 or 13, wherein after the melt-kneading, the molded body is gradually cooled when extrusion molding.   The method for producing a molded pipe according to any one of claims 12 to 14, wherein the high-viscosity polymer (B) is polyethylene.   The method for producing a molded pipe according to claim 15, wherein the compatibilizer (C) is polyethylene having an epoxy group.   The method for producing a molded pipe according to any one of claims 12 to 16, wherein the polyester (A) is a recycled polyester.   A method for accelerating crystallization of a pipe molded body, wherein the pipe molded body according to claim 6 is maintained at 100 to 200 ° C in a state where the pipe molded body is fixed by a support.   A pipe molded body obtained by the crystallization promoting method of claim 18.   A two-layer pipe obtained by mortar-coating the molded pipe according to claim 6. Including 50% by mass or more of polyester (A),
Vicat softening temperature (1 kg load) ≧ 85 ° C. and Izod impact strength (−60 ° C.) ≧ 5 kg · cm / cm ²
A two-layer pipe in which the molded pipe according to claim 6 is coated with mortar, and in the performance test of the partition penetration part, there is no flame jetting for more than 10 seconds toward the non-heated side, and on the non-heated surface. A two-layer pipe covered with a mortar-coated pipe molded body, characterized in that there is no flame that continues for more than 10 seconds, and there is no damage such as cracks through which the flame passes and no gaps.

Images