JP2008231423A - Thermoplastic polyester mixture and manufacturing process for heat-shrinkable tube using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-shrinkable tube produced by using a new thermoplastic polyester mixture. <P>SOLUTION: The thermoplastic polyester mixture comprises 5-95 wt.% of a component (A): a homopolymer or copolymer polyethylene terephthalate (PET) with intrinsic viscosity of 0.8-1.2 dL/g with respect to the total weight of the components (A) and (B) and 95-5 wt.% of a component (B): a polytrimethylene terephthalate (PTT) with intrinsic viscosity of 0.8-1.2 dL/g with respect to the total weight of components (A) and (B). The heat-shrinkable tube produced by using the thermoplastic polyester mixture shrinks when heated within hot water into the machine direction (MD) by 5% to 15% and into the transverse direction (TD) by more than 35%. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a thermoplastic polymer mixture suitable for the production of heat-shrinkable tubes, more specifically 5 to 95% by weight of component (A) of the total weight of component (A) and component (B): inherent Homopolymerized or copolymerized polyethylene terephthalate (PET) having a viscosity of 0.8 to 1.2 dl / g, and 95 to 5% by weight of component (B) in the total weight of component (A) and component (B): It relates to a thermoplastic polymer mixture comprising polytrimethylene terephthalate (PTT) with an intrinsic viscosity of 0.8 to 1.2 dl / g.

  Heat-shrinkable tubes are usually made from PVC and used as an outer coating that adheres and protects electronic components over a long period of time. However, PVC, when burned incompletely, produces environmental hormones such as dioxins that are seriously harmful to human health. Therefore, the use of PVC in electrical equipment has already been prohibited in European countries and Japan.

  In order to solve the problem of heat-shrinkable tubes made of PVC, Patent Document 1 discloses a certain polyester and a process for producing a heat-shrinkable polyester tube made of the polyester and suitable as a capacitor coating. is doing. The polyester disclosed in Patent Document 1 is composed of a mixture containing 20 to 70% by weight of polyethylene terephthalate (PET) and 30 to 80% by weight of copolyester. The copolyester is obtained from the reaction of a mixture containing 65-95 wt.% Pure terephthalic acid (PTA), 5-35 wt.% Isophthalic acid (IPA), and ethylene glycol of the total dibasic acid.

  Further, the polyester disclosed in Patent Document 1 may be used to produce an unstretched tube using a melt extrusion method, and the obtained unstretched tube is quenched to 72-98 ° C. After being reheated, it is simultaneously biaxially stretched at a stretch ratio of 1.0 to 1.4 times in the machine direction (MD) and at a stretch ratio of 1.3 to 2.2 times in the radial direction (TD). . Finally, the stretched heat shrinkable tube is cooled and wound into a roll.

  A heat-shrinkable polyester tube having a crystallinity of 20% or less made by the method of Patent Document 1 is heated in hot water at a temperature of 98 ± 2 ° C. for 10 seconds, thereby shrinking in the MD direction by 5 to 26%. And a shrinkage of 25% or more in the TD direction is achieved. A heat-shrinkable polyester tube can be fully coated when the condenser is coated by a heat shrink process.

Patent document 2 is disclosing the manufacturing method for improving the printability of a heat-shrinkable polyester tube. The heat-shrinkable polyester tube comprises 20 to 99.5% by weight of polyester containing polyethylene terephthalate and 0.5 to 80% by weight of polyester containing 0.1 to 4% by weight of polyethylene glycol as a glycol component. It is made of a mixture containing a copolymer, and a discharge energy of 100 to 800 W · min / m ² is applied to the tube surface to perform a corona discharge treatment, thereby improving printability.

  Patent Document 3 discloses a process for producing a heat-shrinkable tube made of substantially polyphenylene sulfide by a melt extrusion method for obtaining an unstretched tube. The unstretched tube has a stretch ratio of 1.05 to 4.5 times in the machine direction (MD) and 1.3 to 4.5 times in the radial direction (TD) at a temperature of 85 to 105 ° C. Simultaneous biaxial stretching is performed at a stretching ratio.

  The heat-shrinkable polyester tube made by the method of Patent Document 3 is heated in hot water at a temperature of 98 ± 2 ° C. for 30 seconds to achieve a shrinkage of 25 to 80% in the TD direction. The condenser is covered with the heat-shrinkable tube and heated at a temperature of 180 ° C. for 20 seconds so that the heat-shrinkable tube is in close contact with and covers the condenser. When the condenser is further heated in an oven at a temperature of 160 ° C. for 3 minutes and then removed from the oven, defects such as wrinkles, expansion, peeling, or deformation have occurred in the heat-shrinkable tube that covers and protects the condenser. There wasn't.

  Patent Document 4 discloses a heat-shrinkable polyester made of a resin comprising 80 to 99% by weight of a copolyester resin and 1 to 20% by weight of a polybutylene terephthalate resin for coating an electrolytic capacitor. A tube is disclosed. The copolyester resin has an intrinsic viscosity of 0.65 to 1.0 dl / g and consists of 1 to 15 mol% polyethylene naphthalate and 85 to 90 mol% polyethylene terephthalate.

  In addition, the polyester disclosed in Patent Document 4 may be used to produce an unstretched tube using a melt extrusion method, and the resulting unstretched tube is rapidly cooled to have a glass transition temperature (Tg). ) After being reheated to a higher temperature, it is simultaneously stretched at a stretch ratio of 1.0 to 1.5 times in the machine direction (MD) and at a stretch ratio of 1.7 to 2.5 times in the radial direction (TD). Biaxially stretched. Finally, the stretched heat shrinkable tube is cooled and wound into a roll.

  The heat-shrinkable polyester tube made by the method of Patent Document 4 is heated in hot water at a temperature of 98 ° C. for 30 seconds, so that the shrinkage is 5 to 15% in the MD direction and 40 to 60% in the TD direction. Shrinkage is achieved. Further, the heat-shrinkable tube is coated on a condenser and heated at a temperature of 260 to 280 ° C. for 8 seconds so that the heat-shrinkable tube adheres and covers the condenser by heat shrinkage. The condenser is further heated in an oven at a temperature of 170 ± 5 ° C. for 3 minutes, and then heated in hot water at a temperature of 100 ± 2 ° C. for 10 minutes, and when the condenser is removed, the heat-shrinkable tube covers and protects the condenser. Defects such as wrinkles, expansion, peeling, or deformation did not occur.

  All of the above prior art discloses that polyester can be used to make heat shrinkable tubes, but the methods disclosed in US Pat. It does not disclose the heat degradation resistance of the heat shrinkable tube when coated. Patent Document 4 discloses conditions and procedures for testing the heat resistance of the heat-shrinkable tube. The procedure involves heating a condenser covered with heat shrinkable tubing in an oven at a temperature of 170 ± 5 ° C. for 3 minutes and heating the condenser in hot water at a temperature of 100 ± 2 ° C. for 10 minutes. . Patent Document 3 discloses a heat-shrinkable tube made of polyethylene sulfide and having good heat deterioration resistance, but its cost is relatively high.

Also, none of the above patents disclose that polyester blends containing polytrimethylene terephthalate (PTT) are more suitable for producing heat shrinkable tubes with much improved quality to coat and protect electronic components. Not done.
US Pat. No. 5,368,811 US Pat. No. 5,403,454 US Pat. No. 5,718,953 US Pat. No. 6,528,133

  The main object of the present invention is a thermoplastic polyester mixture suitable for the production of heat-shrinkable tubes, comprising 5 to 95% by weight of component (A) of the total weight of component (A) and component (B): Homopolymerized or copolymerized polyethylene terephthalate (PET) having an intrinsic viscosity of 0.8 to 1.2 dl / g, and 95 to 5% by weight of component (B) in the total weight of component (A) and component (B) Disclosing a thermoplastic polyester mixture comprising polytrimethylene terephthalate (PTT) with an intrinsic viscosity of 0.8 to 1.2 dl / g.

  According to the secondary purpose of the present invention, either of said component (A) and component (B) of the thermoplastic polyester mixture is made of a thermoplastic polyester mixture, further comprising inorganic granules or additives. The heat-shrinkable tube can be more easily stretched after being wound into a roll. This makes the heat shrinkable tube more suitable for a fast heat shrink coating process.

  Another object of the present invention is to disclose a process for making heat shrinkable tubes made from the thermoplastic polyester blends of the present invention. This process involves the extrusion of a thermoplastic polyester mixture to form an unstretched tube, quenching the tube, and 1. in the machine direction (MD) at a temperature above the glass transition temperature (Tg). Performing a blow-expansion process that simultaneously stretches the tube at a stretch ratio of 0-3.0 times and a stretch ratio of 1.3-4.5 times in the transverse direction (TD); Quenching the tube. The obtained heat-shrinkable tube is shrunk by 5% to 15% in the machine direction (MD) and heated by 35% in the transverse direction (TD) when heated in hot water.

  According to yet another object of the present invention, when a heat-shrinkable tube made of the thermoplastic polyester mixture of the present invention is brought into close contact with the surface of an object by heat shrinkage, it has an excellent appearance with no defects. Has an effect. In particular, after heating in an oven at 180 ° C for 30 minutes, 105 ° C for 3 hours, or 250 ° C for 3 minutes, this heat-shrinkable tube is wrinkled, expanded, loosened, peeled, cracked, or risen. Maintain complete coverage without

  The present invention is suitable for the production of a heat-shrinkable tube, and 5 to 95% by weight of component (A) in the total weight of component (A) and component (B): intrinsic viscosity 0.8 to 1.2 dl / g Homopolymerized or copolymerized polyethylene terephthalate (PET) and 95 to 5% by weight of component (B) in the total weight of component (A) and component (B): intrinsic viscosity 0.8 to 1.2 dl / Disclosed is a new thermoplastic polymer blend comprising g of polytrimethylene terephthalate (PTT).

  Component (A) of the present invention may be made by conventional methods of synthesizing polyesters, such as the PTA process or the DMT process. When component (A) is made by the PTA process, dibasic acids and diols are used for direct esterification without the need for a catalyst. The gaseous mixture of ethylene glycol and moisture produced during esterification is separated in a distillation tower, and the separated ethylene glycol flows into the reactor. A polymerization catalyst is then added to the reactor before the esterification reaction is complete. The catalyst selected for this reaction is an antimony catalyst, a germanium catalyst, a titanium catalyst, or a mixture thereof. Stabilizers containing phosphorus, such as phosphoric acid, and inorganic granules such as titanium dioxide, barium sulfate, calcium carbonate, or silicon dioxide are added to the reactor after the esterification reaction and before polymerization begins. The mixture in the reaction furnace undergoes a polymerization reaction in a vacuum environment. When the copolyester viscosity reaches a level higher than 0.6 dl / g, the copolyester product is removed from the reactor, quenched and cut into granular copolyester.

  When component (A) is produced by the DMT process, esters and diols that are dibasic acids are used and a transesterification reaction is performed. Before the reaction begins, a transesterification catalyst such as manganese acetate is added. Methyl alcohol produced in the reaction and separated in the distillation tower does not return to the transesterification tank. After a predetermined theoretical amount of 98% methyl alcohol is collected and removed, a stabilizer containing phosphorus is added so that the transesterification catalyst becomes inactive, and then antimony catalyst, germanium catalyst, titanium catalyst, and their A polymerization catalyst selected from among the mixture is added. The polymerization reaction is performed in a vacuum environment. When the viscosity of the copolyester reaches a level higher than 0.6 dl / g, the product is removed from the reactor, quenched and cut into granules.

  In order to produce component (A) of the present invention, the granular copolyester obtained by the above PTA process or DMT process must have an intrinsic viscosity higher than 0.8 dl / g directly by the melt polymerization process. . Alternatively, the intrinsic viscosity must be raised to a level in the range of 0.80 to 1.20 dl / g through a further solid state polymerization process. Thereby, the desired component (A) of the present invention is obtained.

  Accordingly, component (A) of the present invention has an intrinsic viscosity in the range of 0.8 to 1.2 dl / g. When a heat-shrinkable tube is made with component (A) having an intrinsic viscosity of less than 0.8 dl / g by a melt extrusion process, defects with uneven thickness of the heat-shrinkable tube occur. On the other hand, when the heat-shrinkable tube is made of the component (A) having an intrinsic viscosity exceeding 1.2 dl / g, the heat-shrinkable material having a predetermined thickness is added to the melt extrusion apparatus for producing the heat-shrinkable tube. A fairly large load is applied to melt extrude the tube.

  When using the PTA process to synthesize component (A) of the present invention, the dibasic acid used contains pure terephthalic acid as the main component or 5-15 mol% of the total dibasic acid. It further contains isophthalic acid.

  Further, the dibasic acid used may further contain 2,6-naphthalenedicarboxylic acid or its ester type compound as a minor component and an amount of 8 mol% or less of the entire component (A).

  Further, when the component (A) of the present invention contains isophthalic acid in an amount exceeding 15 mol% of the total dibasic acid, the component (A) is in an amorphous state and is a solid for increasing the intrinsic viscosity. Very prone to clumping during polymerization.

  The diol used in the PTA process for synthesizing the component (A) of the present invention is mainly ethylene glycol, but diethylene glycol, cyclohexanedimethanol, propanediol, 2,2-dimethyl-1,3-propane. It may contain at least one other component of diol (NPG), 2-butyl-2-ethyl-1,3-propanediol (BEPG), and butylene glycol. However, these minor components are not necessary components and, when included, do not exceed 15 mol%, preferably 10 mol% of the total amount of diol. When the minor component exceeds 15 mol% of the total amount of the diol, the component (A) is in an amorphous state, and the intrinsic viscosity cannot be increased by the solid polymerization process.

  A preferred method for synthesizing component (A) of the present invention is to add inorganic granules in the melt condensation polymerization stage. The inorganic granules used in the present invention are one or more substances selected from the group consisting of titanium dioxide, barium sulfate, calcium carbonate, and silicon dioxide or mixtures thereof. More preferably, titanium dioxide or barium sulfate is selected as an additive. The addition amount of the inorganic granules is 0.005 to 0.5% by weight of the weight of the component (A). The size of the inorganic granules is less than 1 μm, preferably between 0.1 and 0.5 μm.

  The purpose of adding the inorganic granules in the melt condensation polymerization stage for synthesizing the component (A) of the present invention is to make it easier to stretch the heat-shrinkable tube of the present invention wound in a roll. Thus, the heat shrinkable tube of the present invention can be suitable for high speed heat shrink coating processes.

  You may add another additive to the component (A) of this invention as needed during a process. These additives include, for example, halogen-free flame retardants, dyes, antioxidants, lubricants, ultraviolet absorbers or antistatic agents.

  Similarly, component (B) of the present invention is also made by conventional methods of synthesizing polyesters such as PTA process, DMT process and the like. When component (A) is made by the PTA process, purified terephthalic acid (PTA) and propylene glycol are used for direct esterification without the need for a catalyst. The gaseous mixture of ethylene glycol and moisture produced during esterification is separated in a distillation tower, and the separated ethylene glycol flows into the reactor. A polymerization catalyst is then added to the reactor before the completion of the esterification reaction. The catalyst selected for this reaction is an antimony catalyst, a germanium catalyst, a titanium catalyst, or a mixture thereof. Stabilizers containing phosphorus, such as phosphoric acid, and inorganic granules such as titanium dioxide, barium sulfate, calcium carbonate, or silicon dioxide are added to the reactor after the esterification reaction and before polymerization begins. The mixture in the reaction furnace undergoes a polymerization reaction in a vacuum environment. When the viscosity of the copolyester reaches a level higher than 0.6 dl / g, the copolyester product is removed from the reactor, quenched and cut into granular copolyester.

  When component (B) is produced by the DMT process, esters and diols that are dibasic acids are used and a transesterification reaction is performed. Before the reaction begins, a transesterification catalyst such as manganese acetate is added. Methyl alcohol produced in the reaction and separated in the distillation tower does not return to the transesterification tank. After a predetermined theoretical amount of 98% methyl alcohol is collected and removed, a stabilizer containing phosphorus is added so that the transesterification catalyst becomes inactive, and then antimony catalyst, germanium catalyst, titanium catalyst, and their A polymerization catalyst selected from among the mixture is added. The polymerization reaction is performed in a vacuum environment. When the viscosity of the copolyester reaches a level higher than 0.6 dl / g, the product is removed from the reactor, quenched and cut into granules.

  In order to produce the component (B) of the present invention, the granular copolyester obtained by the PTA process or the DMT process has an intrinsic viscosity in the range of 0.75 to 1.20 dl / g by the melt polymerization process. Must be raised directly to the level. Alternatively, the intrinsic viscosity must first be increased to 0.8 dl / g by a melt polymerization process and then further increased to a level in the range of 0.80 to 1.20 dl / g by a solid polymerization process. Thereby, the desired component (B) of the present invention is obtained.

  Accordingly, component (B) of the present invention has an intrinsic viscosity in the range of 0.8 to 1.2 dl / g. If the heat-shrinkable tube is made from a component (B) having an intrinsic viscosity of less than 0.8 dl / g by a melt extrusion process, defects with uneven thickness of the heat-shrinkable tube occur. On the other hand, when the heat-shrinkable tube is made of the component (B) having an intrinsic viscosity exceeding 1.2 dl / g, the heat-shrinkable device having a predetermined thickness is added to the melt extrusion apparatus for producing the heat-shrinkable tube. A fairly large load is applied to melt extrude the tube.

  A preferred method for synthesizing component (B) of the present invention is to add inorganic granules in the melt condensation polymerization stage. The inorganic granules used in the present invention are one or more substances selected from the group consisting of titanium dioxide, barium sulfate, calcium carbonate, and silicon dioxide or mixtures thereof. More preferably, titanium dioxide or barium sulfate is selected as an additive. The addition amount of the inorganic granules is 0.005 to 0.5% by weight of the weight of the component (B). The size of the inorganic granules is less than 1 μm, preferably between 0.1 and 0.5 μm. However, it is not necessary to add inorganic granules to both component (A) and component (B) of the present invention.

  You may add another additive to the component (B) of this invention as needed during a process. These additives include, for example, halogen-free flame retardants, dyes, antioxidants, lubricants, ultraviolet absorbers or antistatic agents. However, it is not necessary to add these additives to both component (A) and component (B) of the present invention.

  These additives including the above-mentioned titanium dioxide, barium sulfate, calcium carbonate, silicon dioxide, halogen-free flame retardants, dyes, antioxidants, lubricants, ultraviolet absorbers or antistatic agents are the components of the present invention (A ) Or other than melt condensation polymerization to synthesize component (B) may be added in a melt extrusion process to make a heat shrinkable tube.

  In the following description, a method for producing a heat shrinkable tube comprising the thermoplastic polyester mixture disclosed in the present invention will be described.

  There are three ways to make molten colloid from uniformly mixed components (A) and (B). The first method measures the amount of each of component (A) and component (B), makes component (A) and component (B) as a thermoplastic polyester mixture, and uniformly by a physical mixing process using a mixer. To mix.

  After the thermoplastic polyester mixture comprising the components (A) and (B) of the present invention is completely dried in a dryer containing dehumidified air at 150-170 ° C. for 4-6 hours, the thermoplastic polyester mixture Is continuously conveyed to the extruder and melted, and the molten colloid in which the component (A) and the component (B) are uniformly mixed by the extruder reaches a predetermined melting temperature higher than the melting point (Tm).

  In the second method, the component (A) and the component (B) of the present invention are each dried at 150 to 170 ° C. for 4 to 6 hours in a dryer containing dehumidified air, and then measured weight or The component (A) and the component (B) are continuously added to the mixer by the volume and mixed uniformly as a thermoplastic polyester mixture. The dried thermoplastic polyester mixture is continuously conveyed to an extruder and melted, and the molten colloid in which the component (A) and the component (B) are uniformly mixed by the extruder is higher than the melting point (Tm). Reach melting temperature.

  In the third method, the component (A) and the component (B) of the present invention are each dried at 150 to 170 ° C. for 4 to 6 hours in a dryer containing dehumidified air, and then the component (A) and Component (B) is continuously conveyed to separate extruders and melted, and each molten colloid reaches a predetermined melting temperature above the melting point (Tm).

  Each melted colloid of component (A) and component (B) is pumped up by a gear pump by a measured amount and put into a mixer to be mixed uniformly, and component (A) and component (B) are mixed uniformly. A molten colloid.

  The thermoplastic polyester mixture of the present invention comprises 5 to 95% by weight of component (A) in the total weight of component (A) and component (B): homopolymerized or copolymerized polyethylene terephthalate (PET) and component (A ) And component (B) in a total weight of 95 to 5% by weight of component (B): polytrimethylene terephthalate (PTT). Inorganic thermoplastic granules and / or additives may be added to the thermoplastic polyester mixture of the present invention. The total amount of component (A), component (B), inorganic granules and / or additives is 100% by weight.

  Therefore, the molten colloid in which the component (A) and the component (B) are uniformly mixed is extruded through the annular opening of the extrusion mold and then rapidly cooled with cooling air or water to form an unstretched circular tube. Is done. The tube is then carried into a hot water or infrared tube by a set of feed rollers, heated to a temperature higher than the glass transition temperature, then compressed air is introduced and stretched to a predetermined diameter by a blow expansion process. The tube is made as a heat shrinkable tube. Then, it is carried by a set of cooling nip rollers and rolled into a roll to form a heat shrinkable tube roll. With the above process, transverse (TD) stretching is achieved in the blow expansion step and longitudinal (MD) stretching is achieved by the speed difference between the nip and feed rollers.

  Since the heat-shrinkable tube is rapidly cooled after biaxial stretching, it can shrink in both the transverse direction (TD) and the longitudinal direction (MD) after cooling. For this reason, this heat-shrinkable tube is suitable as an outer coating for electronic components. The thickness of the heat-shrinkable tube of the present invention is preferably between 20 and 200 μm, and the diameter is preferably between 4 and 400 mm.

  A heat shrinkable tube made of the thermoplastic polyester blend of the present invention has a machine direction (MD) stretch ratio equal to the ratio of the speed of pulling the stretched heat shrinkable tube to the feed speed of the unstretched tube, and a blown tube. It has a transverse (TD) stretch ratio equal to the ratio of the tube diameter after expansion to the diameter of the unstretched tube.

  When the heat shrinkable tube is made of the thermoplastic polyester blend of the present invention, the preferred temperature for the blow expansion process is between 85-105 ° C. The stretch ratio in the machine direction (MD) is preferably 1.0 to 3.0 times, and the stretch ratio in the transverse direction (TD) is preferably 1.3 to 4.5 times.

  The heat-shrinkable tube made of the thermoplastic polyester mixture of the present invention is heated in hot water at 100 ° C. for 30 seconds, thereby causing 5% to 15% of heat shrinkage in the machine direction (MD), (TD) heat shrinkage exceeding 35%. When the thermal shrinkage in the machine direction (MD) is less than 5%, the edge of the heat-shrinkable tube cannot adhere to the surface of the electronic component. On the other hand, when the heat shrinkage in the machine direction (MD) exceeds 15%, deformation and displacement of the heat shrinkable tube occur when the electronic component is covered with the heat shrinkable tube. When the thermal shrinkage in the transverse direction (TD) is less than 35%, the heat-shrinkable tube cannot adhere to the surface of the electronic component.

  Therefore, when an electronic component covered with the heat-shrinkable tube of the present invention is heated to a temperature higher than 90 ° C., the heat-shrinkable tube will shrink uniformly and adhere to the surface of the electronic component as its outer coating.

  Even after an electronic component covered with the heat-shrinkable tube of the present invention is heated in an oven at 180 ° C. for 30 minutes, 105 ° C. for 3 hours, or 250 ° C. for 3 minutes, the heat-shrinkable tube of the present invention is It was shown that there was no defect such as expansion, loosening, peeling, cracking or rising, and it remained fixed and adhered to the surface of the electronic component.

  The heat-shrinkable tube made of the thermoplastic polyester blend of the present invention did not become hazy or obscured after printed and washed with acetone.

  Heat shrinkable tubes made of the thermoplastic polyester blends of the present invention can be easily cut with a blade and are suitable for high speed heat shrink coating processes.

  In order to further illustrate the present invention, several examples and comparative examples of the present invention are given below. However, these examples are not intended to limit the scope of the invention.

Ingredient (A1)
A weight ratio of 10.81 parts bishydroxyethyl terephthalate monomer (BHET) and a weight ratio of 3,243 parts ethylene glycol (EG) were measured, and these materials were put into a reactor. When the temperature exceeded 190 ° C., the esterification reaction started. The reaction pressure was 1.0 to 1.5 kg / cm ² . The reaction lasted 180 minutes and the esterification rate reached 95%. Next, 0.035 parts by weight of titanium dioxide, a phosphoric acid stabilizer, and a manganese acetate catalyst were added, the internal pressure was lowered to approximately 1 torr at a temperature of 250 to 280 ° C., and the viscosity of the reaction product was reduced to 0. Continued until it exceeded 60 dl / g. The reaction was then removed from the reactor and cooled to form cylindrical amorphous granules. The obtained amorphous granules are put into a solid polymerization reactor filled with nitrogen gas or in a substantially vacuum state, the polyester granules continue to react at a temperature of 190 to 220 ° C., and the viscosity of the polyester granules is 0.00. Increased to 95 dl / g.
The obtained polyester granule is a component (A1) which is a kind of homopolymer.

Ingredient (A2)
Weighed 10.27 parts by weight bishydroxyethyl terephthalate monomer (BHET), 0.432 parts by weight isophthalic acid (IPA), and 3,243 parts by weight ethylene glycol (EG). These materials were put into a reactor for melt polymerization reaction. Using the same method as component (A1), the desired cylindrical amorphous granules were obtained. The obtained amorphous granules were put into a solid polymerization reactor, and the viscosity of the polyester granules increased to 0.83 dl / g.
The obtained polyester granule is a component (A2) containing 5 mol% isophthalic acid (IPA).

Ingredient (A3)
A weight ratio of 9.73 parts of bishydroxyethyl terephthalate monomer (BHET) and a weight ratio of 0.864 parts of isophthalic acid (IPA) were measured, and these materials were put into a reactor for melt polymerization reaction.
After completion of the melt polymerization reaction, solid polymerization was performed, and the viscosity of the polyester granules increased to 0.90 dl / g.
The obtained polyester granule is a component (A3) containing 10 mol% isophthalic acid (IPA).

Ingredient (A4)
A weight ratio of 9.186 parts bishydroxyethyl terephthalate monomer (BHET) and a weight ratio of 1.296 parts isophthalic acid (IPA) were measured, and these materials were put into a reactor for melt polymerization reaction.
After completion of the melt polymerization reaction, the viscosity of the reactant in the reactor reached 0.70 dl / g. Next, solid polymerization was performed, and the viscosity of the polyester granules increased to 1.20 dl / g.
The resulting polyester granules contained lumps generated during solid polymerization. The polyester granule obtained by completely removing these lumps with a sieve is a component (A4) containing 15 mol% of isophthalic acid (IPA).

Ingredient (A5)
Measure the weight ratio of 8.970 parts bishydroxyethyl terephthalate monomer (BHET), weight ratio 1.470 parts isophthalic acid (IPA) and weight ratio 3,243 parts ethylene glycol (EG) These materials were put into a reactor for melt polymerization reaction.
After completion of the melt polymerization reaction, the viscosity of the reaction product in the reactor reached 0.75 dl / g. Next, solid polymerization was performed to obtain polyester granules.
The resulting polyester granules contained lumps after solid polymerization. Polyester granules not containing lumps were taken out and the viscosity was analyzed. The finally obtained polyester granule having an intrinsic viscosity of 1.0 dl / g is a component (A5) containing 17 mol% of isophthalic acid (IPA).

Ingredient (B1)
81 parts by weight of purified terephthalic acid (PTA) and 37 parts by weight of 1,3-propanediol were measured, and these materials were put into a reaction furnace for direct esterification.
After completion of the direct esterification, the reaction product in the reactor was further polymerized in a vacuum environment to obtain polytrimethylene terephthalate (PTT) having an intrinsic viscosity of 0.75 dl / g. This is component (B1).

Ingredient (B2)
The component (B1), polytrimethylene terephthalate (PTT) having an intrinsic viscosity of 0.75 dl / g, was further filled with nitrogen gas or subjected to a solid polymerization reaction at a temperature of 190 to 220 ° C. in a substantially vacuum reactor. The viscosity of polytrimethylene terephthalate (PTT) increased to 0.80 dl / g.
The obtained polytrimethylene terephthalate (PTT) is component (B2).

Ingredient (B3)
The component (B1), polytrimethylene terephthalate (PTT) having an intrinsic viscosity of 0.75 dl / g, was further filled with nitrogen gas or subjected to a solid polymerization reaction at a temperature of 190 to 220 ° C. in a substantially vacuum reactor. The viscosity of polytrimethylene terephthalate (PTT) increased to 1.0 dl / g.
The obtained polytrimethylene terephthalate (PTT) is component (B3).

Ingredient (B4)
The component (B1), polytrimethylene terephthalate (PTT) having an intrinsic viscosity of 0.75 dl / g, was further filled with nitrogen gas or subjected to a solid polymerization reaction at a temperature of 190 to 220 ° C. in a substantially vacuum reactor. The viscosity of polytrimethylene terephthalate (PTT) increased to 1.2 dl / g.
The obtained polytrimethylene terephthalate (PTT) is component (B4).

Ingredient (B5)
The component (B1), polytrimethylene terephthalate (PTT) having an intrinsic viscosity of 0.75 dl / g, was further filled with nitrogen gas or subjected to a solid polymerization reaction at a temperature of 190 to 220 ° C. in a substantially vacuum reactor. The viscosity of polytrimethylene terephthalate (PTT) increased to 1.2 dl / g.
The obtained polytrimethylene terephthalate (PTT) is component (B5).

Example 1
A component (A1) having a weight ratio of 5 parts and a component (B2) having a weight ratio of 95 parts are measured, and the components (A1) and (B2) are uniformly mixed using a mixer, and a thermoplastic polyester mixture is obtained. made.
After drying with moisture-free air at a temperature of 150 ° C. for 4 hours, the thermoplastic polyester mixture is put into an extruder, a melt extrusion process is performed at a temperature of 250 to 270 ° C., and the molten colloid is extruded through an annular opening of the extrusion mold After forming an unstretched tube and immediately cooling it in the cooling water tank, the unstretched tube is conveyed by a pair of feed rollers with a rotation speed of 100 rpm, passed through a heater and heated to a temperature of 90-100 ° C. It was. Compressed air was then introduced and the unstretched tube was expanded by the blow expansion process, resulting in a tube having a diameter 1.3 times the original diameter. The expanded tube was stretched by a pair of nip rollers having a rotation speed of 105 rpm, and a desired heat-shrinkable tube was obtained.
Next, a series of tests were conducted to confirm the quality of the heat shrinkable tube made by the above process.
The test was printed as a tube blow stability test, a test in which the tube was heated in an oven at 105 ° C for 3 hours, or 180 ° C for 30 minutes, or 250 ° C for 3 minutes to check the integrity of the coating appearance. And testing the integrity of the printed text after the tube is cleaned with acetone.
Another easy-to-cut test examines whether a heat-shrinkable tube made of a thermoplastic polyester mixture can be easily cut with a blade, and checks whether the heat-shrinkable tube has a flat cut section.
All test results are shown in Table 1.

Example 2
The same method as in Example 1 was used except that the component (A1) having a weight ratio of 95 parts and the component (B2) having a weight ratio of 5 parts were measured.
The test results are shown in Table 1.

Example 3
The same method as in Example 1 was used except that the component (A2) having a weight ratio of 5 parts and the component (B3) having a weight ratio of 95 parts were measured.
The test results are shown in Table 1.

Example 4
The same method as in Example 1 was used except that the component (A2) having a weight ratio of 95 parts and the component (B3) having a weight ratio of 5 parts were measured.
The test results are shown in Table 1.

Example 5
The same method as in Example 1 was used except that the component (A3) having a weight ratio of 5 parts and the component (B4) having a weight ratio of 95 parts were measured.
The test results are shown in Table 1.

Example 6
The same method as in Example 1 was used except that the component (A3) having a weight ratio of 80 parts and the component (B4) having a weight ratio of 20 parts were measured.
The test results are shown in Table 1.

Example 7
The same method as in Example 1 was used except that the component (A3) having a weight ratio of 95 parts and the component (B4) having a weight ratio of 5 parts were measured.
The test results are shown in Table 1.

Example 8
The same method as in Example 1 was used except that the component (A4) having a weight ratio of 5 parts and the component (B4) having a weight ratio of 95 parts were measured.
The test results are shown in Table 1.

Example 9
The same method as in Example 1 was used except that the component (A4) having a weight ratio of 95 parts and the component (B4) having a weight ratio of 5 parts were measured.
The test results are shown in Table 1.

Comparative Example 1
A heat-shrinkable tube comprising only the component (A1) and produced in the same manner as in Example 1.
The test results are shown in Table 1.

Comparative Example 2
A heat-shrinkable tube comprising only the component (A2) and produced in the same manner as in Example 1.
The test results are shown in Table 1.

Comparative Example 3
A heat-shrinkable tube comprising only the component (A3) and produced in the same manner as in Example 1.
The test results are shown in Table 1.

Comparative Example 4
A heat-shrinkable tube comprising only the component (A4) and produced in the same manner as in Example 1.
The test results are shown in Table 1.

Comparative Example 5
A heat-shrinkable tube comprising only the component (A5) and produced in the same manner as in Example 1.
The test results are shown in Table 1.

Comparative Example 6
A heat-shrinkable tube comprising only the component (B3) and made in the same manner as in Example 1.
The test results are shown in Table 1.

Comparative Example 7
A heat-shrinkable tube comprising a component (A3) having a weight ratio of 97 parts and a component (B3) having a weight ratio of 3 parts, and made in the same manner as in Example 1.
The test results are shown in Table 1.

Comparative Example 8
A heat-shrinkable tube comprising a component (A3) having a weight ratio of 3 parts and a component (B3) having a weight ratio of 97 parts, and made in the same manner as in Example 1.
The test results are shown in Table 1.

Comparative Example 9
A heat-shrinkable tube comprising a component (A3) with a weight ratio of 97 parts and a component (B5) with a weight ratio of 3 parts and made in the same manner as in Example 1.
The test results are shown in Table 1.

Comparative Example 10
A heat-shrinkable tube comprising a component (A3) having a weight ratio of 97 parts and a component (B1) having a weight ratio of 3 parts and made in the same manner as in Example 1.
The test results are shown in Table 1.

Discussion of test results All heat shrinkable tubes made of thermoplastic polyester blends shown in Table 1 have tube blow stability and oven for 3 hours at 105 ° C, or for 30 minutes at 180 ° C, or for 3 minutes at 250 ° C. Any of the heating has excellent properties in the coating appearance integrity, the printed character integrity on the tube after washing with acetone, and ease of cutting and flatness.

表１に示す各成分の含有量は熱可塑性ポリエステル混合物における含有量である。表１内の記号の意味は下記のとおりである。
◎：良好； △：平均； ×：不良

The content of each component shown in Table 1 is the content in the thermoplastic polyester mixture. The meanings of the symbols in Table 1 are as follows.
A: Good; Δ: Average; ×: Poor

Claims (6)

  A thermoplastic polyester mixture suitable for the production of a heat-shrinkable tube, wherein 5 to 95% by weight of component (A) in the total weight of component (A) and component (B): intrinsic viscosity 0.8 to 1 .5 dl / g homopolymerized or copolymerized polyethylene terephthalate (PET) and 95 to 5% by weight of component (B) of the total weight of component (A) and component (B): intrinsic viscosity 0.8 to A thermoplastic polyester blend consisting of 1.2 dl / g polytrimethylene terephthalate (PTT).   The component (A) is obtained by reacting pure terephthalic acid or its ester with a diol, which contains ethylene glycol (EG) as a main component, and includes diethylene glycol, cyclohexanedimethanol (CHDM), propanediol, 2 , 2-dimethyl-1,3-propanediol (NPG), 2-butyl-2-ethyl-1,3-propanediol (BEPG), and at least one minor diol component selected from the group consisting of butylene glycol. The thermoplastic polyester mixture of claim 1 comprising less than 10 mole percent of the total diol.   One of the component (A) and the component (B) includes 0.005 to 0.5% by weight of one or more inorganic granules in the total weight of the component (A) and the component (B), The thermoplastic polyester mixture according to claim 1 or 2, wherein the inorganic granules are selected from the group consisting of titanium dioxide, barium sulfate, calcium carbonate, and silicon dioxide, and the size is less than 1 µm.   The thermoplastic polyester mixture according to claim 1 or 2, wherein one of component (A) and component (B) comprises a halogen-free flame retardant. A process for producing a heat-shrinkable tube that contracts 5% to 15% in the machine direction (MD) by heating in hot water and contracts more than 35% in the transverse direction (TD),
Extruding the thermoplastic polyester mixture to form an unstretched tube;
Quenching the tube;
The tube at a temperature higher than the glass transition temperature (Tg) at a stretch ratio of 1.0 to 3.0 times in the machine direction (MD) and 1.3 to 4.5 times in the transverse direction (TD) at the same time. Performing a blow expansion process to stretch
Quenching the stretched tube; and
The thermoplastic polyester mixture is a homopolymer or copolymer of 5 to 95% by weight of component (A): intrinsic viscosity 0.8 to 1.2 dl / g of the total weight of component (A) and component (B). 95 to 5% by weight of component (B) in the total weight of polyethylene terephthalate (PET) and component (A) and component (B): polytrimethylene terephthal having an intrinsic viscosity of 0.8 to 1.2 dl / g Manufacturing process of heat-shrinkable tube comprising tarato (PTT).   After the obtained heat-shrinkable tube is adhered to an electronic component as an outer coating and heated at a temperature of 180 ° C. for 30 minutes, 105 ° C. for 3 hours, or 250 ° C. for 3 minutes, the outer coating is wrinkled. The process for producing a heat-shrinkable tube according to claim 5, wherein the heat-shrinkable tube is maintained in a completely covered state without being deformed, expanded, loosened, peeled, cracked, or risen.