JP2007231137A - Polyester resin composition and molded product using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester resin composition and its molded product having drastic enhancement of hydrolysis resistance, no scattering of a chemical agent during producing the composition and the molded product, and no problems such as gelation and thickening. <P>SOLUTION: This polyester composition comprises a monofunctional epoxy-based terminal blockading agent with a monoglycidyl isocyanurate skeleton, at least one part of which is reacted with the polyester. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides a polyester resin composition having improved hydrolysis resistance and a molded product thereof.

  Polyesters typified by polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polylactic acid (PLA), polycaprolactone (PCL), polybutylene succinate (PBS), etc. have mechanical properties. It is excellent in chemical properties, and is used, for example, in fibers for clothing and industrial materials according to the properties of each polyester. For example, in the case of polyethylene terephthalate (PET), an aromatic polyester mainly composed of aromatic dicarboxylic acid and alkylene glycol, which is a typical polyester, is esterified or esterified with terephthalic acid or dimethyl terephthalate and ethylene glycol. Bis (2-hydroxyethyl) terephthalate is produced by exchange, and is industrially produced by a polycondensation method or the like in which polycondensation is performed using a catalyst at high temperature and under vacuum. On the other hand, polylactic acid contained in aliphatic polyester is produced by ring-opening polymerization of lactide or direct polymerization of lactic acid.

  These aromatic / aliphatic polyesters generally have a problem that their molecular weight decreases with time due to hydrolysis of ester bonds in the molecular chain. Polyesters with reduced molecular weights have many problems, such as poor mechanical properties and unusable use.

  Therefore, for example, Patent Document 1 describes a technique for substituting the acid terminal of polyester with another compound to suppress hydrolysis. The technique described in this document describes that a carbodiimide compound or an epoxy compound is used as a terminal blocking agent. However, when the compound described in this document is mixed and reacted with polyester as an end-capping agent, the end-capping agent bleeds during the manufacturing process due to the high melt molding temperature of the polyester, resulting in a working environment caused by fumes and odors. In addition, the drug reaction efficiency was poor.

On the other hand, as a method for adding a terminal blocker having high heat resistance, it is known to use a trifunctional epoxy compound described in Patent Document 2. However, in this method, since the trifunctional epoxy compound reacts with the polyester, there are problems of thickening and gelation, and it is difficult to adopt as a general-purpose technique. Scattering during the process could not be sufficiently suppressed.
JP-A-8-120520 (page 3, paragraph [0014]) JP 2005-314444 A (page 2)

  The present invention drastically improves hydrolysis resistance, does not cause chemical scattering in the production process of the polyester composition and molded product, and further has no problem of gelation or thickening, and the polyester resin composition and molded product thereof Is going to get.

  A polyester characterized in that an isocyanurate compound represented by the following formula (I) is added as a monofunctional epoxy-based end-capping agent to the polyester, and at least a part of the isocyanurate compound is reacted with the polyester. The above problems are solved by the resin composition and the molded product thereof.

(In the formula, R1 and R2 are groups containing an aromatic hydrocarbon group in the structure thereof.)

  As the polyester used in the present invention, for example, an aromatic polyester can be used. Examples of the aromatic polyester include polyethylene terephthalate (PET), polypropylene terephthalate (PPT), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN). Commercially available ones can be used. Among these polyesters, polyethylene terephthalate, polypropylene terephthalate, and polybutylene terephthalate are preferably used because of their versatility, heat resistance, mechanical properties, and ease of molding. In particular, polyethylene terephthalate is preferably used in terms of versatility, heat resistance, mechanical properties, and ease of molding.

  The number average molecular weight of the aromatic polyester suitably used in the present invention is preferably in the range of 10,000 to 60,000 because of excellent moldability and mechanical properties. Among them, the number average molecular weight of polyethylene terephthalate that is particularly preferably used is preferably in the range of 10,000 to 50,000 because of excellent moldability and mechanical properties. At this time, intrinsic viscosity (IV) is preferably used as a means for simply obtaining the number average molecular weight, but when the preferred range of the number average molecular weight is converted to this intrinsic viscosity (IV), 0.46 to The range is 2.04.

  Among the polyesters used in the present invention, aliphatic polyesters obtained by polycondensation of saturated dicarboxylic acid and diol or those obtained by polycondensation of hydroxycarboxylic acid are used. Examples of aliphatic polyesters obtained by polycondensation include polylactic acid (PLA), polyglycolic acid (PGA), poly (3-hydroxybutyrate), and poly (3-hydroxybutyrate / 3-hydroxyvalerate). Examples thereof include a polymer, a polycaprolactone (PCL), a polypivalolactone, or a polyester comprising a glycol such as ethylene glycol or 1,4-butanediol and a dicarboxylic acid such as succinic acid or adipic acid.

  Although these aliphatic polyesters have the disadvantage of faster hydrolysis than aromatic polyesters, their raw materials are easily derived from natural products, and are generally superior in transparency and flexibility compared to aromatic polyesters. Therefore, it is also preferable to use an aliphatic polyester as the polyester. Of these aliphatic polyesters, polylactic acid is superior to other aliphatic polyesters in terms of mechanical properties, heat resistance and transparency, and is particularly preferably used.

  In addition, two types of polylactic acid that are particularly preferably used in the present invention are known, one mainly composed of L lactic acid and one mainly composed of D lactic acid. In the present invention, polylactic acid mainly used is used. However, it is preferable that the optical purity of lactic acid in polylactic acid is 97% or higher because the melting point of the resin can be increased, that is, the heat resistance is excellent. In general, the polylactic acid particularly preferably used in the present invention has a crystallinity that decreases when the optical purity is lowered. Therefore, the obtained molded product generally has a reduced heat resistance, and a practical molded product cannot be obtained. . For this reason, polylactic acid having an optical purity of 98% or more is preferably used. When the optical purity in the polymer satisfies the above value, for example, polylactic acid obtained by melt-mixing a polymer mainly composed of L lactic acid and a polymer mainly composed of D lactic acid can be used. In this case, the polylactic acid molecular chain mainly composed of L lactic acid and the polylactic acid molecular chain mainly composed of D lactic acid form a stereocomplex crystal, and the crystal has a higher melting point than that of a single polylactic acid. Therefore, it is preferable because of excellent heat resistance.

  The polylactic acid preferably has a weight average molecular weight of 100,000 or more from the viewpoints of heat resistance and moldability. By setting the weight average molecular weight to 100,000 or more, not only can the obtained molded product be excellent in mechanical properties and durability, but also the melt flowability and crystallization properties can be set in a preferable range. Accordingly, the weight average molecular weight is more preferably in the range of 120,000 to 400,000, and most preferably in the range of 120,000 to 250,000. Moreover, when the most preferable range of this weight average molecular weight is converted into solution specific viscosity ((eta) r), it will be 2.6-4.0.

  The amount of unreacted monomers and oligomers contained in the polylactic acid particularly preferably used in the present invention is preferably in the range of 0.01 to 0.3% by weight. Unreacted monomers and oligomers bleed during melt molding and contaminate the apparatus. However, if a very small amount is present, it acts as a so-called plasticizer and can improve moldability. Therefore, the amount of the monomer and oligomer is preferably in the range of 0.01 to 0.2% by weight, and more preferably in the range of 0.01 to 0.15% by weight.

  In addition, the polyester used in the present invention may contain other modifiers and other polymers as long as the characteristics are not changed. These modifiers, additives and other polymers may be added at the time of polymerization, may be in the form of master pellets previously kneaded, or may be directly mixed with polyester pellets and melt molded. Examples of modifiers include lubricants, matting agents, antioxidants, plasticizers, pigments, dyes, and various fillers. Other polymers include other polyesters, polyamides, polymethyl methacrylates, polystyrenes, polyethylenes, and polypropylenes. And olefin polymers. Regarding these modifiers and other polymers, one or more optimum ones can be selected and used in consideration of compatibility with the polyester of the present invention, modification effects, costs, and the like.

  Further, the polyester of the present invention can be copolymerized with other monomers as long as the characteristics are not changed. Examples of the copolymer component include dicarboxylic acid, diol, hydroxycarboxylic acid, and modified products thereof. The content of these copolymerization components is not particularly limited, but if the copolymerization is carried out in a range not exceeding 40 mol%, a modification effect can be obtained without significantly changing the properties of the substrate polyester. Therefore, it is preferable.

  In the present invention, it is important to improve the hydrolysis resistance of the polyester by reacting at least part of the isocyanurate compound represented by the above formula (I) with the terminal of the polyester as a monofunctional epoxy-based endblocker. is there. In particular, it is important that the monofunctional epoxy-based endblocker has one epoxy group in one molecule of the endblocker. The reason for having only one epoxy group for one molecule of the end-capping agent is that there is no problem of thickening when reacting with the polyester compared to the polyfunctional end-capping agent, and molding. There is an advantage that processing can be carried out stably. In addition, even when the reaction proceeds, gelling, curing, viscosity spots, etc. do not occur, piping parts of the melt molding equipment, filters, etc. are not clogged. Can be obtained.

  Moreover, it is preferable that the added monofunctional epoxy-type terminal blocker is blocking the terminal group of polyester, mainly all or one part of the acid terminal. It is known that the acid terminal of the polyester generates free protons in a hot and humid environment, and it is known that hydrolysis is promoted because the free protons act as a catalyst. Therefore, the monofunctional epoxy-based end-blocking agent of the present invention can reduce the catalytic effect by blocking mainly the acid ends of the polyester. From this, it is preferable that 50% is blocked with respect to the acid terminal amount of the base polyester, and more preferably 80% or more is blocked. In addition, when the acid terminal absolute amount is 15 equivalents / t or less, a molded article having excellent hydrolysis resistance can be obtained. From the above viewpoint, the acid terminal absolute amount is 10 equivalents / t or less. It is preferable that it is 5 equivalent / t or less.

  The 1% heat loss temperature in thermogravimetry (TG) of the monofunctional epoxy-based end-capping agent of the present invention is preferably 230 ° C. or higher. If the 1% heat loss temperature in the TG of the monofunctional epoxy-based endblocking agent is 230 ° C. or higher, it is possible to suppress bleeding of the monofunctional epoxy-based endblocking agent from the resin during melt molding, and fuming during melt molding This not only prevents the working environment from being deteriorated due to odor and odor, but also increases the reaction efficiency. Therefore, the 1% heat loss temperature is more preferably 235 ° C. or more, and most preferably 238 ° C. or more.

  It is important that the monofunctional epoxy-based endblocker of the present invention has an isocyanurate skeleton. Isocyanuric acid is a very stable compound having a thermal decomposition temperature of 330 ° C. or higher, and a monofunctional epoxy-based end-capping agent having its skeleton is suitable because of its excellent heat resistance.

  Further, it is important that the monofunctional epoxy compound of the present invention is a compound represented by the above formula (I).

  In the above formula (I), R1 and R2 are groups containing an aromatic hydrocarbon group in the structure.

  The compound represented by the above formula (I) is a compound in which one epoxy group is added to the skeleton of isocyanuric acid, and a monofunctional epoxy-based end-blocking agent is a compound having the above structure. In addition to dramatically improving the heat resistance of the epoxy, it is possible to dramatically improve the reactivity of the epoxy group specifically. The reason for this is not clear, but it is presumed that among the carbon atoms constituting the epoxy group, a pseudo-bonded state is created between the C2 carbon and the adjacent carbonyl oxygen. That is, when a pseudo bond state is formed between the C2 carbon and the carbonyl oxygen, the stability of the epoxy ring itself is greatly reduced. It is estimated that the addition reaction proceeds. Furthermore, the epoxy group added to the above isocyanuric acid structure is most preferably a 2,3-epoxypropyl group because it easily forms a pseudo-bonded state and has good reactivity. A structure in which a methyl group is added to the C2 carbon is preferable because the reactivity of the epoxy ring can be improved.

  In addition, it is important that the group bonded to the portion represented by R1 or R2 of the isocyanurate compound represented by the above formula (I) includes an aromatic hydrocarbon group in the structure thereof. The aromatic hydrocarbon group can dramatically improve the thermal stability of the monofunctional epoxy-based end-capping agent itself from the stability of the ring. Aromatic hydrocarbon groups include groups derived from those having a benzene ring skeleton such as benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, propylbenzene, butylbenzene, and t-butylbenzene. , Naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, 2-isopropylnaphthalene, 2,6-dimethylnaphthalene, dipropylnaphthalene, 1,2-dihydroacenaphthylene, acenaphthylene, α-naphthol, β-naphthol, etc. Examples include groups derived from a compound having a structure. In general, the higher the molecular weight of the substituent, the better the heat resistance of the resulting compound. However, on a weight basis, the amount of the monofunctional epoxy-based end-capping agent of the present invention increases, which leads to cost and moldability. It will be disadvantageous. Therefore, the functional group preferably has 20 or less carbon atoms, more preferably 10 or less. Furthermore, it is preferable that the aromatic hydrocarbon group constituting R1 and R2 does not have a reactive substituent. Specific examples of reactive substituents include unsaturated hydrocarbon groups, carboxyl groups, formyl groups, amino groups, nitro groups, nitroso groups, cyano groups, cyanato groups, isocyanato groups, sulfo groups, mercapto groups, and the like. It is done. In the case of compounds that do not contain these reactive substituents, the monofunctional epoxy-based end-capping agent may cause side reactions during melt molding or during product use, accelerate the hydrolysis of the polyester, It is possible to suppress the occurrence of thickening or gelation due to the linking of molecular chains.

  From these facts, the groups constituting R1 and R2 represented by the above formula (I) include phenyl group, benzyl group, p-tolyl group, 2,4-xylyl group, mesityl group, p-cumenyl group, phenethyl group. Group, 1-methyl-1-phenylethyl group, p-methylbenzyl group, 1-naphthyl group, 2-naphthyl group, 1-naphthylmethyl group, 1-naphthyl-2-ethyl group, 1-naphthyl-1-ethyl Group, 2-naphthylmethyl group, 2-naphthyl-2-ethyl group, 2-naphthyl-1-ethyl group and the like are preferable, and phenyl group, benzyl group, p-tolyl group, 1-naphthyl group, 2-naphthyl group, etc. Group, 1-naphthylmethyl group, 1-naphthyl-2-ethyl group, 1-naphthyl-1-ethyl group, 2-naphthylmethyl group, 2-naphthyl-2-ethyl group, 2-naphthyl-1-ethyl group If there, It is more preferable from the heat resistance of a functional epoxy-based endblocker and ease of synthesis, and it may be a phenyl group, a benzyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-naphthylmethyl group, or a 2-naphthylmethyl group. For example, there are few steric hindrance problems with respect to the isocyanuric acid skeleton, and it is most preferable from the viewpoint of ease of synthesis, availability of raw materials, and the like.

  Preferred isocyanurate compounds for use in the present invention include di (substituted- or unsubstituted-) phenyl monoglycidyl isocyanurate, di (substituted- or unsubstituted-) aralkyl monoglycidyl isocyanurate, di (substituted- or unsubstituted). -) Naphtyl monoglycidyl isocyanurate, di (substituted- or unsubstituted-) naphthylalkyl monoglycidyl isocyanurate and the like, and specific examples include dibenzyl monoglycidyl isocyanurate, diphenyl monoglycidyl isocyanurate, dinaphthyl monoglycidyl. Isocyanurate, dinaphthylmethyl monoglycidyl isocyanurate, dibenzyl monomethyl glycidyl isocyanurate, diphenyl monomethyl glycidyl isocyanurate, dinaphthyl monomethyl glycidyl iso Cyanurate, etc. dinaphthyl methyl monomethyl glycidyl isocyanurate.

  Moreover, it is preferable that melting | fusing point of the monofunctional epoxy-type terminal blocker of this invention is 50 degreeC or more. If the melting point is 50 ° C or higher, blocking does not occur during storage in the summer, and since it is a powder at room temperature, it is excellent in handleability when added to polyester, and thus the cost of the addition process It will also lead to down. Moreover, in order to add a monofunctional epoxy-type terminal blocker uniformly in polyester, it is preferable that it is a liquid state in polyester which the terminal blocker melt | dissolved. From this, it is preferable that the melting point of the monofunctional epoxy-based end-blocking agent is the melting point (Tm) of the polyester −20 ° C. or less, and the monofunctional epoxy-based end-blocking agent is uniformly added to the resin when the polyester is melt-mixed. is there. From these facts, the melting point of the monofunctional epoxy-based end capping agent of the present invention is preferably in the range of 70 ° C. to Tm-20 ° C., and most preferably in the range of 80 ° C. to Tm-20 ° C.

It is preferable that the addition amount of the monofunctional epoxy-type end blocker with respect to the polyester of this invention is the range of 0.8-30 times with respect to the theoretical addition amount W shown by following formula (1).
W (%) = AD × MW × 10 ⁻⁴ (1)
W: Theoretical addition amount (%)
AD: Concentration of acid end groups (mol / t)
MW: molecular weight (g / mol) of monofunctional epoxy-based endblocker.

  When the addition amount of the monofunctional epoxy-based end-blocking agent is 0.8 times or more than the theoretical addition amount W, the acid end of the polyester is effectively blocked to greatly improve the hydrolysis resistance. Is possible. In addition, if the addition amount is 30 times or less than the theoretical addition amount W, the monofunctional epoxy-based endblocking agent is less likely to bleed from the polyester resin molded product, and the polyester resin molded product is molded in the molding process. In addition to ensuring the properties, the monofunctional epoxy-based end-capping agent can be prevented from scattering during the process. Therefore, the addition amount of the monofunctional epoxy-based end-blocking agent is more preferably in the range of 0.9 to 20 times the theoretical addition amount W, and most preferably in the range of 0.9 to 10 times.

  Further, in order to improve the reactivity of the monofunctional epoxy-based end-capping agent, a catalyst is preferably used in combination. The catalyst may be any as long as it promotes the ring opening of epoxy, and examples thereof include various metal complexes, metal oxides, metal halides, complex salts, and organic metal salts. Of these, organometallic salts are preferably used because they have good compatibility with polyester and are excellent in handling. Furthermore, when the monofunctional epoxy-based endblocker and the polyester end react, there is a correlation between the temperature and the reaction rate, so when the melt molding temperature is low, the catalyst is added. As a result, the reaction rate between the monofunctional epoxy-based end-capping agent and the polyester can be improved.

  In addition, an acid-terminal reactive substance other than the monofunctional epoxy-based end-blocking agent can be added to the polyester resin composition of the present invention in combination. Examples of the acid terminal reactive substance include a carbodiimide compound, an isocyanate compound, an epoxy compound, an oxazoline compound, an oxazine compound, and a polymer obtained by polymerizing these compounds. These acid-terminal-reactive substances can suppress bleeding out at the time of molding by setting the amount to 50% or less with respect to the addition amount of the monofunctional epoxy-based end-blocking agent, and are blocked with the monofunctional epoxy-based end-blocking agent. This is preferable because the acid terminal of the polyester that could not be removed can be blocked.

  The method for adding the monofunctional epoxy-based end-blocking agent to the polyester of the present invention is not particularly limited. For example, the method of adding directly to the can at the final stage of polymerization, the polyester pellet and the monofunctional epoxy-based end-capping agent. Any known technique can be used in which the polyester and the monofunctional epoxy-based end-blocking agent can be mixed and added uniformly in a molten state, such as a method of mixing the blocker with a melt kneader. good. When the polyester and the monofunctional epoxy-based endblocker are mixed in the molten state, the epoxy group reacts with the acid terminal of the polyester by the heat during melting, and when mixed in the molten state, uniform addition is realized. It is preferable in that it is easy. In the sense that uniform addition can be realized, when the polyester is added at the polymerization stage, a monofunctional epoxy end-capping agent dissolved in a solution in a monomer, for example, as a slurry or a monofunctional epoxy end-capping A method in which an agent is directly added to a polymerization can in a molten state and stirred and reacted is preferable. When an already polymerized polyester is used as a raw material, it is preferably melt-mixed using a biaxial extruder type kneader. .

The temperature T when the monofunctional epoxy-based endblocker of the present invention is added to the polyester preferably satisfies the following formula (2) with respect to the melting point Tm of the polyester.
Tm + 10 ≦ T ≦ Tm + 70 (2)
Tm: Melting point of polyester (° C.)
T: Melting temperature (° C.).

  Polyester melt-mixed under the conditions in the above range is less susceptible to denaturation and coloration of the polyester itself due to heat, and can be suitably implemented for applications such as fibers and nonwoven fabrics where color tone is particularly important.

  Further, the residence time at the time of melting is preferably in the range of 1 to 60 minutes. If the residence time at the time of melting is 1 minute or more, the monofunctional epoxy-based end-capping agent is sufficiently dispersed in the polyester due to the kneading effect of the kneader or the extruder, and the acid ends can be efficiently blocked. On the other hand, if the residence time at the time of melting is 60 minutes or less, the modification and coloring of the polyester due to heat can be suppressed. Accordingly, the residence time at the time of melting is more preferably in the range of 1 minute 30 seconds to 50 minutes, and most preferably in the range of 2 minutes to 40 minutes. In particular, when a biaxial extruder type kneader is used, the melt residence time in the biaxial extruder type kneader is in the range of 1 to 3 minutes from the viewpoint of suppressing uniform addition and polyester modification. preferable. Here, since the residence time at the time of melting represents the thermal history received by the polymer, for example, a monofunctional epoxy-based end-blocking agent is kneaded with polyester in a kneading machine in advance and pelletized, and then melt-molded again. When melt molding is performed, the total time of all the melting times is represented.

Moreover, about the polyester resin composition of this invention, it is preferable that the melt viscosity after adding a monofunctional epoxy type terminal blocker satisfies the following formula (3) with respect to the melt viscosity of polyester used as a substrate.
0.5 ≦ ηb / ηa ≦ 1.2 (3)
ηa: Polyester melt viscosity (Pa · sec)
ηb: Melt viscosity (Pa · sec) of the polyester resin composition.

  Since the monofunctional epoxy-based endblocker of the present invention is a monofunctional compound, the melt viscosity of the polyester is not increased, and the moldability is equivalent to that of the unadded polyester. Therefore, ηb is preferably 1.2 times or less of ηa. Moreover, since it is preferable to maintain the melt viscosity of the polyester resin at a level that facilitates molding, ηb is preferably 0.5 times or more of ηa. The melt viscosity can be measured using, for example, a Capillograph 1B manufactured by Toyo Seiki. However, the melt viscosity is the pressure of the resin under the same molding conditions (temperature, flow rate, flow path shape such as piping and mold). Therefore, the pressure gauge installed in the molding machine at the time of melt molding can be read, and the pressure ratio of the polyester resin composition to which the virgin resin and the monofunctional epoxy-based endblocker are added can be read. In this case, ηa can be calculated as the polyester resin pressure, and ηb as the resin pressure of the polyester resin composition.

  Moreover, it is preferable that the polyester resin molding obtained from the polyester resin composition of the present invention is used as a master batch by adding a monofunctional epoxy-based end-blocking agent to the polyester once, melt mixing, and pelletizing. By setting it as such a form, it can prevent that the reactivity of a monofunctional epoxy type terminal blocker falls at the time of storage, and it is excellent also in terms of handling.

  Furthermore, the polyester resin molded product obtained from the polyester resin composition of the present invention can be obtained by a conventionally known molding method such as extrusion molding, blow molding, injection molding, and melt spinning. Examples of polyester resin molded products include films, sheets, bottles, fibers, fabrics, and nonwoven fabrics. Among these, the polyester resin composition melted in the production process has a large specific surface area, and the molded product such as a fiber or a non-woven fabric has less scattering of the end-blocking agent by using the monofunctional epoxy-based end-blocking agent of the present invention. Since the working environment can be prevented from deteriorating due to smoke or odor in the process, and safety can be improved, it can be particularly preferably employed.

  In addition, since the monofunctional epoxy-based endblocker of the present invention rarely thickens the polyester, it is excellent in high-speed yarn-forming properties when it is formed into a fiber that is suitably produced in the present invention. High-speed spinning means winding at a winding speed of 2500 m / min or more, and polyester fibers obtained at this spinning speed are excellent in mechanical properties and because oriented crystallization proceeds on the spinning line. It can be suitably used as a raw yarn for false twisting and the like. However, in order to carry out stable production without yarn breakage, the spinning speed is preferably 7000 m / min or less. Therefore, it is more preferable that the spinning speed range is 3000 to 6000 m / min. Further, it is preferable that the obtained wound yarn is stretched, false twisted, or subjected to various known yarn processing, and then formed into a fabric such as a woven fabric or a knitted fabric.

  It is preferable that the fiber which is a preferable aspect of the polyester resin molded product of the present invention has a strength of 2.0 cN / dtex or more. When the strength is 2.0 cN / dtex or more, there is little yarn breakage when producing a woven fabric or knitted fabric, and a uniform fabric can be produced. The boiling water shrinkage of the fiber is preferably 0 to 40% from the viewpoint of maintaining dimensional stability.

  Preferred embodiments of the present invention are shown below, but the present invention is not limited to these descriptions.

A. Number / Weight Average Molecular Weight A sample solution was prepared by dissolving 10 mg of a sample in 4 ml of tetrahydrofuran (for high performance liquid chromatograph) and filtering using a membrane filter having an opening of 0.15 μm. Then, it measured at 25 degreeC using Waters gel permeation chromatography (GPC) Waters2690, and calculated | required the number average molecular weight in polystyrene conversion. Here, in the case of aliphatic polyester, the solvent was changed to chloroform (for high performance liquid chromatograph), and the weight average molecular weight was measured by the same method.

B. 1% thermal weight loss temperature of monofunctional epoxy-based end-capping agent Using a differential thermothermogravimetric simultaneous measuring instrument (TG-DTA6200 model manufactured by Seiko Instruments Inc.), a sample that was vacuum-dried at 40 ° C. for 5 hours was weighed. 10 mg, heating rate 10 ° C /
The temperature range was from room temperature to 300 ° C., and the 1% heat loss temperature in a nitrogen atmosphere was measured.

C. Monofunctional Epoxy End Blocking Agent and Polyester Melting Point Using a DS instrument 2920 modulated DSC manufactured by TA instruments, a melting point peak was obtained at a heating rate of 16 ° C./min and a sample amount of 10 mg, and the peak top position was determined as a monofunctional epoxy end blocking agent. Of melting point. Further, the melting point of the polyester was determined by the same measuring method.

D. A sample for measurement precisely weighed to 0.5 g of acid terminal amount of polyester was dissolved in an o-cresol (5% water) adjustment solution, and after adding an appropriate amount of dichloromethane to this solution, 0.02 N KOH methanol solution was used. It was measured by titration. At this time, the polyester oligomer may be hydrolyzed to produce a COOH end group. Therefore, the COOH end group concentration obtained by adding up all of the COOH end group of the polymer, the COOH end group derived from the monomer, and the COOH end group derived from the oligomer is I want.

E. Melt Viscosity of Polyester and Polyester Resin Composition Using Capillograph 1B manufactured by Toyo Seiki, the measurement temperature is set to the melting point Tm + 30 ° C. of the polyester, the capillary viscosity is 10 mm, the capillary pore diameter is 1.0 mmφ, and the melt viscosity is 1216 sec ⁻¹ . It was measured. Moreover, the pressure change by the presence or absence of the addition of the monofunctional epoxy-type terminal blocker in melt molding was observed, and this was used as the index of melt viscosity.

F. Work environment evaluation When the polyester is mixed with a monofunctional epoxy end-capping agent and melt-molded, it is subjected to a sensory evaluation on the amount of scatter and odor derived from the monofunctional epoxy end-capping agent, and there is no problem in the work environment. Those with ◯, those with no problem in the work environment, △ with the work environment having a problem, △, and those with poor work environment with x, passed.

G. Fiber Strength A Tensilen UCT-100 manufactured by Orientec was used to draw a strong elongation curve at a sample length of 200 mm and a tensile speed of 200 mm / min, and the stress value at the maximum point was defined as the fiber strength.

H. The shrinkage rate of the fiber A thread length of 49.8 cm was prepared, and the thread length was immersed in hot water kept at 98 ° C. for 15 minutes with no load, and the length of the treated ring was measured. Fiber shrinkage was obtained from the equation.
Shrinkage rate (%) = (49.8−length after treatment) ÷ 49.8 × 100.

I. Hydrolysis resistance of the fiber Saturated steam treatment is carried out at 155 ° C for 6 hours when the aromatic polyester is used as the yarn for each of the fibers without addition of the monofunctional epoxy-based endblocker and after addition. did. In the case of aliphatic polyester, saturated steam treatment was performed at 130 ° C. for 1 hour. Thereafter, each strength retention was calculated by the following formula, and those having a TI / TN of 1.1 or more were regarded as acceptable.
TN (%) = TN1 / TN0 × 100
TI (%) = TI1 / TI0 × 100
TN0: Strength of polyester fiber with no monofunctional epoxy-based end-blocking agent added (untreated)
TN1: Strength of polyester fiber with no monofunctional epoxy-based endblocker added (after treatment)
TI0: Strength of polyester fiber with monofunctional epoxy-based endblocker added (untreated)
TI1: Strength of the polyester fiber added with a monofunctional epoxy-based endblocker (after treatment).

J. et al. Resin pressure ratio The resin pressure ratio was calculated by the following formula from the resin pressure P2 of the resin added with the monofunctional epoxy-based endblocker and the resin pressure P1 of the resin not added. In addition, the viscosity change of the polyester resin composition was observed with this value, and the resin pressure ratio in the range of 0.5 to 1.2 was regarded as acceptable.
Resin pressure ratio (−) = P2 / P1.

K. Intrinsic viscosity (IV)
0.8 g of the sample polymer was dissolved in 10 ml of orthochlorophenol (hereinafter abbreviated as OCP), the relative viscosity ηr was determined by the following equation using an Ostwald viscometer at 25 ° C., and IV was calculated.
ηr = η / η ₀ = (t × d) / (t ₀ × d ₀ )
IV = 0.0242ηr + 0.2634
Where η: viscosity of polymer solution, η ₀ : OCP viscosity, t: solution drop time (seconds), d: solution density (g / cm ³ ), t ₀ : OCP drop time (seconds), d ₀ : Density of OCP (g / cm ³ ).

[Production Example 1]
Polyethylene terephthalate (PET) as the polyester {number average molecular weight 195,000, intrinsic viscosity (IV) 0.656, titanium dioxide 0.2wt%, acid end amount 20 equivalent / t, melt viscosity (280 ° C) 137Pa · sec }, And 1 wt% of dibenzyl monoglycidyl isocyanurate (1% heat loss temperature 245 ° C.) as a monofunctional epoxy-based end-capping agent is blended with powder to PET, and a twin screw extruder manufactured by Technobel (KZW-15TWIN) was used for melt mixing at a kneading temperature of 280 ° C. and an average residence time of 3 minutes, and then pelletized to obtain polyester resin pellets.

[Production Example 2]
Polyester resin pellets were obtained in the same manner as in Production Example 1, except that diphenylmonoglycidyl isocyanurate (1% heat loss temperature 241 ° C.) was used as the monofunctional epoxy-based endblocker.

[Production Example 3]
Polyester resin pellets were obtained in the same manner as in Production Example 1, except that dinaphthyl monoglycidyl isocyanurate (1% heat loss temperature 258 ° C.) was used as the monofunctional epoxy-based endblocker.

[Production Example 4]
Polyester resin pellets were obtained in the same manner as in Production Example 1 except that diallyl monoglycidyl isocyanurate (1% heat loss temperature 190 ° C.) was used as a monofunctional epoxy-based end-blocking agent, but a large amount of smoke was generated in the pelletizing process. Observed.

[Production Example 5]
Polypropylene terephthalate {number average molecular weight 153,000, intrinsic viscosity (IV) 0.907, acid end amount 13.3 equivalent / t, melt viscosity (250 ° C.) 310 Pa · sec} is used as the polyester, and the kneading temperature is 250 ° C. A polyester resin pellet was obtained in the same manner as in Production Example 1 except that.

[Production Example 6]
As the polyester, polylactic acid {weight average molecular weight 145,000, solution specific viscosity ηr3.08, acid end amount 24.7 equivalent / t, melt viscosity (200 ° C.) 220 Pa · sec} was used, and the kneading temperature was 210 ° C. Except for the above, polyester resin pellets were obtained in the same manner as in Production Example 1.

[Example 1]
Using the polyester resin pellets produced in Production Example 1, with a spinning temperature of 280 ° C., a residence time in the spinning machine of 15 minutes, a discharge rate of 50 g / min, a spinning speed of 3000 m / min, a die hole diameter of 0.3 mm, and a die hole number of 48 Winding to obtain a highly oriented undrawn yarn (POY) of 167 dtex-48F. In addition, melt spinning was performed on the polyester pellets produced in Production Example 1 under the same spinning conditions, and the pressure was monitored. However, there was no noticeable increase in melt viscosity compared to Comparative Example 1 described later, and spinnability was improved. It was excellent. Thereafter, the obtained POY was stretched with a hot roller type stretching machine at a stretching temperature of 85 ° C. and a heat setting temperature of 130 ° C. at a draw ratio of 1.8 times to obtain a stretched yarn of 93 dtex-48F. The obtained drawn yarn had a strength of 4.5 cN / dtex and a boiling water shrinkage of 7%, and exhibited good mechanical properties and dimensional stability. Furthermore, the acid terminal amount of the obtained fiber was 2 equivalent / t, and showed excellent hydrolysis resistance. The results are shown in Table 1.

[Example 2]
POY and drawn yarn were obtained in the same manner as in Example 1 except that the polyester resin pellets produced in Production Example 2 were used. The resulting fiber showed excellent hydrolysis resistance. The results are shown in Table 1.

[Example 3]
POY and drawn yarn were obtained in the same manner as in Example 1 except that the polyester resin pellets produced in Production Example 3 were used. The resulting fiber showed excellent hydrolysis resistance. The results are shown in Table 1.

[Comparative Example 1]
POY and drawn yarn were obtained in the same manner as in Example 1 without adding a monofunctional epoxy-based end-blocking agent to the polyethylene terephthalate produced in Production Example 1. The hydrolysis resistance of the obtained fiber did not reach the desired characteristics and was inferior in durability. The results are shown in Table 1.

[Comparative Example 2]
POY and drawn yarn were obtained in the same manner as in Example 1 except that the polyester resin pellets produced in Production Example 4 were used. A large amount of smoke was observed in the melt spinning process, and the working environment deteriorated. The results are shown in Table 1.

[Example 4]
POY and drawn yarn were obtained in the same manner as in Example 1 except that the polyester resin pellets produced in Production Example 5 were used and the spinning temperature was changed to 255 ° C. The resulting fiber showed excellent hydrolysis resistance. The results are shown in Table 2.

[Example 5]
POY and drawn yarn were obtained in the same manner as in Example 1 except that the polyester resin pellets produced in Production Example 6 were used and the spinning temperature was 220 ° C. The resulting fiber showed excellent hydrolysis resistance. The results are shown in Table 2.

[Example 6]
POY and drawn yarn were obtained in the same manner as in Example 5 except that 0.01 wt% of magnesium acetate was added as a catalyst. The resulting fiber showed excellent hydrolysis resistance. The results are shown in Table 2.

[Comparative Example 3]
POY and drawn yarn were obtained in the same manner as in Example 4 except that the polyester resin pellets of Example 4 were polyesters of Production Example 5 (no addition of a monofunctional epoxy-based endblocker). The resulting fiber had low hydrolysis resistance. The results are shown in Table 2.

[Comparative Example 4]
POY and drawn yarn were obtained in the same manner as in Example 5 using the polyester resin pellet of Example 5 as the polyester of Production Example 6 (without adding a monofunctional epoxy-based endblocker). The resulting fiber had low hydrolysis resistance. The results are shown in Table 2.

[Production Example 7]
Polyester resin pellets were obtained in the same manner as in Production Example 1 except that 0.5% by weight of dibenzyl monoglycidyl isocyanurate (1% heat loss temperature 245 ° C.) was added as a monofunctional epoxy-based endblocker.

[Production Example 8]
Polyester resin pellets were obtained in the same manner as in Production Example 1 except that 2% by weight of dibenzylmonoglycidyl isocyanurate (1% heat loss temperature 245 ° C.) was added as a monofunctional epoxy-based endblocker.

[Production Example 9]
Polyester resin pellets were obtained in the same manner as in Production Example 1, except that 10% by weight of dibenzyl monoglycidyl isocyanurate (1% heat loss temperature 245 ° C.) was added as a monofunctional epoxy-based endblocker.

[Production Example 10]
Polyester resin pellets were obtained in the same manner as in Production Example 1 except that 20% by weight of dibenzyl monoglycidyl isocyanurate (1% heat loss temperature 245 ° C.) was added as a monofunctional epoxy-based endblocker.

[Production Example 11]
Polyester resin pellets were obtained in the same manner as in Production Example 7, except that diphenylmonoglycidyl isocyanurate (1% heat loss temperature 241 ° C.) was used as the monofunctional epoxy-based endblocker.

[Production Example 12]
Polyester resin pellets were obtained in the same manner as in Production Example 8, except that diphenyl monoglycidyl isocyanurate (1% heat loss temperature 241 ° C.) was used as the monofunctional epoxy-based endblocker.

[Production Example 13]
Polyester resin pellets were obtained in the same manner as in Production Example 9, except that diphenyl monoglycidyl isocyanurate (1% heat loss temperature 241 ° C.) was used as the monofunctional epoxy-based endblocker.

[Production Example 14]
Polyester resin pellets were obtained in the same manner as in Production Example 10 except that diphenylmonoglycidyl isocyanurate (1% heat loss temperature 241 ° C.) was used as the monofunctional epoxy-based endblocker.

[Example 7]
POY and drawn yarn were obtained in the same manner as in Example 1 except that the polyester resin pellets produced in Production Example 7 were used. The obtained fiber was excellent in durability. The results are shown in Table 3.

[Example 8]
POY and drawn yarn were obtained in the same manner as in Example 1 except that the polyester resin pellets produced in Production Example 8 were used. The obtained fiber was excellent in durability. The results are shown in Table 3.

[Example 9]
POY and drawn yarn were obtained in the same manner as in Example 1 except that the polyester resin pellets produced in Production Example 9 were used. Although slight fuming was observed in the production process, the yarn could be produced without any problems. Moreover, the obtained fiber was excellent in durability. The results are shown in Table 3.

[Example 10]
POY and drawn yarn were obtained in the same manner as in Example 1 except that the polyester resin pellets produced in Production Example 10 were used. Although a slight amount of smoke was observed in the production process, the yarn could be produced without any problems. Moreover, the obtained fiber was excellent in durability. The results are shown in Table 3.

[Example 11]
POY and drawn yarn were obtained in the same manner as in Example 1 except that the polyester resin pellets produced in Production Example 11 were used. The obtained fiber was excellent in durability. The results are shown in Table 4.

[Example 12]
POY and drawn yarn were obtained in the same manner as in Example 1 except that the polyester resin pellets produced in Production Example 12 were used. The obtained fiber was excellent in durability. The results are shown in Table 4.

[Example 13]
POY and drawn yarn were obtained in the same manner as in Example 1 except that the polyester resin pellets produced in Production Example 13 were used. Although slight fuming was observed in the production process, the yarn could be produced without any problems. Moreover, the obtained fiber was excellent in durability. The results are shown in Table 4.

[Example 14]
POY and drawn yarn were obtained in the same manner as in Example 1 except that the polyester resin pellets produced in Production Example 14 were used. Although a slight amount of smoke was observed in the production process, the yarn could be produced without any problems. Moreover, the obtained fiber was excellent in durability. The results are shown in Table 4.

[Production Example 15]
The same method as in Production Example 1 except that the trade name “Denacol EX-731” {N-glycidylphthalimide (1% heat loss temperature 168 ° C.)} manufactured by Nagase ChemteX Corp. was used as the monofunctional epoxy-based endblocker. Polyester resin pellets were obtained.

[Production Example 16]
Polyester resin pellets in the same manner as in Production Example 1 except that the product name NCN {monocarbodiimide compound (1% heat loss temperature 183 ° C.)} manufactured by Matsumoto Yushi Seiyaku Co., Ltd. was used instead of the monofunctional epoxy-based endblocker. Got.

[Production Example 17]
Polyester resin pellets are obtained in the same manner as in Production Example 1, except that monoallyl diglycidyl isocyanurate {bifunctional epoxy compound (1% heat loss temperature 192 ° C.)} is used instead of the monofunctional epoxy-based endblocker. It was.

[Production Example 18]
Polyester in the same manner as in Example 1, except that TEPIC-S {Trifunctional epoxy compound (1% heat loss temperature 220 ° C.)} manufactured by Nissan Chemical Industries, Ltd. was used instead of the monofunctional epoxy-based endblocker. An attempt was made to obtain resin pellets, but the thickening in the kneader was so intense that a sample could not be obtained.

[Comparative Example 5]
POY and drawn yarn were obtained in the same manner as in Example 1 except that the polyester resin pellets produced in Production Example 15 were used. The obtained fiber was inferior in durability, and a large amount of smoke was observed in the spinning process, and the working environment deteriorated. The results are shown in Table 5.

[Comparative Example 6]
POY and drawn yarn were obtained in the same manner as in Example 1 except that the polyester resin pellets produced in Production Example 16 were used. Although the obtained fiber was excellent in durability, a large amount of smoke and irritating odor was observed in the spinning process, and the working environment was deteriorated. The results are shown in Table 5.

[Comparative Example 7]
POY and drawn yarn were obtained in the same manner as in Example 1 except that the polyester resin pellets produced in Production Example 17 were used. Although the obtained fiber was excellent in durability, smoke and an irritating odor were observed in the spinning process, and the spinnability deteriorated due to thickening. The results are shown in Table 5.

Claims (4)

A polyester characterized in that an isocyanurate compound represented by the following formula (I) is added as a monofunctional epoxy-based end-capping agent to the polyester, and at least a part of the isocyanurate compound is reacted with the polyester. Resin composition.

(In the formula, R1 and R2 are groups containing an aromatic hydrocarbon group in the structure thereof.)   2. The polyester resin composition according to claim 1, wherein the polyester is an aliphatic polyester.   The polyester resin composition according to claim 2, wherein the aliphatic polyester is polylactic acid.   A polyester resin molded article comprising the polyester resin composition according to claim 1.