KR920009689B1 - Thermoplastic polyester block copolymer having excellent flexibility and impact resistance and its manufacturing method - Google Patents

Abstract

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Description

Thermoplastic polyester block copolymer having excellent flexibility and impact resistance and its manufacturing method

The present invention relates to a polyester block copolymer having excellent flexibility and impact resistance consisting of a random block copolymer of the following structural formulas (I) and (II) and a method for producing the same.

In the above structural formula, R is an ester-forming dicarboxylic acid or lower alkyl esterified product, mainly terephthalic acid, isophthalic acid, and the like, and naphthalenedicarboxylic acid, adipic acid, suberic acid, sebacic acid, Decanedicarboxylic acid, dodecanedicarboxylic acid, cyclohexanedicarboxylic acid, etc. can be mixed and used, D mainly uses ethylene glycol, 1, 4- butanediol as an ester formation glycol component, and 1, 2- or 1,3-propanediol, 1,6-hexanediol 1,4-cyclohexane dimethanol, etc. can be mixed and used, B is a polybutadiene or a butadiene which has a carboxyl terminal, and an acrylonitrile copolymer.

In the related art, block copolymers having flexibility and impact resistance are mainly made of polyethylene terephthalate and polybutylene terephthalate as a base resin, and mixed with ingredients capable of improving flexibility and impact resistance. Examples include U.S. Patent Nos. 4,141,863, 4,327,199 and 4,327,198, and U.S. Patent No. 4,141,863 is a rubber component capable of enhancing flexibility and impact resistance, and includes nitrile rubber, ethylene-propylene-diene rubber, and butadiene. Rubber, styrene-butadiene rubber, etc. were used, and acrylic rubber was used in US Pat. No. 4,327,199 and polyethylene was used in US Pat. No. 4,327,198.

However, the resins prepared by the above technique must be prepared separately from the basic resin and rubber components, and then reprocessed using a heat melting mixer such as a screw type. It was very severe, and there were various problems such as changes in physical properties with prolonged use. Therefore, in recent years, polyester block copolymers have made polybutylene terephthalate a crystalline segment, copolymerized polyether segments in the form of blocks to give a rubbery property, and produced them in thermoplastic elastomers in the early 1970s. Has replaced the existing use of vulcanized rubber.

The polyester block copolymer copolymerizes the ester unit and the ether unit in the form of a block, so that excellent rubber flexibility due to the ether unit and excellent processability due to the crystallinity of the ester unit can be simultaneously satisfied. When mixing various components such as rubber components, crosslinking agents, stabilizers, etc., and then injecting them into a mold and vulcanizing them by applying heat to them, it eliminates complicated processes such as single injection, extrusion, and the like. The same molding process could be simplified. In addition, polyester block copolymers are easy to use scraps that can be reused once molded products, has been consistently replacing the use of conventional rubber, automotive parts, various tubes, hoses, sheets and wire coatings that require flexibility It has been mainly used for applications requiring low temperature flexibility.

On the other hand, in the polyester block copolymer, poly (alkylene oxide) glycol was commonly added as an ether unit to give flexibility, and such a poly (alkylene oxide) glycol has a free rotation around the bond and a chain. Since it is formed of ether bonds such as -O- which can impart flexibility, it has been known to have a very large effect on the provision of rubber flexibility.

However, polyethers such as poly (alkylene oxide) glycols have a very high activity of hydrogen bonded to the carbon adjacent to the ether bonds, so they are easily absorbed by heat or force from the outside and separated from radicals. The polyester block copolymer containing poly (alkylene oxide) glycol has a high thermal stability, as a result of the fact that hydrogen having poor thermal stability is placed adjacent to the ester group having the poorest thermal stability among the polyester units. Had been degraded.

In order to solve this disadvantage, in the present invention, as a component to give rubber flexibility, by using a polybutadiene having a carboxyl end or a butadiene and an acrylonitrile copolymer instead of a conventional poly (alkylene oxide) glycol, It is an object of the present invention to prepare a polyester block copolymer that can be used as a thermoplastic polyester elastomer that solves the problem of lowering the thermal stability due to the presence.

Hereinafter, the present invention will be described in detail.

The present invention relates to a polyester block copolymer in which a crystalline polyester unit and a polyether unit of a rubber component are copolymerized in a block form, wherein a polybutadiene or butadiene and acryl are used as rubber components based on 35 to 95% by weight of the crystalline polyester component. 5 to 65% by weight of ronitrile copolymer is copolymerized in the form of a block, and has a flexible and impact resistant polyester block copolymer having a molecular weight of 15,000 to 90,000 having the following structural formulas (I) and (II) as repeating units. do.

In the above formula, R is dicarboxylic acid or lower alkyl esterified product of ester formation, terephthalic acid, isophthal or naphthalenedicarboxylic acid, adipic acid, suberic acid, sebacic acid, decandicarboxylic acid, Dodecanedicarboxylic acid, cyclohexanedicarboxylic acid, etc. are mixed, and D is an ester-forming glycol component, which is ethylene glycol, 1,4-butanediol, 1,2- or 1,3-propanediol, 1, 6-hexanediol, 1,4-cyclohexanedimethanol, and B is a polybutadiene having a carboxyl end or an acrylonitrile copolymer with butadiene.

In addition, the present invention is to produce a polyester block copolymer consisting of a hard segment and a soft segment by copolymerizing a polyether unit of a rubber component to a crystalline polyester unit, it is soft with respect to 35 to 95% by weight of the crystalline polyester component 5 to 65% by weight of the polybutadiene or butadiene and acrylonitrile copolymer and the glycol component constituting the segment are first reacted at 50 to 200 ° C. under a pressure of 1.5 to 2.0 kg / Cm ² , and then the hard segment There is also a method for producing a polyester block copolymer having the above general formulas (I) and (II) as repeating units, characterized by adding and reacting the acid component constituting the reaction mixture with various reaction aids.

Referring to the present invention in more detail as follows.

Structural formula (I) of the present invention acts as a hard segment in the block copolymer of the present invention as a oriented linear polyester, wherein R is an ester-forming dicarboxylic acid or lower alkyl ester compound, mainly terephthalic acid. Isophthalic acid, naphthalenedicarboxylic acid, adipic acid, suberic acid, sebacic acid, decandicarboxylic acid, dodecanedicarboxylic acid, cyclohexanedicarboxylic acid and the like can be used here. D is an ester-forming glycol component, and mainly ethylene glycol and 1,4-butanediol are commonly used, and 1,2- or 1,3-propanediol, 1,6-hexanediol, and 1,4-cyclo Hexane dimethanol and the like may be mixed, and the structural formula (II) serves as a soft segment as a rubbery polyester component of a long chain, where D is the same as mentioned above, and B is a A copolymer of polybutadiene or butadiene and ahkeul reel nitrile with acid terminal, Good Rich [GOODRICH] as a reactive liquid polymer is produced between the product of the trade name "hayika City Wien [HYCAR ^R CTBN]", the following structure: Is displayed.

In the structural formula a is 1 to 10, b is a constant of 7 to 13.

The “Hica Citibiene” is prepared by copolymerizing 1 to 10 moles of butadiene with respect to 1 mole of acrylonitrile, and is preferably prepared by an oxidation process. Preferably, 3 to 7 moles of butadiene per mole of acrylonitrile is used. It is good to copolymerize.

The polyester block copolymer is a component that imparts rubber properties, and can induce a function as an elastomer through the same mechanism as compared with a conventional polyether ester block copolymer using poly (alkylene oxide) glycol. While replacing the function of the polyether component in the existing polyether ester block copolymer, the polybutadiene having a carboxyl end or the butadiene and acrylonitrile copolymer solve the problems of heat resistance and flowability that the polyether has structurally. Could.

In the present invention, the soft segment in the polyester block copolymer is a major factor in the flexibility and impact resistance of the entire chain, while entropy deformation of the external stress, the content is 5 to 65% by weight. If the content of the soft segment is less than 5% by weight, the content is so small that it is difficult to exhibit the properties of the elastomer, and if it is more than 65% by weight, the reaction process becomes difficult, and the content of the hard segment Since it is reduced to less than 53% by weight, the resistance to external force is weak and easy deformation occurs, the crystal melting point is lowered, there is a disadvantage that the thermal stability is poor. In addition, the polyester block copolymer of the present invention has a molecular weight of about 15,000 to 90,000, but a molecular weight of 15,000 or less is not only low in polymerization degree but also poor in long-term stability such as heat resistance, fatigue resistance, creep resistance, etc. The molecular weight of 90,000 or more improves long-term physical properties, but from the molecular weight of about 50,000, the extent of improvement of physical properties is drastically reduced due to the increase in molecular weight. Therefore, it is difficult to expect the improvement of physical properties in proportion to the molecular weight phase. It is almost impossible to achieve without the redesign of the reaction tube and complementary equipment, resulting in economic loss.

In general, the polyester block copolymer can be prepared by the following method. First, all the reactants, catalysts, and stabilizers necessary for the polymerization are introduced into a conventional polyester reaction tube, and the reaction tube temperature is 200 to. The mixture is stirred while rising to 23 ° C, and water or a low molecular weight substance of methanol corresponding to the same equivalent of all acid components is allowed to flow out.

After the esterification reaction or the transesterification reaction is completed as described above, the reaction tube temperature is heated to 250 to 280 ° C. while the vacuum is slowly applied to about 0.5 mmHg or less for about 60 minutes to stop the reaction at a suitable agitator load. The polyether ester copolymer can be manufactured by discharging the same and discharging the same.

However, in the present invention, the polyester block copolymer may be prepared by the conventional polyester polymerization method as described above, but by using the following production method, more excellent flexibility and elastic properties may be expressed. In the reaction tube used in the method, polybutadiene having a carboxyl end or butadiene, acrylonitrile copolymer and glycol component were added, the reaction tube was sealed, and the reaction tube was sealed at 50 to 200 ° C. under a pressure of 1.5 to 2.0 kg / cm 2. After reacting for a minute, the acid component of the remaining hard segment and various reaction aids were added, followed by esterification or transesterification at 200 to 230 ° C., and then condensation polymerization was carried out in the same manner as the above method while removing excess glycol components. do. At this time, if the reaction temperature of polybutadiene or butadiene, acrylonitrile copolymer and glycol component having a carboxyl terminal is 50 ° C. or less, the reaction of each terminal does not proceed well, and a high temperature of 200 ° C. or higher than the end temperature of the ester reaction There is no need to react.

At this time, the reaction catalyst used may be tetraalkyl titanate alone or a mixture of magnesium or calcium acetate, and a titanate such as Mg [HTi (OR) ₆ ] ₂ produced from an alkoxide compound of alkaline earth metal and an ester compound of titanate. Inorganic titanate compounds such as complex compounds and titanium titanates, mixtures of calcium acetate and antimony trioxide, lithium or magnesium acetate, organotin compounds or mixtures of organotin compounds and organotitanium compounds also exhibit excellent polymerization catalyst performance. In the above catalyst formula, R may be an alkyl group such as methyl, ethyl, propyl, isopropyl, butyl, bis-2-ethylhexyl and the like.

And, in the present invention, to improve the melt strength of the final polymer, the carboxyl, polyfunctional component and acryl compound composed of hydroxyl group, primary or secondary amine group, isocyanate group, glycidyl ether group and the like It may be introduced to induce a small amount of chemical bonds in the chain.

The polyester block copolymer to be drawn in the above manner uses poly (alkylene oxide) glycol by using a polybutadiene having a carboxyl end or a copolymer of butadiene and acrylonitrile as a component to impart rubber properties. Compared with the conventional polyether ester block copolymer, there is no ether linkage due to the absence of poly (alkylene oxide) glycol, so that the heat resistance of the final product can be prevented from being lowered, so that the flexibility and various elastic properties are similar. The thermoplastic polyester elastomer excellent in heat resistance can be manufactured.

Catalysts and additives used in the examples of the present invention were used to prepare a slurry in the following manner.

Catalyst: A catalyst slurry was prepared by mixing 90% by weight of 1,4-butanediol and 10% by weight of tetrabutyl titanate at 50 ° C. for 3 hours.

Additives: 20 g of 3,7-dioctylphenothiazine, 40 g of dilaurylthiopropionate, 24 g of 1,1,3-tris (2-methyl-4-hydroxy-5 tert-butylphenyl) butane 1,4 Slurry was prepared to mix to butanediol to 1 Kg.

Hereinafter, the present invention will be described in more detail with reference to the following examples.

Example 1

A rubber component having a carboxyl end in a conventional polyester reaction tube made of stainless steel was charged with 700 g of 1,4-butyol and 700 g of Zephyr's "Citibiene" 130X31 from Goodrich Inc., and the temperature of the reaction tube was 140 ° C. The pressure was maintained at 1.7 kg / cm 2, and after 30 minutes of reaction, water was allowed to flow out. 1000 g of dimethyl terephthalate, 15 g of slurry, and 18 g of additive slurry were added thereto, and methanol was distilled out while raising the reaction tube temperature to 200 ° C. at normal pressure.

After the methanol was completely discharged, the pressure in the tube was reduced to 0.5 mmHg for 0.5 hour, the temperature was raised to 255 ° C for 45 minutes, the stirring was stopped and nitrogen was introduced into the tube to discharge the polymer. An ester copolymer was obtained.

The resin thus prepared was dried under reduced pressure at 120 ° C. for 6 hours, dissolved in orthochlorophenol at 30 ° C., and the intrinsic viscosity was measured using a capillary viscometer. The crystal melting point was measured using a differential calorimeter, and the ASTM properties were measured using a 2-oz injection molding machine. Test specimens were prepared, various mechanical properties were measured, and the results are shown in Table 1 below.

[Examples 2 to 5 (Comparative Examples 1 to 2)]

In Example 1, the composition of the main component was added to the amounts shown in Table 1, and the catalyst additives, various conditions, and the like were carried out in the same manner as in Example 1, and the results are shown in Table 1 below.

[Comparative Examples 3-4]

Next, 15 g and 18 g of the composition, the catalyst, and the additive slurry of the composition shown in Table 1 were added thereto, and methanol was discharged while reacting at 200 ° C. for 1.5 hours. After methanol was distilled off, it carried out in the same manner as in Example 1, and the results are shown in Table 1 below.

Comparative Example 5

In Example 1, all the reactants were added at the beginning of the reaction, the reaction tube temperature was raised to 200 ° C., and methanol was immediately discharged. The following methods were carried out in the same manner as in Example 1, and the results are shown in Table 1 below. It was.

Comparative Example 6

When the rubber component and the glycol component were added and reacted in Example 1, the reaction tube pressure was reacted at 170 ° C. for 45 minutes without raising the reaction tube pressure, and all the methods were performed in the same manner as in Example 1 below. It is shown in Table 1 below.

Comparative Example 7

When the rubber component and the glycol component were added and reacted in Example 1, the reaction tube temperature was reacted at 80 ° C. for 30 minutes, and all the following methods were performed in the same manner as in Example 1, and the results are shown in Table 1 below. .

TABLE 1

DMT: Dimethyl Terphthalate

DMI: Dimethylisophthalate

AA: adipic acid

PAOG: Poly (alkylene oxide) glycol

PTGB: Poly (tetramethylene oxide) glycol (average molecular weight 1,000)

SA: Subersan

BD: 1,4-butanediol

EG: ethylene glycol

HD: 1,6-hexanediol

CHDM: 1,4-cyclohexanedimethanol

Hardness: Shore hardness D-TYPE

Melting Point: Unit ℃

Intrinsic viscosity: unit dl / g

Tensile strength: measured according to ASTM D-412 (unit kg / ㎠)

Elongation at Break: Measured according to ASTM D-412 (Unit%)

Resilience modulus: measured according to ASTM D-1058 (unit%)

Heat resistance: The value of elongation at break measured by the initial elongation after 100 hours heat treatment in an oven at 150 ℃ (unit:%)

Claims (5)

In a polyester block copolymer in which a crystalline polyester unit and a polyether unit of a rubber component are copolymerized in the form of a block, the polybutadiene or butadiene or acrylonitrile is used as a rubber component with respect to 35 to 95% by weight of the crystalline polyester component. A polyester block copolymer having excellent flexibility and impact resistance, wherein 5 to 65% by weight of the copolymer is copolymerized in the form of a block and has a molecular weight of 15,000 to 90,000 having the following structural formulas (I) and (II) as repeating units.

In the above structural formula, R is an ester-forming dicarboxylic acid or lower alkyl esterified product, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, adipic acid, suberic acid, sebacic acid, decandicarboxylic acid, dodecanedi Carboxylic acid, cyclohexanedicarboxylic acid, D denotes ethylene glycol, 1,4-butanediol, 1,2 or 1,3-propanediol, 1,6-hexanediol, 1, 4-cyclohexane dimethanol, B represents a polybutadiene having a carboxyl end or a copolymer of butadiene and acrylonitrile. The polyester block copolymer according to claim 1, wherein the component B is a compound represented by the following general formula (III).

In the above structural formula, a is 1-10, b is an integer of 7-13. In preparing a polyester block copolymer comprising a hard segment and a soft segment by copolymerizing a polyether unit of a rubber component with a crystalline polyester unit, the rubber component and the glycol component constituting the soft segment are 1.5 to 2.0 kg / cm 2. Under the pressurization, the reaction is first carried out at 50 to 200 ° C., and then the acid component constituting the hard segment and various reaction aids are added thereto, followed by reaction of the polyester block having the following general formulas (I) and (II) as repeating units. Process for the preparation of coalescing.

In the above structural formula, R is an ester-forming dicarboxylic acid or lower alkyl esterified product, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, adipic acid, suberic acid sebacic acid, decandicarboxylic acid, dodecanedicarboxylic acid Acid, cyclohexanedicarboxylic acid, D is an ester-forming glycol component, ethylene glycol, 1,4-butanediol, 1,2 or 1,3-propanediol, 1,6-hexanediol 1,4-cycle Heximethanethanol, B represents polybutadiene having a carboxyl end or a copolymer of butadiene and acrylonitrile. The method for producing a polyester block copolymer according to claim 3, wherein as the rubber component constituting the soft segment, polybutadiene or butadiene and acrylonitrile copolymer are used. The method for producing a polyester block copolymer according to claim 4, wherein the polybutadiene or butadiene and acrylonitrile copolymer are used in an amount of 5 to 65% by weight based on 35 to 95% by weight of the crystalline polyester component. .