JPS61162513A - Polyester type block copolymer composition - Google Patents

Abstract

PURPOSE:The titled composition that is obtained by adding an epoxide and a polyfunctional isocyanate to a polyester-type block copolymer, thus being suitable as a material for forming, adhering and coating, because of its good moldability and high water resistance. CONSTITUTION:(i) A crystalline aromatic polyester such as polyethylene terephthalate is allowed to react with (ii) a lactone such as epsilon-lactone so that the content of lactone becomes 3-95wt% in the copolymer. (A) The resultant product is combined with (B) 0.3-10wt% of an epoxy compound of the formula (R1 is methyl) bearing an epoxy group in the molecule and (C) 0.2-15wt% of an isocyanate bearing 2 or more isocyanate groups in the molecule such as diphenylmethane diisocyanate, then, the mixture is melted and mixed to give the objective compound.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a polyester block copolymer composition having rubber-like elasticity. More specifically, the present invention relates to improving the moldability and water resistance of a polyester block copolymer obtained by reacting an aromatic polyester with a lactone.

(Prior Art) Polyester block copolymers, so-called polyester elastomers, obtained by reacting aromatic polyesters with tectonic compounds have recently attracted interest in various uses due to their good heat resistance, light resistance, and low-temperature properties. The material is made of Examples of methods for reacting aromatic polyesters and lactones include a method for reacting crystalline aromatic polyesters and lactones (Japanese Patent Publication No. 48-4116), and a method for reacting crystalline aromatic polyesters and lactones to form a block with initial weight. A method in which a polyfunctional acylating agent is reacted with a polyfunctional acylating agent to effect chain extension (Japanese Patent Publication No. 48-4115), a method in which lactone is polymerized in the presence of a crystalline aromatic polyester while the former is in a solid phase (Japanese Patent Publication No. 48-4115) No. 52-49037) is known. However, the viscosity of the obtained polymer is low, and it hydrolyzes in water (therefore, there are limits to its use as fibers, films, and molding materials. For example, in applications such as injection molding, the viscosity Since the is low, Paris occurs frequently.

As a method for improving the viscosity of polyester ester ester,
There are methods for increasing the degree of polymerization by melt polymerization and in-phase polymerization, but it is difficult to achieve a high degree of polymerization, and even if it is possible to increase the degree of polymerization, it has the disadvantage of poor water resistance. There is. As a result of intensive study on a method for obtaining good viscosity, the present inventors discovered the use of incyanate compounds, and have already proposed the method (Japanese Patent Application No. 111297/1982).
. Although the above polyester type block copolymer composition has the effect of improving viscosity and water resistance, it is difficult to improve both properties as desired, and the effect of improving water resistance is particularly small.

In addition, the method of adding polycarbodiimide etc. as a hydrolysis-resistant stabilizer for polyester has been known for a long time, but although it has an effect on hydrolysis resistance, it is expensive.
It has drawbacks such as discoloration when heated for a long time.

As a result of intensive study on a method for obtaining good hydrolysis resistance, the present inventors discovered the use of an epoxy compound and have already proposed the use of epoxy compounds.

Although the polyester type block copolymer composition described above has the effect of improving water resistance, it is difficult to improve the viscosity property as desired. That is, when an l-functional epoxy compound is used, there is no effect of improving viscosity. Furthermore, when an epoxy compound having two or more functionalities is used, the effect of improving the viscosity is recognized, but the viscosity increases due to retention in the molding machine, resulting in short shots and poor gloss of the molded product.

(Problems to be Solved by the Invention) It has been difficult to desirably improve both the viscosity and water resistance of polyester block copolymers. The object of the present invention is to obtain a polyester block copolymer having good moldability and hydrolyzability.

(Means for Solving the Problems) That is, the present invention adds 0.3% by weight of an epoxy compound having an l-functionality or higher to a polyester block copolymer obtained by reacting a crystalline aromatic polyester with a lactone.
This is a polyester-type block copolymer composition characterized in that it contains ~10 tt% and 0.2 qb to 15 wt% of a bifunctional or higher incyanate compound.

In the present invention, a polyester elastic body having excellent moldability and water resistance can be obtained. In addition, although it has heat resistance and light resistance equivalent to polyester Pro 7 copolymer, it has high military resistance and crystallization temperature, and has a high melt viscosity, making it suitable for injection molding. It can also be easily used for extrusion molding, greatly expanding the applications of polyester block copolymers.

The polyester block copolymer in the present invention consists of a crystalline aromatic polyester segment and a poly2 ctone segment, and is obtained, for example, by reaction of a crystalline aromatic polyester and lactones.

Crystalline aromatic polyester is a polymer that mainly contains ester bonds or ester bonds and ether bonds, has at least one type of aromatic group as the main repeating unit, and has a hydroxyl group at the end of the molecule, and is used as a molding material. preferably has a molecular weight of 5,000 or more. Note that the adhesive and coating material may be polyester having a molecular weight of 5000 or less.

Preferred specific examples include polyethylene tere 7 tallate, polytetramethylene terephthalate, poly 1.4-7
Homopolyesters such as chlorhexylene dimethylene tere-7thaleate and polyethylene 2,6-naphthalate; polyester ethers such as polyethyleneoxybenzoate and poly-p-phenylene bisoxyethoxy terephthalate, mainly consisting of tetramethylene terephthalate units or ethylene terephthalate units; , and other copolymerized components such as tetramethylene or ethylene isoheptalate units, tetramethylene or ethylene adipate units, tetramethylene or ethylene/sepacate units, 1,4-cyclohexine dimethylene terephthalate units, tetramethylene or ethylene-p-oxybenzoate units, etc. Copolymerized polyester or copolymerized polyester ether, etc.

In the case of a copolymer, it is preferable that the content of tetramethylene or ethylene terephthalate is 60 mol% or more.

As the lactone, ε-caprolactone is most preferable, and enantolactone, cabrylolactone, etc. can also be used, but two or more types of lactones can also be used at the same time.

1 of the methods for obtaining the polyester elastomer used in the present invention
For example, when reacting crystalline polyester with lactones, the present invention may be reacted without a catalyst or with a catalyst. In the polyester block copolymer, the lactone content is 3 to 95% by weight,
Preferably it is 20 to 80% by weight.

The structure of the epoxy compound used in the present invention is not particularly limited as long as it has one or more epoxy groups in the same molecule. Specifically, the following general formula (I)
Examples include compounds represented by .

(In the formula, R1 is an alkyl group with or without a side chain such as methyl, ethyl, propyl, butyl, etc., A') "Ih
, an aromatic group such as a phenyl group or a naphthalene group, or a derivative having a substituent group, an alicyclic group such as a 7-chlorohexyl group, or a [
A derivative having a substituent, R2 is an alkylene group with or without a side chain, an alicyclic group with or without a substituent, an aromatic group, represented by the general formula 1 R'0)nR'- Polyether group (R/ has a fullylene group or phenylene group having 2 to 6 carbon atoms, and n represents an integer of 1 to 20.) When melt-mixing an epoxy compound and a polyester type Pro7 copolymer Although the reaction between the polyester type block copolymer and the epoxy group is effective even without a catalyst, it is significantly accelerated when a catalyst is used. As the catalyst, any catalyst generally used for warping epoxies can be used. Catalysts are generally amines, phosphorus compounds, and carbon atoms. Particularly preferred are trivalent phosphorus compounds such as tributylphosphine and triphenylphosphine. When using these catalysts, they may be used in combination with Catalysts 28 or higher. The effects of the above epoxy compound and catalyst remain the same whether they are added all at once or in parts.

The amount of the epoxy compound used varies depending on the amount of terminal groups of the polyester block copolymer required, but it is usually 0.2% to 1% by weight based on the polyester block copolymer.
It is 0 times. Particularly preferred is 0.5% to 4% by weight. If it is less than 0.2% by weight, the effect will be small, and if it exceeds 10% by weight, the narrow surface of the molded product will become rough due to the influence of unreacted epoxy compounds, which is not preferable.

The structure of the isocyanate compound used in the present invention is not limited to % as long as it has two or more incyanate groups in the same molecule.

Examples of diincyanate compounds include diphenylmethane diisocyanate, 2,4- or 2,6-tolylene diisocyanate, 1,5-naphthalene diisocyanate, tolydine diisocyanate), 1)-phenylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, etc. Examples include isocyanate, inphorone diisocyanate, bis(isocyanatomethyl)cyclohexane, dicyclohexylmethane diinocyanate, lysine diisocyanate, and trimethylhexamethylene diisocyanate. Examples of trifunctional or higher functional polyisocyanates include triphenylmethane triisocyanate and tri(incyanate phenyl)thiophosphate.

Further examples of the polyisocyanate having two or more functions are shown below.

Polymeric (diphenylmethane diisocyanate):
Urethane modified product made by reacting polyhydric alcohol and monomeric isocyanate: A(○C!0NH-R-IC!O)n Allophanate modified product: 0ON-R-N-00-A-QC! 0-NH-R-N(
! 0Co-NH-R-NCO biraleft modified product: 0ON-R-NC! 0-Nl'1-R-NCO■ Co-NH-R-NC0 dimer: ! Trimer: 鵞-NOO Carbodiimide modified product: 0CN-R-N=O=N-R-NC0 0=(!-N-R-NOO (In the above formula, n#'i is an integer greater than or equal to 1, A is a (R represents a diisocyanate residue.) In the present invention, a monoinocyanate compound may be used in combination with polyin 7anate.

The amount of incyanate compound to be used varies depending on the amount of terminal groups of the polyester type block copolymer required, but is usually 0.2% to 15% by weight based on the polyester type block copolymer. Particularly preferably from 0.5% by weight
It is 10% by weight. If it is less than 0.2% by weight, the thickening effect will be small, and if it exceeds 15% by weight, the surface condition of the molded product will become rough due to the influence of unreacted incyanate compounds, which is not preferable.

The mixing method is to mix polyester block copolymer chips with EBOKI 7 compound catalyst, etc., heat and melt mix after death, mix with incyanate compound, then heat and melt mix, etc., which can be uniformly melt-mixed. There are no particular restrictions on the method.

The melting and mixing temperature is preferably 3°C higher than the crystalline melting point of the elastic body to 280'C1. Mixing time is 30 seconds to 12
It takes about 0 minutes, and is determined by the mixing method and temperature.

The composition of the present invention may contain crystalline polyesters such as polyethylene tere-7-talate and polytetramethyleneterephthalate.

Moreover, even if pigments, various stabilizers, and additives are added at the same time during mixing, the effects on water resistance and moldability of the present invention will not change.

(Effects of the Invention) According to the present invention, a polyester elastic body having excellent water resistance and moldability can be obtained.

(Example) The present invention will be described in detail below with reference to Examples, but the present invention is not limited thereto. In the examples, the reduced specific viscosity and tensile strength were measured according to the following procedure.

(1) Reduced specific viscosity Measured under the following conditions Solvent = Phenol/Tel! i Weight ratio 6/4 concentration:
50 rin F/25111 Temperature: 30°C (2) Tensile strength/elongation The chip was formed into a 2+W4 flat plate using a heat press, a dumbbell-shaped No. 3 test piece was punched out, it was stretched at a speed of 50 fins per minute, and it broke. The value obtained by dividing the load at the time of rupture) by the initial cross-sectional area (-) is taken as the strength (seismic P/-), and the ratio of the elongation of the sample until it breaks to the original sample length is taken as the elongation.

Production Example 1 Polybutylene terephthalate 70 EF, ε-caprolactone 30 (into the reaction vessel), after purging 23
After carrying out a melt reaction for 2 hours while stirring at 0°C, unreacted ε-caprolactone was removed under vacuum.

The obtained polyester block copolymer had a reduced specific viscosity of 1.160. The tensile strength at break was 315 cm/-1 and the tensile elongation at break was 743 cm.Reference Example 1 The polyester block copolymer chips obtained in Production Example 1 with a mark of 2.0 and phenyl glycidyl ether 2. o
P I R triphenylphosphine o, IPlim
was placed in a drum tumbler and stirred at room temperature for 30 minutes. The mixture was extruded at 230° C. using a 400 mm twin screw extruder, cooled with water, and then cut into pieces.

The resulting chip had a reduced specific viscosity of 1.042, a tensile strength at break of axz/cd, and a tensile elongation at break of 680 chi.

Reference Example 2 Polyester block copolymer 2 obtained in Production Example 1
．． 0 and diethylene glycol diglycidi 1m ether 1.5,) IJ phenylphosphin 0
．． Place in a 1Plin drum tumbler, stir and mix.
The same treatment as in Reference Example 1 was carried out.

The resulting chip had a reduced specific viscosity of 1.526, a tensile strength at break of 3904/cJ, and a tensile elongation at break of 485 m.

Reference Example 3 The nine polyester type block co-ilf body z and orll diphenylmethane diisocyanate obtained in Production Example 1 was prepared in 1.
Place 0PIIIt in a drum tumbler and heat at room temperature for 3
Stirred for 0 minutes. The mixture was extruded at 230° C. using a 4Qff/twin-screw extruder, cooled with water, and then cut into chips.

The resulting chip had a reduced specific viscosity of 1.317, a tensile strength at break of 34 a4/al, and an elongation of 605 chi.

Example 1 The polyester type block copolymer composition 2.0- and diphenylmethane diincyanate obtained in Reference Example 1 and Reference Example 2 were mixed in a predetermined amount (0,5PI'''1.QpHll).
) After mixing for 30 minutes at room temperature in a drum tumbler,
The same treatment as in Reference Example 3 was carried out using a shaft press ratio machine.

The reduced specific viscosity and tensile strength and elongation at break of the obtained chips (NO5 to N07) were measured. Furthermore, the results of MI measurement at 230°C are shown in Table 1.

As is clear from Table 1, both the melt viscosity (MI) and the reduced specific viscosity are significantly improved by the combined use of an epoxy compound and an isocyanate compound.

Example 2 The chips obtained in Production Example 1, Reference Examples 1 to 3, and Example 1 were held in a molten state at 230°C for 30 minutes to examine the stability of melt viscosity. However, it is difficult to simultaneously improve melt viscosity and stability. The results are shown in Table 2.

Table 2 Changes in MI and holding time at 230°C Example 3 Production Example 11 Reference Examples 1 to 3 The chips obtained in Example 1 were dried under reduced pressure at 100°C, and then formed into a 2 m sheet using a host press. , molded into a No. 3 dumbbell. The dumbbell was kept in warm water at 100°C and its water resistance was measured. The results are shown in Table 3.

Table 3 Water resistance 100℃ x 5 days

Claims (1)

[Claims] A polyester type block copolymer obtained by reacting a crystalline aromatic polyester and a lactone is mixed with 0.3% by weight or more of one or more monofunctional or more functional epoxy compounds.
A polyester type block copolymer composition characterized in that it contains 10% by weight and 0.2% to 15% by weight of one or more difunctional or more functional isocyanate compounds.