JP2534271B2 - Polycarbonate polyamide copolymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a polycarbonate-polyamide copolymer having excellent hydrolysis resistance, low-temperature flexibility, heat aging resistance and mechanical properties as well as excellent transparency. The present invention relates to a polymer (hereinafter sometimes simply referred to as polyamide).

[Prior art]

Polyester polyamide copolymer by the reaction of organic diisocyanate and dicarboxylic acid and a method for producing the same, for example, U.S. Pat.Nos. 4,087,481, 4,129,715 and 4,
As already described in 156,065, etc.,
It is well known that the copolymer has good flexibility, elastic properties, mechanical properties, oil resistance, chemical resistance, and heat resistance.

[Problems to be solved by the invention]

However, the above-mentioned polyester-polyamide copolymer is inferior in hydrolysis resistance. Therefore, when the polyester-polyamide copolymer is formed into a film, its surface becomes tacky or cracks in a relatively short period of time. Therefore, the polyester-polyamide copolymer is considerably limited in use. This type of polyester-polyamide copolymer has some ester groups,
There is a limit to improving the hydrolysis resistance. On the other hand, when polyether is used instead of polyester, the hydrolysis resistance is improved, but the oxidation deterioration resistance is extremely poor.

Further, the above polyester-polyamide copolymer has problems in heat aging resistance and transparency.

The object of the present invention is a polyamide copolymer having excellent heat resistance, mechanical properties and low-temperature flexibility equivalent to those of conventional polyester-polyamide copolymers, and further having improved transparency, hydrolysis resistance and heat aging resistance. It is to provide a coalesce.

[Means for solving problems]

The present inventors have conducted extensive studies to achieve the above-mentioned object, and as a result, by using a polyamide copolymer having a polycarbonate skeleton as a soft segment, hydrolysis resistance and heat aging resistance are started, and surprisingly. It was found that a polyamide copolymer excellent in transparency can be obtained, and further, a polyamide copolymer excellent in low-temperature flexibility can be obtained by partially introducing a branched structure into the polycarbonate skeleton of the soft segment. The present invention has been completed.

That is, the present invention provides the following general formulas [I] and [II]
A polycarbonate-polyamide copolymer comprising the repeating unit represented by the formula (II), containing 10 mol% or more of the repeating unit [II] and having a number average molecular weight of 5,000 to 250,000.

Here, A is at least one or more of a molecular weight of 300 to 8,000. Is a divalent group obtained by removing both end carboxyl groups from a carbonate-based polymeric dicarboxylic acid having
R ₁ , R ′ ₁ , R ₂ and R ₃ are each the same or different hydrocarbon residue, and R ₃ includes a branched aliphatic hydrocarbon residue.

In the present invention, the polyamide comprising the repeating units represented by the general formulas [I] and [II] is obtained, for example, from an organic diisocyanate component and a specific dicarboxylic acid component by a known production method, It is not limited to this. The production method can be carried out in the presence or absence of an inert organic solvent and in the presence or absence of a catalyst, in which case the equivalent ratio of isocyanate to carboxyl group (NCO / COOH) is , 0.97 or more and 1.03 or less, and more preferably 0.98 or more and 1.02 or less.

If the equivalent ratio is less than 0.97, the degree of polymerization does not increase and good mechanical properties cannot be obtained. If it exceeds 1.03, gelation occurs and the polymerization itself becomes difficult.

R ₁ and R _'1 in the polycarbonate polyamide copolymer comprising repeating units represented by the general formula [I] and [II] of the present invention respectively represent the same or different hydrocarbon residues. The source of the compound that gives such a hydrocarbon residue is not particularly limited, but examples thereof include organic diisocyanate. As typical organic diisocyanates, 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, phenylenediisocyanate,
1,5-naphthylene diisocyanate, 3,3'-dichloro-
4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate, and other aromatic diisocyanates having 6 to 20 carbon atoms, hexamethylene diisocyanate, isophorone diisocyanate, 4, Examples thereof include aliphatic or alicyclic diisocyanates having 8 to 20 carbon atoms such as 4'-dicyclohexylmethane diisocyanate.

From the viewpoints of mechanical properties and heat resistance, R ₁ and R ′ ₁ are preferably aromatic hydrocarbon residues, and particularly preferably aromatic hydrocarbon residues represented by the following formula.

Further, R ₁ and R ′ ₁ are not limited to one kind of hydrocarbon residue, and may contain two or more kinds of hydrocarbon residue.

In the general formula [I], R ₂ represents a hydrocarbon residue. The source of the compound giving R ₂ is not particularly limited,
Typical examples thereof include dicarboxylic acids, and specific examples thereof include glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decanedioic acid, dodecanedioic acid and dimer acid having 4 to 4 carbon atoms. 54 aliphatic dicarboxylic acids and aromatic dicarboxylic acids having 8 to 20 carbon atoms such as isophthalic acid, terephthalic acid, phthalic acid and naphthalenedicarboxylic acid. From the standpoint of moldability, R ₂ is preferably an aliphatic hydrocarbon residue rather than an aromatic hydrocarbon residue.

R ₂ is not limited to one kind of hydrocarbon residue and may contain two or more kinds of hydrocarbon residue.

It is essential that the polycarbonate-polyamide copolymer of the present invention contains 10 mol% or more of the repeating unit represented by the general formula [II], and preferably 20 mol% or more. If it is less than 10 mol%, the object of the present invention cannot be sufficiently achieved. The upper limit of the content of [II] is not particularly limited, but preferably
It is 60 mol% or less, more preferably 50 mol% or less. [II] in the polycarbonate-polyamide copolymer of the present invention
As the content increases, the flexibility and molding processability improve, but the heat resistance decreases. In the formula [II], A is at least one or more of a molecular weight of 300 to 8,000. It is a divalent group obtained by removing the carboxyl groups at both ends from a carbonate-based polymeric dicarboxylic acid having the unit:

Here, l is an integer of 0 to 100, m is an integer of 0 to 100,
n is an integer of 0 to 100, R ₃ , R ₄ and R ₅ are the same or different hydrocarbon residues (provided that at least a part of R ₃ is a branched aliphatic hydrocarbon residue). When m is 1 or more, l does not become 0 at the same time as n, and when m is 2 or more, l never becomes 0.

In the above formula [III], R ₃ is a hydrocarbon residue of the diol in the polycarbonate, and it is necessary that at least a part thereof contains an aliphatic hydrocarbon residue having a branch. The diol used in the present invention is not particularly limited and is usually used in the production of polycarbonate and polyester. For example, ethylene glycol, 1,
4-butanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 2,2-diethyl-1,3-propanediol , 2-ethyl-1,3-hexanediol, 1,1-dimethylolheptane, 1,9-nonanediol, 2-methyl-1,8-octanediol, 1,10-
Examples thereof include aliphatic diols having 2 to 16 carbon atoms such as decanediol, and these can be used as a mixture of two or more kinds.

However, 1,4-butanediol, 1,6-hexanediol, 1,9 as the diol component of polycarbonate
-When a linear diol such as nonanediol is used, the polycarbonate itself has a high freezing point, so that it has a drawback of being poor in low-temperature flexibility.

In the present invention, it is necessary that at least a part of the diol component is a branched aliphatic diol in order to improve low temperature flexibility, and as the diol component, 3-methyl-1,5-pentanediol, 2 -Methyl-1,3-propanediol, 2-methyl-1,8-octanediol,
A branched aliphatic diol having 2 to 16 carbon atoms such as 2,2-diethyl-1,3-propanediol and 1,1-dimethylolheptane is converted to 1,9-nonanediol and 1,6-hexanediol. It is preferably used together with a linear aliphatic diol having 2 to 16 carbon atoms, and more preferably 2-methyl-1,8-
Octanediol and 1,9-nonanediol in a molar ratio of 5/95
It is to be used at a ratio of ~ 80/20.

The carbonate-based polymeric dicarboxylic acid used in the present invention has a carboxyl group at both ends, and the method for producing the carbonate-based polymeric dicarboxylic acid is not particularly limited, and a known method can be applied. For example,
First, there is a method of producing a polycarbonate diol and then converting the terminal into a carboxyl group.

The method for producing the polycarbonate diol is not particularly limited, and a known method can be applied. For example, it can be produced by reacting a glycol and a carbonate compound in an inert gas under heating and reduced pressure. Frequently used carbonate compounds are diphenyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate and the like.

As the polycondensation catalyst used in the production of the polycarbonate, a wide range of catalysts can be used, but titanium compounds such as tetramethoxy titanium, tetraethoxy titanium, tetra-n-propoxy titanium, tetraisopropoxy titanium, tetrabutoxy titanium, etc. Examples include a combination of a tin compound such as -n-butyltin oxide, di-n-butyltin dilaurate and dibutyltin diacetate, an acetate salt such as magnesium, calcium and zinc and antimony oxide or the above titanium compound. These catalysts are preferably used in the range of 5 ppm to 1,000 ppm based on the total polycarbonate produced.

As another production method, a method of reacting a diol with phosgene or a chloroformate is also known.

The method of using a carboxyl group at the terminal of the polycarbonate diol is not particularly limited, and a known method can be applied. For example, a terminal hydroxyl group polycarbonate can be converted into a terminal carboxyl group by heating and reacting it with an acid anhydride such as succinic anhydride or phthalic anhydride. In another method, the terminal hydroxyl group polycarbonate can be converted into the terminal carboxyl group by heating and dehydrating the organic dicarboxylic acid.

In the general formula [III], R ₄ is a hydrocarbon residue. Specifically, R ₄ is an aliphatic hydrocarbon residue having 2 to 16 carbon atoms and / or an aromatic hydrocarbon residue having 6 to 16 carbon atoms. preferable. Examples of the compound source that provides these residues include succinic anhydride, phthalic anhydride, and dicarboxylic acids such as adipic acid and azelaic acid.

In the general formula [III], R ₅ is derived from an organic dicarboxylic acid, and the organic dicarboxylic acid is not particularly limited and examples thereof include an aliphatic dicarboxylic acid and an aromatic dicarboxylic acid. Examples of the aliphatic dicarboxylic acid include dicarboxylic acids having 4 to 54 carbon atoms such as glutaric acid, adipic acid, azelaic acid, pimelic acid, sebacic acid, decanedioic acid and dodecanedioic acid. Examples of the aromatic dicarboxylic acid include dicarboxylic acids having 8 to 20 carbon atoms such as isophthalic acid, terephthalic acid, phthalic acid and naphthalenedicarboxylic acid. Preferred examples include aliphatic dicarboxylic acids, particularly C4-12 aliphatic dicarboxylic acids. These carboxylic acids can be used alone or in combination.

Although a polycarbonate having a desired molecular weight can be produced by such a production method, its molecular weight is 300 to 8,000.
Is preferable, and more preferably 500 to 5,000. If the molecular weight is less than 300, the molding processability will decrease, and if it exceeds 8,000, the transparency and mechanical performance will decrease. In particular, since the copolymer of the present invention is preferably an elastomer, the molecular weight of the polycarbonate as the soft segment is most preferably about 800 to 5,000 from this point of view.

The number average molecular weight of the polycarbonate polyamide copolymer of the present invention is 5,000 to 250,000, preferably 5,000 to 1
It is 50,000, more preferably 20,000 to 150,000. When the molecular weight is less than 5,000, strength properties, flex resistance and abrasion resistance are poor, and when it exceeds 250,000, moldability is deteriorated.

Since the polycarbonate-polyamide copolymer of the present invention has excellent moldability and heat resistance, it is easily molded by a commonly used injection molding machine, extrusion molding machine, plow molding machine, etc., and has excellent hydrolysis resistance and transparency. It is used for sheets, films, tubes, hoses, rolls, gears, packing materials, anti-vibration materials, belts, laminated products, automobile parts, sporting goods, etc. by taking advantage of its properties, mechanical properties and heat aging resistance.

Hereinafter, the present invention will be specifically described with reference to examples. In the examples, the tensile strength was measured by hot pressing at 270 ° C. and punching a film having a thickness of 100 μm with a dumbbell. The hydrolysis resistance was evaluated by the DiYoungle test. The DiYoungle test is performed at 70 ° C and 95% relative humidity for 10
A film having a thickness of 0 μm was left standing for 56 days, and the film was evaluated by the tensile strength retention rate before and after the DiYoungle test. For heat aging resistance, a film with a thickness of 100 μm is placed in a gear oven 1
The tensile strength after holding at 50 ° C. for 5 days was measured and evaluated by the holding ratio.

For low-temperature flexibility, a test piece was made from a 0.2 mm-thick copolymer film of the present invention, and a direct-reading dynamic viscoelasticity measuring instrument Vibron Model DDV- manufactured by Toyo Baldwin Co., Ltd.
It was evaluated by measuring Tα (° C.) according to II (110 HZ).

Regarding the transparency, the polyamide sheet of the present invention having a thickness of 10 mm was placed on the character, and the character was clearly readable, ◯, the poor clarity was Δ, and the fairly difficult character was x.

〔Example〕

Synthesis Example 1 1,6-hexanediol 1534 g (13 mol) under nitrogen stream
And a mixture of 2,568 g (12 mol) of diphenyl carbonate was heated, and the phenol was distilled off from the reaction system at 190 ° C. Raise the temperature gradually to 210 ℃ -220 ℃, distill off most of the phenol, and then evacuate it under reduced pressure of 6-10mmHg.
The remaining phenol was completely distilled off at 210 ° C to 220 ° C. As a result, a polycarbonate diol having a hydroxyl value of 62 KOHmg / g was obtained. 1800 g of this polycarbonate diol and 210 g of succinic anhydride were placed in a flask and heated to 100 ° C. with stirring to complete the reaction after 4 hours. The reaction mixture was purified by molecular distillation to obtain polycarbonate A having carboxyl groups at both ends. The acid value was 56 KOHmg / g, and the average molecular weight determined from them was 2,000.

Synthesis Example 2-7 Polycarbonates (BG) having carboxyl groups at both ends having the compositions shown in Table 1 were synthesized in the same manner as in Synthesis Example 1.

Synthesis Example 8 A mixture of 1,770-hexanediol (1,770 g, 15 mol) and diphenyl carbonate (2,140 g, 10 mol) was heated under a nitrogen stream, and the phenol was distilled off from the reaction system at 190 ° C. The temperature was gradually raised to 210 to 220 ° C, most of the phenol was distilled off, and then vacuum was applied to completely distill off the remaining phenol at 210 to 220 ° C under a reduced pressure of 6 to 10 mHg.
As a result, a polycarbonate having a hydroxyl value of 276 KOHmg / g was obtained. 2,030 g of this polycarbonate diol and adipic acid
2,190 g and tetraisopropoxy titanate as catalyst
0.5g is heated under nitrogen flow and reacted at 200 ℃ for 5 hours,
Finally, the reaction was terminated under a reduced pressure of 1 mmHg to obtain a polycarbonate H having carboxyl groups at both ends. Acid value is 95.9KOHm
It was g / g, and the average molecular weight determined from these was 1,170.

Synthesis Example 9 Polycarbonate I having carboxyl groups at both ends having the composition shown in Table 1 was obtained in substantially the same manner as in Synthesis Example 8.

Comparative Synthesis Example-1 1,870 g (1 mol) of polyester diol having a molecular weight of 1,870 (glycol: neopentyl glycol, dicarboxylic acid: adipic acid-azelaic acid (5/95)) in a reactor,
Azelaic acid 338.4g (1.8mol) Adipic acid 29.2g (0.2mol)
Mol) and 2.0 l of xylene were charged and heated to reflux. At this time, water distilled continuously. When no water was distilled off, the pressure was reduced to distill off xylene, and then the reaction was terminated by applying a vacuum. As a result, the OH number is 0.1 KOHmg / g and the acid number is
51.0 KOHmg / g of both end carboxyl group polyester J was obtained.

Comparative Synthesis Example-2 The same procedure as in Comparative Synthesis Example 1 was carried out to obtain polyesters K having carboxyl groups at both ends shown in Table 1.

Comparative Example 1 A beaker was charged with 0.2 mol (200 g) of the carboxyl group-containing polycarbonate prepared in Synthesis Example 1 and 0.3 mol (56.4 g) of azelaic acid, heated to 120 ° C. to melt, and dehydrated under reduced pressure for 30 minutes. Further, 125 g (0.5 mol) of molten 4,4'-diphenylmethane diisocyanate was added at once, and the mixture was vigorously stirred for about 10 minutes.

The prepolymer was placed in a plastograph (manufactured by Brabender) kept at 260 ° C. to accelerate the polymerization, kneaded for 10 minutes, and then taken out to obtain a light yellow transparent rubber-like substance (L). The intrinsic viscosity of this substance was 0.95 dl / g in 30 ° C. N-methyl-2-pyrrolidone. The number average molecular weight in terms of styrene was 80,600. The infrared absorption spectrum of this product was 1650 cm ^-1 1530 cm ^-1 with an absorption derived from an amide group,
Shows the absorption derived from polycarbonate 760 cm ^-1 1250 cm ^-1, the hydrogen of the amide group by ¹ H nuclear magnetic resonance spectrum
9.7 ppm, hydrogen of methylene group adjacent to carbonate is 4.
A resonance peak was shown at 0 ppm, and it was found that the obtained rubber-like substance was a polycarbonate-polyamide copolymer.
The results of various performance evaluations are shown in Table 2. The polycarbonate-polyamide copolymer showed good results in all of mechanical properties, heat aging resistance, hydrolysis resistance, and transparency, but it was insufficient in low-temperature flexibility.

Examples 1 to 6 and Comparative Examples 2 to 7 Copolymers M to X were obtained with the compositions shown in Table 2 in the same manner or in accordance with Comparative Example 1. The number average molecular weight (Pst conversion) of the obtained copolymer was 60,000 to 90,000. The results of various performance evaluations are shown in Table 2.

With regard to the copolymers obtained in Examples 1 to 6, good results were obtained in all of mechanical performance, heat aging resistance, hydrolysis resistance, transparency and low temperature flexibility. On the other hand, when polyester is basically used as the soft segment instead of polycarbonate (Comparative Examples 6 to 7), a system using polycarbonate in all of hydrolysis resistance, mechanical performance, heat aging resistance, and transparency. Poorer results were obtained.

Example 7 Carboxyl group-containing polycarbonate (C) at both ends was added to 0.1
A polycarbonate-polyamide copolymer (Y) having a molecular weight of 80,000 was obtained in the same manner as in Comparative Example 1 except that the amount of mols (120 g) and azelaic acid were 0.4 mols (75.2 g). As a result, the copolymer had excellent tensile strength, heat aging resistance, hydrolysis resistance, transparency and low temperature flexibility as shown in Table 2.

Example 8 0.4% of both end carboxyl group polycarbonate (C)
A polycarbonate-polyamide copolymer (Z) having a molecular weight of 85,000 was obtained in the same manner as in Comparative Example 1 except that the moles (480 g) and the azelaic acid were 0.1 moles (18.8 g). As a result, the copolymer had excellent tensile strength, heat aging resistance, hydrolysis resistance, transparency and low temperature flexibility as shown in Table 2.

ADVANTAGES OF THE INVENTION According to the present invention, hydrolysis resistance, transparency, heat aging resistance, mechanical properties and low temperature flexibility, which cannot be achieved with conventionally known polyamide copolymers, are simultaneously highly satisfied. It becomes possible to obtain a polycarbonate-polyamide copolymer.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP 62-256820 (JP, A) JP 59-80423 (JP, A)

Claims (14)

(57) [Claims] 1. A polycarbonate-polyamide copolymer comprising repeating units represented by the following general formulas [I] and [II], containing 10 mol% or more of repeating units of [II] and having a number average molecular weight of 5,000 to 250,000. A polycarbonate-polyamide copolymer characterized by the following. Here, A is at least one or more of a molecular weight of 300 to 8,000. Is a divalent group obtained by removing both end carboxyl groups from a carbonate-based polymeric dicarboxylic acid having
R ₁ , R ′ ₁ , R ₂ and R ₃ are each the same or different hydrocarbon residue, and R ₃ includes a branched aliphatic hydrocarbon residue. 2. A polycarbonate-polyamide copolymer according to claim 1, wherein A is a divalent group represented by the following general formula [III]. Here, l is an integer of 0 to 100, m is an integer of 0 to 100, n
Is an integer of 0 to 100, R ₃ , R ₄ and R ₅ are the same or different hydrocarbon residues, and R ₃ includes a branched aliphatic hydrocarbon residue, and m is 1 or more. At the same time, l and n never become 0 at the same time, and l does not become 0 when m is 2 or more. Wherein R ₁ and / or R _'1 is the first term claims is an aromatic hydrocarbon residue or polycarbonate polyamide copolymer of the second Claims. 4. The polycarbonate / polyamide copolymer according to claim 3, wherein R ₁ and / or R ′ ₁ is at least one aromatic hydrocarbon residue selected from the group represented by the following formula. . 5. The polycarbonate / polyamide copolymer according to claim 4, wherein R ₁ and / or R ′ ₁ is an aromatic hydrocarbon residue represented by the following formula. 6. The polycarbonate-polyamide copolymer according to claim 4, wherein R ₁ and / or R ′ ₁ is an aromatic hydrocarbon residue represented by the following formula. 7. The polycarbonate-polyamide copolymer according to any one of claims 1 to 6, wherein R ₂ is an aliphatic hydrocarbon residue having 4 to 12 carbon atoms. 8. The polycarbonate-polyamide copolymer according to claim 7, wherein R ₂ is a hydrocarbon residue of a dicarboxylic acid selected from the group consisting of adipic acid, azelaic acid and sebacic acid. 9. The method according to any one of claims 2 to 8, wherein R ₄ is an aliphatic hydrocarbon residue having 2 to 16 carbon atoms and / or an aromatic hydrocarbon residue having 6 to 16 carbon atoms. The polycarbonate-polyamide copolymer according to the item 1. 10. The compound according to claim 1, wherein R ₃ is an aliphatic hydrocarbon residue having 2 to 16 carbon atoms including a branched aliphatic hydrocarbon residue having 2 to 16 carbon atoms. The polycarbonate-polyamide copolymer according to any one of items 1. 11. The polycarbonate polyamide according to claim 10, wherein the branched aliphatic hydrocarbon residue having 2 to 16 carbon atoms is at least one residue selected from the group represented by the following formula. Copolymer. 12. R ₃ is a hydrocarbon residue represented by the following formulas [IV] and [V], and the molar ratio of [IV] and [V] ([IV]
The polycarbonate polyamide copolymer according to claim 10, wherein / [V]) is 5/95 to 80/20. CH _{2 9} [V] 13. The repeating unit of [II] is 10 mol% or more and 60
The polycarbonate-polyamide copolymer according to any one of claims 1 to 12, which is contained in a proportion of not more than mol%. 14. The polycarbonate-polyamide copolymer according to any one of claims 1 to 13 having a number average molecular weight of 5,000 to 150,000.