JP3067861B2 - Polyester-grafted polyamide and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel polymer and a method for producing the same. More particularly, the present invention relates to a polyester-grafted polyamide which can be used as a modifier or compatibilizer for polyamide, thermoplastic polyester and the like in addition to being used as a thermoplastic material, and a method for producing the same.

[0002]

BACKGROUND OF THE INVENTION Polyamides have excellent strength, toughness, wear resistance and heat resistance.
Widely used as fibers, molding materials and the like. However, polyamide has drawbacks such as dimensional change due to water absorption, deterioration of mechanical properties, and the like.In addition, in the case of a polyamide resin having crystallinity, shrinkage during cooling after melt molding is large, and the dimensional accuracy of the molded product is low. It also had drawbacks that led to misalignment and warpage. For this reason, although the polyamide resin is an excellent resin, the marketability as a molding material by itself may be limited.

In order to make up for the disadvantages of such polyamides,
It has been practiced to mix other thermoplastic resins, such as thermoplastic polyesters. However, simply mixing a thermoplastic polyester with these known polyamides has poor compatibility, so that phase separation has proceeded and only a very brittle mixed composition having mechanical properties has been obtained. For this reason, blocking and grafting by the reaction of a polyamide and a thermoplastic polyester have been studied. For example, in JP-A-51-103191, solid-state polymerization is performed after melt-kneading polyamide and polybutylene terephthalate. However, this solid phase polymerization takes a long time,
Furthermore, the terminal condensation reaction occurs only partially. Further, the particle size of the dispersed phase in the melt-blended chip is as large as about 10 μm, which is not preferable.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have established a method for grafting a polyester onto a polyamide, and a method for producing a polyester-grafted polyamide using a polyester as a graft chain. , And a novel polyester-grafted polyamide obtained by this method, and completed the present invention. That is, the present invention provides a method for preparing a polymer having the following general formula (I) in the presence of a polyamide having a hydroxyl group in the molecule

[0005]

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A process for producing a polyester-grafted polyamide, comprising polymerizing a cyclic ester compound represented by the formula (wherein R represents an aliphatic hydrocarbon residue having 3 to 11 carbon atoms) by a ring-opening addition reaction. To provide
Further, the present invention provides the following general formula (II):

[0007]

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Wherein R ¹ is an alkylene group having 4 to 14 carbon atoms, R ² is an alkylene group having 2 to 4 carbon atoms, and p is 1 to 10
00 and q each represent a number of 1 to 10, and r represents a number of 1 to 50. ) Is obtained by polymerizing a cyclic ester compound represented by the general formula (I) by a ring-opening addition reaction in the presence of a polyamide having a hydroxyl group in the molecule represented by the following formula:
3,3,3-hexafluoro-2-propanol (hereinafter HFIP
And a polyester-grafted polyamide characterized by having a number average molecular weight in terms of standard polymethyl methacrylate measured by GPC using 10,000 to 500,000.

The polyamide used in the present invention can be obtained by ring-opening polymerization of lactam, condensation polymerization of diamine and dicarboxylic acid, condensation polymerization of aminocarboxylic acid, and the like. Nylon 6, nylon 66, nylon 610, nylon 612, nylon 11, nylon 12, and the like. Further, in this polyamide, a copolymer composed of two or more kinds of diamines and dicarboxylic acids, a copolymer composed of two or more kinds of lactams, a copolymer composed of two or more kinds of aminocarboxylic acids,
Alternatively, a copolymer polyamide comprising a diamine and a dicarboxylic acid, a lactam, or an aminocarboxylic acid is included. The polyamide also includes a multi-block copolymer composed of a polyamide and a polyether segment, which is called polyetheramide or polyetheresteramide. In the present invention, any method may be used as a method for introducing a hydroxyl group into a polyamide molecule. For example, polyamide in the presence of an alkaline compound,
In addition to a method of obtaining a β-hydroxyalkylated polyamide by reacting with an alkylene oxide having 2 to 4 carbon atoms, ring-opening polymerization of lactam, diamine in the presence of a monomer having a hydroxyl group or a substituent which can be easily converted to a hydroxyl group And a dicarboxylic acid, a condensation polymerization of an aminocarboxylic acid, etc., to obtain a polyamide having a hydroxyl group in the molecule.

Although the molecular weight of the polyamide having a hydroxyl group in the molecule is not particularly limited, the number average molecular weight in terms of standard polymethyl methacrylate measured by gel permeation chromatography (hereinafter referred to as GPC) using HFIP as an eluent is 10,000 to 500,000. (With a polymer concentration of 1 g / 100 ml using 98% sulfuric acid and a number average molecular weight of 10,000 to 40,000 measured at 25 ° C.). The apparent number average molecular weight of the polyamide as measured by GPC in HFIP in terms of standard polymethyl methacrylate tends to be considerably larger than the actual number average molecular weight. As the polyamide having a hydroxyl group in a molecule used in the present invention, a polyamide represented by the following general formula (II) is particularly preferable.

[0011]

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(Where R ¹ is an alkylene group having 4 to 14 carbon atoms, R ² is an alkylene group having 2 to 4 carbon atoms, p is 1 to 10
00 and q each represent a number of 1 to 10, and r represents a number of 1 to 50. ) Specific examples of R ¹ and R ² in general formula (II), R ¹ is butylene group, hexylene group, nonylene group, decylene group, undecylene group, dodecylene group, as R ² is an ethylene group, propylene And the like. The above general formula (I
In the range of p, q, r in I), p is 1 to 1000, q
Is a number of 1 to 10 and r is a number of 1 to 50. If p is small and q is large in this range, the polyalkylene oxide chain component increases and the advantage of polyamide is lost. The same applies if r exceeds 50. For this reason, as the range of p, q, and r, the number of p being 20 to 200, q being 1 to 2, and r being 1 to 10 is most practically preferable. The cyclic ester compound used in the present invention is represented by the general formula (I), and specifically, γ-butyrolactone, δ-valerolactone, ε
-Caprolactone and the like, and ε-caprolactone is preferred.

In order to produce the polyester-grafted polyamide of the present invention, for example, a ring-opening addition reaction catalyst is used in an amount of 0.01 to 1 with respect to 100 parts by weight of a polyamide having a hydroxyl group in a molecule.
And a method of mixing 10 to 100 parts by weight of a cyclic ester compound in a suspended or molten state. As the ring-opening addition reaction catalyst to be used, tetrabutoxytitanate, stannous chloride and the like are preferably used. As a method for confirming the difference in properties between the polyester-grafted polyamide of the present invention and the polyamide having a hydroxyl group in a molecule as a raw material thereof, there is a measurement with a differential scanning calorimeter (hereinafter, referred to as DSC). Here, it is recognized that the melting peak, which is considered to be derived from the polyamide measured in the polyester-grafted polyamide, is shifted to a lower temperature side as compared with the melting peak of the polyamide having a hydroxyl group in the molecule of the raw material. This is presumably because the crystallization of the polyamide was inhibited by the grafting of the polyester onto the polyamide. In the polyester-grafted polyamide of the present invention, the graft ratio and the graft efficiency are mentioned as indices indicating the proportion of the aliphatic polyester grafted to the raw material polyamide having a hydroxyl group in the molecule. These are defined by the following formula.

[0014]

(Equation 1)

Regarding the polyester-grafted polyamide of the present invention, a method of determining the number average molecular weight in terms of standard polymethyl methacrylate by GPC measurement using HFIP as an eluent is used to determine how much the polyester chain is grafted on the polyamide chain. No. The standard polymethyl methacrylate-equivalent number average molecular weight of the polyester-grafted polyamide is larger than that of the raw material polyamide having a hydroxyl group in the molecule. However, the apparent number average molecular weight in terms of standard polymethyl methacrylate in the HFIP of the polyamide tends to be considerably larger than the actual number average molecular weight. In addition, there is a tendency that the difference in the number average molecular weight in terms of standard polymethyl methacrylate from the polyamide having a hydroxyl group in the molecule of the raw material hardly appears. This is HF
FIG. 3 shows a difference in behavior between a polyamide considered to be linear in IP and a polyester-grafted polyamide considered to be bulk. The molecular weight of the polyester-grafted polyamide of the present invention is not particularly limited, but the number average molecular weight in terms of standard polymethyl methacrylate by GPC measurement using HFIP is preferably in the range of 10,000 to 500,000.

The determination of whether or not the polyester chain is reliably grafted on the polyamide chain of the polyester-grafted polyamide of the present invention includes a ¹³ C-nuclear magnetic resonance absorption spectrum (hereinafter referred to as ¹³ C-NMR). Although the polyester monomer was completely removed by the extraction, the peaks of the polyamide and the polyester were confirmed by ¹³ C-NMR, and one of the polyesters at the end of the polyester chain considered to be grafted was confirmed.
The peak of the unit methylene carbon can be confirmed. Particularly preferred polyester-grafted polyamides in the present invention include the following structural formulas in the presence of nylon 6 or nylon 12 having a hydroxyl group in the molecule.

[0017]

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Is obtained by polymerizing ε-caprolactone, which is a cyclic ester compound represented by the following formula, by a ring-opening addition reaction. According to DSC measurement, an endothermic peak accompanying the melting of the crystal derived from the polyamide was confirmed at a slightly lower temperature. And polyester-grafted polyamide having a number average molecular weight in terms of standard polymethyl methacrylate measured by GPC using HFIP of 10,000 to 500,000.

Since the polyester-grafted polyamide of the present invention is grafted with a polyester having low water absorption, it has low water absorption as compared with ordinary polyamide, and is extremely excellent in dimensional stability and stability of mechanical properties. ing. Further, when grafted onto a polyamide resin having crystallinity, there are few problems such as inconsistent dimensional accuracy and warpage of the molded product after melt molding. In addition, glass fiber, metal fiber, aramid fiber, ceramic fiber, potassium whisker, carbon fiber, fibrous reinforcing agent such as asbestos, talc, calcium carbonate, mica, clay, oxidation Granular reinforcing agents such as titanium, aluminum oxide, glass flakes, milled fibers, metal flakes, and metal powders may be mixed. In particular, by mixing 10 to 50% by weight of the glass fiber of the chopped strand type with 50 to 90% by weight of the polyester-grafted polyamide of the present invention, not only the mechanical strength and the heat resistance temperature are significantly improved, but also the water resistance is improved. Is also preferable because further improvement can be seen. Further, one or more additives such as a heat stabilizer, an oxidation stabilizer, a light stabilizer, a lubricant, a pigment, a flame retardant, and a plasticizer may be mixed.
Also, since the polyester-grafted polyamide of the present invention has very good compatibility with thermoplastic polyester and polyamide resin, it can be mixed as a modifier for these thermoplastic polyester and polyamide resin, It is also very excellent as a compatibilizer between thermoplastic polyester and polyamide resin.

[0020]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
In the following examples,% and parts indicate% by weight and parts by weight, respectively.

Example 1 (PCL-g-nylon 6 polymer (1)
Production of Nylon 6 (Ube Industries, Ltd., Ube Nylon 6, P1022) β-hydroxyalkylated polyamide obtained by adding 5 parts of ethylene oxide to 100 parts (manufactured by Nisso Oil Chemical Co., Ltd.) Nylon 6-EOA-YIK-2SI, hereinafter EOA Ny
-6) was used as a polyamide having a hydroxyl group in the molecule. Before assembling a nitrogen introducing tube, a stirring rod, and a separable flask, the mixture was heated at 150 ° C. for 1 hour in a dryer. Assemble them hot and equip a vacuum pump. EOA Ny-6 1 dried in a vacuum dryer in a flask
50 g and 300 g of ε-caprolactone dehydrated by a molecular sieve are charged, and the pressure in the flask is reduced by a vacuum pump at 80 ° C. for 1 hour to dehydrate the flask. Then, the inside of the flask was returned to normal pressure while replacing with nitrogen, and heated to 230 ° C. in an oil bath to melt the nylon particles. Then, 30 mg of stannous chloride was added as a ring-opening addition reaction catalyst and reacted for 5.5 hours.
It was scraped out with a metal bar while hot. After returning to room temperature, 50 g was pulverized, extracted with methanol five times, and the insoluble portion was extracted with chloroform or methylene chloride.
Extracted times. The insoluble portion was dried to obtain 32.2 g of PCL-g-nylon 6 polymer (1). FIG. 1 shows the infrared absorption spectrum of PCL-g-nylon 6 polymer (1).

[0022]

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Further, the methanol and the soluble portion of chloroform or methylene chloride were concentrated and dried. As for the methanol-soluble portion, 5.9 g of a liquid was obtained. In this infrared absorption spectrum, the material ε
-The same absorption peak as that of caprolactone could be confirmed.
11.9 g of a solid was obtained with respect to the chloroform or methylene chloride soluble part. In this infrared absorption spectrum, 1730cm
^{At -1} , the absorption peak attributed to the ester group of polycaprolactone (PCL) could be confirmed, and the absorption peak attributed to the amide group could not be confirmed. Therefore, it was concluded that this was a homopolymer of PCL.

Example 2 (PCL-g-nylon 6 polymer (2)
Dehydration was performed in the same manner as in Example 1, the inside of the flask was replaced with nitrogen, and the pressure was returned to normal pressure.
The mixture was heated to ℃ and stirred in a suspended state. Then, as a ring-opening addition reaction catalyst, 30 mg of tetrabutoxytitanate was added, and 7.5
After reacting for hours, it was scraped out with a metal rod while hot. After returning it to room temperature, 50 g of the powder was extracted with methanol and chloroform or methylene chloride as in Example 1, the insoluble portion was dried, and 20.1 g of PCL-g-nylon 6 polymer (2) I got The infrared absorption spectrum of PCL-g-nylon 6 polymer (2)
This was consistent with that of CL-g-nylon 6 polymer (1). The same operation as in Example 1 was performed for the above methanol and chloroform or methylene chloride soluble parts. As for the methanol-soluble portion, 27.9 g of a liquid was obtained. This was confirmed to be ε-caprolactone by infrared absorption spectrum. 2 g of a solid was obtained for the chloroform or methylene chloride soluble part. This infrared absorption spectrum was consistent with that of Example 1.

Example 3 (PCL-g-nylon 12 polymer (3)
Production of Nylon 12 powder (Nylon 12, L1940, manufactured by Daicel Huls Co., Ltd.) and β-hydroxyalkylated polyamide (Nylon 12-, manufactured by Nisso Oil Chemical Co., Ltd.) obtained by adding 5% of ethylene oxide. EOA, hereinafter referred to as EOA Ny-12)
Was used as a polyamide having a hydroxyl group in the molecule.
Dehydration was performed in the same manner as in Example 1, and the mixture was stirred and melted at 200 ° C. in a nitrogen atmosphere. Then, 17.0 mg of tetrabutoxytitanate was added as a ring-opening addition reaction catalyst, reacted for 10 hours, and scraped off with a metal rod while hot. After the temperature was returned to room temperature, 50 g of the powder was extracted with methanol and chloroform or methylene chloride as in Example 1, and the insoluble portion was dried. 28 g of PCL-g-nylon 12 polymer (3)
I got The same operation as in Example 1 was performed on the above methanol and chloroform or methylene chloride soluble parts. As for the methanol-soluble portion, 12.0 g of a liquid was obtained. 1 for chloroform or methylene chloride soluble part
0.0 g of a solid was obtained.

Experimental Example 1 The thermal behavior of the polyester-grafted polyamide obtained in Examples 1 to 3 was measured by a differential scanning calorimeter. DSC measurement of the measurement sample (temperature range from room temperature to 250 ° C, heating rate 20 ° C
/ Min), and the obtained DSA curve was defined as first heat.
After cooling the measurement sample in the molten state at a constant rate of 20 ° C / min, immediately perform DSC measurement (temperature range from room temperature to 250 ° C, heating rate 20 ° C / min), and obtain the DSC curve by Second hea
t. Second heat of the PCL-g-nylon 6 polymer (1) obtained in Example 1 is shown in FIG.
Figure 3 shows the second heat of PCL-g-nylon 12 polymer (3).
It was shown to. Table 1 summarizes the values of the endothermic peaks associated with the crystal melting of the polyester-grafted polyamide obtained in Examples 1 to 3, EOA Ny as the raw material, and PCL (Placcel H-7, manufactured by Daicel Chemical Industries, Ltd.). Shown. It can be seen that the endothermic peak accompanying the crystal melting of the raw material EOA Ny-6 is 220.7 ° C., whereas the endothermic peak considered to be derived from EOA Ny-6 of the polyester-grafted polyamides of Examples 1 and 2. Is slightly shifted to a lower temperature side. In addition, an endothermic peak presumed to be derived from the PCL chain of the polyester-grafted polyamide is not shown in Example 2 in which the graft chain is considered short, but in Example 1 in which the graft chain is considered to be long, the peak is associated with PCL crystal melting. The endothermic peak is at 60.0 ° C, whereas it is observed at a lower temperature. This is presumably because the grafting of PCL lowered the melting point of the nylon 6 chain component, and the grafted PCL chain component also lowered the melting point for the same reason. These phenomena and measured values indicate that a cyclic compound was polymerized from a polyamide having a hydroxyl group in the molecule.

[0027]

[Table 1]

Experimental Example 2 With regard to the polyester-grafted polyamide obtained in Examples 1 to 3, since a homopolymer of ε-caprolactone and polycaprolactone is considered as an impurity, 50 g of powder was extracted with methanol to obtain ε-caprolactone. Caprolactone was removed, and polycaprolactone was removed by methylene chloride extraction. Then, each weight was clarified and applied to the following definition formula to determine the graft ratio and the graft efficiency. This indicates the ratio of polycaprolactone chains grafted to the polyamide. Table 2 shows the results.

[0029]

(Equation 2)

[0030]

[Table 2]

Experimental Example 3 Example by gel permeation chromatography
Polyester grafted polyamide obtained in 1 and 2
Of standard polymethyl methacrylate
Specified. <Measurement conditions> Instrument TOSOH-CCPE detector UV 225 nm Eluent HFIP Flow rate 0.5 ml / min Pressure 15 kg / cm^Two  Temperature 20 ° C Polyester grafted polyester obtained in Examples 1 and 2
Obtained by GPC measurement of lamide and raw material EOA Ny-6
Standard polymethyl methacrylate-equivalent number average molecular weight
Are shown in Table 3. In addition, the PCL obtained in Example 1 was used.
-G-Nylon 6 polymer (1) and raw material EOANy-
Figure 6 shows the gel permeation chromatogram of
4 (a) and (b).

[0032]

[Table 3]

All of the polyester-grafted polyamides obtained in Examples 1 and 2 have a higher standard number-average molecular weight in terms of polymethyl methacrylate as compared with the raw material EOA Ny. This clearly indicates that the polyester grafting reaction is in progress. In addition, a peak may appear on the low molecular weight side. This may be due to the possibility of polyester oligomer, but PCL-g-
About nylon 6 polymer (1), chloroform solvent, 80
As a result of re-extraction at 5 ° C. for 5 hours, almost no polyester oligomer was extracted. From this, it is considered that the peak on the low molecular weight side is due to a side reaction such as thermal decomposition.

Experimental Example 4 The PCL-g-nylon polymer (2) obtained in Example 2
FIG. 5 shows the ¹³ C-NMR spectrum. Here, the peak of PCL is (CF ₃ ) ₂ CHOH, δ (PPM): 26.78, 27.59, 30.15, 3
6.60, 68.05, 180.47 and other large peaks are assigned to EOANy-6. Where δ: 7
The peaks at 0.52 to 73.52 and 118.04 to 130.51 are the absorptions attributed to the solvent. The other small absorptions are the shift of the methylene carbon of one unit of nylon having a graft chain and the PCL grafted.
One unit of PCL with a -OH group at the end of the chain is shifted. Although the PCL homopolymer was extracted and removed in this way, the peak attributed to PCL was confirmed, and the terminal of the PCL chain was confirmed. It is confirmed that.

Production Example 1 (Production of PCPA resin) 22.8 g of nylon 6 (P1022, manufactured by Ube Industries, Ltd.), 34.2 g of PC (S3000, manufactured by Mitsubishi Gas Chemical Co., Ltd.) and PCL obtained in Example 2 3 g of -g-nylon 6 polymer (2) was melt-kneaded with Brabender (250 ° C, 50 rpm, 5 min) to obtain 59.5 g of a resin mixture (hereinafter referred to as PCPA resin).

Experimental Example 5 A scanning electron microscope (hereinafter abbreviated as SEM) showing the crystal structure of each fractured surface of a resin and a PCPA resin obtained by simply blending nylon 6 and PC with 24 g and 36 g, respectively.
The photographs are shown in FIGS. 6 (a) and 6 (b). According to this, according to the SEM photograph (a) of the simple blend resin, the dispersion diameter of about 3
μm nylon 6 particles were observed. This indicates that the compatibility between PC and nylon 6 is poor, and particularly the adhesive strength at the interface is poor. In contrast, the SEM photograph (b) of PCPA resin shows PC
Dispersed particles of nylon 6 are observed in the phase, but the dispersion diameter is considerably smaller than that of the simple blend resin, and the fracture surface is flat, indicating that the interfacial adhesive strength is increased. This is PCL-g-nylon 6 polymer (2)
Implies that the PCL part is compatible with PC and the nylon 6 part is compatible with nylon 6, and exists at the interface of the blend of PC and nylon 6, greatly improving the compatibility between PC and nylon 6. ing. In addition, the fact that the compatibilizing effect is recognized in the PC / nylon system in this way means that PCL-g-nylon has reacted reliably.

[0037]

EFFECTS OF THE INVENTION As graft polymers, hitherto known ones are mostly amorphous polymers and amorphous polymers,
Or a combination of an amorphous polymer and a crystalline polymer. The polyester-grafted polyamide of the present invention is a graft polymer of crystalline polymers, and is of great interest from an academic point of view. In addition, while maintaining the advantages of good mechanical properties, heat resistance, abrasion resistance, chemical resistance, etc., which have polyester and polyamide, deviations in dimensional accuracy and warpage of molded products after melt molding. It also has properties that are not found in perfect crystalline polymers, such as less problems of Furthermore, it has been found that the polyester / polyamide polymer alloy has an excellent effect as a compatibilizer. Thus, the present invention has made it possible to provide a practically useful thermoplastic resin composition.

[Brief description of the drawings]

FIG. 1 is an infrared absorption spectrum of PCL-g-nylon 6 polymer (1).

FIG. 2: DSC curve of PCL-g-nylon 6 polymer (1) (S
econd heat).

FIG. 3 is a DSC curve (S) of PCL-g-nylon 12 polymer (3).
econd heat).

FIG. 4 (a) shows the PCL-g-nylon 6 polymer (1),
(b) is a gel permeation chromatogram of EOA Ny-6.

FIG. 5 is a ¹³ C-NMR spectrum of PCL-g-nylon polymer (2).

6 (a) is a scanning electron micrograph showing the crystal structure of a fractured surface of a simple blend resin of nylon 6 and PC, and FIG. 6 (b) is a PCE resin.

────────────────────────────────────────────────── ─── Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08G 63/00-63/91 C08G 69/00-69/50 CA (STN) REGISTRY (STN)

Claims (2)

(57) [Claims] 1. In the presence of a polyamide having a hydroxyl group in the molecule, a compound represented by the following general formula (I): (Wherein R represents an aliphatic hydrocarbon residue having 3 to 11 carbon atoms). A method for producing a polyester-grafted polyamide, comprising polymerizing a cyclic ester compound represented by the following formula: 2. A compound represented by the following general formula (II): (Where R ¹ is an alkylene group having 4 to 14 carbon atoms, R ² is an alkylene group having 2 to 4 carbon atoms, p is 1 to 1000, and q is 1 to
10, r represents the number of 1 to 50, respectively. ) In the presence of a polyamide having a hydroxyl group in the molecule represented by the following general formula (I): (Wherein R represents an aliphatic hydrocarbon residue having 3 to 11 carbon atoms), which is obtained by polymerizing a cyclic ester compound represented by the following formula: Standard polymethyl methacrylate-equivalent number average molecular weight of 10,000 by GPC measurement using 3-hexafluoro-2-propanol
A polyester grafted polyamide characterized by having a molecular weight of up to 500,000.