JP2723996B2 - Polycaprolactone / styrene / maleic anhydride copolymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a polycaprolactone / styrene / maleic anhydride which can be used as a polymer modifier or a polymer compatibilizer for improving the compatibility of multiple components of a polymer. It relates to a random copolymer.

[Problems to be solved by conventional technology and invention]

In a polymer multi-component system, polymers of different types generally do not dissolve in the molecular dimension, and it is necessary to improve dispersibility in order to obtain the advantage of the kneaded polymers. Therefore, compatibilization can be caused by adding a small amount of a block or graft copolymer of a polymer compatible with A and a polymer compatible with B to a blend system of incompatible A and B polymers. Such a polymer modifier that functions to lower the interfacial tension between polymers is called a compatibilizer.

Since poly-ε-caprolactone has good compatibility with various polymers, it is considered that the utility value of the compatibilizer as one component is large. For example, JP-A-56-50958 uses a block copolymer containing polycaprolactone as a component as a compatibilizer. However, these block copolymers have some difficulty in production, such as utilizing living anionic polymerization.

In addition, if a block copolymer utilizing ring-opening polymerization of caprolactone is used as a compatibilizer, there is a polymer blend system that cannot be practically used.

[Means for solving the problem]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found a poly-ε-caprolactone graft terpolymer which can be polymerized simply and inexpensively and exhibit good compatibility with various polymers. Was completed.

That is, the present invention 10 to 94% by weight of a structural unit represented by 1 to 20% by weight of a structural unit represented by A polycaprolactone / styrene / maleic anhydride random copolymer having a number average molecular weight of 10,000 to 150,000, comprising 5 to 70% by weight of structural units represented by the following formula:

The copolymer of the present invention is a terpolymer obtained by grafting poly-ε-caprolactone, can be easily and inexpensively polymerized, and is used as a compatibilizing agent for a polyamide resin or a thermoplastic resin having compatibility with poly-ε-caprolactone. Can be Here, as the thermoplastic resin compatible with poly ε-caprolactone, polyester resin, aromatic polycarbonate resin,
AS resin, ABS resin, polyvinyl chloride resin and the like. The copolymer of the present invention is composed of styrene, maleic anhydride and polyε-caprolactone. Since the styrene / maleic anhydride copolymer has strong compatibility with the polyamide resin, a specific amount of the copolymer of the present invention is added to a mixture of the polyamide resin and a thermoplastic resin having compatibility with poly ε-caprolactone, When uniformly mixed, a uniform dispersion was achieved.

As a method for producing the copolymer of the present invention, as a first method, poly-ε-caprolactone adduct of styrene, maleic anhydride and 2-hydroxyethyl methacrylate is simultaneously copolymerized by a method such as ordinary radical polymerization. A method of polymerizing is exemplified.

The poly-ε-caprolactone adduct of 2-hydroxyethyl methacrylate used in this case can be easily obtained by ring-opening polymerization of ε-caprolactone using 2-hydroxyethyl methacrylate as an initiator.

As a second method, there is a method in which styrene, maleic anhydride, and 2-hydroxyethyl methacrylate are previously polymerized by a method such as ordinary radical polymerization, and then ring-opening polymerization of ε-caprolactone is started from a hydroxyl group. .

Since the copolymer of the present invention has a graft chain, it is difficult to measure its molecular weight accurately, but as a number average molecular weight converted to standard polystyrene determined by gel permeation chromatography, 10,000 to 150,00
A range of 0 is preferred. Number average molecular weight of the copolymer is 10,000
When the number average molecular weight is less than 150,000, the melt viscosity is too low and it is difficult to knead with another resin.

The polymerization degree n of ε-caprolactone is 10 to 200.
If the degree of polymerization n is less than 10 (that is, the number average molecular weight of polyε-caprolactone per graft chain is about 1,000), the compatibilizing performance of polycaprolactone is reduced, and the function as a compatibilizer cannot be achieved. If n exceeds 200, the reactivity at the time of polymerizing the copolymer decreases, and the grafting efficiency deteriorates, which is not preferable. Such adjustment of the degree of polymerization n can be performed by adjusting the charge ratio of 2-hydroxyethyl methacrylate and ε-caprolactone as initiators when ring-opening polymerization of ε-caprolactone in the first method. In the second method, it is possible to adjust the number of hydroxyl groups in the terpolymer to be polymerized in advance and the amount of ε-caprolactone used in ring-opening polymerization.

As the ratio of each component in the copolymer of the present invention obtained in this way, A styrene structural unit represented by 10 to 94% by weight, A maleic anhydride structural unit represented by 1 to 20% by weight, Is 5-70% by weight of a poly-ε-caprolactone adduct of 2-hydroxyethyl methacrylate represented by the following formula:

The proportion of the maleic anhydride structural unit in the copolymer of the present invention is
When the content exceeds 20% by weight, when the copolymer of the present invention is used as a compatibilizer, when a mixture of a polyamide resin and a thermoplastic resin having compatibility with poly ε-caprolactone is melt-kneaded,
The reaction between polymers including a partial cross-linking reaction becomes remarkable, and foaming is caused and fluidity is reduced, which undesirably impairs moldability. Conversely, if the proportion is less than 1% by weight, the dispersion state between the polyamide resin and the thermoplastic resin having compatibility with poly ε-caprolactone becomes non-uniform, and the mechanical properties of the obtained molded product also become poor. Unsatisfactory, and appearance defects such as surface delamination also occur.

Furthermore, when the poly-ε-caprolactone adduct structural unit of 2-hydroxyethyl methacrylate in the copolymer of the present invention exceeds or falls below the above range,
The dispersion state between the polyamide resin and the thermoplastic resin having compatibility with poly ε-caprolactone is not uniform, and excellent impact resistance cannot be obtained, which is not preferable.

〔Example〕

Hereinafter, the effects of the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

In the following examples, parts and% indicate parts by weight and% by weight, respectively.

Production Example 1 (Polycaprolactone resin containing terminal methacrylic group (1)
Production of 4-hydroxyethyl methacrylate (hereinafter referred to as 2-HEMA) 50 parts, ε-caprolactone 4380 parts, hydroquinone as a polymerization inhibitor 0.48 parts of monomethyl ether (hereinafter referred to as HQME) and 0.217 parts of stannous chloride (hereinafter referred to as SnCl ₂ ) as a reaction catalyst are added, and while passing through air,
The reaction was performed at 120 ° C. for 10 hours. The conversion of ε-caprolactone was 99.4%. According to GPC measurement, the number average molecular weight of this polymer in terms of polystyrene was 19,000. FIG. 1 shows a gel permeation chromatogram of the polymer.

Further analysis revealed that all the hydroxyl groups that 2-HEMA had before the reaction were consumed, and that a polycaprolactone resin containing a terminal methacryl group was formed.

Production Example 2 (Polycaprolactone resin containing terminal methacrylic group (2)
Production of 100 parts of 2-HEMA, 4380 parts of ε-caprolactone, 0.85 part of HQME and 0.285 part of SnCl ₂ were placed in the same apparatus as in Production Example 1, and reacted at 120 ° C. for 10 hours while passing air through. The conversion of ε-caprolactone was 99.0%. According to GPC measurement, the number average molecular weight of this polymer in terms of polystyrene was 9,800. The same analysis as in Production Example 1 revealed that a polycaprolactone resin having a terminal methacryl group was formed.

Example 1 In a four-necked flask equipped with a dropping funnel, a nitrogen inlet tube, a thermometer, a cooling tube, and a stirring rod, 50 parts of the polycaprolactone resin (1) having a terminal methacrylic group obtained in Production Example 1 and styrene (hereinafter, referred to as styrene) St)) 80 parts of a monomer mixture composed of 60 parts of methyl ethyl ketone (hereinafter referred to as MEK)
And heated to 70 ° C. Thereafter, azobisisobutyronitrile (hereinafter, referred to as a polymerization initiator) dissolved in 15 parts of MEK is used.
A monomer mixture consisting of 1.5 parts of AIBN), further 30 parts of St, 5 parts of maleic anhydride (hereinafter referred to as MAH) and 50 parts of MEK was successively added dropwise to carry out polymerization.

After 10 hours, the flask was cooled to room temperature, and at the same time, poured into a large amount of methanol, the precipitated polymer was separated by decantation, and further dried under reduced pressure in a vacuum dryer,
It was pulverized and powdered to obtain a copolymer (a).

According to GPC measurement, the number average molecular weight of this copolymer (a) in terms of polystyrene was 52,000. FIG. 2 shows a gel permeation chromatogram of the copolymer (a). As compared with the chromatogram of the polycaprolactone resin (1) having a terminal methacryl group shown in FIG. 1, the number average molecular weight is greatly increased, and almost no unreacted polycaprolactone resin (1) is observed. This indicates that the polymerization reaction is proceeding promptly.

FIG. 3 shows the infrared absorption spectrum of the copolymer (a). Starting with characteristic absorption peak of the anhydride groups is seen in 1860,1780cm ^-1, absorption peaks belonging to the styrene (1600,760,700cm ^-1 etc.) and polycaprolactone (1740,1180cm ^-1, etc.) can be confirmed .

FIG. 4 shows the nuclear magnetic resonance absorption spectrum of the copolymer (a). According to this, styrene (CDCl ₃ δ 6.2 ~ 6.8,
6,8-7,3) and polycaprolactone resin (CDCl ₃ δ
The integrated intensity of the peak attributed to 2.3, 4.05, t) indicated that the graft polymer was polymerized at almost the same ratio as the monomer used in the reaction.

Table 1 shows the elemental analysis values of the copolymer (a). The calculated values in Table 1 are values when it is assumed that the initiator and the monomer used in the polymerization reaction are all polymerized as a polymer.
A comparison of the results shows that the polymerization was carried out almost as charged with the monomer.

Further, the thermal behavior of the copolymer (a) was measured by a differential scanning calorimeter, and the first heat was measured as shown in FIG.
t is shown in FIG. 5 (b). The endothermic peak accompanying the crystal melting of the polycaprolactone portion was 65.7 ° C for the first heat, but decreased to 55.6 ° C for the second heat, and the amount of heat absorbed sharply decreased. This indicates that the crystallization rate of the polycaprolactone portion of the copolymer (a) is significantly reduced, that is, the polycaprolactone resin (1) is efficiently grafted into the copolymer.

Example 2 In a device similar to that of Example 1, a monomer mixture comprising 30 parts of polycaprolactone resin having terminal methacrylic group (2) and 60 parts of St was dissolved in 150 parts of MEK, and the temperature was raised to 70 ° C. Thereafter, a mixture of 1.2 parts of AIBN dissolved in 50 parts of MEK, further a mixture of 20 parts of St, 10 parts of MAH, and 50 parts of MEK was sequentially dropped to carry out polymerization.

After 10 hours, the flask is cooled to room temperature, and at the same time, poured into a large amount of methanol, the precipitated polymer is separated by decantation, further dried under reduced pressure in vacuum drying, pulverized and powdered to obtain a copolymer (b). I got

According to GPC measurement, the number average molecular weight of the copolymer (b) in terms of polystyrene was 47,000.

An infrared absorption spectrum and a nuclear magnetic resonance absorption spectrum confirmed that the copolymer was efficiently produced.

Production Example 3 (Production of styrene / maleic anhydride / 2-hydroxyethyl methacrylate copolymer) St90 parts, MAH1 in a device similar to that for production of polycaprolactone graft-styrene / maleic anhydride copolymer (a)
A monomer mixture consisting of 0 parts and 2-HEMA
And heated to 70 ° C. Thereafter, 1.5 parts of AIBN dissolved in 50 parts of MEK were added dropwise to carry out polymerization.

After 10 hours, the flask was cooled to room temperature, and at the same time, poured into a large amount of methanol, the precipitated polymer was separated by decantation, further dried under reduced pressure in vacuum drying, pulverized and powdered to obtain styrene, maleic anhydride, A 2-hydroxyethyl methacrylate copolymer was obtained.

According to GPC measurement, the number average molecular weight of this resin in terms of polystyrene was 27,000.

Example 3 In a device similar to that of Example 1, 100 parts of the styrene / maleic anhydride / 2-hydroxyethyl methacrylate copolymer obtained in Production Example 3, 100 parts of ε-caprolactone, and HQME0.
1 part, and the reaction catalyst tert-butyl titanate 0.0
One part was added and reacted at 120 ° C. for 10 hours while passing air.
Thereafter, the reaction solution was poured into a large amount of methanol, the precipitated polymer was separated by decantation, further dried under reduced pressure in a vacuum dryer, pulverized and powdered to obtain a copolymer (c). At this time, the reaction rate of ε-caprolactone was 99.2%. According to GPC measurement, the number average molecular weight of this polymer in terms of polystyrene was 48,000.

An infrared absorption spectrum and a nuclear magnetic resonance absorption spectrum confirmed that the copolymer was efficiently produced.

Application Examples 1 to 10 Polycaprolactone graft-styrene / maleic anhydride copolymers (a), (b) and (c) obtained in Examples 1, 2 and 3; nylon 6;
(Ube Nylon 6 1013B manufactured by Ube Industries, Ltd., hereinafter referred to as nylon) and polybutylene terephthalate resin (Duranex 200 manufactured by Polyplastics Co., Ltd.)
0, hereinafter referred to as PBT), polycarbonate resin (Iupilon S-3000, manufactured by Mitsubishi Gas Chemical Co., Ltd., hereinafter referred to as PC), AS resin (Sebian NO50, manufactured by Daicel Chemical Industries, Ltd., hereinafter referred to as AS) or ABS resin A predetermined amount of (Sebian V300 manufactured by Daicel Chemical Industries, Ltd .; hereinafter, referred to as ABS) was weighed at the ratio shown in Table 1 and mixed at room temperature for 15 minutes using a Henschel mixer.

The obtained resin mixture was heated at 240 ° C using a 40 mmφ single screw extruder.
And melt-kneaded into pellets, which were similarly molded at 240 ° C. using a screw-type injection molding machine to prepare predetermined test pieces.

For these test pieces, the flexural modulus (sample thickness
3.2 mm, measurement temperature 23 ° C, hereinafter referred to as FM)
Izod impact strength (sample thickness 3.2mm, measurement temperature 23
° C, with cutting notch, hereinafter referred to as IS) to JIS K 7110,
Heat distortion temperature (sample thickness 3.2 mm, bending stress 4.6 kgf / cm ² and 18.6kgf / cm ^2, without annealing, hereinafter referred to as HDT) of JIS
Measured according to K 7207.

 The results obtained are shown in Table 1.

Comparative Examples 1 to 7 Polycaprolactone Graft-Styrene / Maleic Anhydride Copolymer (A), (B) and (C) were not used, and PBT, PC, AS and ASB were compared to nylon in Table 2. In the same manner as shown in Application Examples 1 to 10, melt kneading and injection molding were performed at the ratios shown in Table 1 to obtain test pieces.

The physical properties of these test pieces were measured by the same methods as those shown in Application Examples 1 to 10, and the obtained results are shown in Table 2 together.

[Effects of the Invention] In general, the appearance of a molded piece and the mechanical physicochemical performance of a mixed composition obtained by mixing different kinds of polymers have been unfavorable. However, the random copolymer of the present invention has a specific composition, a thermoplastic resin and a polyamide resin having compatibility with poly ε-caprolactone such as polyester resin, aromatic polycarbonate, ABS resin and / or AS resin or polyvinyl chloride resin. By blending it with a mixture with the above, it is possible to achieve extremely excellent dispersion, not only to reduce various properties such as mechanical performance, but also to obtain a polyamide resin composition having high impact resistance. Became possible. In addition, it has become possible to provide a polymer compatibilizer that can provide a practically useful thermoplastic resin composition by compensating for the disadvantages of each of the polyamide resin and the other thermoplastic resin.

[Brief description of the drawings]

FIG. 1 is a gel permeation chromatogram of the polymer obtained in Production Example 1, FIG. 2 is a gel permeation chromatogram of the copolymer (a) obtained in Example 1, and FIG. 4 is an infrared absorption spectrum of the copolymer (a) obtained in Example 1, FIG. 4 is a nuclear magnetic resonance spectrum of the copolymer (a) obtained in Example 1, and FIG. 5 is a spectrum obtained in Example 1. It is a graph which shows the thermal-analysis result by a differential scanning calorimeter of a copolymer (a), (a) is first heat, (b)
Indicates second heat.

Claims (1)

(57) [Claims] (1) 10 to 94% by weight of a structural unit represented by 1 to 20% by weight of a structural unit represented by A random copolymer of polycaprolactone / styrene / maleic anhydride having a number average molecular weight of 10,000 to 150,000, comprising 5 to 70% by weight of structural units represented by the following formula: