JPH0347843A - Production of polyolefin-polyester graft copolymer - Google Patents

Abstract

PURPOSE:To obtain the title copolymer effective as a compatibilizing agent, preventing occurrence of gel resulting from excessive reaction which maintaining graft ratio and good fluidity by reacting a specific polyester with a carboxyl group-containing modified polyolefin in the presence of water. CONSTITUTION:(A) 10-90 pst.wt. polyester having 0.05-1.8 intrinsic viscosity [7] and 10-100 equivalent/kg end cardoxyl group concentration is reacted with (B) 10-90 pst.wt. modified polyolefin containing 0.2-5mol% carboxyl group or epoxy group and having 8,000-140,000 weight-average molecular weight at 260-320 deg.C in a molten state by adding (C) 0.05-2.0 pst.wt. water based on 100 pst.wt. total amount of the components A and B to give the aimed copolymer effective as a compatibilizing agent between an engineering plastics and polypropylene.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to the production of a polyolefin-polyester graft copolymer that is effective as a compatibilizer for engineering plastics such as polycarbonate and polyolefin in resin compositions. More specifically, the present invention relates to a method for preventing gel formation when producing a graft copolymer from a polyester having a specific intrinsic viscosity and terminal carboxyl group concentration and a modified polyolefin containing an epoxy group.

[Conventional technology]

Aromatic polycarbonate has excellent impact resistance, heat resistance,
Although it has rigidity and dimensional stability, it has the drawbacks of poor solvent resistance and moldability. In order to overcome these drawbacks and obtain a composition that has well-balanced mechanical properties, various studies have been made regarding blends with polyolefins. However, since the compatibility between polyolefin and polycarbonate is not very good, attempts have been made to add various third components to improve the compatibility.

For example, as a third component added to a composition of polycarbonate resin and polyolefin resin, JP-A-57-10
No. 8151 discloses butyl rubber, and JP-A-57-1
No. 08152 discloses ethylene-propylene copolymer and/or ethylene-propylene-diene copolymer, and JP-A-57-111351 discloses isoprene rubber and/or ethylene-propylene-diene copolymer.
or methylpentene polymers.

However, none of these third components is sufficient as a compatibilizer for polycarbonate resin and polyolefin,
If the amount of polyolefin increases, not only the impact resistance of the molded article will sharply decrease, but also the problem of surface peeling will occur.

Therefore, the present inventors first determined that the intrinsic viscosity [η] was 0.3.
0 to 1.2 and the concentration of terminal carboxyl group is 15 to 200
m equivalent/kg polyester 15-85 weight R, 0
゜Modified polyolefin 85-1 containing 2 to 5 mol% of epoxy groups and having a weight average molecular weight of 8,000 to 140,000
A method for producing a polyolefin-polyester graft copolymer that can be used as a good compatibilizer for polycarbonate resin and polyolefin by reacting 5 parts by weight with a twin-screw extruder at 260 to 320°C. (Japanese Patent Application No. 63258883).

[Problem to be solved by the invention]

However, after further consideration,
In the above method, a gel is likely to be formed due to overreaction, which may cause blockage of the extruder, making it difficult to stably produce a polyolefin-polyester graft copolymer that is effective as a compatibilizer. It was revealed.

Therefore, an object of the present invention is to produce a polyolefin-polyester graft copolymer, which is a good compatibilizer between engineering plastics such as polycarbonate resin and polyolefin, in a stable manner without clogging the extruder while preventing gel formation. An object of the present invention is to provide a manufacturing method.

[Means to solve the problem]

As a result of extensive studies to achieve the above object, the present inventors have determined that the intrinsic viscosity and terminal carboxyl group concentration of polyester are reacted with the functional group content and molecular weight of modified polyolefin, each of which is limited to a specific range. , and discovered that it is sufficient to add water to the reaction system, and came up with the present invention.

That is, the method for producing a polyolefin-polyester graft copolymer of the present invention includes (a) polyester 910-910 having an intrinsic viscosity [η] of 0.50-1.8 and a terminal carboxyl group concentration of 1O-100 m equivalent/kg; and (c) 260 to 32 parts by weight of a modified polyolefin containing 0.2 to 5 mol% of carboxyl groups or epoxy groups and having a weight average molecular weight of 8,000 to 140,000.
When melt-kneading and reacting at 0° C., 0.05 to 2.0 parts by weight of water is added to a total of 100 parts by weight of the polyester and the modified polyolefin.

The present invention will be explained in detail below.

The polyester used in the present invention is generally a thermoplastic resin made of a saturated dicarboxylic acid and a saturated dihydric alcohol, such as polyethylene terephthalate, polypropylene terephthalate, polytetramethylene terephthalate (polybutylene terephthalate), polyhexamethylene terephthalate, polycyclohexane- Examples include 1,4-dimethylol terephthalate and polyneopentyl terephthalate. Among these, polyethylene terephthalate and polybutylene terephthalate are particularly preferred.

The polyester must have an intrinsic viscosity [η] of 0.50 to 1.8 and a terminal carboxyl group concentration of 10 to 100 m equivalent/kg. Here, the intrinsic viscosity [η:] (dA
/g) was determined from the solution viscosity measured at 25° C.5 in 0-chlorophenol solvent.

When the intrinsic viscosity [η] of polyester is less than 0.50,
The effect of improving compatibility is insufficient, and if it exceeds 1.80, the melt viscosity of the reactant becomes high, making it difficult to process. On the other hand, regarding the concentration of terminal carboxylic groups, 10
If it is less than m equivalent/kg, the reactivity with the modified polyolefin will be low, and if it exceeds 100 m equivalent/kg, the reactivity with the modified polyolefin will be too high, making it easy to form a gel.

Especially in the case of polyethylene terephthalate, the intrinsic viscosity [η
] is 0.50 to 1.0, and the terminal carboxyl group concentration is 1.
Preferably, it is between 0 and 100 m equivalents/kg.

When the intrinsic viscosity [η] exceeds 1.0, the melt viscosity of the graft copolymer increases to form a gel. The terephthalic acid component in polyethylene terephthalate may be substituted with an alkyl group, a halogen group, etc., and the glycol component may contain up to about 50% by weight of other glycols, such as 1,4-butylene, in addition to ethylene glycol. It may contain glycol, propylene glycol, hexamethylene glycol, etc.

In addition, in the case of polybutylene terephthalate, the intrinsic viscosity [
η] is 0.5 to 1.8, and the terminal carboxyl group concentration is 1
It is sufficient if it is 0 to 100 m equivalent/kg. In this case as well, the terephthalic acid component may be substituted with an alkyl group, norylogen group, etc., and the glycol component may be substituted with 1,
In addition to 4-butylene glycol, it may contain up to about 50% by weight of other glycols, such as ethylene glycol, propylene glycol, hexamethylene glycol, and the like.

Furthermore, the modified polyolefin used in the present invention is a polyolefin copolymerized with an unsaturated monomer having a carboxyl group or an epoxy group.

Examples of unsaturated monomers having a carboxyl group include unsaturated carboxylic acids or their anhydrides, such as monocarboxylic acids such as acrylic acid and methacrylic acid, dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid, maleic anhydride, Examples include dicarboxylic acid anhydrides such as itaconic anhydride, and dicarboxylic acids and their anhydrides are particularly preferred. Examples of the unsaturated monomer having an epoxy group include glycidyl methacrylate and glycidyl acrylate.

Further, examples of the olefin to be copolymerized with the unsaturated polymer having an epoxy group include olefins such as ethylene, propylene, butene-1, and pentene-1. These olefins can be used alone or in combination of two or more.

Note that monomers such as vinyl acetate, isoprene, chloroprene, butadiene, etc. may be added to these olefins in an amount of 10% by weight or less, if necessary. Among these modified polyolefins, copolymers of acrylic acid, glycidyl methacrylate, etc., and ethylene are particularly preferred.

The carboxyl group- or epoxy group-containing modified polyolefin may be a block copolymer, a graft copolymer, a random copolymer, or an alternating copolymer.

The weight average molecular weight of the modified polyolefin is 8000~
140,000, and the amount of carboxyl groups or epoxy groups in the modified polyolefin needs to be 0.2 to 5 mol%. The weight average molecular weight is measured by gel permeation chromatography (GPC) method.
It is calculated in terms of unmodified polyolefin. In addition, the carboxyl group content was determined from elemental analysis values,
The epoxy group content was determined from the analytical value of oxygen element. If the weight average molecular weight is less than 8,000, the effect of improving compatibility will be insufficient, and if it exceeds 140,000, the melt viscosity will increase and moldability will deteriorate. Moreover, if the carboxyl group or epoxy group is less than 0.2 mol %, the reactivity with polyester is low and a graft copolymer is difficult to form. Moreover, if it exceeds 5 mol%, the reactivity with the polyester becomes too high, the melt viscosity of the reactant increases, and a gel-like substance is likely to be produced.

In order to graft-polymerize the above-mentioned polyester and modified polyolefin, after tri-blending them,
Melt and knead at 320°C for 0°5 to 15 minutes.

Melt-kneading is preferably carried out in an extruder, particularly in a twin-screw extruder. If the reaction temperature is less than 260°C, grafting will not be sufficient, and if it exceeds 320°C, overreaction will occur, resulting in clogging of the extruder due to gel formation. At the same time, the resin tends to deteriorate.

The blending amount of the polyester and modified polyolefin is 10 to 90 parts by weight, preferably 20 to 80 parts by weight for the former, and 90 to 10 parts by weight, preferably 80 parts by weight for the latter.
~20Mit part. If the amount of polyester is less than 10 parts by weight or greater than 90 parts by weight, the amount of graft copolymer produced will be small.

Furthermore, in the present invention, when melt-kneading and reacting the above-mentioned polyester and modified polyolefin, 0.05 to 2.0 parts by weight of water is added per 100 parts by weight of the above-mentioned polyester and modified polyolefin in total. shall be. If the amount of water added is less than 0.05 parts by weight, it will not be possible to sufficiently prevent gel formation, and if it exceeds 2.0 parts by weight, the molecular weight of the graft copolymer will become too low and the compatibility will not be improved. become insufficient. When an extruder is used for melt-kneading, water is continuously supplied into the extruder by a pump.

In particular, it is preferable to add water after the kneading zone of the extruder.

The polyolefin-polyester graft copolymer thus obtained is good as a compatibilizer for polycarbonate resin and polyolefin, and is generally added in an amount of 1 to 30 parts by weight per 100 parts by weight of both.

[For production]

By limiting the intrinsic viscosity [η] and the concentration of terminal carboxyl groups of the polyester to be grafted, and the carboxyl group or epoxy group content and weight average molecular weight of the modified polyolefin to specific ranges, and adding water during the grafting reaction. , it becomes easier to control the grafting reaction, and generation of gel due to overreaction can be prevented.

In particular, when water is added, the polyester moiety of the graft copolymer is hydrolyzed, resulting in a decrease in molecular weight. the result,
It is possible to suppress generation of gel due to excessively high molecular weight due to overreaction, and to prevent clogging of the extruder 1-2. Moreover, the grafting rate does not decrease.

〔Example〕

The present invention will be explained in further detail by the following examples.

Note that in each Example and Comparative Example, the characteristic values were measured as follows.

(1) Intrinsic viscosity [η] It was determined from the solution viscosity measured at 25°C in 0-chlorophenol solvent.

(2) Terminal carboxyl group concentration A benzyl alcohol solution of polyester was diluted with chloroform, and a 0.1% alcohol solution of phenol red was used as an indicator. It was determined by titrating IN with a sodium hydroxide benzyl algol solution.

(3) Weight average molecular weight Measured by GPC method and calculated as polyethylene equivalent value.

(4) MFR Measured at 280°C under a load of 2160 g or 21.6 kg.

(5) Gel generation A film with a thickness of about 100 μm was produced by press molding, and the presence or absence of gel was determined visually.

(6) Blockage of extruder with resin Using a 45 mInφ twin-screw extruder, the discharge amount is 30 kg/
After the reaction was carried out for 1 hour, the presence or absence of gel blockage at the die part was observed.

(7) Grafting rate m-cresol (100°C) and xylene (100°C)
The components insoluble in both are isolated as a graft copolymer,
The grafting rate was determined.

Examples 1 to 8, Comparative Examples 1 to 2 As shown in Table 1, polyethylene terephthalate or polybutylene terephthalate having various intrinsic viscosities [η] and terminal carboxyl group concentrations, and various epoxy groups or carboxyl groups were used. 9 with a content and weight average molecular weight
After tri-blending modified polyethylene (a copolymer of glycidyl methacrylate or acrylic acid with ethylene and 3-4) at a ratio of 30/70 (weight ratio), it was fed to a 45+++nφ twin-screw extruder and heated at 280°C. The grafting reaction was progressed by melt-kneading at 20 rpm. At this time, water was added downstream of the kneading zone of the twin-screw extruder in a proportion shown in Table 1 based on the total weight of polyethylene terephthalate and modified polyethylene of 100. Residence time in the extruder was about 1 minute.

The MFR of the reaction product, the grafting ratio, the gel generation status, and the extruder blockage status are as shown in Table 1.

Example 9 As polyester, 50% by weight of polyethylene terephthalate having an intrinsic viscosity [η] of 0.70 and a terminal carboxyl group concentration of 35 m equivalent/kg, and an intrinsic viscosity [η] of 0.70 were used.
A copolymer was produced in the same manner as in Example 1, except that a mixture of 73 and 50% by weight of polybutylene terephthalate having a terminal carboxyl group concentration of 60 m equivalents/kg was used, and the same measurements were performed. The results are shown in Table 1.

Example 10.11 Ratio of polyethylene phthalate and modified polyethylene (
weight ratio) 50150 (Example 10) and 80/2
0 (Example 11) A copolymer was produced in the same manner as in Example 1, and the same measurements were performed.

The results are shown in Table 1.

Note = (1)...Polyethylene terephthalate (TR4
550, Deniri @luri (2)...Polybutylene terephthalate (TRB-K
(manufactured by Denirimasu) (3)...glycidyl methacrylate (4)...acrylic acid (5)...parts by weight per 100 parts by weight of polyester + modified polyethylene [Effects of the invention] As mentioned above, this book In the invention, a polyester having an intrinsic viscosity [η] and a terminal carboxyl group concentration in a specific range is reacted with a modified polyolefin having a carboxyl group or epoxy group content and a weight average molecular weight in a specific range, and at that time, Because water is added, there is no decrease in grafting rate, while maintaining good fluidity.
It is possible to prevent the generation of gel due to overreaction and to prevent clogging of the extruder with the resin.

The polyolefin-polyester graft copolymer of the present invention thus obtained is extremely effective as a compatibilizer for engineering plastics such as polycarbonate resins and polyolefins.

Claims (2)

[Claims] (1) In the method for producing a polyolefin-polyester graft copolymer, (a) 10 to 90 weight polyester having an intrinsic viscosity [η] of 0.50 to 1.8 and a terminal carboxyl group concentration of 10 to 100 m equivalent/kg; and (b) 90 to 10 parts by weight of a modified polyolefin containing 0.2 to 5 mol% of carboxyl groups or epoxy groups and having a weight average molecular weight of 8,000 to 140,000.
A method characterized in that 0.05 to 2.0 parts by weight of water is added to a total of 100 parts by weight of the polyester and the modified polyolefin when melt-kneading and reacting at 0°C. (2) In the method according to claim 1, the polyester is polyethylene terephthalate and/or polyethylene terephthalate having an intrinsic viscosity [η] of 0.50 to 1.0 and a terminal carboxyl group concentration of 10 to 100 m equivalent/kg. [η] is 0.5
0 to 1.8 and the concentration of terminal carboxyl group is 10 to 100
m equivalent/kg of polybutylene terephthalate.