JPH0347844A - Polypropylene-polyester graft copolymer and method for producing the same - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention provides a polypropylene-polyester graft copolymer that is effective as a compatibilizer for polycarbonate and polyolefin, particularly polypropylene, in a resin composition, and a method for producing the same. More specifically, it relates to a graft copolymer of a polyester having a specific intrinsic viscosity and terminal carboxyl group concentration and a modified polypropylene having a specific melt flow rate (MFR), and a method for producing the same.

[Conventional technology]

Aromatic polycarbonates have excellent impact resistance, heat resistance, rigidity, and dimensional stability, but have the drawbacks of poor solvent resistance and moldability. In order to obtain a composition that has well-balanced mechanical properties while covering these drawbacks,
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.

As a third component added to a composition of polycarbonate resin and polyolefin resin, JP-A-57-108151
No. 57-10815 discloses butyl rubber.
No. 2 discloses ethylene-propylene copolymers and/or ethylene-propylene-diene copolymers, and JP-A-57-111351 discloses isoprene rubber and/or methylpentene polymers.

However, none of these third components is sufficient as a compatibilizing agent for polycarbonate resin and polyolefin, especially polypropylene, and as the amount of polyolefin increases, not only does the impact resistance of the molded product sharply decrease, but it also causes surface peeling. Problems also arose.

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
Contains 15 to 85 parts by weight of polyester of m equivalent/kg and 0.2 to 5 mol% of epoxy groups, and has a weight average molecular weight of 8.
000-140000 modified polyolefin 85-15
A method for producing a polyolefin-polyester graft copolymer that can be used as a good compatibilizer between a polycarbonate resin and a polyolefin by reacting parts by weight at 260 to 320°C in a twin-screw extruder. (Patent application No. 63258883).

[Problem to be solved by the invention]

However, after further consideration,
When polypropylene is used as the polyolefin in a blend of polyolefin and polycarbonate, the polyethylene-polyester graft copolymer obtained by the above method does not have sufficient affinity with polypropylene, and the polypropylene-polyester copolymer is produced by the above method. However, it has become clear that the polymer reaction between modified polypropylene and polyester is difficult to occur.

It is therefore an object of the present invention to provide polypropylene-polyester graft copolymers that act as good compatibilizers for polycarbonate resins and polyolefins, especially polypropylene.

Another object of the present invention is to provide a method for producing such polypropylene-polyester graft copolymers.

[Means to solve the problem]

As a result of intensive studies to achieve the above object, the present inventors have found that a graft copolymer of polyester and functional group-containing modified polypropylene is effective as a compatibilizing agent for polycarbonate resin and polyolefin, especially polypropylene. By limiting the intrinsic viscosity and terminal carboxyl group concentration of the polyester and the functional group content and melt flake (MFR) of the modified polypropylene to specific ranges, the desired polypropylene-polyester graft copolymer can be produced in the graft reaction. The inventors have discovered that it is possible to obtain the desired results, and have come up with the present invention.

That is, the polypropylene-polyester graft copolymer of the present invention has an intrinsic viscosity [η] of 0.5 to 1.8 and a terminal carboxyl group concentration of 1O to 100 m equivalent/k.
10 to 90 parts by weight of polyester and 0.1 to 2.0 g of polyester
Melt flow rate (MFR)
Modified polypropylene 90 to 0.5 to 80 g/10 min
Parts by weight of IO.

The method for producing a polypropylene-polyester graft copolymer of the present invention includes (a) a polyester 10-90 having an intrinsic viscosity [η] of 0.5-1.8 and a terminal carboxyl group concentration of 10-100 m equivalent/kg; and (b) 90 to 10 weight parts of modified polypropylene containing 0.1 to 2.0 weight % of functional groups and having a melt rate (MFR) of 0.5 to 80 in a twin screw extruder. The reaction is carried out at 240 to 300°C.

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.

Polyester has an intrinsic viscosity [η] of 0.5 to 1.8 and 1
It is necessary to have a terminal carboxyl group concentration of 0 to 100 m equivalents/kg. Here, the intrinsic viscosity [η] (di/g
) was determined from the solution viscosity measured at 25°C in 0-chlorophenol solvent.

When the intrinsic viscosity [η] of the polyester is less than 0.5, the effect of improving compatibility is insufficient, and when it exceeds 1.8, the melt viscosity of the reactant becomes high, making it difficult to process. On the other hand, regarding the concentration of terminal carboxylic groups, if it is less than 10 m equivalents/kg, the reactivity with the modified polypropylene will be low, and if it exceeds 100 m equivalents/kg, the reactivity with the modified polypropylene will be too high and a gel will easily be formed. Become.

Especially in the case of polyethylene terephthalate, the intrinsic viscosity [η
] is 0.5 to 1.0, and the terminal carboxyl group concentration is 10
~100m equivalent/kg. Intrinsic viscosity [η] is 1.
When it exceeds 0, the melt viscosity of the graft copolymer becomes high and a gel is formed. The terephthalic acid component in polyethylene terephthalate may be substituted with an alkyl group, a halogen group, etc., and the glycol component may include up to about 50% by weight of other glycols in addition to ethylene glycol.
For example, it may contain 1.4-butylene glycol, propylene glycol, hexamethylene glycol, and the like.

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 may be 0 to 100 m equivalent/kg. In this case as well, the terephthalic acid component may be substituted with an alkyl group, a halogen group, etc., and the glycol component may be substituted with a 1,4-
In addition to butylene glycol, it may contain up to about 50% by weight of other glycols, such as ethylene gelcol, propylene glycol, hexamethylene gelcol, and the like.

0 Furthermore, the modified polypropylene used in the present invention is polypropylene copolymerized with an unsaturated monomer having a functional group.

The functional group contained in the modified polypropylene is reactive with the terminal carboxyl group or hydroxyl group of polyester, and examples thereof include carboxyl group, epoxy group, hydroxyl group, and amino 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 polymer having an epoxy group include glycidyl methacrylate and glycidyl acrylate.

The skeleton of the functional group-containing modified polypropylene may be any propylene block copolymer, graft copolymer, random copolymer or alternating copolymer, but in particular the following general formula: (However, R1-R4 are It is preferably a propylene random copolymer containing a non-conjugated diene comonomer represented by H or an alkyl group having 1 to 6 carbon atoms, and n represents an integer of 1 to 20.

Examples of the non-conjugated diene include 1,4-hexadiene, 7-methyl-1,6-octadiene, 5-methyl-
Examples include 1,4-hexadiene, 9-decadiene, 4-methyl-1,4-heptadiene, 4-ethyl-1,4-hexadiene, and 1,13-tetradecadiene.

Among these, 1,4-hexadiene, 7-methyl-1,6-octadiene, 5-methyl-1,4-hexadiene, 1,9-decadiene and the like are particularly preferred. Two or more of these non-conjugated diene comonomers can also be used in combination.

To randomly copolymerize propylene and a nonconjugated diene comonomer, a conventional copolymerization method using a Ziegler-Natsuta catalyst may be applied. In this -11-2- case, the proportion of the non-conjugated diene is 0.05 to 10 mol%
It is desirable to make it so that If the content of non-conjugated diene is less than 0.05 mol%, a high grafting rate cannot be obtained in the subsequent grafting reaction. Moreover, if it exceeds 10 mol%, the crystallinity of the copolymer will be significantly reduced. A more preferable content of non-conjugated diene is 0.1 to 3 mol%.

In addition, the propylene to be copolymerized with the unsaturated monomer having the above-mentioned functional group may optionally contain 10% by weight or less of ethylene, olefins such as butene-11pentene-1, vinyl acetate, isoprene, chlorobrene, butadiene, etc. Monomers may also be added.

The following method is used to graft react an unsaturated monomer having a functional group to this polypropylene-nonconjugated diene random copolymer. That is, the random copolymer, 1,000 yen, and Any method can be used, such as a melt-kneading method in which a radical generator is melt-kneaded and reacted. In particular, the melt-kneading method is suitable because continuous reaction is easy.

In addition, in the case of the melt-kneading method, the reaction time is preferably 10 seconds to 20 minutes.

Examples of radical generators (reaction initiators) include benzoyl peroxide, lauroyl peroxide, and ditertiary peroxide.
Peroxides such as butyl, acetyl peroxide, tert-butyl peroxybenzoic acid, dicumyl peroxide, peroxybenzoic acid, peroxyacetic acid, tert-butyl peroxypivalate, diazo compounds such as azobisisobutyronitrile, etc. is preferred. The blending ratio is 0.1 to 10 parts by weight per 100 parts by weight of the radically polymerizable monomer.
A range of parts by weight is desirable. Note that the graft reaction can also be caused by kneading in a heated state without using a radical generator.

Melt flow rate (MFR) of the above modified polypropylene
) is 0.5 to 80 g/10 min, and the amount of functional groups in the modified polypropylene is 0.1 to 2.0% by weight.
3-4- are required. In addition, melt flow rate) (MFR)
was measured at 230°C under a load of 2160g, and 871
It is expressed in 0 minutes. Further, the functional group content was determined from the analytical value of oxygen element. melt flowray)
When (MFR) exceeds 80 g/10 min (i.e., when the molecular weight becomes too low), almost no reaction occurs with the polyester, making it difficult to synthesize the graft copolymer, and 0.5 g/10 min If it is less than that (that is, if the molecular weight becomes too high), the melt viscosity will increase and moldability will deteriorate. Generally, the weight average molecular weight (TX w ) of modified polypropylene having an MPR of 0.5 to 80 g/10 min.
is about 70,000 to 300,000. Also, the functional group is 0.1% by weight.
If it is less than 20%, the reactivity with polyester will be low and a graft copolymer will be difficult to form. On the other hand, if it exceeds 2.0% by weight, the melt viscosity of the reactant increases due to overreaction, and a gel-like substance is likely to be produced.

In order to graft polymerize the above polyester and modified polypropylene, after tri-blending them,
Melt and knead at 300°C. Melt-kneading is preferably carried out in an extruder, particularly in a twin-screw extruder. The reaction temperature is 24
If the temperature is lower than 0°C, grafting will not be sufficient, and if the temperature is lower than 300°C,
If the temperature exceeds .degree. C., overreaction will occur, the melting temperature of the reactants will increase, and there is a risk that the extruder will be blocked. In addition, deterioration of the modified polypropylene is likely to occur. The grafting reaction time varies depending on the reaction conditions, but is usually about 0.5 to 15 minutes.

The blending amount of polyester and modified polypropylene 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.
~20 parts by weight. 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.

The polypropylene-polyester graft copolymer thus obtained is good as a compatibilizing agent for polycarbonate resin and polyolefin, especially polypropylene, and is generally added at a rate of 1 to 30 parts by weight per 100 parts by weight of both. do.

[For production]

= 15 6 By limiting the intrinsic viscosity [η] and the concentration of terminal carboxyl groups of the polyester to be grafted, and the functional group content and melt fluororate (MFR) of the modified polypropylene to specific ranges, the grafting reaction is facilitated. A graft copolymer having a sufficient grafting rate can be obtained, and the generation of gel due to overreaction can be prevented, making it a good compatibilizer.

〔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 titration with a sodium hydroxide benzyl alcohol solution of IN.

(3) Melt flow rate (MFR) Measured at 230°C under a load of 2160g.

(4) 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.

(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 by resin When reaction was carried out for 1 hour using a 45 mmφ twin-screw extruder at a discharge rate of 30 kg/hour, the presence or absence of blockage by gel at the die part was observed.

Examples 1 to 6, Comparative Examples 1 to 3 As shown in Table 1, polyethylene terephthalate or polybutylene terephthalate having various intrinsic viscosities [η] and terminal carboxyl group concentrations, and various functional group contents and melt flow rates were used. ) (MF7 8 R) (graft copolymer of propylene non-conjugated diene random copolymer and maleic anhydride or glycidyl methacrylate) at 20/80
After tri-blending at a ratio of (weight ratio), 45++
＋＋＋＋φ twin screw extruder, 280℃, 20Or
The grafting reaction was allowed to proceed by melt-kneading at pm. Residence time in the extruder was about 1 minute.

The grafting rate of the reaction product was as shown in Table 1. In the examples, no gel formation or clogging of the extruder was observed.

Example 7 As polyester, 50% by weight of polyethylene terephthalate having an intrinsic viscosity [η] of 0.72 and a terminal carboxyl group concentration of 30 m equivalent/kg and an intrinsic viscosity [η] of 0.72 were used.
85 has a terminal carboxyl group concentration of 52m! A copolymer was prepared as in Example I, except that a mixture with 50% by weight of polybutylene terephthalate/kg was used;
Similar measurements were made. The results are shown in Table 1. Also in this example, no gel formation or clogging of the extruder was observed.

Example 8.9 The ratio (weight ratio) of polybutylene terephthalate and modified polypropylene was 50150 (Example 8) and 80
/20 (Example 9) 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. Also in this example, no gel formation or clogging of the extruder was observed.

JP-A-3 47844 (7) Note+ (1)...Polyethylene terephthalate (TR4
550 mouth H1 made by Teijin ■) (2)... Holifthylene terephthalate (TRB-, made by Deniri ■) (3)...2160 g load (230℃) (4)...
・Maleic anhydride (5)...Glycidyl methacrylate As is clear from the results in Table 1, the polypropylene-polyester copolymer of the present invention has a high grafting rate, and moreover, it prevents the formation of gel due to overreaction. This also prevented resin clogging in the extruder.

On the other hand, in the copolymer of the comparative example, the graft ratio was O, indicating that the graft reaction did not proceed.

〔Effect of the invention〕

As described above, in the present invention, a polyester having an intrinsic viscosity [η] and a terminal carboxyl group concentration in a specific range, and a modified polypropylene having a functional group content and melt flow rate (MFR) in a specific range are used. Because of the reaction, a copolymer can be obtained with a high grafting rate of 22-23-.

The polypropylene-polyester graft copolymer of the present invention thus obtained is extremely effective as a compatibilizer for polycarbonate resin and polyolefin, particularly polypropylene.

Applicant: Toenen Co., Ltd.
Company representative Patent attorney Takaishi Hashima 24

Claims (7)

[Claims] (1) 10 to 90 parts by weight of polyester having an intrinsic viscosity [η] of 0.5 to 1.8 and a terminal carboxyl group concentration of 10 to 100 m equivalent/kg, and 0.1 to 2.0 weight % of functional groups. melt flow rate (MFR, 2 at 230°C)
A polypropylene-polyester graft copolymer comprising 90 to 10 parts by weight of a modified polypropylene having a weight ratio of 0.5 to 80 g/10 min (measured under a load of 160 g). (2) In the polypropylene-polyester graft copolymer according to claim 1, the modified polypropylene has the following general formula: ▲There are numerical formulas, chemical formulas, tables, etc.▼ (However, R_1 to R_4 are H or have a carbon number of 1 to 6 alkyl group, and n represents an integer of 1 to 20. (3) The polypropylene-polyester graft copolymer according to claim 1 or 2, wherein the polyester has an intrinsic viscosity [η] of 0.5 to 1.0 and a terminal carboxyl group concentration of 10 to 100 m equivalent/kg. polyethylene terephthalate and/or has an intrinsic viscosity [η] of 0.5 to 1.
8, the concentration of terminal carboxyl group is 10 to 100 m equivalent/
A polypropylene-polyester graft copolymer, characterized in that it is polybutylene terephthalate. (4) The polypropylene-polyester graft copolymer according to any one of claims 1 to 3, wherein the functional group of the modified polypropylene is a carboxyl group, an acid anhydride, or an epoxy group.
Polyester graft copolymer. (5) In the method for producing a polypropylene-polyester graft copolymer, (a) 10 to 90 weight polyester having an intrinsic viscosity [η] of 0.5 to 1.8 and a terminal carboxyl group concentration of 10 to 100 m equivalent/kg; and (b) a modified polypropylene containing 0.1 to 2.0% by weight of functional groups and having a melt flow rate (MFR, measured at 230° C. under a load of 2160 g) of 0.5 to 80 g/10 min. A method characterized by reacting 90 to 10 parts by weight with a twin screw extruder at 240 to 300°C. (6) In the method according to claim 5, the polyester is polyethylene terephthalate and/or polyethylene terephthalate having an intrinsic viscosity [η] of 0.5 to 1.0 and a terminal carboxyl group concentration of 10 to 100 m equivalent/kg. [η] is 0.5~
1.8 A method characterized in that the polybutylene terephthalate has a terminal carboxyl group concentration of 10 to 100 m equivalent/kg. (7) The method according to claim 5 or 6, wherein the functional group of the modified polypropylene is a carboxyl group, an acid anhydride, or an epoxy group.