JPH04300954A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To provide a thermoplastic resin composition having improved compatibility of polyester and polyethylene, low density, excellent impact resistance, tensile elongation and mechanical strength and good moldability. CONSTITUTION:The objective thermoplastic resin composition contains (A) 50-95wt.% of a polyester and (B) 5-50wt.% of a polyethylene resin containing a glycidyl compound having acrylamide group and epoxy group.

Description

Description [0001] [Industrial Application Field] The present invention relates to a thermoplastic resin composition containing polyester and polyethylene, and in particular, the polyester and polyethylene are well compatible, and the composition has excellent impact resistance, The present invention relates to a lightweight thermoplastic resin composition that has good mechanical strength such as tensile elongation and tensile yield strength, and good moldability. [Prior Art and Problems to be Solved by the Invention] Polyester is used in various electrical components such as automobiles and home appliances because of its excellent insulation, mechanical strength, impact resistance, and heat resistance. However, since it has a high specific gravity, it becomes particularly heavy when used for large objects. On the other hand, polyethylene has excellent moldability, chemical resistance, water resistance, etc., but has the disadvantage of being inferior in rigidity, heat resistance, etc. Therefore, attempts have been made to alleviate the drawbacks of both polyesters and polyethylene to create a well-balanced resin. However, since polyethylene and polyester do not have sufficient compatibility, there is a problem in that impact resistance and surface releasability deteriorate when simply blended. [0003] Therefore, in order to improve the compatibility between the two, it has been considered to make polyester and polyethylene compatible by adding an epoxy group-containing ethylene copolymer such as an ethylene-glycidyl methacrylate copolymer. However, compositions containing epoxy group-containing ethylene copolymers have lower mechanical strengths such as rigidity and tensile elongation, and furthermore, polyethylene and polyester are not sufficiently compatible. There is a problem that impact resistance is not sufficient. [0005] Conventionally, mixing polyethylene and polyester improves mechanical strength, insulation, impact resistance,
Physical properties such as moldability, chemical resistance, water resistance, and surface peeling resistance are significantly reduced, making it difficult to obtain a composition that satisfies all properties, that is, a well-balanced resin. [0006] Therefore, the object of the present invention is to make polyester and polyethylene well compatible, and to have good mechanical strength such as impact resistance, tensile elongation, and tensile yield strength, and good moldability.
An object of the present invention is to provide a lightweight thermoplastic resin composition. [Means for Solving the Problems] As a result of intensive studies in view of the above object, the present inventors have developed a method for modifying polyester and polyethylene with a specific glycidyl compound having an acrylamide group and an epoxy group as a compatibilizing agent. We discovered that compositions containing polyethylene have good compatibility between polyester and polyethylene, and have a good balance of mechanical strength such as impact resistance, tensile elongation, and tensile yield strength, as well as formability. I came up with an invention. That is, the thermoplastic resin composition of the present invention comprises (a) 50 to 95% by weight of polyester, and (b)
The following general formula [Formula 2] (wherein, R is H or an alkyl group having 1 to 6 carbon atoms,
Ar is an aromatic hydrocarbon group having 6 to 20 carbon atoms and having at least one glycidyloxy group, and n is 1 to 4.
represents an integer. ) It is characterized by containing 5 to 50% by weight of a polyethylene resin containing a glycidyl compound represented by: The present invention will be explained in detail below. In the present invention, (a) polyester is generally a thermoplastic resin consisting 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, and polybutylene terephthalate is particularly preferred. The polyester preferably has an intrinsic viscosity [η] of 0.30 to 1.8 and a concentration of terminal carboxyl groups of 10 to 200 m equivalent/kg. Here, the intrinsic viscosity [η] (dl/g) is determined from the solution viscosity measured at 25° C. in an o-chlorophenol solvent. In the case of polybutylene terephthalate, the intrinsic viscosity [η] is preferably 0.30 to 1.8, and the terminal carboxyl group concentration is preferably 10 to 200 m equivalent/kg. In this case as well, the terephthalic acid component is an alkyl group,
It may be substituted with a halogen group or the like, and the glycol component may contain up to about 50% by weight of other glycols in addition to 1,4-butylene glycol, such as ethylene glycol, propylene glycol, hexamethylene glycol, etc. good. In the case of polyethylene terephthalate, it is preferable that the intrinsic viscosity [η] is 0.30 to 1.2 and the terminal carboxyl group concentration is 10 to 200 m equivalent/kg. 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 in addition to ethylene glycol, such as 1,4-butylene. It may contain glycol, propylene glycol, hexamethylene glycol, etc. In the present invention, the polyethylene resin (b) contains 2% by weight or more of modified polyethylene obtained by graft polymerization of a monomer consisting of a specific glycidyl compound having an acrylamide group and an epoxy group. The above glycidyl compound has the following general formula (1
) : [Formula 3] (wherein, R is H or an alkyl group having 1 to 6 carbon atoms,
Ar is an aromatic hydrocarbon group having 6 to 20 carbon atoms and having at least one glycidyloxy group, and n is 1 to 4.
represents an integer. ). Preferred glycidyl compounds include those represented by the following general formula (2). [Formula 4] (In the formula, R represents H or an alkyl group having 1 to 6 carbon atoms.) Such a glycidyl compound can be prepared, for example, by the following method shown in JP-A-60-130580. It can be manufactured by First, at least one phenolic hydroxyl group
By condensing an aromatic hydrocarbon having 1 or more with N-methylol acrylamide, N-methylol methacrylamide, or an alkyl ether derivative of N-methylol methacrylamide (hereinafter referred to as N-methylol acrylamides) using an acid catalyst. , the following general formula (3) [Chemical formula 5] (wherein, R is H or an alkyl group having 1 to 6 carbon atoms,
Ar' has at least one hydroxyl group and has 6 carbon atoms
~20 aromatic hydrocarbon groups, and n represents an integer of 1 to 4. ) is produced. The aromatic hydrocarbon having at least one phenolic hydroxyl group is not particularly limited;
For example, phenol, o-cresol, m-cresol,
p-cresol, 2,6-xylenol, 2,4-xylenol, o-chlorophenol, m-chlorophenol, p-chlorophenol, o-phenylphenol,
Phenolic compounds such as 2,6-diphenylphenol, polyphenolic compounds such as hydroquinone, catechol, and phloroglucinol, polycyclic hydroxy compounds such as 1-naphthol, 2-naphthol, and 9-hydroxyanthracene, 2,2-bis (4-hydroxyphenyl)propane (bisphenol-A), bis(4-
Examples include bisphenols such as hydroxyphenyl and methane. Next, by glycidylating the hydroxyl group of the compound represented by general formula (3) above, general formula (1) is obtained.
A glycidyl compound represented by can be obtained. For this glycidylation, it is preferable to conduct an addition reaction between the compound represented by the general formula (3) and epihalohydrin, and then perform dehydrohalogenation using a caustic alkali. The addition reaction with epihalohydrin is carried out using a phase transfer catalyst. The epihalohydrin mentioned above is
Epichlorohydrin, epibromohydrin, epiiodohydrin, etc. can be used. Examples of phase transfer catalysts include quaternary ammonium salts such as tetrabutylammonium bromide, trioctylmethylammonium chloride, benzyltriethylammonium chloride, and quaternary phosphonium salts such as tetraphenylphosphonium chloride and triphenylmethylphosphonium chloride. Salt etc. can be used. The amount of the phase transfer catalyst used is determined by the general formula (3
) as 100 mol%, 0.0
It is preferably used in a range of 1 to 100 mol%. A particularly preferred amount of phase transfer catalyst used is 0.05 to 10 mol%. In addition, the reaction time and reaction temperature are 50 to 120
5 minutes to 2 hours at ℃, more preferably 80 to 110 ℃
It takes 10 to 30 minutes. Subsequently, dehydrohalogenation is performed using caustic alkali. The above caustic alkali includes caustic soda,
Caustic potash, lithium hydroxide, etc. can be used. These can be used as solids or as aqueous solutions. Further, as a catalyst for dehydrohalogenation, the same one as the above-mentioned phase transfer catalyst can be used. Catalysts other than the above phase transfer catalysts include crown ethers,
Examples include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, and the like. The amount of the caustic alkali used is determined by the general formula (3
) It is preferred to use equimolar amounts with respect to the compound represented by. More preferably, 1.1 to 1.5 times the amount is used. In addition, the reaction time and reaction temperature are 20 to 90°C for 10 minutes to 3
The time is preferably 30 minutes to 2 hours at 40 to 70°C. The polyethylene modified with the above-mentioned modifying monomer is a polymer compound having ethylene as a constituent unit, and has a melt index (MI 190°C, 2.16
kg load) 0.01~50g/10 min, density (
ASTM D1505) is 0.955 to 0.885
g/cm3, and contains about 10% by weight or less of other α
- May be copolymerized with olefin. Examples of such polyethylene include low-density polyethylene, linear low-density polyethylene, and high-density polyethylene, but high-density polyethylene is particularly preferred because it has high rigidity and the resulting composition has a good balance. In the present invention, the high density polyethylene has a density of 0.935 g/cm3 or more and a melt index (MI 190
°C, 2.16 kg load) is 0.1 to 10 g/
Preferably it is 10 minutes. Modification (graft polymerization) of polyethylene with such a glycidyl compound can be carried out by either a solution method or a melt-kneading method. In the case of melt kneading method,
Polyethylene, the above-mentioned glycidyl compound for modification, and a catalyst if necessary are put into an extruder, twin-screw kneader, etc., and kneaded for 0.1 to 20 minutes while heating and melting at a temperature of 120 to 300°C. do. In the case of a solution method, the above starting material is dissolved in an organic solvent such as xylene, and the starting material is dissolved in an organic solvent such as xylene.
The mixture is stirred at a temperature of 0° C. for 0.1 to 100 hours. In either case, a conventional radical polymerization catalyst can be used as a catalyst, such as benzoyl peroxide, lauroyl peroxide, ditertiary butyl peroxide, acetyl peroxide, tertiary butyl peroxybenzoic acid, dicumyl peroxide, peroxybenzoic acid, peroxyacetic acid,
Peroxides such as tert-butyl peroxypivalate and 2,5-dimethyl-2,5-diter-butyl peroxyhexine, and diazo compounds such as azobisisobutyronitrile are preferred. The amount of catalyst added is 0.1 to 1 per 100 parts by weight of the modified glycidyl compound.
It is about 0 parts by weight. In the present invention, a phenolic antioxidant may be added during the graft reaction. However, if a radical polymerization catalyst is not added, it is preferable not to add it. The content of the glycidyl compound in such modified polyethylene is preferably within the range of 0.01 to 30% by weight, more preferably 0.01 to 30% by weight.
It is 1 to 10% by weight. If the amount of modification by the glycidyl compound is less than 0.01% by weight, there will be no sufficient effect on improving the compatibility between polyethylene and polyester;
If it exceeds % by weight, the mechanical strength will decrease. [0028] In the polyethylene resin, as the unmodified polyethylene other than the modified polyethylene, the same polyethylenes as those to be modified by the above-mentioned modified polyethylene can be used. [0029] The polyethylene resin is the above-mentioned modified polyethylene alone or a mixture of modified polyethylene and unmodified polyethylene, but the content of the above-mentioned modified polyethylene in the polyethylene resin is (b) polyethylene It is 2% by weight or more based on 100% by weight of the system resin. If the content of modified polyethylene is less than 2% by weight, there is no sufficient effect in improving the compatibility between polyethylene resin and polyester. The preferred content of modified polyethylene is 10 to 50% by weight. [0030] However, the entire polyethylene resin is 100%
As weight%, the content of a specific glycidyl compound having an acrylamide group and an epoxy group is 0.01% by weight
It is preferable to set it to the above value. If the content of the glycidyl compound is less than 0.01% by weight based on the entire polyethylene resin, there is no sufficient effect in improving the compatibility between the polyethylene resin and the polyester. More preferably 0.1
% by weight or more. (a) polyester as described above;
(b) The blending ratio with polyethylene resin is first determined by (a
) + (b) as 100% by weight (a)
50-95% by weight of polyester, preferably 60-9%
0% by weight, and (b) polyethylene resin is 5 to 5% by weight.
0% by weight, preferably 10-40% by weight. (a)
If the polyester content is less than 50% by weight (if the polyethylene resin exceeds 50% by weight), the properties of the polyester will be impaired, while if the polyester content exceeds 95% by weight (if the polyethylene resin is less than 5% by weight), the polyester properties will be impaired. The effect of adding resin is not fully exhibited. [0032] In the present invention, the above-mentioned (
(c) A styrene block copolymer can be added to a) polyester and (b) polyethylene resin for the purpose of further improving impact resistance, moldability, elongation properties, etc. In the present invention, the styrenic block copolymer (c) is a copolymer consisting of a polystyrene block and a polyolefin block, or a hydrogenated product thereof. It also includes those obtained by modifying the above copolymers with epoxy group-containing monomers, unsaturated carboxylic acids, or anhydrides thereof. Examples of such styrene block copolymers include styrene-isoprene-styrene block copolymers (SIS, including styrene-isoprene block copolymers), styrene-butadiene-styrene block copolymers (SBS, (including styrene-butadiene block copolymer), styrene-hydrogenated isoprene-styrene block copolymer (styrene-ethylene-propylene-styrene block copolymer: SEPS), styrene-
Hydrogenated butadiene-styrene block copolymer (styrene-ethylene-butylene-styrene block copolymer:
SEBS), etc. In the case of the modified styrenic block copolymer, examples of the modifying monomer include epoxy group-containing monomers, unsaturated carboxylic acids, or their anhydrides. Examples of the epoxy group-containing monomer include glycidyl methacrylate and glycidyl acrylate. Further, a specific glycidyl compound having an acrylamide group and an epoxy group, which is a monomer for modifying the above-mentioned modified polyethylene, can also be used. Examples of unsaturated carboxylic acids or anhydrides thereof include monocarboxylic acids such as acrylic acid and methacrylic acid, dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid, maleic anhydride, itaconic anhydride, Examples include dicarboxylic anhydrides such as endo-bicyclo-[2,2,1]-5-heptene-2,3-dicarboxylic anhydride (himic anhydride), and dicarboxylic acids and their anhydrides are particularly preferred. Modification of the styrenic block copolymer with such an epoxy group-containing monomer or an unsaturated carboxylic acid or its anhydride is carried out by graft polymerization or random polymerization of the above-mentioned modifying monomer onto the styrenic block copolymer. This can be done depending on the situation. In the case of graft polymerization, first, a styrenic block copolymer, an unsaturated carboxylic acid or its anhydride for modification, or an epoxy group-containing monomer and, if necessary, a catalyst are mixed in an extruder or twin-screw kneader. etc., 150
The mixture is kneaded while melting at about 300°C, preferably about 180 to 250°C. At this time, the amount of unsaturated carboxylic acid or its anhydride, or epoxy group-containing monomer added is about 0.1 to 20 parts by weight, preferably 0.5 to 1 part by weight, based on 100 parts by weight of the styrenic block copolymer.
It is about 0 parts by weight. The amount of the above-mentioned styrenic block copolymer added is 1 to 15 parts by weight based on the total of (a) + (b) 100 parts by weight. If the content of the styrenic block copolymer is less than 1 part by weight, the effect of its addition on improving moldability, elongation properties, etc. will not be sufficient, and if it exceeds 15 parts by weight, heat resistance and rigidity will decrease. The preferred content of the styrenic block copolymer is 2 to 10
Parts by weight. The thermoplastic resin composition of the present invention has the above composition, but for the purpose of strengthening and modifying it, other fillers, reinforcing materials, heat stabilizers, light stabilizers, flame retardants, plasticizers, Antistatic agents, foaming agents, nucleating agents, etc. can be added. [0042] The thermoplastic resin composition of the present invention as described above can be prepared by mixing the above-mentioned components at 220 to 300°C using a kneading machine such as a single screw extruder, twin screw extruder, Banbury mixer, kneading roll, or Brabender. Preferably 230 to 280
It can be obtained by heating and kneading in a molten state at °C. Note that the melt-kneading can be performed for each component all at once or divided into two or more steps. [Function] The thermoplastic resin composition of the present invention contains a polyethylene resin containing polyethylene modified with a specific glycidyl compound having an acrylamide group and an epoxy group, and a polyester. It is well compatible with polyethylene, and has good mechanical strength such as impact resistance and elongation properties, and moldability.
Moreover, it is lightweight. The reason why such effects are obtained is not necessarily clear, but polyester with excellent mechanical strength, insulation properties, and impact resistance and polyethylene with excellent moldability, chemical resistance, and water resistance are combined with acrylamide groups. It is thought that this is because polyethylene modified with a specific glycidyl compound having an epoxy group can be better compatible with the polyethylene, and the advantages of both can be well exhibited. EXAMPLES The present invention will be explained in more detail with the following specific examples. In addition, in each Example and Comparative Example, the following materials and additives were used. [1] Polyester polybutylene terephthalate PBT: [TRB J manufactured by Teijin Ltd., intrinsic viscosity [η]
0.87] [2] Polyethylene/high density polyethylene HDPE: [Melt index (MI, 190 °C,
2.16 kg load) 0.2 g/10 min, density (A
STM D1505) 0.935g/cm 3 ]・Linear low density polyethylene LLDPE: [Melt index (MI, 190 ℃
, 2.16kg load) 4.0g/10 min, density (AS
TM D1505) 0.934 g/cm3]・Low density polyethylene LDPE: [Melt index (MI, 190 ℃,
2.16 kg load) 2.4 g/10 min, density (A
STM D1505) 0.923 g/cm3] [3
] Modifying monomer AXE: Glycidyl compound represented by the following chemical formula [Chemical formula 6] [Kanebuchi Chemical Co., Ltd.]
[4] Modified styrenic block copolymer CMSEBS
: [Epoxy-modified styrene-hydrogenated butadiene-styrene block copolymer, manufactured by Asahi Kasei Corporation: Tuftec Z
513] [5] Epoxy group-containing ethylene copolymer/ethylene-glycidyl methacrylate random copolymer EGMA: [Bonto First E manufactured by Sumitomo Chemical Co., Ltd.] Synthesis Example 1 Production of modified polyethylene Linear low density Polyethylene (LLDPE: MI 4.0
g/10 min, density 0.934 g/cm3) 100
parts by weight, 5 parts by weight of AXE, and a radical generator (POX).
:Perhexine 2-5B) 0.05 parts by weight, and then clew diameter 45mmφ, L/D=
The mixture was extruded using a No. 28 twin screw extruder at 190° C. and 200 rpm to obtain AXE modified polyethylene (CMPE). The melt index of the modified polyethylene thus obtained was 1.8 g/10 minutes, and A
The grafting rate of XE was 4.6% by weight. Examples 1 to 6, Comparative Examples 1 to 3 Polyester (PBT) and polyethylene (HDPE, LDPE)
or LLDPE), modified polyethylene (CMPE), and modified styrenic block copolymer (CMSEBS) in the proportions shown in Table 1, after dry blending with a Henschel mixer, screw diameter 45 mmφ, L / D = 2
The mixture was kneaded at 250° C. and 200 rpm using a twin-screw extruder No. 8 to obtain a thermoplastic resin composition. Melt flow rate of the thermoplastic resin composition thus obtained (250°C, 2.16kg
load), tensile yield strength, tensile elongation at break, flexural modulus,
Izod impact strength, heat distortion temperature, and specific gravity were measured. The results are shown in Table 2. For comparison, in the compositions of Examples 1, 5 and 6, ethylene-
Glycidyl methacrylate random copolymer (EGMA)
), melt flow rate (250°C, 2.16 kg load), tensile yield strength,
Tensile elongation at break, flexural modulus, Izod impact strength, heat distortion temperature, and specific gravity were measured. The results are shown in Table 2. [0051] No.
1 Table Composition Weight part Example 1 Example 2 Example 3
Example 4 Example 5 Example 6 PBT
80 80 80 8
0 80 60HDPE
10 6 -
- 16 30LLDPE
- - 10
- - -L
DPE − −
-10-
-CMPE 10 10
10 10 4
10CMSEBS-
4 - -
− − 0052]
Table 1 (continued)
Composition Parts by weight Comparative example 1 Comparative example 1 Comparative example 2 PBT
80 80 6
0 HDPE 10
16 30
EGMA10
4 10 0053
2 Surface properties Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 MFR

(g/10
minutes) (1) 7.5 10
8.3 8.1
12 14 Tensile yield strength


(kg/cm2) (2) 480
490 480 4
60 480 410 Tensile elongation at break

(%) (3)
80 160 80
100 60
150 flexural modulus

(kg/c
m2) (4) 22000 21000
21000 20000
22000 19000 Izod impact strength


(kg ・cm/cm) (5) 8
16 7 12
7 8 Heat distortion temperature


(℃) (6) 120
118 118
110 122 108
specific gravity

(g/cm3
) (7) 1.22 1.22
1.22 1.21 1
．． 21 1.15 0054
2 Table (continued)
Comparative example 1 Comparative example 2
Comparative example 3 MFR


(g/10 minutes) (1) 2
．． 1 0.4 1.
3 Tensile yield strength

(kg/
cm2) (2) 420
410 360
Tensile elongation at break

(%) (3)
100 30
80
flexural modulus

(kg/cm2) (4)
16000 19000
14000 Izod impact strength
(kg
・cm/cm) (5) 12
8 15
heat distortion temperature

(℃) (6)
117 120
90
specific gravity

(g/cm3) (7)
1.22 1.22
1.15 0055
] (1) MFR: 250 according to ASTM D1238
Measured at ℃ and 2.16 kg load. (2) Tensile yield strength: Measured according to ASTM D638. (3) Tensile elongation at break: Measured according to ASTM D638. (4) Flexural modulus: Measured according to ASTM D790. (5) Izod impact strength: Measured according to ASTM D256 at 23°C with a notch. (6) Heat distortion temperature: 4 according to ASTM D648.
Measured at 6kg/cm2. (7) Specific gravity: Measured according to ASTM D792. As is clear from Table 2, Examples 1 to 6
The thermoplastic resin composition had good and well-balanced tensile yield strength, tensile elongation at break, flexural modulus, Izod impact strength, and heat distortion temperature. In particular, the thermoplastic resin composition of Example 2 containing the modified styrenic block copolymer was particularly excellent in tensile elongation at break and impact resistance. On the other hand, the thermoplastic resin compositions of Comparative Examples 1 to 3 were inferior in tensile yield strength and flexural modulus compared to the corresponding examples. Effects of the Invention As detailed above, the thermoplastic resin composition of the present invention uses modified polyethylene using a specific glycidyl compound having an acrylamide group and an epoxy group as a compatibilizer for polyester and polyethylene. Since the polyester and polyethylene are well compatible with each other, it has an excellent balance of mechanical strength such as impact resistance, tensile elongation, and flexural modulus, as well as formability, and is lightweight. has been done. The thermoplastic resin composition of the present invention is suitable as various engineering plastics, particularly as a resin composition for automobile interior and exterior parts, home appliance parts, industrial material parts, packaging materials, and the like.

Claims (3)

[Claims] Claim 1: (a) 50 to 95% by weight of polyester, and (b) the following general formula [Formula 1] (wherein R is H or an alkyl group having 1 to 6 carbon atoms,
Ar is an aromatic hydrocarbon group having 6 to 20 carbon atoms and having at least one glycidyloxy group, and n is 1 to 4.
represents an integer. ) A thermoplastic resin composition comprising 5 to 50% by weight of a polyethylene resin containing a glycidyl compound represented by: 2. The thermoplastic resin composition according to claim 1, wherein the polyester (a) is polybutylene terephthalate or polyethylene terephthalate. 3. The thermoplastic resin composition according to claim 1 or 2, wherein the (a) polyester and (b)
A thermoplastic resin composition further comprising (c) 1 to 15 parts by weight of a styrene block copolymer based on a total of 100 parts by weight of the polyethylene resin.