JPH05331358A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic resin compsn. excellent in strengths and stiffness, high in impact strength, and good in dimensional stability by compounding specified amts. of an arom. polyester, a modified polyolefin, and a poly(glutarimide). CONSTITUTION:The compsn. comprises 30-90wt.% arom. polyester (e.g. polybutylene terephthalate), 5-40wt.% modified polyolefin (e.g. polypropylene having 1-10wt.% glycidyl ether groups and 0.05-1wt.% acid anhydride groups), and 5-30wt.% poly(glutarimide) of the formula (wherein R1 and R2 are each H or lower alkyl; and R1 is H, alkyl, aryl, alkaryl, or aralkyl) [e.g. an N-(lower alkyl)dimethylglutarimide], can be prepd. by any method for mixing solid materials, and is excellent in strengths and stiffness and good in dimensional stability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition, and more particularly to a thermoplastic resin composition having excellent strength and rigidity and excellent dimensional stability.

[0002]

BACKGROUND ART Aromatic polyesters are generally thermoplastic materials having various excellent properties such as oxidation resistance and solvent resistance, and have good physical and mechanical properties by melt molding. Suitable for obtaining films or general moldings.

Recently, products have become thinner due to lighter, thinner, shorter, and smaller products. At that time, conventional PBT resins lack sufficient toughness represented by impact strength, and have poor dimensional stability due to crystallization shrinkage. There are drawbacks, and the demand for quality improvement is increasing. A method of adding an elastomer is known as a method for improving toughness and mechanical strength.In this case, although the elastomer is a soft component, it is effective for improving impact strength, but it is possible to overcome the drawback of lowering rigidity. Not not.

The present inventors maintain the rigidity of PBT resin,
In addition, as a result of intensive studies to further improve toughness and dimensional stability, the present invention has been accomplished.

[0005]

OBJECT OF THE INVENTION It is an object of the present invention to provide a new resin composition having excellent strength and rigidity and excellent dimensional stability.

[0006]

The present invention relates to (a) 30 to 90 wt% of aromatic polyester, (b) 5 to 40 wt% of modified polyolefin, and (c) poly (glutarimide) represented by the following formula based on the whole composition. ) A thermoplastic resin composition comprising 5 to 30 wt%

[0007]

[Chemical 2]

[0008] The present invention will be described in detail below.

The aromatic polyester (a) used in the present invention is a polyester having an aromatic ring in the main chain of the polymer, and is an aromatic dicarboxylic acid or its ester-forming derivative and diol, or its ester-forming derivative. It is a polymer or copolymer obtained by a condensation reaction containing as a main component. Examples of the aromatic dicarboxylic acid component include dicarboxylic acids having a benzene nucleus such as terephthalic acid and isophthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, naphthalene-
Examples thereof include dicarboxylic acids having a naphthalene nucleus such as 2,7-dicarboxylic acid or ester-forming derivatives thereof.

In place of the aromatic dicarboxylic acid or the ester-forming derivative thereof, a dicarboxylic acid other than the aromatic dicarboxylic acid, which is 20 mol% or less of the acid component, such as adipic acid, sebacic acid or an ester-forming derivative thereof is used. can do. Examples of the diol component include aliphatic glycols such as ethylene glycol, tetramethylene glycol, hexamethylene glycol, diethylene glycol and cyclohexanedimethanol, 1,
A diol having an aromatic ring such as 4-bisoxyethoxybenzene or bisphenol A, or an ester-forming derivative thereof can be applied. Polybutylene terephthalate is particularly preferable as the aromatic polyester.

The modified polyolefin (b) used in the present invention is a polyolefin containing polypropylene and a glycidyl ether group and an acid anhydride group.

Polypropylene is not limited to a homopolymer, and the propylene component is 50 mol% or more, preferably 80%.
Random or block copolymers with other α-olefins containing more than mol% or ethylene-propylene-diene terpolymer rubber, ethylene-
It also includes a blend of about 40 wt% of an olefin elastomer such as propylene copolymer rubber and ethylene-butene copolymer rubber. Examples of the comonomer copolymerized with propylene include ethylene and other α-olefins, and ethylene is particularly preferable.

The polyolefin is a polyolefin obtained by copolymerizing an unsaturated monomer having a glycidyl ether group and an acid anhydride group. Examples of the unsaturated monomer having a glycidyl ether group include glycidyl methacrylate and glycidyl acrylate. Examples of the unsaturated monomer having an acid anhydride group include maleic anhydride and itaconic anhydride.

Examples of the olefin copolymerizable with the unsaturated monomer having the glycidyl ether group and the acid anhydride group include olefins such as ethylene, propylene, 1-butene and 1-pentene. These olefins may be used alone or in combination of two or more.

Further, the following general formula (II):

[0016]

[Chemical 3]

A propylene random copolymer containing a non-conjugated diene comonomer represented by: can also be used. In addition, 10w may be added to these olefins if necessary.
Monomers such as vinyl acetate, isoprene, chloroprene, and butadiene of t% or less may be added.

When the glycidyl ether group in the modified polyolefin is less than 1 wt% and the acid anhydride group is less than 0.05 wt%, the reactivity with polyester is low and the compatibility is insufficient, while the glycidyl ether group is 10 wt%. % Or the acid anhydride group exceeds 1 wt%, reactivity is increased, melt viscosity is increased, and gelation is not preferable.

Poly (glutarimide) used in the present invention
Means a polymer containing the following cyclic groups.

[0020]

[Chemical 4]

Here, R ₁ and R ₂ are hydrogen atoms or lower alkyl, preferably both R ₁ and R ₂ are methyl, and R ₃ is hydrogen atom, alkyl, aryl,
It is alkaryl or aralkyl. Lower alkyl refers to an alkyl group having 1 to 8 carbon atoms, such as methyl, ethyl, n-propyl, sec-propyl, isobutyl, pentyls, hexyls including cyclohexyl, heptyls, octyls and the like. Including straight chain, branched chain and cyclic alkyl. Substituents such as a hydroxyl group, a halogen atom and chlorine and fluorine may be present in these groups. R ₃ is preferably an alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group.

The glutarimide group comprises the only repeating unit in the polymer or other monomer, preferably a lower alkyl (meth) acrylate, more preferably methyl (meth) acrylate. Styrene, vinyl chloride,
(Meth) acrylic acid, (meth) acrylic anhydride, (meth) acrylic imide such as methacrylamide, N-methylmethacrylamide, N, N-dimethylmethacrylamide, other (meth) acrylamide, (meth) acrylonitrile Etc. are included. Preferred glutarimide polymers contain at least about 50% glutarimide, and more preferred glutarimide polymers contain at least about 80% glutarimide.

The glutarimide polymer is methacrylic acid,
Methacrylic acid ester copolymer and ammonia, amine,
Reaction of urea or unsubstituted urea at high temperature, reaction of polymethacrylic anhydride with ammonia or amine, thermal reaction to generate imide ring of methacrylic acid ester-methacrylamide copolymer, and (meth) acrylic acid ester group Can be prepared by any method known to one of ordinary skill in the art (such as reaction in solution or in the melt) of a polymer containing a high proportion of A with ammonia or amine.
A preferred method of preparation is the RM Coptic (R.
M. Kopchik) in U.S. Pat. No. 4,246,374 by reacting a polyalkylmethacrylate with an amine.

Glutarimide is described in US Pat. No. 4, M. Hallen-Abberton et al.
According to the method described in the specification of No. 727,117, a post-treatment for reducing or removing the acid and / or the acid anhydride may be performed. The acid-reduced polymers of that patent are preferred, but polyglutarimides containing acids and / or acid anhydrides are also useful in the present invention.

Each component (a) in the present invention as described above
Aromatic polyester, (b) modified polyolefin,
The blending ratio of (c) poly (glutarimide) is 30 to 90 wt% of (a) aromatic polyester based on the total composition.
(B) Modified polyolefin 5-40 wt%, (c) Poly (glutarimide) 10-20 wt%, preferably (b) Modified polyolefin 10-20 wt%, (c)
It is 10 to 20 wt% of poly (glutarimide).

When the content of the modified polyolefin (b) is less than 5% by weight, the effect of improving the impact strength of the obtained resin composition is low, and when it exceeds 40% by weight, the rigidity and the heat resistance are significantly deteriorated, which is not preferable.

Further, (c) poly (glutarimide) is 5
When it is less than wt%, the effect of improving the rigidity of the obtained resin composition is small, and when it exceeds 30 wt%, the toughness such as impact strength and tensile elongation is remarkably deteriorated, which is not preferable.

Various additives (for example, polymers, stabilizers, pigments, flame retardants, release agents, inorganic fillers, etc.) may be added to the resin composition of the present invention within the range not impairing the object of the present invention. Can be included.

Examples of stabilizers include phenolic antioxidants, phosphorus antioxidants, and sulfur antioxidants.

The phenolic antioxidant is a hindered phenol compound which is generally added to improve the heat resistance of the resin. Examples of phenolic antioxidants include, for example, 2,6-di-t-butyl-p-cresol, 2,
2'-methylene-bis (4-methyl-6-t-butylphenol), 4,4'-thiobis (3-methyl-t-butylphenol), 1,1,3-tris (2-methyl-)
4-hydroxy-5-t-butylphenyl) butane, pentaerythrityl-tetrakis [3- (3,5-di-t
-Butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t-butyl-
4-hydroxyphenyl) propionate and the like can be mentioned.

Examples of phosphorus antioxidants are triphenyl phosphite, trioctadecyl phosphite, trisnonyl phenyl phosphite, trilauryl trithiophosphite, bis (2,4-di-t-butylphenyl). Pentaerythritol-diphosphite, bis (3-methyl-1,5-di-t-butylphenyl) pentaerythritol-diphosphite, tris (2,4-di-t-butylphenyl) phosphite and the like can be mentioned. ..

As a method for preparing the thermoplastic resin composition of the present invention, any method for mixing solid substances (for example, a method using a Banbury mixer, a heating roll or a single or multi-screw extruder) can be applied.

[0033]

EXAMPLES The effects of the present invention will be further described below with reference to examples. Incidentally, all% in the examples are based on weight,
Tensile elongation is ASTM: D-638, bending strength is AST
M: D-790, impact strength was ASTM: D-256, and dimensional stability was evaluated by shrinkage.

The intrinsic viscosity is a value measured by dissolving 1.2 g of the polymer in 100 ml of orthochlorophenol and measuring at 35 ° C.

[0035]

Examples 1 to 5 and Comparative Examples 1 to 6 Polybutylene terephthalate (intrinsic viscosity 1.10) dried as an aromatic polyester at 130 ° C. for 5 hours and polypropylene modified with glycidyl ether groups and acid anhydrides. Polyolefin [Tonen Kagaku: Tonen CMP HA-30
0] and commercially available poly (glutarimide) [ROHM & Haas Co .; EXL-4241] produced by the reaction of polymethylmethacrylate and methylamine were uniformly mixed in various proportions shown in Table 1 with a V-type blender.

The obtained mixture was melt-kneaded at a barrel temperature of 250 ° C. with a twin-screw extruder having a diameter of 44 mm, and the threads discharged from the die were cooled and cut to obtain molding pellets.

Then, the pellets were dried with hot air at 130 ° C. for 5 hours, and then a test piece mold for measuring physical properties was attached to a 5 ounce injection molding machine, a cylinder temperature was 260 ° C., a mold temperature was 40 ° C., an injection pressure was 700 kg / cm ^2. , Cooling time 20
The test piece was molded under the molding conditions of second and total cycle of 35 seconds.
The results are shown in Table 1.

As shown in Table 1, when (a) PBT resin is blended with only (b) modified polyolefin, the effect of improving impact strength is observed, but the rigidity represented by flexural modulus is largely decreased (comparative). Example 2). On the other hand, (a) PB
When only the T resin (c) poly (glutarimide) resin is oriented, the rigidity is improved but the impact strength is greatly reduced (Comparative Example 3). According to the present invention, (a) PBT resin,
By combining the modified polyolefin (b) and the poly (glutarimide) resin (c) in specific amounts, it becomes possible to obtain a resin composition having excellent strength and rigidity, high impact strength, and good dimensional stability. ..

[0039]

[Table 1]

Claims (4)

[Claims] 1. (a) 30-90 w of aromatic polyester
t%, (b) modified polyolefin 5-40 wt%, and (c) poly (glutarimide) 5-30 represented by the following formula.
A thermoplastic resin composition comprising wt%. [Chemical 1] 2. The thermoplastic resin composition according to claim 1, wherein the aromatic polyester is polybutylene terephthalate. 3. The modified polyolefin has a glycidyl ether group of 1 to 10 wt% and an acid anhydride group of 0.05 to 1 wt.
The thermoplastic resin composition according to claim 1, which is polypropylene containing 10% by weight. 4. The thermoplastic resin composition according to claim 1, wherein the poly (glutarimide) is N- (lower alkyl) dimethylglutarimide.