KR840000471B1 - Polyethylene terephthalate resin compositions - Google Patents

Abstract

Polyethylene terephthalate resin compsn. consists of (A) PET having intrinsic viscosity of 0.35-0.9(in o-chlorophenol at 35oC) and per 100 pts. wt. PET., (B) 5-200 pts. wt. inorganic filler, (C) 0.1-20 pts. wt. dimethyl or diethyl terephthalate, and (D) 0.01-5 pts. wt. of salt of carboxylic acid with Gp I or II metal or 0.1-10 pts. wt. of ionic copolymer of alpha-olefin with salt of alpha, beta, beta-unsatd. carboxylic acid contg. ion of Gp I or II metal.

Description

Resin composition

The present invention relates to a polyethylene terephthalate resin composition. In particular, the present invention relates to a polyethylene terephthalate resin composition having high crystallinity, excellent moldability and dimensional stability.

Polyethylene terephthalate resins have excellent properties such as mechanical properties, chemical resistance, electrical properties and heat resistance, and are widely used in electrical insulation parts, automobile parts, and the like.

These properties of polyethylene terephthalate resins are improved by adding various additives such as fiber reinforcements, ie, glass fibers or carbon fibers and functional agents such as flame retardants and the like, and thus the use of polyethylene terephthalate resins is gradually expanding.

Polyethylene terephthalate resins belong to crystalline resins and their properties mainly depend on their degree of crystallinity. Therefore, it is necessary to increase the degree of crystallinity in order to improve its dimensional stability and heat distortion temperature. Therefore, various methods have been proposed as a means of promoting the degree of crystallization of polyethylene terephthalate resins. For example, a method has been proposed in which a molded article obtained in a partially crystallized state undergoes post-heat treatment and then proceeds to crystallization, and a method of dipping the molded article into a liquid that promotes crystallization. However, these methods require some post-treatment after molding, but post-treatment is not a preferred method because of the drawback that the molded article is deformed.

Moreover, in order to promote crystallization of the resin during molding processing, a method of injecting molten resin into a mold heated to a high temperature and solidifying it in a mold is known. This method requires the use of a heating medium in order to keep the mold at a high temperature, which, in view of the safety of the molding operation, furthermore is not preferred in that the molding cycle is relatively long.

In recent years, crystal forming agents have been used to shorten the molding cycle. Although such a method enables high crystallinity in a fairly short time, there is still plenty of room for improvement. For example, when a nucleation agent is added to a polyethylene terephthalate resin, it is necessary to use a high temperature mold of about 130 to 140 ° C. British Patent No. 3,015,014 discloses that when a crystal growth agent is used in combination with a nucleation agent, the temperature of the mold can be significantly lowered. However, this method also has a lot of room for improvement in that a very large amount of crystal growth agent to be used is required, and therefore the inherent properties of polyethylene terephthalate resin are adversely affected. By combining a specific amount of dimethyl terephthalate or dimethyl terephthalate with a specific metal salt of carboxylic acid or a specific ion copolymer and blending it with polyethylene terephthalate resin, molding is possible at a molding temperature of 85 ° to 110 ° C. In addition, it was found that a molded article having excellent dimensional stability and heat resistance was obtained.

Therefore, it is the most important object of this invention to provide the polyethylene terephthalate resin composition which can obtain the molded article of the outstanding characteristic by shape | molding at the shaping | molding temperature of 85 degreeC-110 degreeC.

Other objects to be seen in the above object and the following technology can be achieved by the polyethylene terephthalate resin composition according to the present invention composed of the following (A), (B), (C), (D).

(A) polyethylene terephthalate having an intrinsic viscosity of 0.35 to 0.9 per 100 parts by weight of polyethylene terephthalate resin as measured in an ortho-chlorophenol solution at 35 ° C .; (B) 5 to 200 parts by weight of the inorganic filler; (C) 0.1 to 20 parts by weight of dimethyl terephthalate or diethyl terephthalate; And (D) α, β-unsaturated carboxylates and α- containing 0.01 to 5 parts by weight of a carboxylic acid salt by a metal of Group I or Group II of the Periodic Table, or metal ions of Group I or Group II of the Periodic Table. 0.1 to 10 parts by weight of the ionic hybrid polymer with olefins.

The polyethylene terephthalate resin which can be used as the component (A) belongs to polyethylene terephthalate which can be obtained by using terephthalic acid or its ester derivative as an acid component and ethylene glycol or its ester derivative as a glycol component. However, polyethylene terephthalate obtained by substituting a part of the terephthalic acid component or the ethylene glycol component with a component capable of hybrid polymerization is also useful. Examples of such hybrid polymerizable components include isophthalic acid, phthalic acid, alkyl-substituted phthalic acids (e.g., methyl terephthalic acid and methylisophthalic acid), naphthalene-dicarboxylic acids (e.g., naphthalene-2,6-dicarboxylic acid, Such as naphthalene-2,7-dicarboxylic acid and naphthalene-1,5-dicarboxylic acid), diphenoxyethanedicarboxylic acids (e.g., 4,4'-diphenoxyethanedicarboxylic acid) Aromatic dicarboxylic acids; Aliphatic and alicyclic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, azelaic acid, decadicarboxylic acid and cyclohexanedicarboxylic acid; Aliphatic and alicyclic diols such as trimethylene glycol, tetramethylene glycol, hexamethylene glycol, neopentyl glycol, diethylene glycol, 1,4-cyclohexanedimethanol and the like; Dihydroxybenzenes such as hydroquinone and resorcinol; Bisphenols such as 2,2-bis (4-hydroxyphenyl) -propane and 2,2-bis (4-hydroxydiphenyl) -sulfone; Ether diols obtained from bisphenols and glycols such as ethylene glycol; hydroxycarboxylic acids such as ε-hydroxycaproic acid, hydroxybenzoic acid and hydroxyethoxybenzoic acid, and the like. These hybridizable components can be used alone or as a mixture of two or more. Preferably, they are used in amounts up to 20 mol% of the total amount of carboxylic acids (hydroxycarboxylic acids should be calculated in half of the carboxylic acid).

Polyethylene terephthalate undergoes side chain hybridization with trifunctional or tetrafunctional ester-forming compounds such as tricarvalic acid, trimesic acid or trimellitic acid. Polyesters can be used alone or as a mixture of two or more.

The polyethylene terephthalate resin usable in the present invention should have an intrinsic viscosity of 0.35 to 0.9 preferably 0.45 to 0.8 when measured at 35 ° C. using ortho-chlorophenol as the solvent. When polyethylene terephthalate resin having an intrinsic viscosity of 0.35 or less is used, a molded article having low strength is obtained. When the intrinsic viscosity is 0.9 or more, the molded article produced has a poor gloss surface appearance due to the low dispersibility of the resin composition and is unstable in mechanical and thermal properties.

Inorganic fillers (B) usable in the present invention include fibrous reinforcements such as glass fibers, asbestos, carbon fibers and potassium titanate, powders such as mica, silica, talc, potassium carbonate, glass beads, glass flakes, clay and wollastonite, Granular and plate-shaped inorganic fillers;

Dimethyl or diethyl terephthalate usable as component (C) are combined with the carboxylate or inorganic ion hybrid polymer of component (D) to function as intended in the present invention. The amount of terephthalate added is 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight per 100 parts by weight of polyethylene terephthalate resin. If the amount of terephthalate added is 0.1 parts by weight or less, the practical effect of promoting crystallization cannot be achieved. In the case where terephthalate is added in an amount of 20 parts by weight or more, the crystallization promoting effect does not increase and the strength of the resulting molded article decreases.

Carboxylic acid salts usable as component (D) are selected from carboxylate salts of Group I and Group II metals of the periodic table, for example acetic acid, propionic acid, caproic acid, palmitic acid, stearic acid, oleic acid, behenic acid, mon Metal salts of aliphatic monocarboxylic acids such as carbonic acid, methacrylic acid, and acrylic acid, metal salts of aliphatic dicarboxylic acids such as oxalic acid, adipic acid, succinic acid, sebacic acid, maleic acid and fumaric acid, benzoic acid, terephthalic acid and phthalic acid; The metal salt of the same aromatic carboxylic acid, etc. belong. Suitable metals include sodium, potassium, lithium, magnesium, potassium, zinc and the like. Not all carboxyl groups should always be neutralized with such carboxylic acid salts, but some of the carboxyl groups are in the form of salts and the remaining groups may be in free acid or ester form.

The component (D) is preferably an ion interpolymer with α, β-unsaturated carboxylates and α-olefins containing ions of Group I or Group II metals of the periodic table. Such ion interpolymers can be prepared by known methods described in US Pat. Nos. 3,639,527, 3,264,272, 3,338,739 and 3,404,134.

An example of an ionic hybrid polymer is a polymer having units of the following structural formula.

In the above formula,

R ₁ is hydrogen, phenyl or alkyl of 1 to 12 carbon atoms,

R ₂ is hydrogen, methyl or ethyl,

Me is a metal element of group I or group II of the periodic table,

X and Y are each an integer from 1 to 100

n is an integer from 10 to 10,000.

Ionic interpolymers of α-olefins with α, β-unsaturated dicarboxylates, such as ionic hybrids of maleate or itaconic acid salts containing ethylene and Group I or Group II metal ions can also be used.

Another example of an ionic interpolymer is an ionic graft interpolymer obtained by graft polymerizing an α, β-unsaturated carboxylic acid ester to a polyolefin, saponifying a graft polymer, and then reacting with an alkali metal hydroxide.

It is preferable that the above-mentioned ion hybrid polymer contains at least 50 weight% of olefins. Particularly suitable are interpolymers having an olefin content of 80 to 99% by weight.

Another example of an ionic interpolymer is an interpolymer having the following units (a), (b) and (c).

In the above formula

R ₁ , R ₂ and Me are the same as defined above,

R ₃ is hydrogen, methyl or ethyl,

R ₄ is hydrogen or alkyl of 1 to 12 carbon atoms,

X, Y and Z are each an integer of 1 to 100.

These ionic interpolymers should contain at least 50% by weight of olefins, in particular interpolymers having an olefin content of 80 to 90% by weight. It is preferable that the total content of the ester component ((c)) and the ionic component ((b)) is at least 10% by weight and the content of the ionic component ((b)) is at least 3% by weight of the weight of the ionic hybrid polymer. Not all carboxyl groups of the ionic hybrid polymer need always be neutralized, but at least 10% of the carboxyl groups should be neutralized by the metal ions.

Particularly preferred metal ions are alkali metal ions, with sodium ions being particularly preferred. Particularly preferred ionic hybrid polymers are ionic hybrid polymers containing alkali metal ions, in particular sodium ions.

The carboxylic acid salt of component (D) described above should be added in an amount of 0.01 to 5 parts by weight, preferably 0.05 to 3 parts by weight, per 100 parts by weight of polyethylene terephthalate resin. If the amount added is 0.01 part by weight or less, the practical effect of promoting crystallization cannot be obtained. If the amount is 5 parts by weight, the crystallization promoting effect does not increase and the strength of the resulting molded article is lowered. The ion interpolymer should be added in an amount of 0.1 to 10 parts by weight per 100 parts by weight of polyethylene terephthalate. If the amount is 0.1 parts by weight or less, the crystallization promoting effect is practically not obtained, and the crystallization promoting effect does not increase even when the amount is 10 parts by weight or more.

The polyethylene terephthalate resin composition may further mix various additives to improve other properties. Halogen-containing compounds such as, for example, decabromobiphenyl ether, octabromobiphenyl ether, halogenated polycarbonate oligomers (eg, polycarbonate oligomers obtained from brominated bisphenol A) or halogenated epoxy compounds, Phosphorus compounds such as red or triphenylphosphate, phosphorus-nitrogen compounds such as phosphonic acid amide, and the like can be blended as carbonaceous agents, or carbon adjuvant such as antimony trioxide or zinc borate can be added. In addition, in order to improve heat resistance, the resin composition may contain an antioxidant or a heat stabilizer such as a hindered phenol compound, an organophosphorus compound, or a sulfur compound. Moreover, an epoxy compound may be added to the resin composition to improve melt viscosity stability, hydrolysis resistance or similarity thereof. Examples of such epoxy compounds include bisphenol A epoxy compounds obtained by the reaction of bisphenol A and epichlorohydrin, glycols or aliphatic glycidyl ethers obtained by the reaction of glycerol and echlorohydrin, novolak resins and echlorohydrin. Novolak-type epoxy compounds obtained in the reaction, aromatic or aliphatic carboxylic acid-type epoxy compounds and alicyclic compound-type epoxy compounds obtained from alicyclic compounds, and the like, bisphenol A epoxy compound and diglycidyl ether of low molecular weight polyethylene glycol Is preferred. Other additives such as ultraviolet absorbers, colorants, lubricants, blowing agents and the like may also be added as desired.

In addition, other thermoplastic resins such as styrene resin, acrylic resin, polyethylene, polypropylene, fluoroplastic resin, polyamide resin, polycarbonate resin or polysulfone; Thermosetting resins such as phenol resins, melamine resins, unsaturated polyester resins or silicone resins; Or small amounts of resins such as ductile thermoplastics such as ethylene-vinyl acetate interpolymers or polyester elastomers and the like.

The polyethylene terephthalate resin composition according to the present invention may be prepared by any conventional compounding method. Each of the components is preferably dispersed uniformly throughout the composition, and the components can be mixed evenly by introducing all or separately separated into a mixing machine such as a blender, kneader, roll, extruder and the like. Typically, the components are previously dry mixed, the mixture melt mixed in a heated extruder to be extruded into bed, and finally the extruded yarn can be cut into granules of the desired length. The molding composition thus obtained is usually dried and then molded. On the other hand, components (B) and (D) may be added to component (A) before, during or after polycondensation in the production of polybutylene terephthalate resin.

The polyethylene terephthalate resin composition according to the present invention can make a molded article with excellent crystallinity which can be molded at a wide range of molding temperatures, and can provide a molded article with excellent dimensional stability. It is advantageous that the polyethylene terephthalate resin composition has a high dispersibility as measured in an injection molding machine having a screw die.

The invention will be explained in more detail by the following examples, where the properties of the product were determined as follows.

(1) Heat deflection temperature.

It is measured according to the method of ASTM D648 with a load of 264 psi.

(2) appropriate strength.

Tensile strength is measured according to the method of ASTM D638, and flexural strength and modulus are measured according to the method of ASTMD790.

(3) shrinkage.

Injection molding is performed using a mold having an internal volume of 110 mm x 110 mm x 2 mm, and the molding shrinkage rate and heat shrinkage rate are calculated by the following equation:

The molded product dimension mentioned above is this dimension after leaving to stand at 25 degreeC for 48 hours. The molded product dimensions after heat treatment are the molded product dimensions after being annealed at 130 ° C. for 2 hours and then left at 25 ° C. for 48 hours.

[Examples 1-3 and Comparative Examples 1-8]

Polyethylene terephthalate resin having an intrinsic viscosity of 0.64 was dried at 130 ° C. for 5 hours, and the additives shown in Table 1 were added in the given amounts, followed by uniform mixing in a V-type mixer. The mixture is melt kneaded at a barrel temperature of 270 ° C. in an injection molding machine with a diameter of 68 mm, and then pelletized by cooling to cut the yarn injected from the mold.

The pellet was hot-air dried at 130 ° C. for 5 hours, and then injection molded into a small sample at an injection pressure of 800 kg / cm ^{2 at a} mold temperature of 85 ° C. and a cylinder temperature of 270 ° C. The cool down time is 20 seconds and the cycle is completely over in 35 seconds.

The obtained results are also shown in Table 1.

TABLE 1

^* DMT: Dimethyl Terephthalate

^** DET: Diethyl Terephthalate

^*** Sodium montanate is based on partial salts of aliphatic carboxylic acid mixtures with 22 to 32 carbon atoms.

^**** X: Flow pattern observed. ○: no flow pattern was observed.

It can be clearly seen from Table 1 that in the absence of both component (C) and component (D) a molded article with low crystallinity and inferior surface appearance is produced. In contrast, the molded article used by combining both component (C) and component (D) has high crystallinity, high heat deformation temperature, low shrinkage rate and excellent surface appearance.

[Examples 4 to 9 and Comparative Examples 9 to 11]

The results described above using polyethylene terephthalate resin (A), inorganic filler (B), crystal growth body (C) and crystal nucleating agent (D) having an intrinsic viscosity of 0.65 as shown in Table 2 below. Repeat.

The results obtained are shown in Table 2.

TABLE 2

^{*, **, ***, ****} : DMT, DET, Sodium Montanate and the surface outline are the same as defined in Table 1 above.

It can be clearly seen from Table 2 that when the component (C) is 1 part by weight or less, high crystallinity cannot be obtained, and when the component (D) is 5 parts by weight or more, the strength decreases. However, molded articles of the composition within the scope of the present invention have high crystallinity and good surface appearance.

[Examples 10-12 and Comparative Examples 12-15]

Polyethylene terephthalate pellets having an intrinsic viscosity of 0.64 were dried at 130 ° C. for 5 hours, in a V-type mixer in the amounts given in Table 3 together with 3 mm long chopped glass fibers and dimethyl terephthalate or diethyl terephthalate and an ionic copolymer. Mix uniformly at The mixture was the pellet to cool following which a barrel temperature of 280 ℃ melted in a diameter of 65mm extruder, dried at 130 ℃ 5 hours hot air, silryeon Temperature 270 ℃, mold temperature 85 ℃, injection pressure 800kg / cm ² Cooling time 20 Secondly, injection molding is performed on the specimen by a 5 oz. Injection molding machine with a specimen mold under conditions of 35 sec. The properties of the molded article thus obtained are shown in Table 3 below.

The sounded ion interpolymer in this example is an interpolymer having 90 parts by weight of ethylene and 10 parts by weight of methacrylic acid in which the carboxyl group is neutralized with sodium ions. The melt index of this hybrid polymer is 0.1g / 10min or less according to the method of ASTM D1238-57T and the particle size is 300 to 500.

TABLE 3

^{*, **, ***, ****} : DMT, DET, and sodium montanate and the surface outline are the same as defined in Table 1 above.

In the absence of component (C) or component (D), a low crystalline molded product is produced, and when (C) component and (D) component are blended according to the present invention, high crystallinity, high heat distortion temperature, and low It is clearly shown in Table 3 that molded articles having shrinkage and good surface appearance are made.

Example 13

100 parts by weight of polyethylene terephthalate pellet having an intrinsic viscosity of 0.72 was dried at 140 ° C. for 4 hours, uniformly mixed with 42 parts by weight of cut glass fiber having a length of 3 mm and 3 parts by weight of diethyl terephthalate in a tumbler machine, and the mixture was mixed. Pelletizing was carried out in the same manner as in Example 10. The pellets thus obtained were hot-air dried at 140 DEG C for 3 hours, and then 5 parts by weight of an ion hybrid polymer (particle size of about 500 mu) of high-pressure polyethylene neutralized with sodium hydroxide and grafted with 6 mol% of acrylic acid per 100 parts by weight of pellets. Mix it up. This mixture is injection molded under the same conditions as in Example 10. The molded article thus obtained has the following characteristics including gloss and excellent surface appearance.

Heat deformation temperature: 206 ℃ Tensile strength: 1,300kg / cm ²

Mold shrinkage rate: 1.3% Flexural strength: 1,900kg / cm ²

Heat Shrinkage: 0.13% Wogo Modulus: 88,000kg / cm ²

Example 14

64 parts by weight of polyethylene terephthalate pellets having an intrinsic viscosity of 0.64 were dried at 130 ° C. for 5 hours, and 10 parts by weight of cut glass fiber having a length of 3 mm, 20 parts by weight of talc (Talcum Powder PKN, manufactured by Hayashi Kasei Co., Ltd., Japan) and dimethyl 1 part by weight of terephthalate and 5 parts by weight of the same ionic hybrid polymer as used in Example 10 were mixed and pelletized in the same manner as described in Example 10, and the pellet was made into the same molded article as in Example 10. The molded article thus obtained has the following characteristics including gloss and excellent surface appearance.

Heat deformation temperature: 200 ℃, shrinkage rate: 0.8%, heat shrinkage rate: 0.1%, tensile strength: 1,100kg / cm ² , bending strength: 1,400kg / cm ²

Claims (1)

(A) Polyethylene terephthalate resin having intrinsic viscosity of 0.35 to 0.9 per 100 parts by weight of polyethylene terephthalate resin, as measured in an ortho-chlorophenol solution at 35 ° C., (B) 5 to 200 parts by weight of inorganic filler, (C (Alpha), beta containing 0.1 to 20 parts by weight of dimethyl terephthalate or dietherephthalate and (D) 0.01 to 5 parts by weight of carboxylate salts of Group I or II metals of the Periodic Table or Group I or II metal ions of the Periodic Table. A polyethylene terephthalate resin composition composed of 0.1 to 10 parts by weight of an ionic polymer of an unsaturated carboxylate and an α-olefin.