JPS5891760A - Polyester composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. consisting of a specified organic crystallization accelerator, a polyepoxy compd. and a solid inorganic filler, having excellent moldability at low temp. and producing molding products with a high surface luster. CONSTITUTION:The compsn. is prepared by adding (B) 0.1-20wt% at least one organic crystallization accelerator selected from among higher fatty acid ester (e.g. methyl stearate) and polyhydric alcohol deriv. (e.g. neopentyl glycol distearate), (C) 0.1-15wt% polyepoxy compd. (e.g. ethylene glycol diglycidyl ether), (D) 5-40wt% solid inoganic filler with a particle diameter of 30mu or smaller (e.g. talc) and, when necessary. (E) 10wt% or less reaction catalyst (e.g. sodium stearate) are added to (A) polyethylene terephtalate or copolyester containing at least 80% ethylene terephalate repeating unit which has an intrinsic viscosity of 0.4 or higher.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyester composition suitable as a low temperature molding material. More specifically, it relates to a new polyester composition that exhibits excellent moldability when molded at a low mold temperature of 100°C or less, and provides molded products with excellent surface properties and physical properties.0 Polyethylene terephthalate has excellent heat resistance, chemical resistance, and mechanical properties. Fiber with excellent physical and electrical properties.

It is used as a film in many industrial products.

However, when used in plastic applications as injection molded products, polyethylene terephthalate suffers from many drawbacks in molding due to its special crystallization behavior. That is, polyethylene terephthalate is originally a crystalline polymer, but because it has a high secondary transition point, it is typically processed using molding machines for general-purpose thermoplastic resins.
When molding is performed at a low source mold temperature below .degree. C., the shape stability of the molded product at temperatures above the secondary transition point becomes significantly poor.

Furthermore, it has disadvantages such as a long residence time in the mold and poor mold releasability, as well as the formation of avatar-like or flow patterns on the surface of the resulting molded product. In order to improve these drawbacks, it is necessary to shift the crystallization initiation acidity of polyethylene terephthalate to the lower humidity side, increase the crystallization rate, and sufficiently promote pressure crystallization to the surface layer of the molded article. In order to increase the crystallization rate, a nucleating agent, especially an inorganic filler such as talc or titanium oxide, is generally mixed in at a rate of 0.5 to 1 g#,%. It has the disadvantage that its effectiveness as a crystallization nucleating agent varies greatly depending on its diameter distribution, uniform dispersibility, etc., and that a sufficient effect cannot be obtained even if the amount added is increased. In particular, it is difficult to shift the crystallization initiation humidity to the lower side, and crystallization of the surface layer of the molded product in the lower mold is completely insufficient.

In addition, compositions containing metal salts of mono- or polycarboxylic acids to promote crystallization are also available under Japanese Patent Publication No. 47-4097'.
8, Japanese Patent Publication No. 47-14502, and compositions containing both the above-mentioned inorganic fillers and carboxylic acid metal salts are also known from Japanese Patent Publication No. 47-32435"l, etc., but none of the compositions It is impossible to obtain a molded product having high surface layer crystallinity and excellent i-type properties and physical properties by molding at a low temperature of 100° C. or lower.

The present inventors have conducted intensive research on a method for shifting the crystallization initiation temperature of polyethylene terephthalate to a lower temperature side and increasing the crystallization rate, and as a result, they have arrived at the composition of the present invention. That is, the present invention provides at least one organic crystallization promoter (b) selected from polyethylene terephthalate or polyethylene having at least 80 repeating units of ethylene terephthalate (a), higher fatty acid esters, and polyhydric alcohol derivatives. , polyepoxy compound (
c) A composition comprising a solid inorganic filler (d) with a particle size of 30 μm or less as an essential component, and optionally a reaction catalyst, wherein the component (b) is 0.00% of the component (a). 1-20
This is a polyester composition characterized by containing Mk%, component (C) of 15% by weight or less, and component (d) of 5 to 40% by weight.

The composition of the present invention has excellent moldability at low mold temperatures of 100°C or less, ie, short molding cycles.

It exhibits excellent surface properties and mold releasability, and can be molded with a low-temperature mold using a general-purpose injection molding machine to obtain a molded product with good surface gloss and no flow patterns.

In addition, it has great industrial value because molded products with excellent heat resistance and low heat deformation and shrinkage can be obtained by low-temperature mold molding. Further, even when a molded product is molded at a mold temperature of 100° C. or lower, the surface layer crystallinity of the molded product can easily reach 0.5 or higher.

Surface crystallinity (A) in the present invention is 100 mm in diameter and 3 in thickness.
Crystalline band 1 of the total internal reflection infrared absorption spectrum of a sample cut from the molded product by injection molding
335 muscle-1 (I) and correction band 1405 cm-' (
Io) is calculated by equation (1).

■ The scale A used in the present invention is a factor that accurately represents the crystallinity of the surface layer of a molded product. When polyethylene terephthalate is molded at a mold temperature of 100°C or less, the surface layer of the molded product is almost transparent and the value of A is is about 0.15 or less. - When the sample is heat-treated at 150°C for 1 hour, crystallization progresses almost completely and the value of A increases to 1.05. Low-crystalline molded products become highly crystalline through high-temperature heat treatment, but they also undergo thermal deformation, making them completely unsuitable as molded products. Therefore, the object of the present invention is to provide a composition that provides a molded article with high surface layer crystallinity even after being heat-treated after low-temperature molding.

In order to provide high surface crystallinity during molding at low mold temperatures, the type and blending ratio of the organic crystallization accelerator are particularly important. It is also important to appropriately select the diameter and blending ratio, the type and blending ratio of the polyfunctional compound such as polyepoxide, the type and blending ratio of the reaction catalyst for the polyfunctional compound, and the combination and blending ratio of these various compounding agents. It is. In the composition of the present invention, the organic crystallization accelerator mainly activates the mobility of the glycol moiety of polyethylene terephthalate and promotes the crystallization of the surface layer of the molded article, but the polyfunctional compound also partially acts on the polyethylene terephthalate. It is thought that it reacts with the end groups and causes a crosslinking reaction with a low partial crosslinking density to induce molecular orientation of polyethylene terephthalate in the mold during injection molding, promoting crystallization. The polyfunctional compound reacts with the carboxyl group at the end of the polyester, etc., even in the absence of a catalyst, and exhibits its effect, but in order to effectively exhibit the effect of the polyfunctional compound, it is preferable to use a reaction catalyst in combination.

In the present invention, it is important to further incorporate a large amount of solid inorganic filler. The solid inorganic filler, in combination with the organic crystallization promoter, polyfunctional compound, etc., can promote crystallization and improve heat-resistant dimensional stability.

The polyester used in the present invention is polyethylene terephthalate or at least 80% or more, preferably 90%
This is a copolyester containing the above ethylene terephthalate repeating units. The copolymerization components include conventionally known acid components and /-! or glycol components can be used. That is, as a copolymerization component, for example, isophthalic acid,
Naphthalene 1,4-4-2,6-dicarboxylic acid, diphenyl ether 4,4'-dicarboxylic acid, adipic acid,
Acid components such as sebacic acid, propylene glycol, butylene glycol, diethylene glycol, neopentyl glycol, cyclohexane dimetatool, 2.
Examples include glycol components such as 2-bis(4-hydroxyphenyl)furopane, oxyacids such as p-oxybenzoif'[, and p-hydroxyethoxybenzoic acid. In addition, polyester has an intrinsic viscosity of about 0.4 or more when measured at 30°C with a phenol/tetrachloroethane mixed m lf'l' = (6/4 weight ratio) solution, but it is usually about 0.5. It is preferable that it is equal to or more than 0, and more preferably 0
．． It is particularly preferable that it is 55 or more. Further, the polyester may be partially branched within a range that does not impair moldability.

In addition, examples of the organic crystallization promoter used in the present invention include higher fatty acid esters, polyhydric alcohol derivatives, etc., and specifically higher fatty acid esters such as edel montanate and methyl stearate, neopentyl esters, etc. Examples include polyhydric alcohol esters such as glycol distearate and pentaerythritol distearate. The compound lid is 0.1 to 20% by weight based on polyester.
It is preferably 0.2 to 15 times, particularly preferably 1 to 15 times.

In addition, the polyepoxy compound used in the present invention is not particularly limited as long as it has two or more epoxy groups in the molecule, but in particular, ethylene glycol diglycidyl ether, propylene gelicol diglycidyl ether, butylene Glycol diglycidyl ether, hexamethylene glycol diglycidyl ether, glycerin polyglycidyl ether, neopentyl glycol diglycidyl ether, pentaerythritol polyglycidyl ether, trimethylolpropane polyglycidyl ether, epoxidized products of polyhydric alcohols and unsaturated acid esters (polyhydric alcohols and unsaturated acid esters) Examples include glycidyl esters of alcohols.

Alternatively, it may be a bisphenol type epoxide. The amount of the compounded lid is usually 15% by weight or less based on the polyester, preferably 0.1 to 10% by weight, particularly preferably 0.2 to 8% by weight.

Furthermore, a common epoxy curing catalyst can be used as a reaction catalyst for the polyfunctional compound which may be added as desired. That is, primary amines, secondary amines,
Examples include tertiary amines, Lewis acid salts, metals from Group 1A'' or Group 1IA of the periodic table, and compounds thereof.
They may be used alone or in combination of two or more. However, particularly preferred catalysts are metal salts of higher fatty acids, such as sodium stearate, calcium stearate, sodium montanate, calcium montanate, and the like. reaction M
K varies depending on the type, the type and amount of the polyfunctional compound used, the type and amount of the organic crystallization accelerator, etc., but is usually 10% or less per polyester, preferably 0.1 to 5. It is a heavy fit%.

It is necessary to further incorporate a solid inorganic filler into the composition of the present invention. The filler can further improve moldability due to its synergistic effect with the organic crystallization promoter, and can provide a molded article with extremely good heat resistance. The solid inorganic fillers used include, for example, Merck (mainly 3Mg0.4Si02.nH20) *clay (mainly A12os.2Si02-10-2H20), kaolin (mainly Al20B.2Si0).
2.2H20), mica (aluminosilicate containing alkali metals, mainly 20.3AJ1208.6Si0)
2.2H20), asbestos (mainly 3Mg0.2S
i02・2H20), silicates such as calcium silicate,
Silica, gypsum, etc. are used alone or in combination. The average particle size of the solid inorganic filler is usually 30μ or less.

The thickness is preferably 10μ or less.

The composition of the solid inorganic filler is 5 to 40% by weight and improves moldability, heat resistance, dimensional accuracy when heated, etc. - The composition of the present invention is a combination of polyester, a specific organic crystallization accelerator, and a polyfunctional The composition consists of a functional compound, a solid inorganic filler as essential components, and a reaction catalyst of a polyfunctional compound as necessary.
The surface layer crystallinity of a molded article molded at a mold temperature of 100° C. or lower is at least 0.5, preferably 0.7 or higher. When the surface layer crystallinity is 0.5 or less, the mold releasability is poor and the surface layer of the molded article is covered by the thin amorphous HK, causing unevenness to appear on the surface layer of the molded article. Therefore, it also has the disadvantage that it is impossible to obtain a molded product with a usable value at a mold temperature of 100° C. or less. When the surface layer crystallinity is 0.5 or more, crystallization up to Table N is promoted, but there are also cases where the mold releasability and surface gloss are poor.

Furthermore, when it is 0.7 or more, both mold releasability and surface gloss are significantly improved. Since the amount of the composition of the present invention differs depending on the type and composition of each of the above-mentioned ingredients, it is difficult to define a uniform ratio of ingredients.

Note that when the composition of the present invention is molded at a mold temperature of 100°C or less, the molded product (disk with a diameter of 100 mm and a thickness of 3 mm)
Another major feature is that it maintains the excellent electrical properties of polyester, as it provides a water absorption rate of 0.2% by weight or less when treated underwater at 3°C for 3 days.

The method for producing the composition of the present invention is not particularly limited, and any method may be used. For example, polyester, an organic crystallization accelerator, and optionally a polyfunctional compound, an inorganic filler, etc. may be made into a powder, and an inorganic filler, a reaction catalyst, etc. may be triblended at the time of molding.
Alternatively, the entire composition may be compounded from the beginning using an extruder.

However, the mixing method and blending timing are not necessarily limited to these.

Furthermore, a fibrous reinforcing agent may be added to improve the heat distortion temperature of the molded article. Examples of the fibrous reinforcing agent include glass fiber, carbon fiber, metal carbide fiber, metal nitride fiber, and the like.

Depending on the use and purpose, the composition of the present invention may further contain stabilizers for polyester, such as antioxidants and ultraviolet absorbers, as well as plasticizers, mold release agents, lubricants, flame retardants, antistatic agents, and antifouling agents. 1.Additives such as colorants may be added. Further, the polyester composition of the present invention may further contain other thermoplastic resins of various types and types without departing from the gist of the present invention, if desired.

The composition obtained in this way can be molded not only in high-temperature molds but also in low-temperature molds to give molded products with excellent moldability and surface properties, so it can be used for various molded parts, sheet-like products, and tubular products. It can be widely used for forming objects, laminates, containers, etc.

13- Considering its excellent electrical resistance, it is particularly suitable for molding electrical parts, automobile parts, etc.

The present invention will be explained below with reference to examples. In addition.

In the examples, "chi" means 1% by weight unless otherwise specified. Further, in one example, molding of the test piece and various evaluations of the obtained molded product were performed according to the following methods.

(1) Test piece molded polyethylene terephthalate (&1iJil viscosity!0.6
(0° melting point: 264°C) and other ingredients were weighed and mixed in a tumble plate. Next, this is 400φ
Pour into the hopper of a vented extruder.

Cylinder temperature (from hopper side) 250-275-2
Compound chips of each composition were produced by melt-kneading at 80°C. The obtained dung pound chips were heated at 120°C, 4
After drying under reduced pressure for an hour, each test piece was molded using an injection molding machine. The molding machine used is Nisko Ankelperg N-95 type, and the molding conditions were: cylinder temperature 280-280-275°C, mold temperature 85°C, injection holding time 15 seconds, cooling time 15 seconds, injection pressure 300~ Molded with 600414-/-.

(2) Mold releasability and surface characteristics of molded products The mold separation and spool removal when molding a disk with a diameter of 100 square meters and a thickness of 3 square feet were evaluated. In addition, the surface characteristics were judged by the surface gloss and flow pattern of the disk.

◎: Very good ○: Good Δ: Fairly good X: Poor
xx: Extremely poor (3) IR surface layer crystallization A 40×18m+ sample was cut out from the above disk.

Total reflection infrared absorption spectrum analyzer (Hitachi 28
Infrared absorption spectrum was taken with 5ffi.

1335m-1 crystalline absorption band CI) and 1405 steel-
The crystallinity (A) of the surface layer of the molded article was determined from the correction band (10) of No. 1 using the equation (1) above.

(4) Heat distortion temperature Measured according to ASTM D-648, with a test piece thickness of 1/8 inch and a load of 18.6 kf/-.

(5) Deformation amount at 120°C (δ120) Using the heat deformation temperature measurement method, the test piece was heated to a thickness of 1/8 inch and a load of 18.6 kf/cFA, and the deformation at 120°C was measured in a cabinet.

(6) Heat Yield N Rate A disk with a diameter of 10 Qaoi and a thickness of 3M is molded, and its length at an angle of 45' to the side gate is io.

After processing for 1 hour at 150℃ in a gear oven, the length is 1
It was calculated using the following formula.

(7) Water absorption rate The water absorption rate when the above disk was treated in water at 23°C for 3 days was determined by the following formula.

Examples 1゜Polyethylene terephthalate, glass chopped strands with a length of 3 mm (glass long chopped strands 48 mm)
6A, Asahi Glass Fiber Company).

Talc (Talcan Powder PK) with an average particle size of ioμ.

Hayashi Kasei), calcium silicate (Silmos T, Shiraishi Calcium Co., Ltd.) with an average particle size of 50 mμ, and organic crystallization promoter 1 reaction catalyst were blended in the proportions shown in Table 1, and the mold temperature was 85°C, radius was 5 cm, and thickness was 3. A disk-shaped test piece was molded. The obtained molded article was evaluated for Wl type property, surface characteristics, and surface layer crystallinity, and the results are shown in Table 1.

17- As is clear from Table 1, all of the compositions of the comparative examples that gave an IR surface crystallinity of 0.5 or less had poor mold releasability and/or surface properties, making it impossible to form into pieces. there were.

Furthermore, when higher fatty acid ester was used alone, the mold release property during low-temperature molding was unsatisfactory even when used with a relatively large number of needles.

On the other hand, the composition of the present invention, which uses a higher fatty acid ester and a polyepoxy compound in combination, has excellent M and moldability.

surface properties and surface layer crystallinity of 0.7 or higher.

Example 2 Polyethylene terephthalate, solid inorganic filler, glass fiber used in Example 1 and the crystallization accelerator shown in Table 2,
The polyfunctional compound 1 reaction catalyst was blended in the proportions shown in Table 2, and a test piece was molded in the same manner as in Example 1.

W1 type property 1 surface characteristics, IR surface layer crystallinity, thermal deformation temperature, and thermal deformation density at 120°C (δ120) of the obtained molded article.

The heat yield N rate and water absorption rate were evaluated and the results shown in Table 1-2 were obtained.

19- -20- The composition of the present invention using a combination of a montanic acid ester and a polyepoxy compound gave a molded article having excellent moldability and thermal dimensional accuracy by low-temperature molding.

Patent applicant: Toyobo Textile Company 21-

Claims (1)

[Claims] 1. Polyethylene terephthalate or at least 8
Polyester having 0% or more of ethylene terephthalate repeating units (a), at least one organic crystallization accelerator selected from higher fatty acid esters and polyhydric alcohol derivatives (b), polyepoxy compound (C) 1 particle size is 30
A composition comprising a solid inorganic filler (d) of μ or less as an essential component, and optionally a reaction catalyst, wherein the component (b) is 0.1 to 20% by weight based on the component (a). A polyester composition characterized in that component (C) is blended in an amount of 15 weight percent or less and 11 it percent or less, and component (d) is blended in a proportion of 5 to 40 weight percent.