JPS58103552A - Polyester composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. capable of giving moldings having a beautiful surface and good shape retention in low-temp. molding, by mixing with a polyethylene terephthalate, a specific amt. of glass fiber, an inorg. filler, and a crystallization accelerator. CONSTITUTION:5-50wt% glass fiber, 5-40wt% inorg. filler (e.g., talc), a particle size <=30mu, 1-15wt% crystallization accelerator selected from epoxy compds of a polyol or derivatives thereof (e.g., ethylene glycol monoglycidyl ether, glycerol diglycidyl ether), and 0-10wt% releasing agent (e.g., sodium stearate) are mixed together to yield a polyester compsn. A molding with a beautiful surface and good shape retentim may be obtained, since crystallization is propagated to the surface layer of the molding even when molding at a temp. below 100 deg.C.

Description

[Detailed description of the invention] The present invention relates to polyester compositions for molding.

More specifically, the present invention relates to a polyethylene terephthalate composition containing specific amounts of gaff steel, an inorganic filler, and a crystallization accelerator.

A new polyester composition for molding that allows crystallization to proceed to the surface layer of the molded product even when molded at a mold temperature of 100°C or less, and allows a molded product with a beautiful surface and good shape stability to be obtained. It provides:

Polyethylene terephthalate has excellent heat resistance, chemical resistance, mechanical properties, electrical properties, etc., and is a fiber.

It is used as a film in many industrial products.

However, when used as a general molded product in plastic applications, polyethylene terephthalate has 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 molded at a mold temperature of 100°C or lower, which is normally used by general-purpose molding machines for thermoformable resins. In this case, the shape stability of the molded product deteriorates considerably. More specific Kij, gold! ! ! Temperature is 50-80
At ℃, the surface of the molded product is rapidly cooled and becomes transparent, while the inside is slowly cooled and becomes an opaque, non-uniform structure. When these molded products are used at a temperature of 80° C. or higher, crystallization of one surface layer gradually progresses, causing the appearance to lose its luster and the dimensions of the molded products to change. In addition, when molding is performed at a mold humidity of 8'0 to 120°C, crystals will partially form on the surface of the molded product, causing apatter collapse and flow patterns, as well as extremely poor mold release properties, making molding virtually impossible. be. The polyethylene terephthalate molding materials that have been developed so far have a gold level of at least 140
If the temperature is not above ℃, it will not be possible to obtain a molded product with excellent heat resistance and 1-dimensional stability. Gold WM knitting with a temperature of 140°C or higher is not common and has extremely low work efficiency.Although polyethylene terephthalate has excellent properties as an engineering plastic, it is not suitable for industrial use under such special molding conditions. Currently, its use is severely restricted.

The inventors have 1 normal hot part! It has excellent moldability even when molded at a mold humidity of 70 to 100°C, where molding of 1-1km 1ll is performed, and has high heat deformation humidity and heat resistance dimension stability. As a result of intensive research, we have arrived at the present invention. i.e. 1
The present invention uses polyethylene terephthalate or a polyester having at least SOS or higher ethylene terephthalate repeating units, (a) 5 to 50 weight glass fibers - 1 (b) 5 to 40 weight inorganic fillers with a particle size of 30 μm or less.
1(C) At least one crystallization accelerator selected from epoxy compounds of polyhydric alcohols or derivatives thereof.
The composition of the present invention has excellent moldability even when molded at a mold humidity of 70 to 100°C. It is possible to provide a molded article having a good surface roughness, excellent 6 o'clock dimensional stability even when exposed to a high humidity atmosphere of 100°C or higher, and a thermal deformation degree of 1lIiVh.

The polyester used in the present invention is polyethylene terephthalate or at least 80- or higher.

Preferably, it is a copolyester containing Fieo- or higher ethylene terephthalate repeating units.

As the copolymerization component, conventionally known acid components and/or glycol components can be used.

That is, as a copolymerization component, for example, isophthale a11. Naphthalene-2,6-dicarboxylic acid.

Acid components such as adipic acid, diphenyl ether 4,4'-dicarboxylic acid, sepacic acid, propylene glycol, neopentyl glycol, diethylene glycol, V
Clohexanedimethanol-7, a glycol component such as 2+2-bis(4-hydroxyphenyl)propane,
p-oki vIj! -Zozoic acid s9-hydroxy V ethoxy 5y
Examples include oxy-V acids such as tRzoic acid. In addition, polyester is a phenol/tetrachloroethane mixed metal solution K.
(6/4 weight ratio) It is preferable that the intrinsic viscosity determined by measuring a solution at 30°C is 0.5 or more, and * is 0.
It is particularly preferable that it is 55 or more. It was. It may also be a mixture consisting mainly of the above polyester and other thermoplastic resins in amounts and types that do not depart from the gist of the present invention.

Further, the glass fiber used in the present invention may be an ordinary glass fiber used for reinforcing plastics, and has a diameter of 3.
~30μ is preferred. Depending on the manufacturing method, various shapes such as roving and chopped strands can be used. Further, it is preferable that the glass fiber has been subjected to a treatment such as V-Fun treatment or chromium treatment for the purpose of improving adhesion to plastics. The blending amount is usually 5 to 50% by weight, preferably 5 to 40% by weight per polyester. Compared to polyester, if it is less than 5% by weight, it cannot be used as an engineering plastic that has low dimensional accuracy and heat deformation humidity in a high temperature atmosphere of 100°C or higher, and has heat resistance.In addition, 1+, the present invention Examples of inorganic fillers used include Merck (mainly 3Mg0.4SiOs.nHsO), clay (mainly Aj, 01.2SiOs.2HsO), kaolin (mainly Ajlol.2S10 snow.2HsO),
Mica (aluminosilicate containing alkali metals (mainly 2
1hO・3AJ*Os・6SiOtomi・2HmO)s
Asbestos (mainly 3M1i0, 2SiO!, 2H
*0), silicates such as calcium silicate, silica, gypsum, etc., and these are used alone or in combination. However, particularly preferred are silicates. Further, the average particle diameter of these inorganic fillers is not more than *aOμ, preferably not more than 1J1Oμ. Particularly preferred are calcium silicate and silica #i with a particle diameter of 500 mμ or less.

Further, as a composition for molding a thin molded article with Kt7't, C, a fine particulate inorganic filler having a particle size of 500 mμ or less and an inorganic filler having a particle size of 30 μm or less and exceeding 500 mμ are used in combination. is more preferable from the viewpoint of dimensional accuracy and heat distortion temperature. The blending amount is usually 5 to 40% by weight per saryester, preferably more than 5% by weight.
The rice weighs less than 0 weight. When the amount of inorganic filler is less than 5% by weight, when molded at 100° C. or less at a total temperature of 1 MM, the surface layer of the molded product becomes amorphous and the dimensional change at 6 o'clock becomes large.

In addition, the heat distortion temperature is lowered. If the weight of the blended lid exceeds 40%, the fluidity during molding will be poor, the surface properties of the molded product will deteriorate, the elongation at break will decrease, and the toughness of the molded product will decrease.

Further, in the composition of the present invention, the combination of glass fiber and inorganic filler has a total content of 10 to 60% of polyester. In particular, it should be 15 to 50 weight cakes [10
One-dimensional stability at heat distortion temperature of molded products obtained by molding with a low mold resistance of 0°C or less.

It has special properties in terms of moldability and other physical properties.

In the present invention, in order to sufficiently promote crystallization of the molded article even when molded at a temperature of 100° C. or less, it is necessary to further include the following crystallization accelerator. That is,
Examples include epoxy compounds of polyhydric alcohols or derivatives thereof.

Compounds belonging to this mK include, for example, a compound similar to the general formula A: aliphatic membered water group with C1<I, hydrogen or glycyl group Ri: ◆Residue of a hydrolic alcohol t or its derivative m = positive integer Examples include compounds represented by: ethylene glycol monoglycidyl ether, ethylene glycol monomethyl ether, propylene glycol monoglycol V-sil ether, propylene gelicol diglycidyl ether, butanediol monoglycidyl ether, butanediol di- Glycidyl ether, hexane V all digly V ether, glycerin sigly V ether.

Glycerin triglycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane diglycidyl ether, glycidyl ether of ethylene glycol monomethyl ether, glycidyl ether of ethylene glycol hair nobutyl ether, glycidyl ether of hexyl glycol dimethyl ether, etc. ) or polyglycidyl ether. Particularly preferred is Sigri V dielether of alkylene glycol.

In the present invention, one or more ears of the above-mentioned crystallization accelerator is blended with the polyester in an amount of 1 to 15 weights, preferably 2 to 10 weights. If the amount of the crystallization accelerator is less than 1 weight, crystallization will not be sufficiently promoted in the molded noodle skin at 100° C. or less.

In the present invention, when a mold release agent is used in combination, the moldability is further improved due to the synergistic effect with the crystallization promoter. The release agent used is preferably an ester of a fatty acid of s C1s -C@・ with an alcohol, a metal salt of the fatty acid of group 1A or Fi group 11A of the periodic table, or a mixture thereof, such as stearic acid. Metal salts of stearic acid such as sodium, magnesium stearate, and calcium stearate.

Examples include metal salts of montanic acid such as sodium montanate and calcium montanate. These may be used alone or in combination of two or more.

The blending amount is 0 to 10 weight based on the polyester, preferably 0.01 to 3 weight i1.

The present invention fundamentally changes the conventional idea of molding polyethylene terephthalate, which is to shorten the molding cycle as much as possible at a high mold temperature of 140°C, and instead The aim is to obtain a molding material with excellent moldability and heat-resistant properties under molding conditions of low mold humidity, similar to enlinear plastics. In order to achieve this purpose, it is possible only by blending appropriate amounts of three components: glass fiber, inorganic filler, and crystallization promoter, and if even one of these components is missing, the moldability and heat resistance will be affected. It is completely impossible to produce a polyethylene terephthalate molding material with excellent physical properties. Furthermore, moldability can be further improved by adding a mold release agent. Also, as a matter of course, this composition is
It is also possible to mold at a high mold temperature.

In that case, the crystallization rate becomes even faster, so the molding cycle becomes shorter and the moldability improves.

The composition of the present invention may further contain polyester stabilizers such as antioxidants and ultraviolet absorbers, as well as additives such as plasticizers, lubricants, flame retardants, antistatic agents, and colorants, depending on the use and purpose. May be blended.

The method for producing the polyester composition of the present invention is not particularly limited, and any method may be used. For example, polyester and all other components are mixed in advance and the mixture is fed to an extruder and melt-mixed, or polyester and all components other than glass fiber are mixed in advance and the mixture is fed into an extruder. , after coating the melt around the glass roving and cooling it! Examples include a so-called electric wire coating method in which the wire is cut into appropriate lengths, a method in which glass fiber or an inorganic filler is added during or after the polyester polymerization, and then all other components are mixed therein.

The molded product obtained from the composition of the present invention undergoes sufficient crystallization under normal molding conditions and maintains excellent performance such as dimensional accuracy, thermal deformation intensity, and mechanical properties. . The composition of the present invention can be widely used for molding various implanted parts, sheet-like products, tubular products, laminates, containers, etc., but considering its excellent electrical resistance, it is particularly suitable for molding electrical parts, automobile parts, etc. suitable.

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

Excellent in the examples means weight, unless otherwise specified. 1
Various measurements in one example and molding of the test piece were carried out in accordance with the following procedures.

(1) Measured in accordance with ASTM D-648, using a test piece with a thickness of 1/B inch and a load of *18.64/-.

(2) 120c [Shape 1t (Jito).

According to heat deformation sensitivity measurement: test piece thickness 1/8 inch;
It was operated under a load of 18.6 kf/- and the quality of the lid was measured at 120°C.

(3) Heat shrinkage: Molding a disk with a diameter of 100 cm and a thickness of 3 cm, the length at an angle of 450 to the side gate is 40, and the length after processing at 150 ° C or 160 ° C for 1 hour in a gear open. Calculated using a linear formula when the value is 1.

(4) Mold releasability and surface characteristics of molded products The mold separation and spool removal during molding of a disc with a diameter of 100 mm and a thickness of 3 mm were evaluated. In addition, the surface characteristics were determined by the surface gloss and flow pattern of the disk.

○: Good Δ: Fairly good Δ~×: Ten-poor The predetermined lid was placed on the lid and mixed in the tampurupre goo. Next, this was put into the hopper of a 40 .phi. pent type extruder and melted and kneaded at 250-275-280 DEG C. (from the hopper side) to produce compound chips of each composition. The obtained compound chips were dried under reduced pressure at 120"cs for 4 hours, and each test piece was molded using an injection molding machine. The molding machine used was a Nichigeki Ankelberg model N-95, and the molding conditions were cylinder noodle skin 280-280-275. ℃, mold humidity 85℃, injection holding time 15 seconds, cooling time 15 seconds, injection pressure 300-6
Molding was performed at 00 kf/clA.

Example 1 Polyethylene terephthalate Talc (Talcan Powder PK, Hayashi Kasei Co., Ltd.) with an average particle size of 10 μm.

Average 'B% 50 mμ calcium silicate (Silmos T
.

Table-1
They were mixed in the proportions shown below and a test piece was molded. The mold releasability, surface properties, thermal deformation degree, and deformation amount at 120°C (
δ12o) and the heat shrinkage rate after treatment at 150° C. for 1 hour were measured, and the results are shown in Table 1.

As is clear from Table 1, the comparative example (Al 2 )ti in which no crystallization accelerator was added had poor mold releasability, and severe flow patterns occurred on the surface of the molded product, especially on the surface including the parting fins. The 126°C quality Sugi Oboro δ110 is also large, and the surface layer of the molded product is not sufficiently crystallized.

On the other hand, the composition of the present invention, in which a polyhydric alcohol epoxy compound is blended as a crystallization accelerator in a composition containing glass fiber and an inorganic filler, has improved mold releasability and surface properties, and has a high silver thermal deformability.

A molded product with a low heat shrinkage rate and an excellent heat deformation temperature was obtained.

Comparative Example Composition #'i containing polyethylene wax, etc. Not only was the mold release property 1 not improved at all, the surface properties were not improved at all.
On the contrary, the mold releasability deteriorated depending on the compounding agent.

In addition, these comparative examples also had high mineral m @ deformed lids.

Example 2 Polymer ethylene terephthalate, talc having an average diameter of toμ, and calcium silicate having an average particle diameter of 50 mμ.

Glass chopped strands of 3M length, ethylene glycol diglycidyl ether and calcium salt of sodium stearate or montanic acid as aHM agent (
Wax OP (Hoechst Japan Co., Ltd.) was blended in the proportions shown in Table 2, and a molded article was molded. Note that the mold release agent was triblended during molding. The molded product was measured for mold release properties (5) and surface characteristics (120°C deformation (6120)), and the results are shown in Table 2.

As is clear from Table 2, by using the crystallization accelerator of the present invention in combination with a mold release agent, even better mold release properties and surface properties could be obtained than in K.

Example 3 Polyethylene terephthalate), talc with an average particle size of 10 μm, and calcium silicate with an average particle size of 50 μm.

Glass chopped strands with a length of 3 mm, a crystallization accelerator (ethylene glycol diglycidyl ether) and a mold release agent (wax OF) were blended in the proportions shown in Table 3,
A test piece was molded. In addition, the mold release agent is triblended during molding.

The a-type 1 surface characteristics and heat absorption Iki and a half of the obtained molded article were measured, and the results are shown in Table 3.

As is clear from Table 3, the amount of the crystallization accelerator needed to be 1% or more based on the polyester.

Preferably it is 2% or more. However, if the glass fiber compounding source or the inorganic filler compounded waste deviates from the scope of the present invention, the improvement of the mold releasability and surface properties will be insufficient even if the crystallization accelerator of the present invention is added. It also has a high heat shrinkage rate.

Claims (1)

[Claims] 1. Polyethylene terephthalate or at least 8
For polyesters having 0- or more ethylene terephthalate repeating units, (a) glass fine 5 to 50
j6. (b) Inorganic filler with a particle size of 30μ or less 5 to 40% by weight 1 (C) Epoxy V of polyhydric alcohol or its derivative
At least 1 crystallization accelerator selected from compounds 1-
15% by weight and (d) a mold release agent in an amount of 0 to 10% by weight. 2. Polyethylene terephthalate or at least 8
A composition according to Patent Application No. 8, Paragraph 1, which comprises a polyester having 0 or more ethylene terephthalate repeating units, and a total of 10 to 60 weight of glass fiber and an inorganic filler.