JPS6268848A - Polyester copolymer composition for injection molding - Google Patents

Abstract

PURPOSE:To obtain a composition injection-moldable with a low-temperature mold, having excellent heat-resistance and surface appearance and exhibiting little lowering of mechanical strength in humid atmosphere, by compounding a specific polyester copolymer with a crystallization nucleus and a reinforcing filler. CONSTITUTION:(A) 100pts.(wt.) of a polyester copolymer containing the segments of (i) a polyethylene terephthalate having an intrinsic viscosity of 0.15-0.38, (ii) 35-80mol% (based on the PET) polyether having an average molecular weight of 300-2,000 and (iii) 10-80mol% (based on the PET) polyether derivative having at least one organic acid metal salt is compounded with (B) 0.01-10pts. of a crystallization nucleus and (C) 0-200pts. of a reinforcing filler. The polyether of the component A is selected from polyalkylene glycol and an alkylene oxide addition polymer of a bisphenol.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a polyester copolymer composition for injection molding. More specifically, it is based on a polyester copolymer containing a low molecular weight ω polyester, a specific polyether, and a specific polyether M conductor as a segment,
A polyester for injection molding that can be injection molded using a low-temperature mold containing a crystallization nucleating agent and a reinforcing filler, has excellent heat resistance, has little mechanical strength loss under high humidity, and has an excellent surface appearance. The present invention relates to polymer compositions.

[Prior art/problems to be solved by the invention] A high molecular weight line obtained from a dicarboxylic acid mainly composed of terephthalic acid or its ester-forming derivative, and a diol mainly composed of ethylene glycol or its ester-forming derivative Polyethylene terephthalate has a high softening point, heat resistance, chemical resistance, light resistance, and other excellent electrical and physical/mechanical properties, so it is widely used in fibers, films, and molded products. has been done.

Since such polyethylene terephthalate has a slow crystallization rate, a mold temperature of 140° C. or higher is required when injection molding is performed.

In order to improve this drawback and allow molding to be performed using a low-temperature mold,
Methods of introducing various crystallization promoters are known.

For example, Japanese Patent Publication No. 48-4097, Japanese Patent Publication No. 48-4
No. 098 discloses the addition of an organic acid metal salt, JP-A-53-6
In JP-A No. 5354, aliphatic oligoester was added, and in JP-A-54-150458, polyalkylene group was added.
- Addition of boxylated substances to recalls, Special Publication No. 11n55-4
Various methods, such as adding a plasticizer and an ionomer, are proposed in Japanese Patent Publication No. 7058 and Japanese Patent Publication No. 55-47059.

However, polyethylene terephthalate to which these crystallization promoters have been added has poor heat resistance and moisture resistance if it can be molded at a mold temperature of 90°C, and conversely, if it can be molded at a mold temperature of 90°C or higher, it can be molded at temperatures above 100°C. mold temperature is required.

On the other hand, it is also known to improve the crystallization rate by introducing a soft segment by copolymerization as a crystallization promoter.

For example, Journal of Polymers +1
Vol. 8, p. 1 (1952) describes a method for copolymerizing polyethylene glycol, and Journal of Polymer Science, vol. 14, p. 15 (1954) describes a method for copolymerizing ethylene oxide addition polymers of bisphenols. JP-A-58-13B753 discloses a method of copolymerizing a condensation of two or more molecules of an alkylene oxide addition polymer of bisphenols. Further, Japanese Patent Publication No. 47-13138 proposes a method of copolymerizing polytetramethylene glycol.

By copolymerizing soft segments, these
This method increases the crystallization rate by increasing the mobility of molecules.

Although it certainly has an improvement effect from the viewpoint of moldability at a mold temperature of 90 to 110°C, if the mold temperature is less than 90°C, the balance between moldability, heat resistance, and moisture resistance is still lacking. In particular, at a mold temperature of 60 to 85°C, the appearance of the molded product is poor, and the reality is that no resin that can be put to practical use as an injection molding resin has yet been produced.

It has long been known that low-molecular-weight polyethylene terephthalate has a high crystallization rate, but it has not been studied much because of its low physical properties such as tensile strength.

The present invention utilizes original low molecular weight polyethylene tere-4
= This was done with the aim of finding a resin that can withstand practical use as a resin without interfering with the high crystallization rate of phthalate.

[Means for solving problems]

Surprisingly, the present invention has been achieved by blending a crystallization nucleating agent and a reinforcing filler into a polyester copolymer in which low-molecular-weight polyethylene terephthalate is linked with a specific polyether compound and a specific polyether derivative. This was made based on the discovery that a material for injection molding with a good balance of moldability, heat resistance, moisture resistance, and surface appearance can be obtained using a low-temperature mold of ~85°C. , +1) (A) polyethylene terephthalate 1-1 having an intrinsic viscosity of 0.15 to 0.38, (B) a polyether having an average molecular weight of 300 to 2000 and 35 to 80 mol% based on component (A); and (C) at least 10% to 80% of component (A).
Polyether derivatives with organic acid metal salts -ρ
- Polyester copolymer 10 containing a conductor as a segment
(2) Crystallization nucleating agent 0 parts (weight part, same below)
．． and (3) 0 to 200 parts of reinforcing filler.

[Example] Polyethylene terephthalate, which is component (A) used in the present invention, is obtained by direct esterification reaction or It is obtained by transesterification, and has a molecular weight of 0.15 to 0.38, preferably 0.20 to 0.3
Intrinsic viscosity of 5 (phenol/tetrachloroethane-50
150 (weight ratio), concentration 0.5%, 25°C).

The remaining dicarboxylic acid component 00 to 10 mol% has 6 carbon atoms.
-14 other aromatic dicarboxylic acids, aliphatic dicarboxylic acids having 4 to 8 carbon atoms, alicyclic dicarboxylic acids having 8 to 12 carbon atoms, or mixtures thereof. Examples of such dicarboxylic acid components include phthalic acid, isophthalic acid,
Examples include 2,6-naphthalene dicarboxylic acid, 4,4°-diphenyldicarboxylic acid, syn-Tnylethane-4,4°-dicarboxylic acid, adipic acid, lobasic acid, and cyclohexyl dicarboxylic acid.

Furthermore, 0 to 10 mol% of the remainder of the diol component is an aliphatic diol having 3 to 1 carbon atoms, an alicyclic diol having 6 to 15 carbon atoms, an aromatic diol having 6 to 12 carbon atoms, or a mixture thereof. 1-1 good.

Examples of such diol components include propane-1,
3-diol, butane-1,4-diol, pentane-
1,5-diol, hexane-1,6-diol, cyclohexane-1,4-dimetatool, 2,2-dimethylbroban-1,3-diol, ? , 2-upper 2-4′-hydroxycyclohexyl)-propane, 2,2-bis(
4-hydroxyphenyl)propane, hydroquinone f
＞What can be said?

Furthermore, 10% of the dicarboxylic acid component and the diol component
Oxycarboxylic acids such as ε-oxycaproic acid, human O-oxybenzoic acid, etc. may be copolymerized in an amount of up to mol%. It may also be branched with a trihydric or tetrahydric alcohol, or a tribasic acid or a tetrabasic acid; examples of such branching agents include trimesic acid, trimellitic acid, trimethylolpropane, and pentameric acid. Examples include erythritol.

The intrinsic viscosity of the polyethylene terephthalate is 0.15.
If the amount is less than 0.38, the amount of polyether, which is the component (B) described below, will increase too much and a composition with excellent physical properties and balance cannot be obtained. If it exceeds 0.38, the resulting polyester The polymer only exhibits a crystallization rate similar to that of regular polyethylene terephthalate.

The polyether component (B) used in the present invention is a bifunctional polyether compound with an average molecular weight of 300 to 300.
2000, preferably 400-1500.

Examples of such include, for example, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, J-ethylene oxide-propylene oxide copolymers (random and/or block).
, polyalkylene glycols such as ethylene oxide-tetrahydrofuran copolymers (random and/or block), propylene oxide gotetrahydrofuran copolymers (random and/or block), general formula: In the formula, A is a substituted or unsubstituted alkylene group having 1 to 8 carbon atoms, a divalent group such as -0-, '-3-, -3o-di or -Co-, and R1 and R2 are 1-1, carbon ethylene oxide, propylene oxide and tetrahydrofuran.
Compounds such as alkylene oxide addition polymers of bisphenols obtained by adding more than one type of bisphenols, and diglycidyl ethers of the aforementioned polyalkylene glycols can be mentioned. These may be used singly or in combination of two or more. Among these, polyalkylene glycols such as polyethylene glycol and alkylene oxide addition polymers of bisphenols are preferred, as the resulting compositions have good moldability in low-temperature molds, heat resistance, and moisture resistance, and have a good balance among them. When the purpose is to do so, alkylene oxide addition polymers of bisphenols are particularly suitable.

If the average molecular weight of these polyethers is less than 300, when two molecules of polyethylene terephthalate are bonded via the polyether, the crystallization rate is the same as simply doubling the molecular weight of polyethylene terephthalate. decreases. When the average molecular weight exceeds 2000, the crystallization rate of polyethylene terephthalate is kept high, but the amount of polyether used increases, so it is necessary to improve physical properties such as heat resistance and moisture resistance, and to maintain a good balance between them. You won't be able to keep it well.

The amount of copolymerization of the polyether can vary depending on the average molecular weight of the polyether itself and the molecular weight of the polyethylene terephthalate, so it cannot be determined unconditionally, but it is usually 35 to 80 mol%, preferably 35 to 80 mol% based on the number of moles of the polyethylene terephthalate. 40-75 mol%, more preferably 45-6
It is used in a range of 0 mol%. When ω is less than 35 mol%, the effect of promoting crystallization becomes significant, and when it exceeds 80 mol%, the balance of physical properties such as moisture resistance deteriorates.

The number of moles of polyethylene terephthalate referred to in this specification refers to the number of moles of polyethylene terephthalate referred to in "Di Macromolekulare Hemy" Vol. 26, 2.
It is based on the number average molecule ω calculated from the following formula described in page 26 (19581): % formula % (in the formula, T and V represent the intrinsic viscosity and Rn represents the number average molecular weight).

The polyether derivative having at least one organic acid metal salt, which is the component (C) used in the present invention, has main repeating units of -0R3, -, (R3 is a divalent hydrocarbon group of 01 to Cog) It is typically represented by the general formula: %Formula%) (wherein, R4 is hydrogen or a p-valent organic group, and R3 is 02-
C4 aliphatic hydrocarbon group, n is 0 or a positive integer, R5
is a group containing hydrogen or an organic acid metal salt, provided that at least one 85 in one molecule is an organic acid metal salt, p is 1
(a positive integer of ~6).

For example, such polyether derivatives are produced by esterifying a polyoxyalkylene of a monofunctional or polyfunctional alcohol with a polyhydric carboxylic acid anhydride in the presence of a basic catalyst or an acid catalyst as necessary, and then converting the remaining carbon It can also be obtained by converting an acid into a metal salt, for example, by combining a polyoxyalkylene of a functional or polyfunctional alcohol with a halide containing a metal salt of sulfonic acid or phosphoric acid in the presence of a catalyst, if necessary. It can also be obtained by reacting below.

Specific examples of such polyether derivatives include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide-propylene oxide copolymer, heptanosuccinic acid ester potassium salt such as alkylene oxide addition polymer of bisphenols, and monophthalic acid. Ester sodium salt, calcium salt, zinc salt, aluminum salt, mono (tetrabromo)
Phthalate ester sodium salt, monotrimellitic acid ester sodium salt, monotrimellitic acid ester monosodium salt of monomethoxypolyethylene glycol, glycerin-alkylene oxide adduct, trimethylolpropane-alkylene oxide adduct, pentaerythritol-alkylene oxide Additive things,
Di- or triphthalic acid ester sodium salt, and mono-, di- or tri(tetrabromo) phthalic acid ester sodium salt, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide-propylene oxide copolymer, polyhydric alcohol-alkylene oxide Examples include sulfonic acid or phosphate sodium salts and calcium salts of mono-, di-, tri- or tetraphenyl ethers such as h1 compounds.

Of course, the polyether derivatives are not limited to those exemplified above.

These may be used alone or in combination of two or more.

Polyether derivatives containing these organic acid metal salts (B
), the surface appearance of molded bodies from the compositions of the invention is significantly improved. This is due to the copolymerization of polyoxyalkylene chains with a low glass transition point into polyester with good compatibility, resulting in a combination of the mobile core of the polyester chains and the effect of the organic acid metal salt, which is a nucleating agent component. It is estimated that

The molecular weight range of the polyether derivative is preferably from 200 to 20,000, more preferably from 300 to 5,000, from the viewpoint of compatibility with the polyester chain.

The amount of the polyether derivative used is usually 10 to 80 mol%, preferably 20 to 60 mol%, based on the number of moles of the polyethylene terephthalate, in view of the level of crystallization promoting effect. If the internuclear content is less than 10% by mole, the surface appearance will not be improved, and if it exceeds 80% by mole, the physical properties such as heat resistance and moisture resistance will be good, and a good balance between them will be obtained. become unable.

The gold content in the polyether derivative varies depending on the type and molecule of the polyoxyalkylene, the type of thermal antioxidant to be blended, etc., but is usually 0.01 to 20% by weight, preferably 1 to 10% by weight. -] b - Yes. Among organic acid metal salts, carboxylic acid metal salts,
Particularly preferred are alkali metal salts of aromatic carboxylic acids.

In addition, polyoxyalkylene compounds containing halogen-containing organic acid metal salts such as tetrabromophthalic acid monoester sodium salt have the effect of improving surface properties, improving flame retardancy, and achieving a high level of thermal oxidative stability. It is preferable to have both.

In the present invention, polyethylene terephthalate, which is the component (A), and component (A), which is the component (B), have a
80 mol% polyether and component (C) (^
) It is essential to use a polyester copolymer containing 10 to 80 mol % of a polyether derivative as a segment based on the component.

In both cases, the copolymer made of polyethylene terephthalate and polyether, and the Kyodo 1fi-copolymer made of polyethylene terephthalate and polyether derivative, have good moldability, heat resistance, moisture resistance, and J: The object of the present invention, which is to obtain a composition with excellent texture and surface appearance, cannot be achieved.

The polyester copolymer used in the present invention contains segments based on polyethylene terephthalate, polyether, and polyether derivatives] and 15% by weight based on the total weight.
Hereinafter, other copolymer segment components and/or other polymers may be used, preferably in an amount of 10% by weight or less.

Specific examples of the above-mentioned copolymer segment components include aliphatic polyester oligomers, polysiloxane compounds, polyconjugated dienes having a terminal hydroxyl M, and specific examples of other polymers include: Examples include polybutylene terephthalate, polycarbonate, and polyamide.

Examples of the crystallization nucleating agent used in the present invention include the following various commonly known crystallization nucleating agents.

-1n- (1) Polyoxyalkylene compounds having organic acid metal salts, such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, disuccinate potassium salt, cyphthalate ester sodium salt, such as ethylene oxide-propylene oxide copolymer, Calcium salts, zinc salts, aluminum salts, di(tetrabromo)phthalate sodium salts, monotrimellitic acid ester sodium salts of monomethoxypolyethylene glycol, glycerin-alkylene oxide adducts, trimethylolpropane-alkylene oxide adducts of triphthalic acid Ester sodium salt, tri(tetrabromo)phthalate sodium salt, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, disulfonic acid ester sodium salt of ethylene oxide-propylene oxide copolymer, silicic acid ester sodium salt or dicurine Trisulfonic acid ester sodium salts such as acid ester sodium salts, alkylene oxide adducts of glycerin or trimethylolpropane, I-lyphosphate ester sodium salts, triphosphite ester sodium salts, calcium salts, and the like.

(2) Refers to salts of ionic copolymers α-olefins or copolymers of aromatic olefins and α,β-unsaturated carboxylic acids, such as sodium salts, potassium salts, or ethylene/maleic acid copolymers. Zinc salts, sodium salts, potassium salts or zinc salts of ethylene/methacrylic acid copolymers, butium salts, potassium salts or zinc salts of ethylene/itaconic acid copolymers, styrene/maleic anhydride copolymers Examples include sodium salt, potassium salt or zinc salt.

The carboxylic acid may be only partially or completely neutralized.

Further, the copolymer of α-olefin and α,β-unsaturated carboxylic acid may be copolymerized with an acrylic acid ester such as methyl acrylate, ethyl acrylate, or butyl acrylate as a third component.

(3) Organic acid salts such as sodium acetate, sodium benzoate, p-t
- Sodium butylbenzoate, sodium hydrogen phthalate, disodium phthalate, magnesium stearate,
Examples include calcium stearate, sodium stearate, and sodium palmitate.

(4) Inert inorganic substances such as sodium carbonate, calcium carbonate, calcium silicate, magnesium silicate, calcium sulfate, magnesium sulfate, barium sulfate, zinc oxide, magnesium oxide,
Examples include titanium oxide, clay, talc, kaolin, alumina, and silica.

The amount of these crystallization nucleating agents added is 10% of the polyester copolymer.
The amount is 0.01 to 10 parts relative to 0 parts, and 1 may be advantageously selected depending on the type of crystallization nucleating agent.

Since the above-mentioned polyester copolymer itself has a high crystallization rate, a sufficient effect can be obtained by adding a small amount. If the - is less than 0.01 part, a sufficient addition effect cannot be obtained,
If it exceeds 10 parts, physical properties such as tensile strength will deteriorate.

Examples of reinforcing fillers used in the present invention include glass fibers, mineral miscellaneous materials, carbon fibers, silicon carbide 111H, and II carbide.
I fiber, potassium titanate fiber, gypsum mII, mica, talc, kaolin, clay, asbestos, calcium silicate, calcium sulfate, calcium carbonate, etc., but especially glass fiber, mica, talc, mineral 11i
1 is preferred, and these may be used singly or in combination of two or more. Further, in order to improve the affinity with the resin, the surface may be treated with a surface treatment agent such as a silane coupling agent.

The amount of reinforcing filler is 0 to 100 parts of polyester copolymer.
It is used in an amount of 200 parts, preferably in the range of 1 to 120 parts.

Conventionally, when fillers, especially glass fibers, are blended, the fillers are exposed on the surface of the molded product and the surface appearance becomes dull, but in the polyester copolymer used in the present invention, mechanical properties can be improved without impairing the surface appearance. Strength is increased.

The compositions may contain conventional crystallization promoters, such as mono- or dinonylphenyl ethers, octylphenyl ethers, oleyl ethers, oleyl ethers, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide-propylene oxide copolymers, etc. Polyoxyalkylene compounds having hydrocarbon groups such as methyl ether; neopentyl glycol dibenzoate, dioctyl phthalate triphenyl phosphate, butane-1,3-diol adipate oligomer, butane-1,4-diol adipate oligomer, hexane-1, Plasticizers such as 6-diol adipate oligomer, dibutyl sebacate and dioctyl sebacate; organic ketones such as benzophenone; organic sulfones such as diphenyl sulfone; organic sulfonamides such as N-ethyl-toluenesulfonamide and N-stearyl-toluenesulfonamide; lauryl nitrile , (2) An organic nitrile such as lucyl nitrile may be used in combination.

Furthermore, if necessary, flame retardancy may be imparted using ordinary salmon flame agents or flame retardant aids, and mechanical and electrical properties may be improved using various polymers, rubbers, etc. , small amounts of other additives such as thermal antioxidants, light stabilizers, pigments, dyes, and lubricants may be added to the extent that the physical properties are not impaired.

In this way, an injection molding material with excellent moldability in a lower mold at 60 to 85°C, heat resistance, mechanical strength under high humidity, surface appearance, etc., and an excellent balance of these properties can be obtained.

The present invention will be described in detail below with reference to Examples, but the present invention is not limited to these Examples.

-Dod- The tensile strength of the test piece is ASTHD 638, thermal deformation M
illll(]-6-”thickness, 18.6Kfl/cd
Weight) was measured in accordance with ASTHD648, heat resistance was evaluated by thermogravimetric analysis at 260°C in the air, and weight loss rate after 1 hour, and moisture resistance was measured in an oven at 70°C with 100% relative humidity. The tensile strength retention rate after being left for one day was evaluated, and the surface appearance was visually evaluated for molded products at a mold temperature of 70°C.

Example 1 Ethylene oxide addition polymer of bisphenol A to polyethylene terephthalate with [η) = 0.30 dllo (bisphenol A/ethylene oxide j =
= 1/16 (mole ratio), average molecular weight 1000) to 5
0 mol % and 25 mol % of polyethylene glycol monophthalate Na salt (average molecular weight: 1373) were added and copolymerized. Obtained polyester copolymer 100
1 part, 45 parts of glass fiber N having a length of 3 mm, and 0.0 parts of an antioxidant (Irganox 1330, manufactured by Ciba Geigy).
5 parts, 6 parts% Na salt of ethylene-methacrylic acid copolymer (ethylene/methacrylic acid = 85/15 (II ratio)) 3
After mixing the parts in an extruder and pelletizing them, injection molding was performed at a mold temperature of 70°C, and test pieces were prepared and evaluated.

The obtained test piece had excellent surface appearance while maintaining heat distortion temperature, heat resistance, moisture resistance, and mold releasability. The results are shown in Table 1.

Example 2 and Comparative Examples 1 to 2 Test pieces were prepared in the same manner as in Example 1, except that the added chain of polyethylene glycol monophthalate Na salt used in Example 1 was changed as shown in Table 1. and evaluated. The results are shown in Table 1.

[Left below] Table 1-97 - Example 3 [η) = 0.20 old/a polyethylene terephthalate, 75 mol% of polyethylene glycol with an average molecular weight of 600 and polyethylene glycol monotrimetate 2Na salt ( Average molecular weight 640) 35 mol%
was added to cause copolymerization.

100 parts of the obtained polyester copolymer, fiber length 3 mm
11,170 parts of glass, ρ-[-butyl benzoic acid Na0
After mixing 53 parts of oxidation protection + L agent (Irganox 1330, manufactured by Ciba Geigy) into pellets using an extruder, injection molding was performed at a mold temperature of 70°C to obtain test pieces, and evaluation was made. .

The obtained test piece had excellent surface appearance while maintaining good tensile strength, heat distortion temperature, heat resistance, moisture resistance, and mold releasability. The results are shown in Table 2.

Examples 4 to 5 Instead of using 35 mol% of polyethylene glycol monotrimetate 2Na salt used in Example 3, ethylene oxide-propylene oxide block copolymer (ethylene oxide/propylene oxide = 20/
The monophthalic acid ester Ha salt (average molecular [823) of 80T weight ratio) was set at 20 mol%, and the monophthalic acid ester Ha salt (average molecular 1573) of Chichi's <Example 4) and the addition polymer of ethylene oxide to bisphenol (average molecular 1573) was
Test pieces were prepared and evaluated in the same manner as in Example 3, except that 5 mol % (Example 5) was used.

The obtained test piece had excellent surface appearance while maintaining good tensile strength, heat distortion temperature, heat resistance, moisture resistance, and mold releasability. The results are shown in Table 2.

[Margin below]

1 28 - [Effects of the Invention] The composition of the present invention can be injection molded with good moldability using a low-temperature mold of about 60 to 85°C, and the obtained molded product has a high heat distortion temperature and is heat resistant. , good moisture resistance and surface appearance, and good general mechanical properties.

Claims (1)

[Scope of Claims] 1(1) (A) polyethylene terephthalate having an intrinsic viscosity of 0.15 to 0.38; (B) polyethylene terephthalate having an average molecular weight of 300 to 2000 and 35 to 80 mol% based on component (A); (2) Crystals per 100 parts by weight of a polyester copolymer containing as segments a polyether derivative having ether and 10 to 80 mol% of at least one organic acid metal salt based on component (C) and (A). A polyester copolymer composition for injection molding, comprising 0.01 to 10 parts by weight of a nucleating agent and (3) 0 to 200 parts by weight of a reinforcing filler. 2. The composition according to claim 1, wherein the polyether of component (B) is a polyether selected from polyalkylene glycols and alkylene oxide addition polymers of bisphenols. 3. The composition according to claim 1, wherein the organic acid metal salt is a carboxylic acid metal salt.