JPH04202557A - Heat-resistant resin composition and heat-resistant tableware for oven produced by molding the resin - Google Patents

Abstract

PURPOSE:To obtain a heat-resistant resin composition having excellent heat- resistance and impact resistance and suitable as a heat-resistant plastic tableware for oven by compounding a specific amount of a specific talc to a copolymerized polyester having a specific structure and exhibiting liquid-crystal nature in molten state. CONSTITUTION:The objective composition is produced by compounding (A) 100 pts.wt. of a copolymerized polyester composed of the structural units of formula I to formula IV (R1 is group of formula V, etc.; R2 is group of formula VI, etc.; X is H or Cl) wherein the molar ratios of (I+II)/(I+II+III) is 80-95mol%, III/(I+II+III) is 20-5mol%, I/II is 78/ 22 to 93/7 and (II+III)/IV is 1/1, having a logarithmic viscosity of 1-3dl/g and a melting point (Tm) satisfying the formula VII [x is ratio of III/(I+II+III)] and exhibiting crystalline nature in molten state with (B) 5-200 pts.wt. of talc having an average particle diameter of 2.5-3.5mum and containing <1wt.% of Fe2O3 and Al2O3 in total and, as necessary, (C) 5-200 pts.wt. of other inorganic fillers.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention provides a heat-resistant resin composition that has excellent heat resistance and thermal shock resistance, and provides a molded article with excellent mechanical properties, particularly impact resistance. This invention relates to oven-use resin heat-resistant tableware made by molding the same.

<Prior Art> In recent years, tableware made of resin, which is lighter in weight and has excellent impact resistance, has come to be used in place of conventionally used tableware made of earthenware, porcelain, glass, etc. Furthermore, as food is now commonly stored frozen and cooked in microwave ovens or electric ovens, there is a need for tableware that can be used in a wide temperature range from low temperatures to heating temperatures in ovens.

Traditionally, resins used for heat-resistant tableware include polymethylpentene, polysulfone, and crystallized PET, but all of them can be used in a microwave oven, but they must be heat resistant to over 200°C. It was unsuitable for use in some ovens.

As heat-resistant resin tableware that can be used in an oven, Japanese Patent Application Laid-open Nos. 56-43319 and 59-361 are known.
54 and JP-A-1-53820 are known.

<Problems to be Solved by the Invention> However, according to the above-mentioned publications, none of the heat-resistant resin tableware that can be used in ovens has sufficient impact resistance and is easily damaged by falling. In addition, there have been problems in that decomposition occurs during molding due to extremely high molding temperatures, and poor molding flowability makes it difficult to mold tableware of complex shapes.

Therefore, the present invention solves the above problems, has excellent moldability,
Another object of the present invention is to obtain a heat-resistant resin composition having excellent impact resistance and a resin heat-resistant tableware for ovens formed by molding the same.

Means for Solving the Problems〉 As a result of intensive studies by the present inventors to achieve the above problems,
A composition obtained by blending talc with a specific particle size and containing almost no impurities iron oxide and aluminum oxide with a copolymerized polyester that exhibits liquid crystallinity when melted has a specific structure, which surprisingly meets the objectives of the present invention. The present invention was achieved by discovering that the two conditions are consistent with each other.

That is, the present invention consists of (1) the following structural units (I) to (TV), where the structural unit [(I>+(It)] is [(II+(II)+(II
880 to 95 mol% of structural unit (1) of [(I>
+ (II) + (II[)] is 220 to 5 mol, and the molar ratio of structural unit (I)/(ffl) is 78/22.
~93/7, has a melting point (Tm('C)) that satisfies formula (i), and further has a logarithmic viscosity of 1.0 to 300 dl/g, and exhibits liquid crystallinity when melted (A) 10
01 parts by weight, the total content of FezOl and Al2O is less than 1% by weight and the average particle diameter is 2.5 to 3.5
A heat-resistant resin composition containing talc (B) 5 to 200 μm: -10<Tm+5.89x-385, 5<10...
...(i) (However, X in formula (i) is [(I) of structural unit (1)
+(II)+(Indicates the ratio (mol%) to II[>].) →○-R1-0su ......(II)+0-
CH, CH2-0← ・・・・・・(II[)→QC-
R2-CO← ... represents one or more groups selected from (IV), and in the formula, X represents a hydrogen atom or a chlorine atom, and the structural unit [(n) + (III)] and the elliptic structural unit TV> are substantially equimolar. ) (2) Copolymerized polyester (A) 100 described in (1)
Talc (B) described in section (1) 5 to 20 parts by weight
0 parts by weight and an inorganic filler (C) other than the above talc (B)
) 5 to 200 parts by weight of the heat-resistant resin composition according to item (1), and (3) the heat-resistant resin composition according to items (1) and (2) for oven use. The present invention provides resin heat-resistant tableware.

The above structural unit (I) is a structural unit of polyester produced from p-hydroxybenzoic acid, and the structural unit (n) is 4,4-dihydroxybiphenyl, hydroquinone,
2.6-Sihydroxynaphthalene, t-butylhydroquinone, 3.3-.

5. Structural unit (III) is a structural unit generated from an aromatic dihydroxy compound selected from 5-tetramethyl-4,4-monodoxybiphenyl and phenylhydroquinone, and structural unit (III) is a structural unit generated from ethylene glycol. , structural unit (IV) is terephthalic acid, 4,4-diphenyldicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 1,2-bis(phenoxy)ethane-4,4-monodicarboxylic acid, 1,2-bis Each structural unit produced from an aromatic dicarboxylic acid selected from (2-chlorophenoxy)ethane-4,4-dicarboxylic acid and diphenyl ether dicarboxylic acid is shown.

On the other hand, among the above structural units (I) to (TV), the structural unit [
(I)+(n)] is [(II+ (II)+(III)
] of 880 to 95 mol, preferably 83 to 95 mol%, more preferably 86 to 93 mol%.

In addition, the structural unit (IIO is [(I) + (n) + (I
II)], preferably 17 to 5 mol.
mol %, more preferably 14 to 7 mol %. The structural unit [(I) + (II)] is the structural unit [(I>+(n
)±(III)], the melt fluidity decreases and solidification occurs during polymerization, and when it is less than 80 mol%, the heat resistance becomes poor, which is not preferable in either case.

In addition, the molar ratio of structural units (I)/(II) is 78/22
~93/7, preferably 85/15 ~ 92/8. If it is less than 78/22 or greater than 93/7, the heat resistance or fluidity will be poor, making it impossible to achieve the object of the present invention.

Moreover, the structural unit (TV) is the structural unit [(II)-)-(
III)] is substantially equimolar.

Typical methods for producing the copolyester used in the heat-resistant resin composition of the present invention include the following methods:
The method (b) is the most preferred.

(b) Acylated products of droxybenzoic acid such as P-acetoxybenzoic acid, diacylated products of aromatic dihydroxy compounds such as 4,4-diacetoxybiphenyl, aromatic dicarboxylic acids such as terephthalic acid, and polyesters such as polyethylene terephthalate. , oligomer or bis(β-
A method of producing by reacting bis(β-hydroxyethyl) ester of an aromatic dicarboxylic acid such as hydroxyethyl) terephthalate and deacetic acid polymerization.

(b) Aromatic dihydroxy compounds such as p-hydroxybenzoic acid and 4,4-dihydroxybiphenyl, aromatic dicarboxylic acids such as acetic anhydride and terephthalic acid, and polyesters, oligomers or bis(β-hydroxyethyl) such as polyethylene terephthalate. Bis(β-hydroxyethyl) of aromatic dicarboxylic acids such as terephthalate
A method in which esters are reacted and produced by deacetic acid polymerization.

Although these polycondensation reactions proceed without a catalyst, it is sometimes preferable to add metal compounds such as stannous acetate, tetrabutyl titanate, sodium and potassium acetate, antimony trioxide, and metallic magnesium.

Furthermore, the melting point (T
m(°C)) must satisfy the following formula (i).

-10<Tm+5.89x-385,5<10...
...(i) Here, X in the formula (i) is the structural unit (]I[>[<I)
+(n)+(In)] (mol%).

Even if the composition ratio of structural units (I) to (IV) satisfies the above conditions, if the melting point of formula (i) above is exceeded due to differences in the composition distribution and randomness of the polymer, the fluidity, The heat resistance and mechanical properties of the molded product may become poor, or
This is undesirable because the polymer tends to decompose at high temperatures and the loss on heating is large. Here, the melting point (T m ) is measured using a differential scanning calorimeter at a heating rate of 20°C/min. +! It refers to the measured endothermic peak temperature, T m 2, which will be described later.

In addition, in the above-mentioned differential calorimetry measurement, the endothermic peak temperature (hereinafter T
(abbreviated as m 1), and after observation of T m 1, T m r
After holding at a temperature of +20°C for 5 minutes, -20°C/
After cooling down to room temperature at a rate of 20°C/min,
IT m 1T m
It is preferable from the viewpoint of randomness of the polymer that there is a relationship of 21≦10°C, and more preferably ITm+Tm21≦6°C.

In addition, the logarithmic viscosity of this copolymerized polyester is 0°1 g
/d 1 concentration, the value measured in pentafluorophenol at 60°C is 1.0 to 3.0 dl/g, and 1.
3 to 2.5 dl/g is preferable, the value of logarithmic viscosity is 1.0
If it is less than dl/g, the mechanical properties are insufficient;
If it exceeds 1/g, the fluidity will be impaired, which is not preferable in any case.

Furthermore, the molecular weight distribution of the copolymerized polyester used in the present invention is described, for example, in Kobunshi Ronshu Vol. 45, p. 531 (1988).
Weight average molecular weight (MW) and number average molecular weight (MN), which show molecular weight distribution, can be measured by the method described in
The value of the ratio MW/MN is preferably less than 3.0 from the viewpoint of randomness, and more preferably less than 2°9.

The melt viscosity of the copolyester used in the present invention is 10
0 to 5,000 voices is preferred, especially 200 to 2,0
00 voids is more preferred.

Note that this melt viscosity is a value measured using a Koka type flow tester at a temperature of melting point <Tm) + 10)°C and a slip rate of 1.000 (1/sec).

In addition, when polycondensing the copolymerized polyester used in the present invention, in addition to the components constituting the structural units (I) to (IV), 3,3-1 diphenyl dicarboxylic acid, 2,2-
Aromatic dicarboxylic acids such as diphenyldicarboxylic acid and isophthalic acid, adipic acid, azelaic acid, sebacic acid,
Aliphatic dicarboxylic acids such as dodecanedioic acid, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, talolhydroquinone, methylhydroquinone, 4,4-dihydroxydiphenylsulfone, 4,4-dihydroxydiphenylpropane, 4,4 --Aromatic diols such as dihydroxydiphenyl sulfide, 4.4-dihydroxybenzophenone, 4.4-1 dihydroxydiphenyl ether, 1゜4-butanediol, 1.6-hexanediol, neopentyl glycol, 1.4-cyclohexane diols, aliphatic and cycloaliphatic diols such as 1,4-cyclohexane dimetatool, aromatic hydroxycarboxylic acids such as m-hydroxybenzoic acid and 2,6-hydroxynaphthoic acid, p-aminophenol and p-aminobenzoic acid. An acid or the like may be further copolymerized within a small proportion that does not impair the purpose of the present invention.

The heat-resistant resin composition of the present invention contains Fe x O3 and A based on 100 parts by weight of the copolyester (A).
It is characterized by containing 5 to 200 parts by weight of talc (B) having a total content of l2O3 of less than 1% by weight and an average particle size of 2.5 to 3.5 μm.

Fe2O3 and Al2O contained in talc (B),
The total content of F e 20's should be less than 1% by weight, preferably less than 0.5% by weight of F e 20's, Al2O3
is less than 0.5% by weight, more preferably Fe2O
3 is less than 0.25% by weight, Al2O is 0.25% by weight
less than Talc with a total content of Fe20s and Al2O of 1% by weight or more does not have sufficient impact strength, so that the object of the present invention cannot be achieved. Also, Cab (calcium oxide), which is also contained in talc (B)
is preferably 0.5 to 1.0% by weight.

Further, the average particle diameter of the talc (B) is 2.5 to 3.5.
It needs to be in the range of μm, more preferably 2.7 to
It is 3.3 μm. The average particle size of talc (B) is 2.5
If it is smaller than μm or larger than 3°5 μm, the impact strength will be low or the surface gloss of the molded product will become poor, so both cases are unfavorable.The average particle size of this talc (B) is It was measured by the sedimentation method.

The content of talc (B) is the same as the above copolymerized polyester (A).
) 5 to 200 parts by weight per 100 parts by weight. If it is less than 5 parts by weight, the abrasion resistance of the molded product surface will not be sufficient;
If the content exceeds 0.00% by weight, the impact strength decreases, which is not preferable in either case.

The above copolymerized polyester (
In addition to A) and talc (B), an inorganic filler (C) other than the above-mentioned talc (B) can be preferably used as the third component. When adding the inorganic filler (C), the amount added is 5 to 20 parts by weight per 100 parts by weight of the copolyester (A).
0 parts by weight is preferred. The inorganic filler (C) that can be used in the heat-resistant resin composition of the present invention is not particularly limited, and known granular, plate-like, and fibrous fillers can be used, but in particular In order to use it as a heat-resistant tableware, it is necessary to consider that it is harmless. Examples of the inorganic filler (C) that can be used in the present invention include calcium silicate (wallastenite), calcium phosphate, calcium sulfate, calcium carbonate, magnesium carbonate, barium sulfate, titanium oxide, aluminum oxide, magnesium oxide, Zinc, silicon oxide, iron oxide, zirconium oxide, molybdenum dioxide, molybdenum disulfide, mica, sericite, talc other than those listed as (B), kaolin, clay, feldspar, vermiculite, silica,
Examples include glass powder, carbon black, graphite, glass fiber, carbon fiber, metal fiber, whiskers, and the like.

Talc (B) and inorganic filler (C) used in the present invention
Although it can be used as it is, it is also preferable to use one whose surface has been treated with a known coupling agent such as a silane coupling agent or a titanate coupling agent.

Furthermore, antioxidants and heat stabilizers (for example, hindered phenol, didroquinone, phosphites, and monoconverters thereof) may be added to the heat-resistant resin composition of the present invention within a range that does not impair the object of the present invention. ), UV absorbers (e.g. resorcinol, salitate, benzotriazole, benzophenone, etc.), lubricants and mold release agents (
montanic acid and its salts, its esters, its half esters, stearyl alcohol, stearamide and polyethylene wax), dyes (e.g. nigrosine) and pigments (e.g. phthalocyanine, carbon black, etc.), plasticizers (e.g. adipine) Conventional additives such as acid esters, phthalate esters, etc.), flame retardants, antistatic agents, and other thermoplastics can be added to impart desired properties.

Melt-kneading is preferred as a method for adding the above-mentioned talc (B), inorganic filler (C), or additives to the copolymerized polyester (A) used in the present invention, and a known method may be used for melt-mixing. For example, it is preferable to use a Banbury mixer, a rubber roll machine, a kneader with one axle or a twin-screw extruder, and melt-knead the composition to form a composition.

The resin composition of the present invention described above has excellent heat resistance and is therefore suitable for use as resin heat-resistant tableware for ovens.

Oven-use resin heat-resistant tableware can be easily obtained by melt-molding the heat-resistant resin composition of the present invention, but known molding methods such as injection molding, extrusion molding, and blow molding can be used. be.

<Example> The present invention will be further explained below with reference to Examples.

Example 1 In a reaction vessel equipped with a distillation tube and a stirring blade, 2293 g (16.6 mol) of P-hydroxybenzoic acid, 298 g (1.6 mol) of 4゜4-1 dihydroxybiphenyl, and 266 g (1.6 mol) of terephthalic acid were added. 346 g (1.8 moles) of polyethylene terephthalate with an intrinsic viscosity of approximately 0.6
And anhydrous vinegar′#! 2224 g (21.8 mol) of i was charged and acetic acid depolymerization was carried out under the following conditions.

First, the temperature was raised to 130 to 150°C for 4 hours under a nitrogen atmosphere, then the temperature was raised to 250°C over 2.5 hours, and then further heated to 250°C.
The reaction was continued for 2.5 hours. Furthermore, after heating the inside of the system to 340°C over 2 hours, ■. 0.0 in the system in 5 hours.
The pressure was reduced to 5111 Hg, and the reaction was continued for an additional 30 minutes to complete the polycondensation. As a result, a nearly stoichiometric amount of acetic acid was distilled out, and a beige polymer was obtained. The theoretical structural formula of this polymer is as follows.

k / 1 / m / n = 83 / 8 /
9/17 Furthermore, when this polyester was placed on a sample stage of a polarizing microscope and the temperature was raised to confirm the optical anisotropy, the liquid crystal initiation temperature was 301° C., indicating good optical anisotropy.

The melting point of this polymer was measured using a PerkinElmer DSC-7 model at a heating rate of 20°C/min.
The peak temperature of Tm+ was 335°C, and the peak temperature of Tmx was 333°C.

(T m + 5.89x −385,5
) is 0°51.

Note that the logarithmic viscosity of this polymer is 2.1 dl/g,
Melt viscosity is 8 at 343℃ and sliding speed of 1000 (1/s).
The fluidity was extremely good with 20 voids.

To 100 parts by weight of the obtained copolymerized polyester (A), 0.15% by weight of F e 20 s and Al2O3
30N containing 65 parts by weight of talc (B) containing 0.14% by weight and having an average particle size of 3.0 μm set at 335°C.
The mixture was melt-mixed and pelletized using an nφ twin-screw extruder.

The obtained pellets were subjected to injection molding III manufactured by Toshiba Machinery Co., Ltd.
Using mold S-80EPN, molding temperature 335°C, mold temperature 100°C, wall thickness 5u+, 100nnx150II
A rectangular parallelepiped tableware measuring II×4011 was molded. Furthermore, 1
A mold notch impact test piece measuring 1/4" thick and 2 1/2 long was molded.

The tableware was subjected to a heat resistance test at 250°C for 1000 hours in an oven, but no changes such as deformation or breakage were observed, and no discoloration was observed. Furthermore, when an Izot impact test was conducted using the obtained test piece, 8,9 kgf-cn
It was found that the material had excellent impact resistance of /cm.

Comparative Examples 1 to 4 - To 100 parts by weight of the same copolymerized polyester (A) as in Example 1, various talcs shown in Table 1 were added in the same amount and in the same manner as in Example 1, and impact test pieces were prepared. It was molded and subjected to an Izot impact test. The results are shown in Table 1.
It was found that both had inferior impact resistance compared to Example 1.

Table 1 Comparative Example 5 A polymer having the following theoretical structural formula was polymerized under almost the same conditions as in Example 1 except that the final polymerization temperature was 390''C.The obtained polymer had poor fluidity and Decomposition and foaming were observed.

k / 1 / m / n = 82 / 15 /
3/18 To 100 parts by weight of the obtained polymer, 65 parts by weight of the same talc as used in Example 1 was added by the method of Example 1, and the same molding evaluation as in Example 1 was performed. Although no changes such as deformation or breakage were observed in the heat resistance test in an oven, it was found that the product was heavily discolored. In addition, the results of the Izotsu impact test are 3,2k
It was found that the impact resistance was inferior to that of gf-cn/cn and Example 1.

Example 2 Talc (B) (same as that used in Example 1) was added to 100 parts by weight of the copolymerized polyester (A) obtained in Example 1.
60 parts by weight and glass fiber as inorganic filler (C)
311 long chopped strand, manufactured by Nittobo Co., Ltd.〉40
The mixture was melt-mixed and pelletized using a 3011φ twin-screw extruder with the weight part set at 330″C. The resulting pellets were molded into tableware and impact test pieces in the same manner as in Example 1. Heat resistance test in the same manner as in Example 1. As a result, no changes such as deformation or damage were observed, and it was found that there was almost no discoloration.

In addition, the result of the Izotsu impact test was 6゜2 kgf-c.
It was n/C1.

<Effects of the Invention> The heat-resistant resin composition according to the present invention is easy to mold and has high heat resistance, as well as excellent impact strength, and can be used as oven-use resin heat-resistant tableware in microwave ovens, ovens, etc. suitable for use in

Claims (3)

[Claims] (1) Consisting of the following structural units (I) to (IV), the structural unit [(I) + (II)] is [(I) + (II) + (III)
], the structural unit (III) is [(I)+
(II) + (III)], the molar ratio of structural units (I)/(II) is 78/22 to 93/7, and the melting point (Tm (℃)) is (i ), Fe
A heat-resistant resin composition containing 5 to 200 parts by weight of talc (B) having a total content of _2O_3 and Al_2O_3 of less than 1% by weight and an average particle size of 2.5 to 3.5 μm. -10<Tm+5.89x-385.5<10...
...(i) (However, x in formula (i) is [( I
)+(II)+(III)] (mol%). ) ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・( I
) ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・(II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・(III
) ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・(IV) (However, R_1 in the formula is ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, R_2 is ▲There are mathematical formulas, chemical formulas, tables, etc.▼
, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas, chemical formulas,
There are tables etc. ▼, indicating one or more groups selected from. In addition, X in the formula represents a hydrogen atom or a chlorine atom, and the structural unit [(II) + (III
)] and structural unit (IV) are substantially equimolar. ) (2) Copolymerized polyester (A) 1 according to claim (1)
00 parts by weight of talc (B) according to claim (1)
Claim (1) containing 5 to 200 parts by weight and 5 to 200 parts by weight of an inorganic filler (C) other than the talc (B).
) The heat-resistant resin composition described. (3) A resin heat-resistant tableware for ovens formed by molding the heat-resistant resin composition according to claims (1) and (2).