JPH0241354A - Polyester resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition with high rate of crystallization excellent in moldability by using a low-temperature mold and having a property of low generation of gas by adding a beta-diketone with respectively specified structure and molecular weight and/or a metal chelate compound thereof to a thermoplastic polyester. CONSTITUTION:To (A) 100 pts.wt. thermoplastic polyester (PETF, PBTF, etc., are preferable) with, preferably 0.25-3, especially 0.4-2.25dl/g intrinsic viscosity, (B) 0.005-10, preferably 0.01-5 pts.wt. beta-diketone with >=150, preferably >=175 molecular weight having a structural unit of formula I (R is H, alkyl or aromatic group and preferably H), preferably formula II or formula III (R1 and R2 are alkyl, aromatic or alicyclic group where R and R1, R1 and R2 may form cyclic structure; n is 2-4; A is direct bond, 2-4 valent hydrocarbon, etc.) and/or metal chelate compound thereof is added to provide the subject resin composition.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention has a fast crystallization rate, excellent mold release properties when using low-temperature molds, generates little gas, and is suitable for use with FM resin. The present invention relates to a polyester resin composition that exhibits a small decrease in molecular weight during composition production and molding.

<Prior Art> Thermoplastic polyester resins are used in a wide range of fields such as fibers, films, and bottles due to their excellent mechanical, physical, and chemical properties. Among them, polyesters with a fast crystallization rate, such as polybutylene terephthalate,
Although it is used in large quantities for injection molding, there is a need to further improve the crystallization rate from the viewpoint of reducing manufacturing costs. In addition, some polyesters, such as polyethylene terephthalate, are currently not widely used for injection molding applications, and the reason for this is that the crystallization rate of these polyesters is slow, resulting in long molding cycles. In addition, there are problems such as the need to set the mold temperature high.

In order to overcome these difficulties, inorganic materials such as talc, and the
Higher fatty acid salts disclosed in JP-A-60552, etc.; acetylacetone alkali metal salts disclosed in JP-A-56-41247 and JP-A-57-14644; and JP-A-63-15840. A method has been proposed in which an alkali metal salt of dehydroacetic acid is added as a crystallinity improver.

<Problems to be Solved by the Invention> However, these methods not only do not significantly improve the crystallization rate of polyester, but also generate a large amount of gas during molding, and the mechanical properties tend to deteriorate.

Means for Solving the Problems> Therefore, the present inventors have developed a method that significantly improves the crystallization rate of polyester and generates less gas during molding.
As a result of intensive research to obtain a crystallinity improver that does not reduce mechanical properties, we found that β
- Adding a diketone and/or its metal chelate to polyester not only solves the initial problem, but also improves the crystallization rate, which was previously thought to be difficult, by increasing the molecular weight during the production of polyester resin compositions. We have discovered that these compounds are extremely effective in preventing the decline, and have arrived at the present invention.

That is, in the present invention, 0.005 to 10 parts by weight of β-diketones and/or metal chelates thereof having a molecular weight of 150 or more and having a structural unit of the following general formula (I) are added to 10 parts by weight of the thermoplastic polyester. The present invention provides a thermoplastic polyester resin composition comprising:

-C-CH-C- 0RO (However, in the formula, R represents a hydrogen atom, an alkyl group, or an aromatic group.) The thermoplastic polyester used in the present invention is a carboxylic acid (or its ester form). conductor) and
It is a polymer or copolymer obtained by a polycondensation reaction containing diol (or its ester conductor) as a main component.

Examples of the radical carboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalene dicarboxylic acid, 2,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, and 2,2-monobiphenyl dicarboxylic acid. Xonic acid, 3,3-bibophenyldicardic acid, 4.4'-biphenyldicartanic acid, 4,4-diphenyl etherdicarboxylic acid, 4
, 4'-diphenylmethane dicarbo.

dicarboxylic acid, 4,4-monodiphenylsul7one dicarboxylic acid,
4,4゛-diphenyliso-10pylidenedicarboxylic acid,
1.2-bis(phenoxy)ethane-4,4-dicarboxylic acid, 2,5-anthracenedicarboxylic acid, 2.6-
These include anthracene dicarboxylic acid, 4.4-P-terphenylene dicarboxylic acid, 2.5-pyridine dicarboxylic acid, and terephthalic acid is preferably used.

Two or more types of dicarboxylic acids may be used as a mixture. In addition, in small amounts, together with these dicarboxylic acids, adipic acid, azelaic acid, dodecanedioic acid,
One or more types of aliphatic dicarboxylic acids such as sebacic acid and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid can be used as a mixture.

In addition, as diol components, ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, 2-methyl-1
, 3-propanediol, diethylene glycol, triethylene glycol and other aliphatic diols, 1,4-cyclohexane dimetatool and other alicyclic diols, and mixtures thereof. In addition, if it is a small amount, the molecular weight is 400 to 6. One or more OOO long-bait diols, ie, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc., may be copolymerized.

Specific polyesters include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polycyclohexane dimethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene-1,2-bis(phenoxy)ethane-4,4°-di In addition to carboxylates,
Examples include copolymerized polyesters such as polyethylene isophthalate/terephthalate, polybutylene terephthalate/isophthalate, and polybutylene terephthalate/decanedicarboxylate. Among these, polybutylene terephthalate, polycyclohexane dimethylene terephthalate, polyethylene naphthalate, and polyethylene terephthalate, which have well-balanced mechanical properties and moldability, can be preferably used.

The polyester used in the present invention has an intrinsic viscosity of 0.25 when a 0-chlorophenol solution is measured at 25°C.
~3.0 dl/g, especially 0.4-2,25
dl/g is preferred.

The β-diketones used in the present invention are of the general formula (I
) and has a molecular weight of 150 or more, it is not particularly limited, but compounds having the following general 2 or 0 structure are particularly preferred.

R OR0 (wherein R1 and R2 represent an alkyl group, aromatic group, or aliphatic alicyclic group, R and R1 or R1 and R2 may be bonded to each other to form a cyclic structure, n is 2 to 4, A is a direct bond, 2 to 4 hydrocarbon groups, or -R3-N-R3-, where R3 is an alkylene group, R4 and R5 are respectively a hydrogen atom, an alkyl group, Indicates an aromatic group, R4 and R
5 may be combined with each other to form a cyclic structure, and X represents 10--8-.

m represents O or 1, R6 is a hydrogen atom, an alkyl group,
(representing an aromatic group or R3) In the present invention, β
- The chemical structures of diketones are all described in the keto form, but they may also be compounds described in the corresponding ethanol structure. In addition, if they have a structural unit of formula 0, a ketone group may be added. Compounds that have, i.e., triketones,
It may also be a compound such as tetraketone.

R, R,, R2, R in the above general 2〇, ■ and 0
4, Rs 1. Specific examples of R6 include alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, octadecyl, benzyl, and cyclohexyl, and aromatic groups such as phenyl, naphthyl, methylphenyl, chlorphenyl, and hydroxyphenyl. R and R,,R.

Examples of the group in which R2 or R4 and R5 combine to form a cyclic structure include trimethylene, tetramethylene, pentamethylene, and the like. Examples of R3 include alkylene groups such as methylene, ethylene, and propylene. Examples of the 2 to 4 hydrocarbon groups in A include methylene, ethylene, propylene, cyclohexylene, vinylene, phenylene, butanetriyl, benzenetriyl, ethylenetetrayl, and the like. Among the compounds represented by the general formula (3), those having at least one unsaturated bond, preferably an aromatic group, in the molecule are preferred,
Furthermore, it is more preferable to have an unsaturated bond, preferably an aromatic group, which is conjugated with at least one carbonyl carbon of the β-diketone, and it is more preferable that R is a hydrogen atom.

Specific examples of the compound represented by the general formula (■) are:
2.4-octadecanedione, benzoylacetone, pensoyltrifluoroacetone, dibenzoylmethane,
Furoylacetone, benzoylfuroylmethane, thenoylacetone, furoylthenoylmethane, 2'-hydroxybezoylacetone, 2-hydroxybenzoyl-benzoylmethane, bis-2'-hydroxybenzoylmethane, 1,1-dibenzoyl Examples include hexane, 1,1-dibenzoyloctadecane, dicyclohexanecarbonylmethane, dinaphthoylmethane, dicinnamoylmethane, benzoylacetone, benzoyltrifluoroacetone, dibenzoylmethane, 70ylacetone,
Benzoylfuroylmethane, tenoylacetone, furoylthenoylmethane, 2-hydroxybenzoylacetone, 2-hydroxybenzoyl-benzoylmethane,
Preferred examples include bis-2-hydroxybenzoylmethane, 1,1-dibenzoylhexane, 1,1-dibenzoyloctadecane, dinaphthoylmethane, and dicinnamoylmethane. Among these, most preferred examples include dibenzoylmethane, 2-hydroxybenzoylacetone, bis-2-monohydroxybenzoylmethane, dinaphthoylmethane, and dicinnamoylmethane.

Among the compounds represented by the general 2〇, R1 or A
It is preferable that at least one of R1 and R1 is an unsaturated bond conjugated with the carbonyl carbon of the β-diketone, preferably an aromatic group, and both R1 and R1 are unsaturated bonds conjugated with the carbonyl carbon of the β-diketone, preferably an aromatic group. is most preferable.

Specific examples of the compound represented by the general formula (1) include those shown below.

It is essential that the molecular weight of the β-diketones of the present invention is 150 or more, more preferably 175 or more, and most preferably 200 or more.

When the molecular weight is less than 150, not only is a large amount of gas generated during molding, but also the crystallinity is poor, and the molecular weight of the polyester is greatly reduced during the production of the resin composition, which is undesirable.

In addition, in the β-diketones represented by the general formula 2 of the present invention, R must be a hydrogen atom, an alkyl group, or an aromatic group, and a hydrogen atom is particularly preferred.

R is a substituent other than these substituents, such as an acyl group,
When it has an alkyloxy group, an amino group, a hydroxyl group, etc., the crystallinity of the polyester resin composition is poor;
Further, the molecular weight of the polyester during production of the resin composition is also greatly reduced, which is undesirable.

In addition, the molecular weight 15 having the structure of the general formula (I) in the molecule
Even if the molecular weight of the polyester at the time of manufacturing the resin composition is 0 or more, even if a compound other than β-diketones, such as β-ketoester, malonic acid ester derivative, or its metal chelate, is added to the thermoplastic polyester. The decrease is also large and undesirable.

Examples of metals constituting the metal chelate from β-diketones of the present invention include alkali metals such as lithium, sodium, potassium A, cesium, and rubidium, barium,
Examples include alkaline earth metals such as strontium, calcium, and magnesium, titanium, and iron, with sodium, potassium, and lithium being preferred.

The β-diketones and/or metal chelates thereof in the present invention may be used alone or in combination of two or more.

Molecular weight 1 having the structural unit of the general formula (I) of the present invention
The amount of β-diketones of 50 or more and/or metal chelates thereof is 5 to 10 parts by weight, preferably 0.01 to 10 parts by weight of O,OO per 100 parts by weight of thermoplastic polyester.
5f! parts by weight, more preferably 0.05 to 5 parts by weight. If the amount added is less than 0.005 parts by weight, the effect of improving the crystallinity of the polyester will not be sufficient, and if it exceeds 10 parts by weight, not only will the molecular weight of the polyester decrease during the production of the polyester resin composition, but also the molding Both are undesirable because they tend to impair the mechanical properties of the product.

In the composition of the present invention, it is preferable to use various organic acid salts and inorganic compounds in combination as necessary from the viewpoint of improving molding processability. Specific examples of these compounds include sodium stearate, barium stearate, and Mongkun. Examples include sodium salts of partially saponified acid esters, barium salts, ionomers, sodium salts of phenols such as nitrophenol and formylphenol, and talc.

Furthermore, moldability can be further improved by adding to the composition of the present invention a compound known as a crystallization accelerator used in thermoplastic polyesters such as polyethylene terephthalate. Specific examples of such crystallization accelerators include polyalkylene glycols such as polyethylene glycol and poly-10-pyrene glycol, their carboxylic acid diesters, α,ω-dialkyl etherified polyethylene glycol, α,ω-dialkyl etherified polypropylene glycol, etc. α of
, ω-dialkyl etherified polypropylene glycol, benzoic acid ester compounds such as neopentyl glycol dibenzoate, and aliphatic polyesters such as polylactone and polyethylene adipate.

Although not particularly essential, by further adding fibrous and/or granular fillers to the composition of the present invention, the rigidity can be significantly improved without impairing the physical properties of the pond.

Such fillers include glass fibers, carbon fibers, metal fibers, aramid fibers, asbestos, potassium ticunate whiskers, wollastenite, glass flakes, glass peas, talc, mica, clay, calcium carbonate, barium sulfate, and titanium oxide. , aluminum oxide, etc. Among them, chopped strand type glass fiber, talc, and titanium oxide are preferably used. The amount of these added is usually 12 parts by weight per 100 parts by weight of polyester.
It is preferable to use 0.011 parts or less.

Furthermore, conventional additives such as antioxidants, heat stabilizers, ultraviolet absorbers, lubricants, mold release agents, dyes, and colorants including pigments may be added to the composition of the present invention within a range that does not impair the purpose of the present invention. One or more types can be added.

Additionally, small amounts of thermoplastic resins (e.g., polycarbonate, polyphenylene ether, polyamide, polypropylene, polyethylene, ionomer, ethylene/propylene copolymer, ethylene/butene-1 copolymer, ethylene/propylene/nonconjugated diene copolymer, ethylene /ethyl acrylate copolymer, ethylene/glycidyl methacrylate copolymer, ethylene/vinyl acetate/glycidyl methacrylate copolymer, ethylene/propylene-maleic anhydride copolymer, etc.) can also be added.

The method for producing the composition of the present invention is not particularly limited, but preferably polyester, β-diketones and/or
Alternatively, examples include a method of melt-mixing the three metal chelates using an extruder, and a method of adding the β-diketone compound or the metal chelate at the final stage of polyester polymerization. When adding inorganic fillers and other additives, it is preferable to melt-knead them together with the above three using an extruder.

The resin composition of the present invention can be easily molded by conventional methods such as injection molding and extrusion molding, and the molded product obtained has a high degree of crystallinity and exhibits excellent performance.

<Example> EXAMPLES Hereinafter, the effects of the present invention will be explained in further detail with reference to Examples.

However, the intrinsic viscosity in the examples is a value measured at 25° C. of a 0-chlorophenol solution, and both parts and % are based on weight.

Examples 1 to 4, Comparative Examples 1 to 7 The following various additives (
Blend A) to ([) in the proportions shown in Table 1 and heat at 280°C.
The mixture was melt-kneaded into pellets using a 30 φ twin-screw extruder set at .

Regarding the obtained polyethylene terephthalate composition,
Differential thermal analysis was performed using a differential scanning calorimeter manufactured by PerkinElmer, and crystallinity was evaluated by measuring the heating-up crystallization temperature and cooling-down crystallization temperature. As is generally known,
Since the crystallinity improves as the cooling crystallization temperature increases and as the heating crystallization temperature decreases, ΔT
8T, where = (crystallization temperature at lower temperature) - (crystallization temperature at higher temperature), was used as a measure of crystallinity.

Next 1 (Measure the viscosity of the obtained pellet,
This was used as a guideline for the molecular weight reduction of polyester and ester during the production of resin compositions. Also, using a thermal differential gravimeter, 290℃ in nitrogen,
When I left it for an hour! The decrease in Ji was measured and used as a guideline for the amount of gas generated during molding.

The above results are shown in Table 1.

(Additives) a a a E: Sodium salt of dehydroacetic acid It is clear that the A-setting properties are greatly improved, gas generation is very low, and the molecular weight decreases little during the production of the composition.

Example 5, Comparative Example 6 Additive (G) was added to 100 parts of polybutylene terephthalate (PBT) having an intrinsic viscosity of 0.74 dl/ in the proportion shown in Table 1, and the mixture was heated to 30+mφ at 260°C.
The mixture was made into a melt mixed wire pellet using a twin-screw extruder.

Next, the intrinsic viscosity of the obtained pellet was measured and used as a measure of the molecular weight reduction of the polyester during production of the resin composition. In addition, using a thermal differential gravimeter, the weight loss when left at 270° C. for 1 hour in nitrogen was measured, and this was used as a guideline for the amount of gas released during molding.

At the same time, the same measurement was performed on an example (Comparative Example 6) in which the additive (G) was not added.

The above results are also shown in Table 1.

Example 6, Comparative Example 7 Additive (A) was added to 100 parts of polycyclohexane dimethylene terephthalate (POT) having an intrinsic viscosity of 0.94 dl/g in the ratio shown in Table 1, and the temperature was set at 305°C. The mixture was melt-kneaded and made into pellets using a 30 mφ twin-screw extruder.

Next, the intrinsic viscosity of the obtained pellets was measured and used as a measure of the molecular weight reduction of the polyester during production of the resin composition. In addition, using a thermal differential gravimeter, the weight loss when left in nitrogen at 310° C. for 1 hour was measured, and this was used as a guideline for the amount of gas generated during molding.

At the same time, the same measurement was carried out for the example of additive (A) flavor addition (Comparative Example 7).

The above results are also shown in Table 1.

Part 1 table *1: The larger the value of ΔT, the better the crystal quality.

*2: The smaller the weight loss value, the less gas is generated and the better.

Examples 7 to 9, Comparative Examples 8 to 11 50 parts of chopped strand type glass fiber II (31 m length, 11 μm diameter) and various nucleating agents ( A) to (F) were mixed in the proportions shown in Table 2, and 280
The mixture was melted into a mixed wire pellet using a 30 part 1 mφ twin-screw extruder set at ℃.

Regarding the obtained polyethylene terephthalate composition,
Differential thermal analysis and differential gravimetric analysis were conducted in the same manner as in Example 1.

In addition, the polyethylene terephthalate resin composition obtained by melt-kneading into pellets is dissolved in O-chlorophenol, the glass fibers are separated using a centrifuge, and the solution is poured into methanol, so that the composition does not contain glass fibers. A polymer was obtained.

By measuring the intrinsic viscosity of this polymer, it was used as a guideline for molecular weight reduction during production of a resin composition in the presence of cod.

Furthermore, after vacuum drying the above pellets at 155°C for 5 hours,
Using a screw in-line injection molding machine with a mold clamping pressure cuff of 5 tons set at 75°C, injection time/cooling time/intermediate time/15 seconds/20 seconds and 15 seconds at a mold temperature of 90°C, I)
A box-shaped molded product of 45 m+, width 651, depth 20 m, and wall thickness 2fi was molded, and the force (mold release force) required to separate the box-shaped molded product from the mold was determined.

Furthermore, ASTM-1 dumbbells were molded under the same injection conditions, and the tensile strength and elongation at break were measured according to ASTM D-638.

The above results are also shown in Table 2.

From the results in Table 2, the composition of the present invention has significantly improved crystal properties even in the presence of glass fibers, exhibits good mold release properties even in low-temperature molds, and also exhibits very little gas generation. It is clear that the molecular weight decreases little during the production of the resin composition.

Table <Effects of the Invention> The polyester resin composition of the present invention has good crystallization properties, excellent moldability in low-temperature molds, little gas generation, and good productivity in injection molding. The molded products obtained have excellent a-mechanical properties and are therefore useful as electrical and electronic parts, automobile parts, mechanical mechanism parts, etc.

Claims (1)

[Claims] β having a molecular weight of 150 or more and having a structural unit of the following general formula (I) based on 100 parts by weight of thermoplastic polyester
- Diketones and/or their metal chelates 0.00
A polyester resin composition containing 5 to 10 parts by weight. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (However, in the formula, R represents a hydrogen atom, an alkyl group, or an aromatic group.)