JPS5924748A - Polyester composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. having a high rate of crystallization in a low-temperature region and excellent heat resistance, mechanical properties and moldability, consisting of an ethylene terephthalate polyester and a specified filler. CONSTITUTION:An acid component consisting of 99-80mol% of terephthalic acid and 1-20mol% of 12C or higher aliph. satd. dicarboxylic acid such as decane-1,10-dicarboxylic acid is reacted with a glycol component to obtain an ethylene terephthalate polyester (A) having a relative viscosity of 1.25 or above. 0.01-20pts.wt. filler selected from inorg. compd. having an average particle size of 50mu or below, such as silica, org. compd. having a carboxylate metal salt group, such as a metal stearate, and high-molecular compd. having a carboxylate metal salt group, such as a metal terephthalate, and optionally 5- 150pts.wt. reinforcing fiber having a length of 0.1-10mm., such as glass fiber, are blended with 100pts.wt. component A.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polynister composition that has good moldability, excellent mechanical properties, and good thermal stability.

More specifically, the crystallization rate is high in the low temperature region,
The present invention relates to an ethylene terephthalate polyester composition that can provide excellent molded products even at a mold temperature of about 120° C. or lower during injection molding and has improved thermal decomposition resistance.

Polyethylene terephthalate has excellent mechanical properties, electrical properties, heat resistance, chemical resistance, etc., and is used in many industrial products as fibers and films.

When used as fibers and films in this way,
Normally, stretched products are used, but when trying to use them for plastic purposes as injection molded products, for example, since they have not been stretched as described above,
It is known that various problems occur in terms of molding and physical properties. In other words, because polyethylene terephthalate has a low crystallization rate at low temperatures, the mold temperature normally used when injection molding other plastics is about 12
Since the crystallization rate is insufficient below 0°C, the resulting molded product has a difference in crystallinity between the surface and the inside, resulting in uneven mechanical properties, dimensional stability, and shape stability. It is extremely difficult to obtain a molded product that can withstand practical use. Conventionally, many methods have been proposed to solve these problems, such as a method of using a high-temperature mold and a method of adding a crystal nucleating agent or a crystallization promoter. However, the method using a high-temperature mold is not practical because the operation for increasing the temperature is complicated, the molding cycle becomes long, and the working efficiency is significantly reduced. On the other hand, although many methods of adding crystal nucleating agents and crystallization promoters have been studied, the crystallization speed during injection molding is still not sufficient.
The molding cycle is longer than that of other plastics, and in some cases, the addition of crystal nucleating agents and crystallization promoters can significantly reduce the surface properties such as surface gloss, mechanical properties, and thermal properties of molded products. Also, additives such as crystallization accelerators may volatilize during molding, causing problems such as emitting odors. As described above, the actual situation is that many problems remain in the method of adding a crystal nucleating agent and a crystallization promoter.

On the other hand, research has been conducted for a long time on a method of increasing the crystallization rate in a low temperature region by introducing into polyethylene terephthalate a segment with a highly mobile molecular chain, that is, a so-called soft segment. For example, Polyme
R, Vol. 10, p. 873 (1969) shows that when polyethylene terephthalate is copolymerized with polyethylene glycol, the crystallization rate increases even in the low temperature range of 120° C. or lower. Furthermore, JP-A-52-
No. 47892, JP-A-53-101094,
JP-A-56-24419 also proposes a method of modifying polyethylene terephthalate with polyalkylene glycol or its reactive derivative. Modifying polyethylene terephthalate with polyalkylene glycol or its reactive derivatives does increase the crystallization rate at low temperatures, but on the other hand, new problems arise in that the heat resistance and mechanical properties of the polymer decrease. It is known to occur. Therefore, ethylene derephthalate polynister modified or copolymerized with such polyalkylene glycol or its reactive derivative has a fatal drawback of being subject to severe restrictions when used as engineering plastics.

As a result of intensive research aimed at obtaining a polyethylene terephthalate-based molding material that has a high crystallization rate in a low-temperature region and has improved heat resistance and mechanical property deterioration, the present inventors found that polyethylene terephthalate has a predetermined long-chain structure. When a predetermined amount of aliphatic dicarboxylic acid units are copolymerized, the crystallization rate in a low temperature region increases, and furthermore, when a specific inorganic compound, an organic compound or a polymeric compound having a metal salt of a carboxyl group is added to this polyethylene terephthalate copolymer, The polyester composition blended in a specific amount has a much higher crystallization rate in the low temperature range, and can be used for injection molding at 120°C.
It has been found that molding can be performed in a short cooling time, ie, in a short cycle, even at a low mold temperature of below, and that the molded product obtained has excellent surface gloss. Furthermore, the inventors have discovered that when a predetermined amount of fibrous reinforcing material is added to the above polyester composition, a polyester composition with excellent moldability, mechanical properties, and heat resistance can be obtained, and the present invention has been achieved.

That is, the present invention is based on 100 parts by weight of an ethylene terephthalate polyester in which the acid component essentially consists of 99 to 80 mol% of terenotalic acid units and 1 to 20 mol% of aliphatic saturated dicarboxylic acid units having 12 or more carbon atoms. te (a)
At least one of an inorganic compound having an average particle size of 50μ or less, an organic compound having a metal salt of a carboxyl group, and a polymer compound having a metal salt of a carboxyl group, from 0.01 to
The present invention relates to a polyester composition containing 20 parts by weight of the polyester composition, and further relates to a polyester composition containing 5 to 150 parts by weight of a fibrous reinforcing material to 100 parts by weight of the above-mentioned polynister composition.

The ethylene terephthalate polynister of the present invention is
The acid component is essentially composed of terephthalic acid units and aliphatic saturated dicarboxylic acid units having 12 or more carbon atoms, but it also includes copolymerized with about 1 mol% or less of other acid components. .

On the other hand, the glycol component of the ethylene terephthalate polyester of the present invention is ethylene glycol, and also includes copolymerized diethylene glycol produced as a result of side reactions in the polymerization reaction and other glycol components of about 1 mol % or less.

If the amount of aliphatic saturated dicarboxylic acid units having 12 or more carbon atoms copolymerized in the ethylene terephthalate polyester of the present invention is less than 1 mol%, the crystallization rate in the low temperature region targeted by the present invention will be increased. On the other hand, if it exceeds 20 mol %, the melting point will be significantly lowered and the maximum operating temperature when used as a plastic will be lowered, which is not desirable. Therefore, the number of carbon atoms copolymerized in ethylene terephthalate polynister is 1.
The amount of aliphatic saturated dicarboxylic acid units having two or more must be 1 to 20 mol%.

The content is preferably 1 to 12 mol%, more preferably 1 to 7 mol%.

Examples of the aliphatic saturated dicarboxylic acids having 12 or more carbon atoms used in the present invention include decane-1,10-dicarboxylic acid, undecane-1,11-dicarboxylic acid, dodecane-1,12-dicarboxylic acid, and tridecane-1,12-dicarboxylic acid. 1,13
-dicarboxylic acid, tetradecane-1,14-dicarboxylic acid, pendadecane-1,15-dicarboxylic acid, hexadecane-1,16-dicarboxylic acid, heptadecane-1,1-dicarboxylic acid
7-dicarboxylic acid, octadecane-1,18-dicarboxylic acid, nonadecane-1,19-dicarboxylic acid, icosane-1,20-dicarboxylic acid, heneicosane-1,21-dicarboxylic acid
-dicarboxylic acid, docosane-1,22-dicarboxylic acid,
Linear dicarboxylic acids such as tetracosane-1,24-dicarboxylic acid, as well as decane-1,6-dicarboxylic acid, 6-
Ethyl-hexadecane-1,16-dicarboxylic acid, 6-
Branched dicarboxylic acids such as ethyl-dodecane-1,12-dicarboxylic acid can be mentioned.

In the present invention, linear dicarboxylic acids are preferable, but usually decane-1,10-dicarboxylic acid, tetradecane-1,14-dicarboxylic acid, and tetradecane-1,14-dicarboxylic acid are easily available as raw materials.
occudecane-1,18-dicarboxylic acid, deca7-1.
6-dicarboxylic acid, 6-ethyl-hexadecane-1,1
6-dicarboxylic acid, 6-ethyl-dodecane-1,12-
Acid derivatives such as dicarboxylic acids or their esters are used.

The ethylene terephthalate polyester of the present invention can be obtained by various polymerization methods, but it can be produced by the melt polymerization method normally used for polymerizing polyethylene prephthalate.
The relative viscosity of the polymer (measured at phenol/tetrachloroethane = 6/4, concentration 0.5%, temperature 20°C) is desirably 1.25 or more, preferably 1.30 or more.

The ethylene terephthalate polyester of the present invention has a higher crystallization rate than polyethylene terephthalate even in a low temperature range, for example, a temperature range of 120°C or lower. However, inorganic compounds with an average particle size of 50μ or less, organic compounds or polymeric compounds having metal salts of carboxyl groups are not sufficiently crystallized in the molding cycle in which the crystallization temperature is insufficient. When at least one of them is blended in a predetermined amount, the crystallization rate in the low temperature region becomes even higher, and a molded article with a sufficiently high crystallization ratio can be obtained, for example, even at a mold temperature of 90° C. or lower and a cooling time of 10 seconds or less.

When a predetermined amount of fibrous reinforcing material is further added to the above composition, a composition with excellent mechanical properties and heat resistance can be obtained.

Specific examples of component (a) used in the present invention, that is, inorganic compounds with an average particle size of 50μ or less, include carbon black, silica, calcium carbonate, synthetic silicon and silicates, zinc white, hallosite clay, and kaolin. , basic magnesium carbonate, mica, talc, quartz powder,
Diatomaceous earth, dolomite powder, titanium oxide, zinc oxide, antimony oxide, barium sulfate, calcium sulfate, alumina, calcium silicate, etc. can be mentioned, and one or more of these inorganic compounds can be used. , among which mica, kaolin, talc, and silica are useful in the present invention.

Further, as the organic compound having a metal salt of a carboxyl group used in the present invention, any compound having a metal salt of a carboxyl group can be used, but usually the number of carbon atoms is about 7. ~30 higher fatty acids, metal salts of aromatic acids are used, such as heptanoic acid,
Metal salts of higher fatty acids such as verargonic acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, cerotic acid, montanic acid, melisic acid, benzoic acid,
Specific examples include aromatic metal salts such as terephthalic acid, terephthalic acid monomethyl ester, isophthalic acid, and isophthalic acid monomethyl ester.

The polymer compound having a metal salt of a carboxyl group is not particularly limited as long as it has a metal salt of a carboxyl group at the end or side chain of the polymer, but for example, a carboxyl compound obtained by oxidizing polyethylene may be used. group-containing polyethylene, carboxyl group-containing polypropylene obtained by oxidation of polypropylene, copolymers of olefins such as ethylene, propylene, butene-1, and (meth)acrylic acid, copolymers of olefins and (meth)acrylic acid, Specific examples include metal salts such as copolymers of styrene and (meth)acrylic acid and copolymers of styrene and maleic anhydride, and usually olefins and (meth)acrylic acid or styrene (meth)
Metal salts of copolymers of acrylic acid are used. As the metal that forms a salt with a carboxyl group, alkaline earth metals, alkali metals, etc. are usually used, and alkali metals have excellent effects as crystal nucleating agents, with sodium and potassium being particularly useful. The amount of at least one of these components (a), that is, an inorganic compound, an organic compound having a metal salt of a carboxyl group, or a polymer compound, is 1% in the ethylene terephthalate polyester.
If the amount is less than 0.01 part by weight, the effect of increasing the crystallization rate will be insufficient, and conversely, even if the amount is more than 20 parts by weight, the effect of increasing the crystallization rate will not change depending on the amount. Anything that is not proportionate and is added in excess only acts as a filler. Therefore, the blending amount of component (a) is 0.01 to 20 parts by weight, preferably 0.01 to 20 parts by weight, per 100 parts by weight of ethylene terephthalate polyester.
0.01 to 10 parts by weight, more preferably 0.05 to 5 parts by weight.

Specific examples of the fibrous reinforcing material used in the present invention include glass fiber, carbon fiber, aromatic polyamide fiber, silicon carbide fiber, titanate fiber, etc., but glass fiber is usually often used. be done. In addition, there are no particular restrictions on the diameter and length of the various fibers, but if the fiber length is too long, it will be difficult to mix and disperse the polyester composition uniformly, and conversely, if the fiber length is too short, it will be reinforced. Since the effect as an agent is insufficient, fibers with a fiber length of 0.1 to 10 mm are used, and especially when the fibrous reinforcement is made of glass fiber, the fiber length is 0.1 to 10 mm. 7mm is preferable, more preferably 0.3~
4mm is desirable. In addition, the fibrous reinforcing material can be treated with various compounds as necessary to improve the interfacial adhesion with the resin and increase the reinforcing effect. When using,
Various surface treatment agents, such as vinyltriethoxysilane, γ-methacryloxypropylmethoxysilane, β-(
Silane treatment such as 3,4-epoxycyclohexyl)-ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-aminepropyltriethoxysilane, γ-chloropropylmethoxysilane, γ-mercaptopropyltrimethoxysilane, etc. Those treated with a chromium-based treatment agent such as methacrylate chromic chloride are used.

Regarding the amount of the fibrous reinforcing material that is optionally blended in the present invention, if the blended amount is less than 5 parts by weight based on 100 parts by weight of the polyester resin composition, the effect of improving mechanical properties will be insufficient. However, if it exceeds 150 parts by weight, it becomes difficult to uniformly mix and disperse the fibrous reinforcing material in the composition. Therefore, the blending amount of the fibrous reinforcement is 5 to 150 parts by weight, preferably 1 to 100 parts by weight of the polyester composition before adding the fibrous reinforcement.
It is 0 to 100 parts by weight.

The composition of the present invention may further contain various organic or inorganic compounds such as antioxidants, ultraviolet absorbers, colorants, mold release agents, fillers, etc., if necessary.

The polyester composition of the present invention can be produced by various methods, and the production method is not particularly limited. However, in general, additives or fibrous reinforcing materials are added to polyester pellets, and then an extruder is used. It is manufactured by mixing using

The compositions of the invention may be in various forms, such as film sheets,
Fibrous material. It can be formed into a tubular shape or the like.

Next, the present invention will be specifically explained with reference to Examples and Comparative Examples. Note that "parts" shown in Examples and Comparative Examples indicate "parts by weight."

Examples 1 and 2, Comparative Example 1 Acid components include terephthalic acid 89.0 mol%, tetradecane-
1,14-dicarboxylic acid 0.8 mol%, octadecane-
Relative viscosity consisting of 10.2 mol% of 1,18-dicarboxylic acid (phenol/tetrachloroethane = 6/4, concentration 0
．． Regarding ethylene terephthalate polyester pellets (Example 1) with a relative viscosity of 1.43 and polyethylene terephthalate pellets with a relative viscosity of 1.41 (Comparative Example 1), the pellets were melted by heating and melted with liquid nitrogen. After cooling rapidly, use a differential calorimeter (manufactured by Birkin Elmer, DS
Type C-1) and heated from room temperature to 90°C at a rate of 320°C/min.
℃, then maintain the temperature at 90℃, and wait until the crystallization peak appears. The so-called crystallization half time (t1/2) was determined. In the pellets of polyethylene derephthalate, no crystallization peak appeared even after 5 minutes, whereas in the pellets of Example 1, t1/2=
It showed a value of 0.89 minutes.

Next, 1 part of talc (Micron Ace K-1, manufactured by Nippon Talc Co., Ltd.) was blended with 100 parts by weight of the pellets of Example 1, and after pelletizing with an extruder, the crystallization half time was measured in the same manner (implemented). In Example 2), it was observed that the crystallization rate was even higher at t1/2=0.41.

Examples 3 to 6, Comparative Example 2 40 parts of the ethylene terephthalate polyester and 60 parts of polyethylene terephthalate shown in Example 1 were added with a predetermined amount of glass fiber (manufactured by Asahi Fiberglass Co., Ltd., 3 mm long chopped strand, product number No. 429). Pellets were created by blending various additives, and the crystallization half time t1/2 of each composition at 90°C was measured.Then, the cylinder temperature was 240-260-270°C, the mold temperature was 90°C, and the injection pressure holding time was measured. 10 seconds, injection pressure 300-600Kg/cm
A test piece of 1/16 inch x 1/2 inch x 5 inch was molded under the conditions of 2, and the minimum cooling time at that time was investigated. The results are shown in Table 1.

Table 1 It can be seen from this that the composition of the present invention has a fast crystallization rate.

Example 7, Comparative Example 3 1/4 inch x 1/2 from the pellet made in Example 3
Inch x 5 inch specimens were molded and untreated and heat treated (
ASTM D
Bending strength was measured according to 790. For comparison, pellets were prepared by blending 40 parts of ethylene terephthalate polyester copolymerized with 10% by weight of polyethylene glycol having a molecular weight of 3,000, 60 parts of polyethylene terephthalate, 2 parts of talc, and 50 parts of the same glass fiber as in Example 4, and bent in the same manner. The strength was measured (Comparative Example 3). The results are shown in Table 2.

Table 2 From this, it can be seen that the composition of the present invention has excellent heat resistance stability.

Example 8 Acid components are 95 mol% of terephthalic acid, 1.5 mol% of 6-ethyl-dodecane-1,12-dicarboxylic acid, and 3.5 mol% of 6-ethyl-hexadecane-1,16-dicarboxylic acid.
60 parts of ethylene terephthalate polyester, 40 parts of polyethylene terephthalate, and 52 parts of glass fiber
A pellet was prepared from 8 parts of Surlyn 1555.

The crystallization half time of this pellet at 90℃ is ■
It has a fast crystallization rate of 1/2=0.87 minutes. The bending strength measured by ASTM D 790 is 2070.
The bending strength after heat treatment at 200 DEG C. for 5 days was 1390 Kg/cm2, and it had excellent heat stability with a strength retention rate of 67.1%.

Patent applicant: Unitika Co., Ltd.

Claims (6)

[Claims] (1) Based on 100 parts by weight of an ethylene terephthalate polyester in which the acid component essentially consists of 99 to 80 mol% of terephthalic acid units and 1 to 20 mol% of aliphatic saturated dicarboxylic acid units having 12 or more carbon atoms, ) Average particle size 5
A polyester composition containing 0.01 to 20 parts by weight of at least one of an inorganic compound having a particle size of 0 μ or less, an organic compound having a metal salt of a carboxyl group, and a polymer compound having a metal salt of a carboxyl group. (2) A polyester composition containing 5 to 150 parts by weight of a fibrous reinforcing material to 100 parts by weight of the polyester composition according to claim 1. (3) Talc as an inorganic compound with an average particle size of 50μ or less,
Claim 1, characterized in that one or more inorganic substances selected from the group of mica, kaolin, and silica are used.
The polyester composition according to Items 1 and 2. (4) The polyester composition according to claims 1 and 2, wherein the metal salt of the carboxyl group is a sodium salt or potassium salt of the carboxyl group. (5) An organic compound having a metal salt of a carboxyl group,
The polyester composition according to claims 1 and 2, which is a compound having about 7 to 30 carbon atoms. (6) Claims 1 and 2, wherein the polymer compound having a metal salt of a carboxyl group is a copolymer of olefin and (meth)acrylic acid or a copolymer of styrene and (meth)acrylic acid. The polynisder composition described in .