JPS59124949A - Master pellet composition containing nucleating agent for polyester resin and production thereof - Google Patents

Abstract

PURPOSE:To provide the titled compsn. for use in the production of polyester resins having excellent mechanical and thermal properties, by blending a nucleating agent with a specified wax in a specified ratio, mixing a polyester resin and optionally a fibrous filler with the blend, and pelletizing the mixture. CONSTITUTION:5-60pts.wt. Group I a or IIa metal salt (A) of an org. carboxylic acid, such as sodium stearate, is mixed with 2-50pts.wt. compd. (B) selected from among alkyl esters of neopentyl polyols, rice wax, paraffin, montanate salts or esters, polyethylene wax, higher fatty acid amides and benzoate esters at a temp. not lower than the m.p. of the compd. B. The mixture is cooled to obtain a mixture in the form of a sheet, flake or powder. The obtained mixture is mixed with 0-100pts.wt. fibrous filler, such as glass fiber, and 100pts.wt. polyester resin, and the resulting mixture is pelletized to obtain the titled compsn.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a nucleating agent master pellet composition for polyester resins and a method for producing the same. For more details, mechanical
In order to obtain polyester resin molded products with excellent thermal properties,
For injection molding.

The object of the present invention is to provide a nucleating agent master pellet composition that is mixed into a polyester resin composition.

Reinforced with glass fiber, carbon fiber, inorganic fillers, etc.1
This polyester resin has excellent heat resistance, electrical properties, and mechanical properties, and is widely used in industrial and mechanical parts.

However, polyester resins, particularly polyethylene terephthalate, have many drawbacks in injection molding due to their slow crystallization rate. That is, when molding is performed at a mold temperature of 120° C. or lower, crystallization is insufficient, resulting in a product with poor heat resistance, as well as significantly poor moldability such as mold releasability and deformation during extrusion. For this reason, it is molded at a mold temperature of 120° C. or higher, but its use as a molding material is limited due to drawbacks such as slow assimilation and a longer molding cycle.

Therefore, various nucleating agents have been investigated and used industrially in order to increase the crystallization rate of polyethylene terephthalate and improve its moldability, thermal and mechanical properties, etc. Metal salts of organic carboxylic acids and inorganic substances such as talc and titanium oxide are generally used as nucleating agents for these, but while metal salts of organic carboxylic acids are highly effective as nucleating agents, they significantly lower the molecular weight of molten polyethylene terephthalate. It has been shown that it reduces For this reason, the actual situation is that polyethylene terephthalate is used in a limited amount.However, due to the decrease in the intrinsic viscosity [η] of polyethylene terephthalate, the physical properties cannot be reduced by 11+! Low polyethylene terephthalate V-) composition mechanical strength.

In particular, if the impact strength is low [η] less than 0.5, it becomes unusable. In order to maintain parabolic properties, it is necessary to take measures such as using expensive solid-state polymerized high [η] polyethylene terephthalate as a raw material or solid-state polymerizing after extrusion shaping. This results in increased costs.

The inventors of the present invention have conducted intensive studies on a method for producing a polyester resin composition with little reduction in [η].

It has been found that the objective can be achieved by blending master pellets of a nucleating agent containing a high concentration of nucleating agent with a polyethylene terephthalate composition to which no nucleating agent has been added, and then injection molding the mixture. That is, polyethylene terephthalate [
It was found that the decrease in [η] was small, and even when the mixture was mixed with master pellets of a nucleating agent and injection molded, the decrease in [η] was small. However, it is very difficult to obtain master pellets containing a high concentration of nucleating agent industrially and stably.For example, if polyethylene terephthalate is mixed with sodium benzoate powder in several parts and extruded, some of the sodium benzoate will be produced. The clumps are discharged, the strands are easy to break, and the molecules of polyethylene terephthalate are severely cut by the sodium benzoate, making it virtually impossible to take off the strands. Even if it is used, the [η] of polyethylene terephthalate decreases significantly, so it is not preferable.

The present inventor further investigated a method for producing master pellets that can stably produce Yastar pellets for polyester resin industrially and does not cause a decrease in [η] of polyester resin, and as a result, the inventors determined that a nucleating agent and a specific wax were used. It was discovered that a master pellet composition obtained by mixing a polyester resin and, if desired, a fibrous filler in a certain proportion, and shaping the mixture into pellets can achieve the intended purpose, and the present invention has been made. reached.

That is, the present invention provides (Al organic carboxylic acids of group 1 a or
At least one compound selected from group a metal salts 5~
60 parts by weight.

(B) 2 to 50 M parts of at least one compound selected from the group consisting of alkyl esters of neopentyl polyol, rhine wax, paraffins, montanic acid esters, montanic acid esters, polyethylene wax, higher fatty acid amides, and benzoic acid esters. .

(C) O to 100 N parts of fibrous filler.

(L)l The invention of a nucleating agent master pellet composition for polyester resins according to 7 to 100 M parts of polyester resins (AJ organic carboxylic acids of group 1 a or 7 of the periodic table)
At least one compound selected from group a metal salts 5~
60 parts by weight and (B) alkyl ester of neopentyl polyol.

Rice wax, paraffins, montanate.

Montanic acid ester, polyethylene wax.

At least one compound selected from the group consisting of 6-molecular fatty acid amides and benzoic acid esters 2-50·'rJO'
17 parts of B are uniformly mixed at a temperature above the melting point of the compound of (Bl) and then cooled to obtain a mixture in the form of a sheet, flake or powder, and then this mixture and (CI K
fM, a method for producing a nucleating agent master pellet composition for polyester resin, characterized in that O to 100 N parts of a string-like filler and (D + 100 N parts of a polyester resin) are mixed and shaped into pellets. .

The nucleating agent used in the present invention is effective as a crystal nucleating agent for polyester resins, and metal salts of organic carboxylic acids belonging to group 1 a or group 11 a of the periodic table are used. The organic carboxylic acid may be either aliphatic or aromatic, and specific examples of these salts include sodium laurate, potassium laurate, sodium myristate, potassium myristate, sodium stearate, potassium stearate, and sodium ophtacoate.

Calcium ophtacoate, calcium stearate, sodium benzoate, potassium benzoate.

Calcium benzoate, potassium terephthalate.

Examples include sodium terephthalate and lithium phthalate. Among these, sodium stearate, sodium benzoate, potassium benzoate, sodium terephthalate and the like are particularly preferred. These specific organic carboxylic acid metal salts can be used alone or in combination.

The amount of polyester resin in the master pellet is 100%
The amount is 5 to 60 parts by weight.

If the amount is more than 60 parts by weight, the nucleating agent tends to be unevenly dispersed during extrusion molding, which is not preferable. Also, if it is less than 5 parts by weight, it is good7. c Master pellets can be obtained, but the concentration is insufficient to be used as master pellets, making them impractical.

The waxes used in the present invention are alkyl esters of neopentyl polyol, rice wax, paraffins,
It is at least one compound selected from the group consisting of montanic acid salts, montanic acid esters, polyethylene waxes, higher fatty acid amides, and benzoic acid esters, and preferably has a melting point in the range of 40 to 200°C.

The amount of polyester resin in the master pellet is 10
2 to 50 parts by weight. This is the vehicle quantity department.

If the hook 7 is less than 2M parts, the dispersion of the nucleating agent becomes opaque when extruding the master pellet of the nucleating agent.
Also 5. If the amount is larger than the ON amount, problems such as poor biting stability will occur.

# used in the present invention! The fibrous filler is glass fiber, inorganic fiber other than glass Q fiber, carbon fiber, and heat-resistant organic fiber, and the blending amount in the master pellet is polyester resin 1
It is used in the range of 0 to 100 parts by weight per 3 to 003 parts. Specifically, the fibrous filler has a fiber diameter of 5
~20μ, chopped strands of glass fiber with a fiber length of 1 or more, these milled fibers, as well as potassium titanate whiskers, silicon nitride fibers, alumina fibers, acrylonitrile carbon fibers with a fiber diameter of 0.05μ or more. , pitch-based carbon fiber, aromatic polyamide fiber, aromatic polyimide fiber, aromatic polyamide-imide fiber, and the like. These fibrous fillers preferably have an aspect ratio of 5 or more.

Although the extrudability and dispersibility of the nucleating agent are significantly improved by adding these fibers to the extrusion strand, addition of more than 100 parts by weight is not preferable because it makes it difficult to pull off the strands.

The main polyester resins used in the present invention are polyethylene V tere Z tallate, polybutylene terephthalate, and polytrimethylene terephthalate.
A part of the acid component or dalicol component may be replaced with another copolymer component. Examples of the copolymerizable acid component include inphthalic acid, adipic acid, cepatic acid, naphthalene dicarboxylic acid, and the like. In addition, copolymerizable glycol components include ethylene/glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol,
Examples include decamethylene glycol. It is also necessary that [η] of the polyester resin is 0.7 or more, preferably 0.75 or more. If [η] is lower than 0.7, the extrusion will not be stable and the strands will not be stable. This is not desirable because it cannot be retrieved. On the other hand, the upper limit of [η] can take a high value within the range where extrusion shaping is possible, but as [η] increases, the extrusion torque becomes too large (and becomes impractical. Practically speaking, 1.4
is the upper limit.

[η] Haphenoltetrachloroethane/tetrachloroethane-5o15o (weight ratio) This is a value determined from the solution viscosity measured at 25°C in a solvent.

The master pellet of the nucleating agent can be extruded using an ordinary single-screw or twin-screw extruder, but at this time, fillers such as Merck and mica, stabilizers against heat and light, and dyes and pigments may be added as necessary.
Be able to grow.

The polyester resin nucleating agent master pellet composition of the present invention is composed of the composition as described above.
) 2 to 50 M parts of the above (Bl component compound) are uniformly mixed in a mixer such as a three roll mixer, a Henschel mixer, or a homo mixer at a temperature above the melting point of the compound of the Bl component, and then cooled into a sheet or flake form, and then If necessary, grind the mixture into flakes or powder.Then, mix the mixture with 100 parts by weight of polyester resin and 0 to 100 parts by weight of fibrous filler, and extrude using an ordinary single-screw or twin-screw extruder. Shape into pellets. At this time, fillers such as talc and mica, stabilizers against heat and light, dyes and pigments, etc. can be added as necessary.

The nucleating agent master pellet composition of the present invention does not contain a nucleating agent or contains a small amount of a polyethylene terephthalate resin composition 9, such as glass fiber.

Other inorganic fibers, carbon flit! The composition is blended into a pellet-like composition containing fibers, fillers, etc., and subjected to injection molding. The injection molded product obtained in this way has little reduction in [η] and has an excellent appearance.

Furthermore, since it has excellent mechanical strength and thermal properties, it can be widely used as an industrial material.

The present invention will be explained below with reference to Examples.

Examples 1-5 65 parts by weight of sodium benzoate and 35 parts of tetrastearyl ester of neopentyl polyol were thoroughly mixed in a homomixer at 100'C.

Pour this mixed solution onto a stainless steel belt soil that can be moved continuously, and then pour it onto J9. It was peeled off from the stainless steel belt that had been cooled to 1 to 2 mm, and then ground to 1.2 mm average particle size.
A flaky powder of 57 nm was obtained.

This one has 1.5 ky, and [η] 1. o polyethylene terephthalate 6.5! i,, fiber diameter 10μ,
Glass fibers with an average fiber length of 150 μm were mixed for 1 minute in a V-type tumbler with a capacity of 70 μm, and L/D=
Pair of 36,65φ nozzle screws 1.Formula-screw extruder, cylinder temperature 270℃, screw rotation speed 10
After one or two extrusions using Orpm, stable pellet-like nucleating agent master pellets (A, 1) were obtained.This nucleating agent master pellet (AJゔ〕〕o, 75 polyethylene terephthalate) 70 x bearing part , fiber diameter 10μ
and chopped strand 30 with fiber length 3:'!
Ui part, 0.5 parts by weight of montan wax was added to the 65φ
In the extruder, the cylinder temperature is 270℃ and the screw rotation speed is 1.
Mixed with CB+ (Belene) which was extruded and shaped under the conditions of 0'Orpm.

Injection molding was performed under the following conditions, and the evaluation results shown in Table 1 were obtained.

Injection molding condition molding machine Neomatsuto 1 manufactured by Sumitomo Heavy Industries, Ltd.
50/75 Molded product ASTM No. 1 dumbbell specimen and Izotsu specimen Molded product weight 35/ Cylinder temperature 270°C Mold temperature 70°C Molding cycle 30 seconds The DSC measurements in Tables 1 and 2 were performed under the following conditions. I went there.

Amount of Xanflu 101n9 Temperature rising/cooling rate 10℃/min Gay, fJ('I
, J, used chilled.

■1 In Table 1, Tc is the temperature of the crystallization peak when the temperature is raised;
Tc- is the peak temperature of crystallization during cooling.

Comparative Examples 2 to 6 in Table 2 are pellets (A
These are the results of evaluating a single molded product in which each raw material was simultaneously mixed in the same proportion as the composition of 1+-(H), extruded and then injection molded.

Examples 6-7 60 parts by weight of sodium stearate and Hoechst OP
wax (product name a) or 4ONit parts of polyethylene wax with a molecular weight of 90'00 in a homomixer for 120'
Mix at C and continuously move the mixed liquid onto a stainless steel belt with a thickness of 1 to 2 tnm.
After cooling, the mixture was peeled off from the stainless steel belt and then crushed to obtain flake-like powders with an average particle size of 1.5 Min'. This one has 1.67 ky and [η] 1.2
Polyethylene terephthalate 6, OK, 7. Chopped strand with fiber diameter 10μ and fiber length 3 ynm2.
0kf1. , titanium late whisker 1.33 k! !
, 70. Mix for 3 minutes in a double carp type tumbler with a capacity of
When extruded at °C and screw rotation speed of 10 Orpm, stable extrusion was obtained, and a nucleating agent master pellet (C1) with a good shape was obtained.This nucleating agent master pellet was obtained.
(C1 was <4 in Examples 1 to 5 with Tabered (B) and (
They were mixed at cl/<Bl = 8/92 (weight ratio) and injection molded to obtain the evaluation results shown in Table 2. The injection molding conditions and DSC measurement conditions are the same as in Example 1.

Comparative Examples 7 to 8 in Table 4 are the results of evaluation of molded products obtained by simultaneously mixing raw materials in the same proportions as in Examples 6 to 7, extrusion shaping, and then injection molding.

Examples 8-9 Sodium benzoate and IU opwax were thoroughly mixed at 120°C in a homomixer in the predetermined amounts shown in Table 5, and the mixture was placed on a stainless steel belt that could be continuously moved. After cooling it down, remove it from the stainless steel belt by pushing it.

It was ground to obtain a flaky powder. This and milled fiber heart [η
:] Polyethylene terephthalate 1 and 2 were mixed in the proportions shown in Table 5 for 2 minutes in a V-type tumbler, and extruded in the same manner as in Example 1.

The following results were obtained.

Extrudability evaluation display Extrusion status ○: The strand is stably discharged.

×: The strands were severely broken and pelletization was not possible.

pellet shape ○: The helet shape is uniform and there are few miscuts.

×: The pellet shape was not uniform and there were many miscuts.

Claims (1)

[Scope of Claims] 1. 5 to 6Q, ii parts of at least one compound selected from (Al organic carboxylic acids Group 1 a or Group 11 a of the Periodic Table of the O) metal salts. (Bl Alkyl ester of neopentyl polyol, rice wax: ) Claraffin, montan n salt 1 Montan acid ester, sz+noethylene wax, higher fatty acid amide: at least one selected from the group consisting of ammonium, silver aromatic acid ester 2 to 50 parts by weight of the compound. (C) O to 100M parts of fibrous filler. (Dl Nucleating agent master pellet composition for polyester resin consisting of 100 parts by weight of polyester resin. 2. (A) At least one metal salt selected from Group 1 a or Group II a of the periodic table of organic carboxylic acids. 5 to 60 parts by weight of compound and (Bl neopentyl polyol σ)
The above (Bl The mixture is uniformly mixed at a temperature higher than the melting point of the compound, and then cooled to form a sheet.A mixture of flakes or powder is obtained, and then this mixture is mixed with (CI fibrous filler θ~100 parts by weight and (D+polyester). A method for producing a nucleating agent master pellet composition for a polyester resin, which comprises mixing 100 tt parts of a resin and shaping the mixture into a pellet shape.