JPH01192551A - Multilayered composite injection molding - Google Patents

Abstract

PURPOSE:To obtain a molded product having high interlaminar bonding strength and high modulus of elasticity, by forming said product of one or more kinds of a polymer being aromatic polyester composed of at least one kind of a specific structural unit and having the heat of fusion of a crystal, which is measured by means of a differential scanning type calorimeter, of a specific value or less and capable of forming an anisotropic melt phase. CONSTITUTION:This molded product is formed from one or more kind of a polymer being aromatic polyester composed of at least one kind of a structural unit selected from ones represented by formulae (I)-(III) and having the heat of fusion of a crystal, which is measured by means of a differential scanning type calorimeter(DSC), of 0.1cal/g or less and capable of forming an anisotropic melt phase. In this case, when the heat of fusion of the crystal of aromatic polyester is larger than 0.1cal/g, the interlaminar bonding strength of a composite injection molded product becomes low and interlaminar release is generated. In performing the multilayer composite injection molding of one or more kinds of the polymer, a sandwich injection molding machine or two-color injection molding machine having two or more injection units or a mixed color injection molding machine is used and, by this method, the lowering of modulus of elasticity when the molded product is thick can be suppressed.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention has high heat resistance and excellent mechanical properties, and is highly oriented during injection molding and can be injected with a high elastic modulus without adding reinforcing materials such as glass fibers. It is known that molded articles can be obtained.

Aromatic polyesters that form an anisotropic melt phase include:
For example, a liquid crystal polymer made by copolymerizing p- and droxybenzoic acid with polyethylene terephthalate (Japanese Unexamined Patent Publication No. 49-7239
3), a liquid crystal polymer copolymerized with p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid (Japanese Unexamined Patent Publication No. 54
-77691), and liquid crystal polymers made by copolymerizing p-hydroxybenzoic acid with 4,4'-dihydroxybiphenyl, terephthalic acid, and isophthalic acid (Japanese Patent Publication No. 57-24
407, JP-A-60-25046), etc. are known.

<Problems to be solved by the invention> However, it is known that these liquid crystal polyesters can produce injection molded products with a high elastic modulus when the molded product is thin, but have a low elastic modulus when the molded product is thick ( W, J, Ja
ckson et al., J.

Polym, Sci, , Polym, Chem
, Ed., l 4.2043 (1976)).

The present inventors have previously discovered that multilayer composite molding is effective in obtaining a high elastic modulus molded product even when the molded product is thick, but many of these liquid crystal polyesters It was found that the multilayer composite molded product had poor properties and a high modulus of elasticity could not be obtained.

Therefore, it is an object of the present invention to obtain a high elastic modulus multilayer composite injection molded product with high interlayer adhesive strength.

Means for Solving the Problems> The present inventors have made intensive studies to solve the problems and have arrived at the present invention.

That is, in the present invention, at least -1 is the following hawking formula ([)
Seedlings consisting of nia units selected from ~(l[) and having a heat of fusion of 0.1 as measured by a differential scanning calorimeter (DSC).
No. 5 relates to a 16-11 composite injection-molded product with Gorima Z), which is an aromatic pyrinistyl which can form an anisotropic melt phase with a cal of 7 y or less.

1+0-X-QC-Y-C)----(M) Shishi〇-Z
-C)-sha...(I[) し) (, indicates one or more groups selected from CI. Also, Z indicates one or more groups selected from.) Anisotropy used in the present invention In the aromatic polyester capable of forming a melt phase, the structural unit (1) is methylhydroquinone, chlorohydroquinone, phenylhydroquinone, t-butylhydroquinone, hydroquinone, 4
．． 4'-; Produced from one or more dihydroquine compounds selected from hydroxybiphenyl, 4.4'-*hydroquine diphenyl ether, 2.6-hydroxynaphthalene, and 2.7-hydroxynaphthalene and 447; phenyl dicarboxylic acid. The structural unit <1) of the polyester is one or more of the above-selected dihydroquine compounds and 1,2-bis(phenoxy)ethano-4,4
'-dicarboxylic acid, 1,2-bis(2-chlorophenoquino)ethane-4,4'-dicarboxylic acid, terephthalic acid, isophthalic acid, 2,6-naphthalene dicarpo:/acid,
414'-diphenyl ether lecarboxylic acid and 1.
It shows the structural unit of polyester produced from one or more dicarboxylic acids selected from 4-cyclohexanedicarboxylic acid.

Moreover, the structural unit (II[) is p-hydroquine benzoic acid,
A polyester produced from one or more aromatic hydroxycarboxylic acids selected from 6-hydroxy-2-naphthoic acid, 3-10-4-hydroxybenzoic acid, and 3-7enyl/-4-hydroquinebenzoic acid. indicates the structural unit of

The above structural unit (1) / ((1,,) + (11L
)] is 220 to 100 mol%, preferably 70 to 100
If it is less than 20 mol%, the effect of the present invention is small.

In addition, the above structural unit (1)/C(1)+(1)+(I
)) is preferably 20 to 100 mol%.

Among the structural units of the aromatic polyester used in the present invention, the structural unit (1) is essential, and the high intermolecular interaction of 4,4'-diphenyldicarboxylic acid, which is one of the components constituting the structural unit (1). It is believed that the object of the present invention can be achieved by the following.

Further, the aromatic polyester used in the present invention can be produced according to the conventional polycondensation method of polyester, and although there is no particular restriction, typical production methods include, for example, the following methods (1) to (4).

m A method for producing an acylated aromatic dihydroquine compound, an acylated aromatic hydroxycarboxylic acid, and an aromatic dicarboxylic acid such as 4.4'-phenyl dicarboxylic acid by deacetic acid polycondensation reaction.

(21 Aromatic dihydroquine compound, a method for producing it by deacetic acid polycondensation reaction from an aromatic hydroxycarboxylic acid, an aromatic dicarboxylic acid such as 4,4'-diphenyldicarboxylic acid, and acetic anhydride.

(3) A method for producing by dephenol polycondensation from an aromatic dihydroxo compound, an aromatic cyclocarboxylic acid nodiphenyl ester such as 4,4'-diphenyldicarboxylic acid, and a phenyl ester of an aromatic hydroxycarboxylic acid.

(4) Aromatic hydroxycarboxylic acid and 4.4'
-A fragrance such as diphenyldicarboxylic acid! ! ! A method of producing i%' carboxylic acid with a desired amount of lephenyl carbonate to phenyl esterify the carboxyl group, then adding an aromatic dihydroxy compound and performing a phenol-depleting polycondensation reaction.

Typical catalysts used in the polycondensation reaction are metal compounds such as stannous acetate, tetrabutyl titanate, lead acetate, antimony trioxide, magnesium, sodium acetate, potassium acetate, and trisodium phosphate, among others. This is effective during dephenolization polycondensation.

Aromatic polyesters that can be preferably used in the present invention form an anisotropic melt phase, but at a shear rate of 1, 60'C higher than the temperature at which it begins to show anisotropy (liquid crystal initiation temperature).
The melt viscosity measured under the condition of 000 (1/sec) is 1O ~
Those with 15,000 voids can be preferably used.

In addition, the aromatic polyester forming the anisotropic melt phase used in the present invention was measured at a heating rate of 2 by differential scanning calorimetry (DSC).
It is necessary that the heat of crystal fusion measured at 0° C./min is 0.1 cal/y or less. The heat of fusion of the crystal is Q, l ca
If it is larger than l/f, the adhesive strength between the layers of the composite injection molded product tends to decrease, which is not preferable because problems such as one-layer peeling occur.

The composite injection molded article of the present invention is formed by a multilayer composite of one or more types of polymers, and the most preferred is a multilayer composite molded article in which the above-mentioned aromatic polyesters of the same type or different types are combined. In this case - the layer thickness is at least 0.2 mm, preferably 0.
．． It is 8H or more.

Furthermore, it is also possible to reduce anisotropy, which is a drawback of liquid crystal polymers, by forming a multilayer composite such that the flow directions of the injection molded products in each layer intersect with each other by 3-00 degrees or more.

By performing multilayer composite injection molding of these aromatic polyesters, for example, when performing multilayer sandwich molding, it is possible to make the elastic modulus of a single layer molded product almost equal to the elastic modulus of a multilayer molded product. The thickness of the molded product (
1) and the elastic modulus at the thickness (nt) of a multilayer (n-layer) molded product are almost equal, and molding starts from the molded product thickness (t), which is a drawback of aromatic polyester that forms an anisotropic melt phase. It is possible to suppress a significant decrease in the elastic modulus when the product thickness (nt) is reached.

On the other hand, when using thermoplastic polymers other than aromatic polyesters that can form an anisotropic melt phase, examples of thermoplastic polymers include polyethylene terephthalate, polybutylene terephthalate, polyarylate, polyester polycarbonate, polycarbonate, polysulfonate, and polyester. Examples include ether sulfo/, polyether ketone, polyether ether ketone, polyetherimide, polyphenylene sulfide, nylon/6, nylon 4°6, nylon 6.6, polyethylene, polypropylene, polystyrene, ABS, etc. It is preferable to add a fluidizing agent or a filler to make the linear expansion coefficient 5×10'ffi/ff/'C or less.

In order to perform multilayer composite injection molding of 1 to 11 or more polymers by using these thermoplastic polymers in combination with an aromatic polyester capable of forming an anisotropic melt phase, injection molding with two or more injection units is required. A molding machine is used, such as a sandwich injection molding machine (for example, synthetic resin 17, (5), 54 ('
71)) or two-color injection molding machine (or multi-material injection molding machine)
and color mixing injection molding machines. Although these injection molding machines are known, thermotropic polymers have never been molded with these machines, and by using these molding machines, the biggest drawback of thermotropic polymers, which is when the molded product is thick, It cannot be predicted from conventional knowledge that the decrease in the elastic modulus of the material can be suppressed.

Multilayer composite injection molded products can be obtained by using these molding machines.

Note that at least -1 of the present invention is GeoLJMIsa13
Polymers (glass fibers, carbon fibers, reinforcing agents such as asbestos, fillers, nucleating agents, pigments, antioxidants, stabilizers, plasticizers, lubricants, mold release agents, flame retardants, etc.) Additives and other thermoplastic resins can be added to molded products to impart desired properties.

The multilayer composite injection molded article of the present invention has an extremely high modulus of elasticity due to its structure and the characteristics of the aromatic polyester that forms an anisotropic melt phase.

Examples will be described below.

<Example> Example I 32.4 M parts of p-acetoquine benzoic acid, 137 iR of chlorohydroquinone diacetate, and 162 i parts of phenylhydroquinone diacetate were charged into a reaction vessel equipped with a stirring blade and a distillation tube for acetic acid depolymerization. I drank it.

First, under a nitrogen gas atmosphere at 250 to 330°C without stirring, L5
After reacting for an hour, stirring was started at 330°C, and
The reaction was allowed to proceed for 25 hours. After that, the temperature was raised to 350°C, the pressure inside the system was gradually reduced, and the reaction was further carried out for 10 hours at 0.5 ffHg to complete the polycondensation. As a result, almost the theoretical amount of acetic acid was distilled out, and the following theoretical structure was obtained. A polymer having the formula was obtained.

1/m/n=6/2/2 In addition, when this polyester was placed on the sample stage of a polarizing microscope and the temperature was raised to confirm the optical anisotropy, the result was 261°C.
It showed good optical anisotropy.

The logarithmic viscosity of this polyester (pentafluorophenol solution 0.1 f/dJ, 60°C) is 3.68, and 3
The melt viscosity at 20° C. and a shear rate of 1000 (1/sec) is 2,000 poise.

The thermal properties of this polymer were also measured using a PerkinElmer DSC.
The melting point was not detected when the temperature was measured using Type-1 at a temperature increase of LL 20° C./min.

This polymer was molded under the following conditions, and the thickness of 3 layers was 8.
A three-layer composite injection molded article of fl was obtained.

Maximum mold clamping force 25 tons, maximum injection amount 20.4CG.

Sumitomo Heavy Industries, Ltd. with a maximum injection pressure of 19oohqf/=
After injection molding the aromatic polyester described above using a two-color injection molding machine manufactured by Sumitomo Nekool at a cylinder temperature of 290 to 310°C and a nozzle temperature of 320°C to form an inner layer 1 of 3 x 8 x 70 fl, the mold was inverted. Two layers of the same polymer on both sides of the inner layer.
．． Sandwich molded with outer layer 2 of 5 x 8 x 5 Qm,
A composite injection molded product consisting of three layers and having a cross section as shown in FIG. 1 and having a thickness of 8 ff was obtained.

In order to measure the elastic modulus of the outer layer and inner layer of this molded product, the three-layer molded product was cut into three layers and the bending elastic modulus of each sample was measured using Tensilon UTM-4 manufactured by Toyo Baldwin Co., Ltd.
The measurement was carried out using a mold at a span distance of 40 ul and a strain rate If/min.

As a result, as shown in Table 1, the flexural modulus of the outer layer was l 7.9 GPa, and the flexural modulus of the inner layer was 20
．． It was 8 GPa. On the other hand, only the inner layer (thickness 3fl)
The flexural modulus of the injection molded product is 2 L 2 GP
a, and the flexural modulus of the outer layer and inner layer samples obtained by cutting these is almost the same as the flexural modulus of the sample obtained by molding only the inner layer, even though the skin layer is cut. It was found that the flexural modulus was comparable.

On the other hand, instead of a composite molded product consisting of three layers, 8X8X
A 60ff single-layer molded product was injection molded, and the single-layer molded product was cut into three layers to a thickness corresponding to the outer layer (2.5fl thickness) and inner layer (3ff thickness), and the bending elastic modulus was measured.The outer layer IL
It was found that the elastic modulus of the inner layer was 5 GPa and the inner layer was 10°7 GPa, and the elastic modulus decreased more than that of the three-layer composite molded product of the present invention.

Furthermore, the obtained three-layer composite injection molded product was divided into two equal parts in the length direction, and the product was manufactured by Toyo Baldwin Co., Ltd. by the method shown in Figure 2.
When the shear adhesive strength between the glabella was measured using Tensilon Model UTM-1, it was found to have a high adhesive strength of IL6&p/d.

Example 2 360 parts by weight of p-7 setkin benzoic acid, 129 parts by weight of hydroquinofure acetate, 1 part by weight of t-butylhydroquinone diacetate) 167ffltf and 323 parts by weight of 4,4'-lephenyldicarboxylic acid were mixed with a stirring blade and distilled. Pour into a reaction vessel equipped with a tube and heat at 250 to 300 ml under nitrogen gas atmosphere.
After reacting at 30° C. for L5 hours without stirring, stirring was started at 330° C. and the reaction was further continued for L5 hours. Then increase the temperature to 3
After raising the temperature stepwise to 50°C and 360°C, the pressure inside the system was gradually reduced and the reaction polycondensation was completed for an additional 2525 hours at 0.5WHg, and almost the theoretical amount of acetic acid was distilled out.
A polymer having the following theoretical structural formula was obtained.

1/m/n=6/2/2 -4 f: , This polyester was placed on the sample stage of a polarizing microscope and the temperature was raised to confirm the optical anisotropy, and the result was 260°C.
It showed good optical anisotropy. The logarithmic viscosity of this polyester was measured under the same conditions as in Example 1 and was 3.25, and the melt viscosity at 320° C. and a shear rate of 1000 (1/sec) was 5.800 poise. Also, Example 1
The melting point and heat of crystal fusion were measured by DSC at the same heating rate of 20°C/min, and the melting point was 294°C, and the heat of crystallization was 0.08 cal/f.

This polymer was molded into a three-layer composite injection molded product using the same molding machine as in Example 1 at a cylinder temperature of 290 to 330°C and a nozzle temperature of 330°C. It was measured by the method. The results are shown in Table 2.

Table 2 Flexural Modulus The glabellar shear adhesive strength of this three-layer composite injection molded product was measured in the same manner as in Example 1 and found to be 3.3.
It has an adhesive strength of kq/d.

Comparative Example 1 Methylhydroquinone reacetate 313 Mlm,
317 parts by weight of 4,4'-diphenyldicarboxylic acid and 1,2-bis(phenoxy)ethane-4,4'-dicarboxylic acid! Part by weight was charged into a reaction vessel equipped with a stirring blade and a distillation tube, and the mixture was reacted at 250 to 330°C under a nitrogen gas atmosphere for 5 hours without stirring, then stirring was started at 330°C, and the reaction was continued for another 5 hours. Ta. Then increase the temperature to 35O℃
After raising the temperature stepwise to 370°C, the pressure inside the system was gradually reduced and the reaction was further carried out for LO0 hours at 0.5 ffHg to complete the polycondensation. Almost the theoretical amount of acetic acid was distilled out, and the following theoretical structural formula was obtained. A polymer having the following properties was obtained.

m/n=9/1 Also, place this polyester on the sample stage of polarized light@@mirror,
Optical anisotropy was confirmed by increasing the temperature, and as a result, optical anisotropy was observed at 295°C. The logarithmic viscosity of this polyester was 3.10 as a result of measurement under the same conditions as in Example 1, and was 3.10 at 355°C.
The melt viscosity at a shear rate of 1000 (1/s) is 6
, 100 voices. In addition, the melting point and crystal heat of fusion were measured by DSC at a heating rate of 20°C/min as in Example 1, and the melting point was 341°C, and the crystallographic heat of fusion was 0.33 c.
It was at 7 y.

This polymer was molded into a three-layer composite injection molded product using the same injection molding machine as in Example 1 at a cylinder temperature of 330 to 360°C and a nozzle temperature of 370°C, but there was no adhesive force between the layers and the molded product was molded into a mold. At the same time as protruding from the forehead, detachment occurred between the eyebrows.

Comparative example 2 A polymer having the following theoretical structural formula was polymerized.

When this polyester was placed on a sample stage of a polarizing microscope and heated to confirm its optical anisotropy, it showed good optical anisotropy at 251°C. The logarithmic viscosity of this polyester was measured under the same conditions as Reference Example 1 and was 3 and 3.
The melt viscosity at 0° C. and a shear rate of 1000 (1/sec) was 1250 poise. Similar to Reference Example 1, this polymer was measured using DSC at a heating rate of 20°C/min, and the results showed a melting point of 275°C and a heat of crystal fusion of 0.35 cal/! Met.

Using the same injection molding machine as in Example 1, this polymer was molded into a three-layer composite injection molded product at a cylinder temperature of 6o to 300°C and a nozzle temperature of 300°C, but there was no adhesive force between the layers.
Peeling between the layers occurred as soon as the molded product was ejected from the mold.

Effects of the present invention> Ivy.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a multilayer composite molded product, and FIG. 2 is a schematic diagram of an apparatus for measuring interlayer adhesive strength of a multilayer composite molded product. 1...Inner layer, 2...Outer layer, 3...Crosshead,
4... Sample, 5Φ eyelids, Al E &%6... Reload cell. Patent applicant: Institute of Industrial Science, Changjeong, Figure 1, Figure 2

Claims (1)

[Scope of Claims] At least one type is composed of a structural unit selected from the following structural formulas (I) to (III), and the heat of crystal fusion measured by a differential scanning calorimeter (DSC) is 0.1 cal/g or less A multilayer composite injection molded article comprising one or more polymers which are aromatic polyesters capable of forming an anisotropic melt phase. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(II) (However, the X in the formula is ▲There are mathematical formulas, chemical formulas, tables, etc.)
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