DD134236B1 - AMPLIFIED POLYOLEFINE - Google Patents

Description

Field of application of the invention

The invention relates to reinforced polyolefins, which are particularly suitable for use under high static load, at high temperatures and different humid Technoklimao Here is a wide range of applications given by excellent dielectric properties, good hydrolysis and oxidation resistance, high dimensional stability and low thermal expansion ·

Characteristic of the known technical solutions

For PlastformteiIe that are exposed to a long-lasting high load or may experience only small expansion changes at greater temperature differences, generally reinforced plastic materials are used. In addition, very specific requirements are made of such mixtures of thermoplastics and reinforcing materials according to the specific application

The selection of suitable reinforced plastic therefore takes place

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according to the application-related characteristic values, which are influenced both by the reinforcing materials and by the polymer matrix and special additives. The known reinforced plastics have therefore developed very specific applications and are not or only partially suitable for other applications due to negative properties »

For example, glass fiber reinforced polyamides-6 and -6.6 are also used for thermal stress due to their good resistance to alternating bending under dynamic loads and because of their high heat distortion resistance. Their dimensional accuracy is often insufficient for precision parts due to the relatively high water absorption of more than 4 % and the changes in volume and lanvature due to different humidities. "Applications in electrical engineering / electronics are, due to the high dielectric constant and its dependence on the V / asser salary imposed restrictions.

Glass fiber reinforced polycarbonates are especially used for molded parts that are exposed to high static loads. For a variety of applications, the flame resistance and heat resistance up to ca, 150 ⁰ C and the generally good for applications in electrical engineering / electronics characteristics are advantageous. However, even polycarbonate reinforced with 20% glass fiber still absorbs about 0.35 % water and polycarbonate reinforced with 40 % glass fibers still absorbs about 0.16 % water at saturation. Furthermore, the dielectric constant with values between 3.times.3 and 3.sup.8 exceeds the limit of about 3 required for many applications in electrical engineering / electronics (H. Jahn, Plaste und Kautschuk 22 (1975), 696 et seq., H. Streib et al. K. Oberbach, Kunststoffe 6 (1966), 100 ff.).

Glass fiber-reinforced polyamides-11 and -12 achieve only one Ε-modulus of little, even with reinforcement with 30 wt .-% glass fibers

over 30 000 kp / cm β This rigidity is not sufficient and corresponds to precision parts subject to high loads

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the widths for unreinforced polystyrene types or polymethylmethacrylate. Furthermore, in the case of these plastic materials, the dielectric constant is more than 4 ×

Reinforced polyolefins have advantages compared to reinforced polyamides and polycarbonates duroh very low water absorption and very good dielectric properties. In order to limit usage, they have the relatively low heat resistance under increased load, the sometimes low hardness or strength values and the relatively high oxidizability. In addition, the use of special adhesion promoters or a polymer modification is required for an effective reinforcement of some polyolefins, so that z. B. form chemical bonds between the polymer and the coated with vinyl silane glass fibers CG Roos, Plastics 60 (1970), p 924 ff).

Thus, the glass fiber-reinforced polystyrene types (standard polystyrene, polystyrene impact, acrylonitrile-butadiene-styrene and styrene-acrylonitrile) limit the useful life to continuous use temp. Under 105 ⁰ O, although the hardness and strength values at normal conditions are good 696 ff and following literature: K. Wilmes, Kunststoffe 8 (1968) 9 ff, ibid % 8 (1968), pp. 133 ff.) and the shear moduli are (H. Jahn, Plaste and Kautschuk 22 (1975), p up to about 100 ⁰ C change only minimally.

Polypropylene can not be effectively reinforced by glass fibers in the same simple way as polyamides or polycarbonate. To achieve high strength values, the addition of special coupling components is required, so that the modification of the polypropylene by glass fibers is more expensive (G. Roos, Kunststoffe 60 (1970), p. 924 ff).

Object of the invention

The aim of the invention is the preparation of a thioplastie

LP 7773

Rials, which has a high heat resistance, a good Y / asseraufnahme, good dielectric properties and a low thermal expansion coefficients and beyond that can be produced without special expenses

Explanation of the essence of the invention

It was therefore an object to produce combinations of thermoplastics and reinforcing materials, which have a good heat resistance, a low water absorption, good dielectric properties and low thermal expansion, the selection of the polymer matrix zuetrückkommto

This object is achieved by reinforced polyolefins with high heat resistance, low water absorption, good dielectric properties and low expansion coefficient with the addition of stabilizers and optionally lubricants, according to the invention the reinforced polyolefins from 50 to 90 wt .-% norbornene-ethylene copolymers or norbornene-JLthylen It is advantageous for the mixtures containing norbornene-ethylene copolymers to contain elastomers as the second main component. As inorganic reinforcing materials, it is possible to use glass fibers or asbestos fibers.

In this case, norbornene-ethylene copolymers or norbornene-ethylene copolymers / elastomers, which are equipped with stabilizers or stabilizer mixtures and / or lubricants as required, are mixed with from 10 to 50% by weight of an inorganic reinforcing material. Surprisingly, in contrast to the experience of polypropylene reinforcement, a good coating of fiber with vinyl silane is sufficient for a good reinforcement of glass fibers

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The inorganic reinforcing materials, when fibrous, may be mixed in extruders with the thermoplastic material so as to be fed as a continuous filament or cut. The metering of the polymer powder or granulate and the inorganic fiber materials can be carried out together after prior mixing or separately. In the case of separate metering, both components can be added without prior mixing into a filler neck of the extruder, or the metering takes place via separate filler neck.

When using injection molding machines with good homogenization effect, the preparation of the mixtures can also be done in these machines. Decisive for the properties of the mixtures are the characteristic values of the polymer material, the proportion of the inorganic reinforcing material and, in the case of fibers, the fiber length.

As the content of inorganic reinforcing material increases, stiffness, tensile and flexural strength, hardness and heat resistance increase, and to a lesser extent the dielectric constant and water absorption. At the same time, the linear thermal expansion decreases.

The stiffness, the tensile and flexural strength as well as the heat resistance increase with fibrous reinforcing materials with increasing fiber length.

The polymer material influences the heat distortion resistance depending on the composition of the norbornene-ethylene copolymers. With increasing norbornene content, the heat resistance increases «

As a result of the reinforcing materials, the Vicat temperatures of the mixtures are only slightly increased compared to the unreinforced thermoplastics, but the Martens tempera tures are markedly increased.

IP 7773

Decisive for the mechanical characteristics also affects the thermoplastic material by the molecular weight height. With increasing molecular weight, especially the tensile and flexural strengths are improved.

embodiments

Stabilization takes place with 0.2 g / ^{l of} 4.4 ^{l of} thio-bis- (3-methyl-6-tert-butylphenol), yß ^ 'thiodipropionic acid dilauryl ester and trinonylphenyl phosphite.

example 1

3.5 kg of a stabilized norbornene-ethylene. Copolymer with a Vicat temperature of

G, one

127 ⁰ C, a minimum tempera- ture of 97 ° ⁿ -

Tensile strength of 525 kp / cm, a Ε-modulus of

ρ 32,000 kp / cm and a dielectric constant

of 2.3 are mixed with 1.5 kg sized and cut glass fibers, dosed together in an extruder and homogenized at 250 ⁰ O. The glass fibers have an average length of 0.07 mm «

The Vicat temperature rises to 129 C, the

least temperature to 114

the modulus of elasticity to approx.

58 000 kp / cm ² , the tensile strength to 640 kp / cm ² and the dielectric constant to 2.7 · The water absorption in boiling water and in water. at 23 + 2 ⁰ C over a period of 30 days is less than 0.2 % ₀

Example 2

3.5 kg of the norbornene-ethylene copolymer used in Example 1 are mixed in a twin-screw extruder at 270 ⁰ C with 1.5 kg of glass fibers, which are fed as continuous fiber, so that the glass fiber length in the granules 0.4 mm

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is. The mixture has the following properties:

Tensile strenght :

Bending strength: modulus of elasticity:

Vicat temperature: Martens temperature:

8 ^ 0 kp / cm * IO5O kp / cm * 97000 kp / cni 130 ⁰ C

119 ⁰ O

Example 3

4.5 kg of the norbornene-ethylene copolymer used in Example 1 and 0.5 kg of sized glass fibers are mixed as in Example 2. The mixture has the following properties:

Tensile strenght :

Bending strength: modulus of elasticity:

Vicat temperature: Martens temperature:

610 kp / cm ^£ kp / cmj 43ООО kgf / cm ² 128 112 ^{0 0} O C

Compared to the mixture of Example 2 increases

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linear expansion coefficient from 18 · 10 Κ to 28 · 10 ~ ⁶ ϊΓ ¹ .

Example 4

3 kg of the norbornene A'thylen copolymer used in Example 1 are mixed with 2 kg of glass fibers in an extruder at 270 ⁰ C so that the average glass fiber length is 0.28 mm. In this mixture are the

Tensile strenght :

Bending strength s of modulus of elasticity:

Vicat temperature: Mar tens temperature:

980 kp / ciQ 1325 kp / cm ² 83000 kp / cm ² 131 ⁰ 119 ⁰ C and

the linear expansion coefficient:

16 · 10 ~ ⁶ Κ ~ ¹

LP 7773 Example 5

3.5 kg of a stabilized norbornene-ethylene copolymer having a Vicat temperature of 103 ⁰ O and a Martens temperature of 72 ⁰ C are mixed with 1.5 kg of glass fibers in the extruder at 240 ⁰ C ·

The mixture vseist Yicat a temper ature of from 107 ⁰ O Martens and a temperature of 91 ⁰ C.

Example 6 7 kg of a stabilized norbornene-ethylene

Copolymer having a Vicat temperature of 165 ⁰ O Martens and a temperature of 131 ⁰ C are mixed with 3 kg of sized glass fibers in the twin screw extruder at 290 ⁰ C. The feeding of the glass fibers was carried out as a continuous fiber in a special nozzle separated from the polymer. The Vicat temperature of the mixture is 169 ⁰ C and the Martens temperature 155 °

Example 7

3.5 kg of a stabilized compound of 80 Ge ^ .-% norbornene-ethylene-Oopolymerisat and 20 Ge ^ .-% Stynol-butadiene rubber (styrene content about 27 Ge ^ -.%) Having a Vicat temperature of 121 ⁰ C, a mark

Tens-Tecmeratur of 84 ⁰ C, a tensile strength of

2

325 kp / cm, a flexural strength of 540 kp / cm

and a Ε module of 23,000 kp / cm vserden mixed with 1.5 kg of glass fibers at 270 ⁰ C in a twin-screw extruder. The mixture has the following characteristics: Vicat temperature: minimum temperature:

: 710 kp / cm ²

: 860 kp / cm ²

131 ⁰ C 116 ⁰ C

Tensile strength Bending strength modulus of elasticity

87000 kp / cni ^c

LP 7773 Example 8

4 kg dea used in Example 1 Norbonnen-ethylene copolymer and 1 kg of asbestos fiber are mixed in the extruder at 290 ⁰ C · The mixture has the following characteristics:

Tensile strength modulus of elasticity

Vicat tempera ture Mar tens tempera ture

600 kp / cm '40000 кр / ст ^й

130 ° c

115 ⁰ O

Example 9

3.5 kg of a compound of 80 wt .-% norbornene-ethylene copolymer and 20 wt .-% ethylene-vinyl acetate copolymer (vinyl acetate content

ca, 32 % by weight ) with the following properties:

Tensile strength Bending strength modulus of elasticity

Vic at-temperature Man tempei atur

410 kp / cm ^£ 580 kp / cm * 20000 kp / cm ² 107 ⁰ O 74 ⁰ O

are mixed with 1.5 ^k S glass fibers at 250 ° C in a twin-screw extruder. Through this VerstsLc-

The tensile strength increases to 725 kp / cm, the flexural strength to 930 kp / cm ² , the modulus of elasticity to 79,000 kp / cm ² , the Yicat temperature to 129 ⁰ C and the Martens temperature to 112 ⁰ C.

Claims (3)

LP 7773 Invention claim 1. Reinforced polyolefins having high heat resistance, low heat and good dielectric properties with the addition of stabilizers and optionally lubricants, characterized in that the reinforced polyolefins comprise from 50 to 90% by weight of norbornene-ethylene copolymers or norbornene Ethylene-copolymer-containing mixtures and 10 to 10% by weight of inorganic reinforcing materials. 2 · Reinforced polyolefins according to item 1, characterized in that mixtures containing norbornene-ethylene copolymers contain elastics as the second main component. 3 · Reinforced polyolefins according to item 1, characterized in that glass or asbestos fibers are used as inorganic reinforcing materials.