DE2354716A1 - GRAVILABLE, LOW-SHRAPING, UNSATURATED POLYESTER MOLDING COMPOUNDS - Google Patents

Description

The present application relates to low shrinkage curable, free-flowing molding compositions based on unsaturated polyester, the thickener metal hydroxide can be prepared without addition of the known metal oxide or injection molding and suitable slnd ₀

Conventional polyester molding compounds show considerable polymerization shrinkage on, which is a serious disadvantage in the manufacture of moldings with a perfect surface represents. From numerous publications (DOS 1 192 820, 1 694 857, 1 803 345, 1 953 062, 2 051 663, 2 061 585, FR-PS 1 148 285) it is now known that polyester molding compounds, to which certain thermoplastics such as polystyrene, polyethylene or poly (meth) acrylate are added before curing, Allow to harden with little shrinkage.

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The subject matter of these applications is both liquid casting resins and the addition of fillers thickened resins due to their stickiness Naturally unsuitable for the production of free-flowing polyester molding compounds without the addition of further auxiliaries are. These sticky resins can only be processed into free-flowing masses by adding such considerable amounts of fillers that the resulting polyester compositions can no longer be processed on injection molding machines and their mechanical properties no longer meet practical requirements.

The object of the invention was therefore to provide free-flowing, low-shrinkage Provide curing, unsaturated polyester molding compositions that can also be used without the addition of thickeners or fillers can be produced and in this form for injection molding processing are suitable.

Recently it has now surprisingly been found (patent application P 23 02 842.4) that by special Combination of cellulose esters of organic acids with one of the polyesters known from DAS A 4446 39c 16, Free flowing masses can be made from

a) 30-70 wt .- # of an unsaturated crystalline polyester, which contains fumaric acid residues and residues of glycols of the formula HO-CH ₂ -R-CH ₂ -OH, where R is an alkylene of the formula (OH ₂ ) " with ζ = 1 - 18 or symmetrical dialkyl derivatives of these alkylene radicals, the alkylene radicals being on the same carbon, or cycloalkylene radicals,

b) 20-75 parts by weight of styrene and

c) 1-30% by weight of cellulose esters of organic acids

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In connection with this work, we have now further found that - similar to cellulose esters - also some other thermoplastics, namely polycarbonates, polyamides, polyvinyl alcohol, polyvinyl alcohol acetals, polyvinyl chloride and preferably polyethylene suitable for such a combination are. With their help, not only unsaturated ones succeed Polyester-styrene mixtures within the meaning of DAS A 4446 39c 16 with the usual styrene content of about 20-40 wt. Ji to free-flowing To process molding compounds which can be cured with little shrinkage; in addition, such Much more styrene is added to mixtures, without affecting the crystallinity *

The subject of the invention are therefore pourable, for Injection molding suitable, low-shrinkage polymerizing haters based on ethylenically unsaturated polyester, polymerizable monomers and thermoplastics, which are obtained by the following Composition are characterized:

a) 30 - 70 wt .- # ₂ -OH contains an unsaturated crystalline polyester which IPumarsäurereste and residues of glycols of the formula HO-CH ₂ -R-CH, wherein R is an alkylene of the formula (CHP) ₂ ζ = 1 ■ - 18 or symmetrical dialkyl derivatives of these alkylene radicals, where the alkyl substituents are on the same carbon atom, or are cycloalkylene radicals,

b) 20-75 wt. 56 styrene and

c) 1 - 30 wt .-? i polycarbonates, polyamides, polyvinyl alcohol, Polyvinyl alcohol acetals, polyvinyl chloride or preferably Polyethylene.

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As component a) all of DAS A 4446 39 c in the broadest sense encompassed polyester can be used. For the purposes of the invention, it is not absolutely necessary to to use fumaric acid as the starting substance for the production of the unsaturated polyester. This can also go through Rearrangement from maleic acid can be formed during manufacture of the unsaturated polyester. Particularly preferred Diols are neopentyl glycol, 1,4-hydroxymethylcyclohexane and Hexanediol-1.6.

The polyesters, like the thermoplastics, can be used for calibration can be used alone or in combination with each other.

The preferred polycarbonates are products with molecular weights > 15,000 based on bisphenol A, chlorinated, brominated or methyl-substituted bisphenol A, e.g. Tetrachloro-, tetrabromo- or tetramethylbisphenol A, as Homo- or used as cocondensates.

All common products with a molecular weight, some of which are also commercially available, are suitable as polyamides > 10,000 based on aminocarboxylic acids, such as 6-aminocaproic acid or 11-aminoundecanecarboxylic acid, from their lactams with at least 5 methylene groups, such as caprolactam or laurolactam, of diamines or dicarboxylic acids each with at least 4 methylene groups, such as hexamethylenediamine, adipic acid or sebacic acid.

Fully and just as advantageously only partially saponified polyvinyl acetates with molecular weights can be used as polyvinyl alcohols > 15,000 and residual acyl contents of 0.1-30 # can be used.

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The suitable polyvinyl alcohol acetals are calibrated preferably around 80% with formaldehyde or butyraldehyde acetalized polyvinyl alcohols with Restacy! held by 2 and molecular weights * -15,000 «,

The suitable polyvinyl chlorides are all common products obtainable by emulsion, suspension and bulk polymerisation processes with a molecular weight of> 15,000. or maleic acid esters are prepared are suitable as thermoplastic component c).

As polyethylene which can be used according to the invention, all can known types of polyethylene with molecular weights > 5000 are used, especially those with up to 10 wt .-? 6 vinyl acetate are copolymerized.

The resin mixture according to the invention is cured in the presence of known initiators, such as peroxides, e.g. benzoyl peroxide, tert-butyl perbenzoate, cyclohexanone peroxide, in the heat under pressure. Of course, the masses can be used not only by injection molding, but also by hot pressing are processed.

The free-flowing, low-shrinkage polymerizing according to the invention Polyester compounds can be mixed with other additives in a known manner, such as molding agents and lubricants, glass fibers, Stabilizers, pigments, fillers are added. Instead of glass fibers, completely or partially synthetic materials can be used Fibers or natural organic fibers' like jute, Sisal, cotton or mineral fibers such as asbestos can be used.

The free-flowing, polymerizing compositions can be preferred Deploy and use where large. Dimensional stability

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is desirable, such as in car carose decoration, in the Furniture industry, in the manufacture of bowls and others Molded parts.

The following examples explain the invention:

A. Production of the unsaturated crystalline polyester according to DAS A 4446 39c 16.

Example 1;

1.000 mol of fumaric acid and 0.982 mol of neopentyl glycol are condensed in the presence of 0.037 g Toluylenhydrochinön within 24 hours at 19O ⁰ C until an acid number of 40th 0.019 g of toluene hydroquinone and 0.016 g of chloranil are then added to the polyester.

At 100 ° C, the polyester is then pulverized with 54.5 g of a Polycarbonates based on bisphenol A (Makroion, commercial product of Pirma Bayer AG) and 216 g of styrene with stirring offset. The polyester mass crystallized during cooling is ground and results in a free-flowing, dry powder, which even after prolonged storage does not cakes.

Examples 2-12

In the examples described below, the procedure is analogous to Example 1 and, instead of the polycarbonate, the same amount of other thermoplastics added. As a rule, they are pulverulent because they are easier to homogenize Additives used.

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fen example no. thermoplastic

η 2 polycarbonate based on tetrabromobisphenol A vjj 3 polycarbonate based on tetrabromobisphenol A

ul 4 polyamide based on caprolactam (Durethan BK, commercial product

from Bayer AG)

5 polyamide based on aminoundecanecarboxylic acid (Rilsan ES, Commercial product from Aquitaine-Organico)

6 polyvinyl alcohol (Mowiol N 50-98, commercial product of the company Farbwerke Hoechst AG-)

to 7 polyvinyl acetal (Pioloform BW, commercial product of the company

oo riacker chemistry),

7t 8 polyvinyl acetal (Pioloform Bl · 24, commercial product of the company

^ Wacker Chemie)

■ ° '9 polyethylene (Baylon YP 105? Commercial product of Bayer AG) to ^ 10 polyethylene (Baylon 1 18 »")

»11 Polyvinyl chloride (Yestolid S, commercial product of the company

Chemical Works Hüls AG)

12 PVC copolymer (Vilit MG, commercial product from Chemische Works Hüls AG) '

In all cases, products are obtained that become free-flowing, dry powders that even after prolonged storage do not stick together, are workable.

Example 15 (comparison):

The procedure is analogous to Example 1. Instead of the polycarbonate, 54.5 g of polymethacrylate (Plexigum H 7, Commercial product from Röhm, Wiesbaden) used. When it cools down, a sticky, doughy polyester mass is obtained, that cannot be ground. Even with the addition of fillers as in the following examples, the mass remains sticky.

B. Production of pourable molding compounds:

Example la:

In a kneader, 1000 g of the polyester composition prepared according to Example 1 at a Knetertemperatür of 80 ⁰ C to be melted. 20 g of 1,3-bis (tert-butylperoxiisopropyl) benzene are added; After 5 minutes, 40 g of zinc stearate and 1000 g of chalk (Dureal 5; commercial product from Omya GmbH / Cologne) and after 10 minutes 300 g of glass fibers (13 mm long) are kneaded in. All work is carried out in a closed kneader to avoid styrene losses.

The paste-like to doughy mass at 80 ^° C. is comminuted in a hammer mill after cooling to room temperature, so that a grist with a grain size of 1-5 mm was obtained. The compositions are processed by hot-pressing at 140-160 ⁰ C to pressed parts which have the following properties:

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Shrinkage according to DIN 53464: 0.2 # Martens degree, standard rod, DIN 53 458: 180 ° bending strength, standard rod 53 452: 600 (kp / cm ² )

Surface markings due to different shrinkage in places of different wall thicknesses are not observed «

Examples 2a-12a

The polyester compositions of Examples 2-12 are analogous. example la processed.

Example no. Shrinkage after
DIN 53 464 Martensg 2a 0.35 180 3a 0.15 180 4a 0.20 180 5a 0.19 * 180 6a 0.38 160 7a; 0.23 : 180 8a 0.24 170 9a 0.12 180 10a 0.11 180 11a 0.22 140 12a 0.18 140

The flexural strength values correspond to those from example la.

Example 14 (comparison):

The procedure is as in Examples 1 and la, however the molding compound does not contain any thermoplastics.

All other components are used in the same amount. The molded parts made with these masses have

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following properties:

Shrinkage according to DIN 53464: 0.6 i "Martens degree standard rod, DIN 53 458: ⁰ 180 C flexural strength, standard rod, DIN 53452: 400 (kgf / cm ²⁾

Strong surface markings were made in places of different wall thicknesses observed,

Example 15

The polyester composition according to Example 9a was made on a piston screw injection molding machine Processed into round disks with a diameter of 100 mm and a wall diameter of 7 mm.

Cylinder temperature: 70 - 75 ⁰ C Injection pressure: 640 kp / cm Back pressure: 80 kp / cm Reprint: 240 kp / cm Mold temperature 150 ⁰ C Hardening time: 120 lake.

The visual curl and the mechanical property values of the shaped bodies correspond to those from Example 9a.

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Claims (1)

Claim:, Free-flowing, non-shrink polymerizing compounds based on ethylenically unsaturated polyester, suitable for injection molding, Polymerizable monomers and thermoplastics, thereby marked that they are out a) 30-70 wt .- # of an unsaturated crystalline polyester which contains fumaric acid residues and residues of glycols of the general formula HO-CH ₂ -R-GH ₂ -OH, where R is an alkylene of the formula (CH ₂ ) _Z with ζ = 1 - 18 or symmetrical dialkyl derivatives of these alkylene radicals, the alkyl substituents being on the same carbon, or cycloalkylene radicals, b) 20 - 75 wt .- ^ styrene and c) 1 - 30 wt .- # polycarbonate, polyamide, polyvinyl alcohol, Polyvinyl alcohol acetals, polyvinyl chloride and / or polyethylene exist. Ie A 15 333 - - 11 - 509819/0922