DE1544870C - Process for crosslinking graft polymers of vinyl chloride - Google Patents

Description

I 544 870

1 2

From British patent specification 772 978 it is said to be sown between 20 and 80 percent by weight, before-

knows, copolymers of vinyl chloride and co- preferably between 30 and 70 percent by weight, are,

polymerizable vinyl compounds, the two oils of particular importance are those ethylene vinyl

contain finically unsaturated groups in the molecule, ester copolymers, which by polymerization

in the presence of other mono- or polyfunctional 5 of the starting components of my predominantly tertiary

To crosslink monomers with the help of peroxides. Butanol-containing liquid phase produced

In contrast, the present process relates to which have been.

Crosslinking of graft polymers of vinyl chloride, as graft monomers of vinyl or vinylidene no olefinically unsaturated double bonds of the monomer type which, in addition to the vinyl chloride, contain as grafts. . ίο monomer components should be used, come

In German patent application P 15.44 859, particular consideration is given to esters of acrylic acid or Has already been proposed, graft copolymerized methacrylic acid with preferably 1 to 12 carbon ends Vinyl chloride on ethylene-vinyl ester copolymer atoms in the ester group, depending on the polysate by means of substances that form free radicals, including acrylic acid, methacrylic acid in particular more organic. Peroxides or high-energy acids or their amides themselves, furthermore in particular Radiation, network. Derivatives of these acids with functional groups such as

In the further development of this process, a —COOH -, - OH-, - NH ₂ -, - NCO-, -; NCS-,

now found. that .also graft copolymers —NHR group, such as. for example Qxyäthyl-

of mixtures of vinyl chloride and other copolyacrylate, N-methylolacrylamide, / I-isocyanatoethyl

merizable monoolefinically unsaturated vinyl acrylate, glycol methacrylate, oxypropyl methacrylate,

and / or vinylidene monomers with. Ethylene vinyl / i-aminoethyl acrylate, also derivatives «, ^ - unsaturated

ester copolymers are radically crosslinkable. . Dicarboxylic acids such as B. Malein (or. Fumar)

In detail it was found that process acid propyl half esters, maleic acid dodecyl half esters, Products with particularly excellent technological maleic anhydride, as well as vinyl esters such as vinylschen Allow properties to be retained if the pre-acetate, vinyl propionate, vinyl butyrate and Λ-chlorine layers are used Process Graft polymerization products of vinyl acetate, ω-chlorovinyl butyrate and also vinylidene set be where chloride.

a) the grafted portion of 55 to 95 percent by weight, process for the production of such graft polymer ^{percent vinyl chloride and 5 to 45 percent by weight s} f ^{e S1} _n ^{nd im} _c ^{e mze ln} _u ^{en 1} ^ ^d ? ^{r German} patent applicant describes at least one other vinyl and / or ³ ° dung P 14 95 735.8. . ■ ·

Vinylidene monomers and the crosslinking of the above-defined graft

b) the graft substrate is an ethylene vinyl ester copolymers of vinyl chloride on ethyl vinyl ester polymer from ethylene and 20 to 80 copolymers by weight should be carried out radically who percent is a vinyl ester, ^the > ^ ₁ ^{1 h} ™ l ^ei especially the crosslinking with

35 free radical forming organic substances, ms-

where the proportion of ethylene-vinyl ester copolymer special organic peroxides and the Vernet

in the graft polymer between 25 and 67 are understood by means of high-energy radiation

weight percent (i.e. the proportion of the graft substrate that should.

up to about two thirds of the total polymer) Substances which form free radicals come into play. 40 particular organic peroxides, more preferably in the temperature According to embodiment of the inventions range between 40 and 18O ⁰ C free radicals, forming such Pfropfcopolyrnerisäte are used, the assets, such into consideration. B. acyl peroxides such as benzoyl peroxide or dichlorobenzoyl peroxide, di-

a) a copolymer of ethylene as the graft substrate. ³ ^ ¹ ", ' ⁰ ^ ¹ " ^or alkyl aryl peroxides such as ζ Β di- and 20 to 80 percent by weight vinyl acetate and * ⁵ cumyl peroxide and tert-buty 1-cumy peroxide, per-

b) as grafted components in addition to vinyl chloride oxydicarbonates such. B dicyclohexyl peroxydicarbo-5 up to 45 percent by weight, calculated on the total, dibenzyl peroxydicarbonate. · total amount of grafted monomers, ...,. ^ e above-mentioned radical formers can

^; '' - I ^ Vi «, / 9-üiigesaturated mono- or dicarbon- ' ^{m Men} S ^en from 0.5 to 10» / ^ based on the total ^{acids with 3 to 4 carbon atoms or' 5a} " ¹ ^ Sf of ^{the to be} crosslinked material used werderen derivatives having functional groups, the quantity preferably come 1-5 ° / ₀ - JI a Vinylesters or ... ⁱⁿ consideration the selection of the respectively employed III vinylidene Radikälbildriers respect to its Zersetzühgstempesowie Mischurigeri-containing monomers of these.: : ^ ^at W depends largely ^ on the intended

55 Use and the processing conditions.

In the context of the present method to be understood as ^energy: is radiation 'particularly applicable forming graft polymers can advertising receive / 3-radiation at the dose of 1 to 50 Mrad, the by the Pfropfmono- defined above, y-radiation or X-radiation into consideration , meren in the presence of an Äthyjen-Vinylester-Copoly- The crosslinking can be carried out in such a way wermerisates in solution or emulsion, preferably 60 den that the radical formers to be crosslinked, however, by polymerization in suspension with the aid of product on suitable mixing units, eg. B. whale-free radical-forming substances polymerized zen or kneading, mixed in and then the. ■ deformed products to temperatures between 40 Copolymers of and 180 ⁰ C come as graft substrates. According to another Aus-Ethylens with vinyl esters, in particular such 65 leadership form, the radical generator is added to the dissolved product with 2 to 4 carbon atoms in the ester group, which after the solvent has evaporated. tion, preferably vinyl acetate, into consideration. The vinyl solvent as a film by increasing the temperature. ester portion in this ethylene-vinyl ester copolymer is wettable. When using peroxides,

appropriately high decomposition temperature (above 150 ° C) the peroxide intended for crosslinking can already be added to the monomeric vinyl chloride before the graft polymerization can be added.

According to a preferred embodiment of the present invention, which enables a particularly extensive crosslinking, this crosslinking is / carried out of the vinyl chloride graft polymers by means of free-radical forming substances simultaneously in the presence of 0.1 to 4 ° ₀ of an organic compound containing at least two, preferably contains three non-conjugated polymerizable carbon-carbon double bonds. These relatively small amounts of such monomers which cause additional crosslinking are chosen so as not to impair the otherwise advantageous property profile of the crosslinking products, ie in principle higher amounts of such a crosslinking monomer are not excluded.

Such crosslinking monomers are preferably di- to tetrallyl compounds, such as Triällyl phosphate, triallyl cyanurate or silicic acid tetraallyl ester into consideration.

According to the present process, the novel crosslinking products obtained, depending on the proportion of Ethylene-vinyl ester copolymer polyvinyl chloride modified to a greater or lesser extent by internal plasticization dar, d. That is, they do not contain any extractable low molecular weight fractions. It results completely cross-linked soft and flexible vinyl chloride polymers with elastic properties. The networking can be driven to a greater or lesser extent depending on the required properties. As special It is interesting to evaluate that within a range of ethylene-vinyl acetate copolymer proportions from 40 to 70% for vinyl chloride polymers considerable elasticities can be achieved. the Process products show good heat stability, aging resistance and resistance to organic Solvent.

The crosslinking of these soft and flexible graft polymers is of particular importance when they are used for floor coverings, conveyor belts, cable sheathing, textile coatings or foils. the Networking harder attitudes, d. H. those with higher vinyl chloride proportions in the graft copolymer, is for use as insulating material or cor-

anti-corrosion agents important. ^:

It is possible to carry out the crosslinking process described in the presence of PVC processing customary plasticizers, stabilizers, anti-aging agents, fillers such as Aerosil, chalk, carbon black or Pigments without significant impairment of the properties. . . ■

Those given in the examples below Parts are parts by weight, unless otherwise noted.

Eg pi e1 1

Graft copolymers of different compositions are dissolved in tetrahydrofuran or methyl ethyl ketone dissolved, mixed with peroxide and poured into a film. The films are baked out in a drying cabinet and are insoluble after treatment. Details can be found in the following table:

Composition of the graft

copolymerisates:

Ethylene-vinyl acetate copolymer,%

Ratio of ethylene to vinyl acetate
Grafted Monomers:

Vinyl chloride,%

Vinyl acetate,%

Acrylic acid ethyl ester, ° / ₀

Oxypropyl methacrylate,%

Maleic acid dodecyl half ester, ° / ₀

Maleic acid propyl half ester, ° / "

Vinylidene chloride, ° / ₀

Butyl methacrylate,% ...
Amount of peroxide added

Dicyclohexyl peroxydicarbonate,%

Benzoyl peroxide,%

Dicumyl peroxide, ° / o

tert-butyl-cumyl peroxide,% ...
Additional crosslinkers and crosslinking conditions

Triallyl cyanurate, ° / ₀

Networking time, minutes

Crosslinking temperature ^{, 0 C}

60
55:45

29
11

57
55:45

59
60:40

35

32
30:70

39.5
3

4.3
21.2

32
30:70

39.5
3

4.3
21.2

32
30:70

39.5
3

4.3
21.2

42
34:66

49
2.7

2.5
3.8

55
29

11
5

15th
120

15 120 15
120

30th
150

30th
160

20th
120

30th
120

30th
120

Example 2 chloride (29 ° / ₀ ) and ethyl acrylate (16%)

a copolymer (55:45) of ethylene and vinyl

On a rolling mill as it is for the production of 65 acetate (55%), 2 parts barium cadmium laurate, 3 parts Commonly used rubber compounds are epoxidized soybean oil (compound A). This mistake the following mixture is produced in the usual manner: Schung (A) is mixed with 3 parts of triallyl cyanurate and 100 parts of a graft copolymer of vinyl 5 parts of dicumyl peroxide in a blend (60:40)

Calcium carbonate intimately mixed and ^{vulcanized at 151 °} C. for 30 minutes (B).

A. B. Tensile strength, kg / cm ²
Elongation at break, ° / ₀
Hardness (Shore A)
at 18 ° C 119
215
90
33
42 191
150
90
76
6th at 75 ° C Permanent stretch after 1 minute ...

The product is insoluble in organic solutions.

Claims (6)

Patent claims: . 1. A method for crosslinking graft polymers of vinyl chloride on copolymers of ethylene and vinyl esters, characterized in that graft polymers of vinyl chloride and at least one other vinyl and / or vinylidene monomers on an ethylene-vinyl ester copolymer, the proportion of ethylene-vinyl ester copolymer between 25 and. 67 percent by weight, a radical crosslinking at temperatures of 40 to 180 ⁰ C are subjected. 2. The method according to claim 1, characterized in that the radical crosslinking means organic peroxides are made which produce free radicals at temperatures between 40 and 180 ° C form. 3. Process according to Claims 1 and 2, characterized in that such graft copolymers be used in which the grafted portion of 55 to 95 percent by weight vinyl chloride and 5 to 45 percent by weight of «, ^ - unsaturated Mono- or dicarboxylic acids with 3 to 4 carbon atoms or their functional derivatives and / or vinylidene chloride and / or vinyl ester and the graft substrate made from an ethylene-vinyl ester copolymer consists of ethylene and 20 to 80 percent by weight vinyl acetate. 4. Process according to Claims 1 to 3, characterized in that the radical crosslinking the graft polymers of vinyl chloride and other copolymerizable vinyl and / or vinylidene monomers on an ethylene-vinyl ester copolymer in the presence of 0.1 to 4 percent by weight, calculated on the polymer of an organic compound which has at least two non-conjugated contains polymerizable carbon-carbon double bonds, is made. 5. Crosslinked graft copolymer of vinyl chloride and other copolymerizable vinyl and / or vinylidene compounds on an ethylene-vinyl ester copolymer as according to the procedure of claim 1 received. 6. Crosslinked graft copolymer of vinyl chloride and other copolymerizable vinyl and / or vinylidene compounds on an ethylene-vinyl ester copolymer as obtained by the procedure of claim 4. _: