DE2926830A1 - CROSSLINKABLE POLYETHYLENE PLASTICS - Google Patents

Description

Misubishi Petrochemical Company Limited

Tokyo / Japan

Crosslinkable polyethylene plastic compounds

The invention relates to crosslinkable polyethylene plastic compositions.

It relates in particular to polyethylene plastic compounds, the plastic components of which can be crosslinked when they exposed to the influence of water.

It is already known to spatially crosslink low-density polyethylenes and other polyethylene resins to thereby improve their mechanical strength, heat resistance and other properties, and are also known
different methods to accomplish this networking.

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According to a known crosslinking method of this type, an organic peroxide is used as a crosslinking agent Add polyethylene and heat the mixture to a temperature sufficient to decompose and thereby break down the peroxide to initiate the crosslinking reaction.

However, since the crosslinking takes place due to the peroxide decomposition before the polyethylene is brought into its final shape has been, the quality of the moldings often leaves something to be desired, and in extreme cases the shape can be no longer perform satisfactorily.

However, if you want the crosslinking after the production of the shaped body make, one needs a peroxide that is effective at high temperature and can withstand the molding temperature can. However, if such a peroxide is to be decomposed, the molded body must be heated to a temperature that is greater than the molding temperature. Accordingly, changes are inevitable, acting on the softening of the molded article are due in the crosslinking reaction, and the quantity of the molded article is still increased be unsatisfactory.

As an example of a polyethylene that does not have such chemical crosslinking problems, mention is made of silicone-grafted polyethylene (for example, described in Japanese Patent Publication 1711/1973 or the Japanese Offenlegungsschriften 8389/1972, 138042/1975 and 9073/1977). If now a If polyethylene grafted with silicone is exposed to the influence of water, hydrolysis of the silicone component occurs on, and the crosslinking reaction can proceed. Since this hydrolysis takes place at a relatively low temperature, large-scale systems for chemical crosslinking are no longer required. For this reason one looks for possible applications for cross-linked moldings.

9Q-888S / Q828

In this Pall, however, several process steps are used Production of the base polyethylene and required for grafting the silicone onto the base polyethylene. Come in addition, that a polyethylene article which has been produced and crosslinked in this way, for example a film, with regard to Odor, mechanical strength, heat resistance and heat weldability is unsatisfactory.

It is known that copolymers of ethylene and vinylalkoxysilane can be crosslinked by heating or by mechanical means To bring about processing (see ÜS-PS 32 25 018 and 33 92 156). The advantage of this procedure over the above-mentioned grafting method is that a spatially crosslinkable polyethylene is achieved in a single process step, i.e. only with the copolymerization stage. However, since the crosslinking must be carried out before the deformation, the same problems as with the chemical crosslinking described above. In addition, the mechanical strength an article molded after the crosslinking reaction leaves something to be desired.

Here she wants. Invention to remedy the situation.

The object of the invention is to develop a plastic compound that can be easily processed into molded bodies, which are crosslinkable under the influence of water and in the crosslinked state not only excellent mechanical ones Have strength and heat resistance, but in film or foil form (films and foils are also among the molded bodies produced by the composition according to the invention) also have very favorable properties, in particular the heat sealability is practically equal to that of a film made of ordinary low density polyethylene.

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It is precisely in this respect that cross-linked foils occur! Prior art polyethylene poses the greatest difficulties on. The same applies to the heat resistance.

According to the invention, this object is achieved by a content on a copolymer of one unit of ethylene and one unit of an ethylenically unsaturated silane compound, wherein the proportion of the unit of the ethylenically unsaturated silane compound is 0.001 to 15% by weight, and a catalyst for the silanol condensation.

The polyethylene resin gains the ability to crosslink when it comes into contact with water due to the fact that the silane group is not by grafting but by copolymerization has been introduced into the polyethylene molecule with random distribution. The one used here and in the following The term "copolymers" does not therefore extend to graft copolymers, unless this is expressly stated. However, this does not exclude graft copolymers, which may inevitably arise in competitive or side reactions.

Although no grafting reaction is provided according to the invention, Instead, a polyethylene in which an unsaturated silane compound is incorporated by copolymerization must be used, are manufactured separately. The production of the silanized copolymers can, however - partly because the unsaturated Silane used in only a small amount is made by a copolymerization, which is practically the Homopolymerization of ethylene corresponds to, and the products can be referred to as modifications of the polyethylenes.

Further features and advantages of the invention emerge from the following description and the subclaims.

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- ν -

1 . Copolymers of ethylene and unsaturated silane (silanized copolymers)

For the sake of brevity, the copolymers, which contain units of ethylene and an unsaturated silane compound, also referred to here as "silanized copolymers".

Various compounds can be used as unsaturated silanes are used, each of which is an ethylenically unsaturated, have a bond copolymerizable with ethylene and a hydrolyzable silane group.

A connection of this kind can be made through the following general formula

R Si R 'L

η 3-n

represent, wherein R is an ethylenically unsaturated hydrocarbon radical or an ethylenically unsaturated hydrocarbon st off -ether group, R 'an aliphatic saturated one Hydrocarbon residue, Y a hydrolyzable organic Group and η 0, 1 or 2 mean. If the substituent Y is present several times, it can also be different groups represent.

Suitable examples of such unsaturated silanes are obtained, inter alia, when R is vinyl, allyl, isopropenyl, butenyl, cyclohexenyl or } f -meth-acryloxypropyl, Y is methoxy, ethoxy, formyloxy, acetoxy, propionyloxy, alkylamino or arylamino, and R * is methyl, ethyl , Propyl, decyl or phenyl.

A particularly useful unsaturated silane compound can be expressed by the formula

CH ₂ = CH Si (OZ)

denote, in which Z is a hydrocarbon radical with Is 1 to 8, preferably 1 to 4 carbon atoms.

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Vinyltrimethoxysilane and vinyltriethoxysilane have proven to be best and vinyl triacetoxysilane.

The copolymerization of the ethylene and the unsaturated silane compound is carried out under conditions which able to initiate the copolymerization of the two monomers.

As far as these copolymerization conditions are concerned, the following values may be mentioned, for example:

Pressure of 500 to 4000 kg / cm, preferably 1000 to 4000 kg / cm ² ,

Temperature 100 to 400 ⁰ C, preferably 150 to 350 ⁰ C, presence of a radical chain polymerization initiator and, if necessary, a chain transfer agent, and use of an autoclave, tubular reactor or the like., Preferably a high pressure reaction vessel in which the two monomers simultaneously, continuously or can be brought into contact with one another in stages.

All free-radical chain polymerization initiators can be used in accordance with the invention and use chain transfer agents known to be useful for polymerization or Copolymerization of ethylene are suitable. Examples of such polymerization initiators are organic peroxides such as lauroyl peroxide, dipropionyl peroxide, benzoyl peroxide, di-t-butyl peroxide, t-butyl hydroperoxide and t-butyl peroxyisobutyrate, more molecular Oxygen and azo compounds such as azo-bis-isobutyronitrile and azo-isobutylvaleronitrile. Examples of suitable chain transfer agents are paraffins such as methane, ethane, propane, butane and pentane; <λ -olefins like Propylene, butene-1 and hexene-1; Aldehydes such as formaldehyde, Acetaldehyde and n-butylaldehyde; Ketones such as acetone, methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons and chlorinated hydrocarbons.

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The copolymer used in the context of the invention contains one unit of the unsaturated silane compound in an amount of 0.01 to 15 %, preferably 0.01 to 5%, in particular 0.5 to 2%, all percentages being given in percentages by weight. In general, a silanized copolymer with a high proportion of an unsaturated silane compound as a building block has excellent mechanical strength and heat resistance after crosslinking by the action of water. However, if this proportion is excessively high, the elongation at break and the hot weldability are impaired. From this point of view, the proportion range from 0.01 to 15 wt. # Was determined.

2. Silanol condensation catalyst

In general, chemicals can be used for the purposes of the invention that act as catalysts for the Acceleration of the dehydration or condensation of silanols are suitable. A silanol condensation catalyst of this kind is generally a carboxylate of metals such as tin, zinc, iron, lead and cobalt, an organic base, an inorganic acid or an organic acid.

Specific examples of the silanol condensation catalysts are dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dioctoate, Tin (II) acetate, tin (II-caprylate, lead naphthenate, Zinc caprylate, cobalt naphthenate; Ethylamine, dibutylamine, hexylamine, pyridine; inorganic acids such as sulfuric acid and hydrochloric acid, as well as organic acids such as toluenesulfonic acid, Acetic acid, stearic acid and maleic acid. The carboxylates of tin are particularly suitable.

The amount in which to use the silanol condensation catalyst can easily be determined for a given catalyst and given copolymer using the following examples. In general, the proportion is

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of the catalyst to be mixed into the mass in the order of magnitude From 0.001 to 10% by weight, preferably 0.01 to 5% by weight, in particular 0.03 to 3% by weight, based on the amount of the silanized copolymer in bulk.

3 · Making the mass

The plastic compositions according to the invention can after each Working method and can be prepared with any device that is suitable for mixing various additives into thermoplastic Have resins used.

Usually one uses for the preparation of the invention Kunststoffmassen a mode of operation that melts or dissolves (especially the former) of the silanized copolymer and / or the silanol catalyst provides. For example, the copolymer, the silanol condensation catalyst (as it is or in the form of a solution or dispersion) and - if necessary - auxiliary materials are kneaded in an extruder and then pressed into the desired shaped bodies, e.g. Injection molded parts, rods, hoses, foils and other objects or materials such as the so-called pellets.

It also proves beneficial that the silanol condensation required amount of catalyst compared to that of the copolymer is only small. One can therefore use a simple Make use of a process that is often used to incorporate small amounts of additives in masses of the type discussed here: one prepares a basic mixture by using the highly concentrated silanol condensation catalyst in one Dispersed medium such as polyethylene and this basic mixture is mixed into the copolymer in such an amount that the Catalyst concentration reaches the desired value.

However, one can also proceed in such a way that the copolymer is first given the desired shape and the one thus obtained

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The workpiece is immersed in a solution or dispersion that Contains silanol catalyst so as to impregnate the article with the catalyst. This can also obtained a plastic mass according to the invention in the molded state.

As is often the case with resin mixtures, the plastic compositions according to the invention can also contain various auxiliary substances Contain additives. Examples of this are mixable thermoplastic resins, stabilizers, lubricants, Fillers, dyes and pigments as well as blowing agents and blowing agents.

4. Networking

When a molded body made of a plastic compound according to the invention is exposed to the influence of water, occurs spatial cross-linking reaction. (It goes without saying, however, that such networking is not a prerequisite for the Invention).

This reaction with water is conveniently effected by reacting the shaped body with water (in liquid form or as a vapor) at a temperature ranging from room temperature to 200 C, usually in the range from room temperature to 10O ⁰ C, 10 see and 1 week, usually 1 minute to 1 day. This contact with water is also possible under increased pressure. To increase the moistening of the shaped body, the water can contain a wetting agent, a surface-active substance, a water-soluble organic solvent or the like. The water can be in its normal state, but also as hot water, steam or humidity.

By the plastic compound according to the invention during their Exposure of manufacturing and shaping to the influence of water,

909 S * 3 /

can just this production and shaping of the mass as well as the Crosslinking reaction can be carried out simultaneously.

5. Modifications

The plastic compositions according to the invention can be in the most varied Way to be modified.

After such a modification, in addition to the two main components, namely the ethylene and the ethylene-like unsaturated silane compound. a terpolymer of these two monomers and a third monomer, which with the two copolymerizable with other monomers than the above-mentioned copolymer can be used. When choosing this comonomer from the large number of available monomers, it is not only important to note that the other two, Monomers must be copolymerizable, so the ethylene and the ethylenically unsaturated silane compound, but also the unsaturated silane must not adversely affect and / or disturb its crosslinking reaction. Examples of such comonomers are vinyl acetate, vinyl butyrate, vinyl pivalate and the like; Methacrylate such as methyl methacrylate, butyl methacrylate and the like; olefinically unsaturated carboxylic acids such as methacrylic acid, maleic acid, fumaric acid and the like; Derivatives of methacrylic acid, such as methacrylamide, methacrylonitrile and the like, and vinyl ethers such as vinyl methyl ether, vinyl phenyl ether and the like as comonomers vinyl esters and methacrylic acid esters have proven particularly useful. The proportion of this comonomer unit in the copolymer is usually up to 40% by weight, preferably 0.5 to 35 wt. #, and particularly 1 to 25 wt. # of the copolymer.

According to another modification, a blowing agent is introduced into the plastic compound according to the invention in order to make it foamable or to make it expandable. In this case it is possible that the copolymer not only consists essentially of the

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Ethylene unit and the ethylenically unsaturated silane unit consists, but is a copolymer of these two monomeric units and a third comonomer, such as has already been explained above. (It is therefore understood that in the embodiments described below, the copolymer in the plastic mass each of these two types "of Copolymers.)

For the purposes of the invention, those substances which can be used for foaming can be used as blowing agents or blowing agents of ethylenic resins are known to be useful.

Typical examples are chemical blowing agents such as azodicarbonamide, dinitrosopentamethylenetetramine, ρ, ρ'-oxybis (benzenesulfonylhydrazide), N, N'-dimethyl-iT, N'-dinitrosoterephthalamide and the like, and physical blowing agents such as hydrocarbons (e.g. butane and pentane ) and halogenated hydrocarbons (e.g. methyl chloride). Of the chemical blowing agents, azodicarbonamide is preferred because of its high stability and decomposition temperature. The blowing agents listed above can each be used alone or mixed with one another. The blowing agent (C) is added in an amount which is usually 0.2 to 30% by weight, preferably 0.5 to 20% by weight , of the total amount (A + C) of copolymers (A) and blowing agent (C) amounts to.

It is also possible to mix a compatible polyolefin into the plastic compound. Examples of such polyolefins are low, medium and high density polyethylene or polypropylene, chlorinated polyethylene and various copolymers of ethylene and one or more other monomers (e.g. vinyl acetate, methyl acrylate, propylene, butene, hexene and the like). The aforementioned polyolefin can be used in pure form or as a mixture of two or more polyolefins. The;. .. proportion of the polyolefin in the plastic composition may contain up to 70% by weight, based on the total amount of this polyolefin and this copolymer..

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The proportion of the ethylenically unsaturated silane compound is then also based on the total amount of this polyolefin and this copolymer.

According to a further modification, a fine inorganic filler is incorporated into the plastic compound according to the invention. Examples of such inorganic fillers are kaolin, pyrophanite, talc, montmorillonite, zeolite, mica, diatomaceous earth, Silicic acid, white carbon, Bolus Alba, calcium silicate, asbestos, glass powder, glass fibers, calcium carbonate, Gypsum, magnesium carbonate, magnesium hydroxide, carbon black, titanium oxide, etc. The proportion of these inorganic fillers is up to to 60 wt. ^, based on the total amount of filler and Copolymer.

According to a specific, concrete example, the invention Plastic compound takes the form of a film. The thickness of this film is usually on the order of 5 to 500 μ. The film can also be a laminate with an or several other films.

The invention is explained in more detail below with reference to preferred exemplary embodiments. All quantities understand themselves in percent or parts by weight.

Example 1, 2 and 3

Ethylene-vinyltrimethoxysilane copolymers were continuously synthesized by adding a mixture of ethylene,; Vinyltrimethoxysilane and propylene as chain transfer agents were introduced into an autoclave serving as a reaction vessel, where t-butyl peroxyisobutyrate was added as a polymerization initiator with stirring, namely under a pressure of 2400 kg / cm and at a temperature of 220 ^° C. The moldings obtained in this way were odorless . The polymerization conditions and the properties of the molded copolymers are shown in Table 1.

For each of these copolymers were 5 wt.% Of a basic mixture of 1 ^ dibutyltin dilaurate and 99% low density polyethylene ( "Yukalon EH-30", manufactured by Mitsubishi Petrochemical Co., Ltd., Japan) was added, and these materials were 7 min mixed on a roll mill at a temperature of 120-125 C and then shaped into a press film. This was immersed in water at 100 ° C. for 1 day so that crosslinking could occur. Tensile strength, elongation and heat sealability of the film produced in this way were determined; the results are summarized in Tables 2 and 3 below.

Comparative example 1

2 # vinyltrimethoxysilane and 0.1 % dicumyl peroxide were dissolved in a low density polyethylene having a melt index of 2 g / 10 min and a density of 0.919 g / cm ^ ("lukalon EH-30", manufactured by Mitsubishi Petrochemical Co., Ltd ., Japan). The dispersion obtained was subjected to graft polymerization, wherein a Dulmage screw extruder of 50 mm of diameter, L / D ratio of 24 and an extrusion temperature of 200 ⁰ C.

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was used. The resulting silicone-grafted polyethylene had a very strong odor. It turned to processed a press film, which also the crosslinking process according to the method of Examples 1, 2 and was subjected.

Comparative example 2

The ethylene-vinyltrimethoxysilane copolymer described in Example 3 of US Pat. No. 3,392,156 was a thermal and subjected to mechanical treatment in a roller mill for 3 hours at a temperature of 145 150 C so that networking could take place. The crosslinked material thus obtained was pressed into a film.

Comparative example 3

A low density polyethylene ("Yukalon ZF-3O", made from Mitsubishi Petrochemical Co., Ltd., Japan), which has a melt index of 1 g / 10 min and a density of 0.920 g / cm was pressed into a film.

The properties of the crosslinked films, prepared according to Comparative Examples 1, 2 and 3, are in Tables 2 and summarized.

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Table 1 polymerization conditions and

Properties of the copolymers formed

Polymerization conditions pressure Tempe
rature Ethylene
supply Vinyl meth
silane
supply Propy
len-
supply Initi
ator-
supply Ethy
len-
Con-
version properties
of the copolymer * 2
Vinyl-
silane
salary ΕΕ » \ 2
kg / cm ⁰ C kg / h g / h Lit / h g / h % *1
Melting
index Weight% O \ 2400
2400
2400 220
220
220 43
43
43 13th
95
190 600
450
400 1.6
2.0
2.4 15th
15th
15th g / 10 min 0.05
0.34
0.72 ? example 1
• s "Example 2
ο
β> example 3 1.0
1.0
1.0

* 1 test method: Japanese Industrial Standards JIS K 6760
* 2 X-ray fluorescence analysis

Table 2 Mechanical properties

\ *1
Vinyl silane
salary * 2
Gel-
salary Tear resistance and ⁰ C % Elongation at break strain example 1 Weight% Weight% 23 Strength elongation 550 80 ⁰ C % 2 0.05 32 2
kg / cm 450 strength 510 3 0.34 71 190 350 ο
kg / cm 430 Comparative
example 1 0.72 79 200 370 55 340 <o 2 0.72 70 185 190 75 370 O
(O
OO 3 0.72 68 165 600 75 230 O"
ti * 0 0 105 60 390 O
co> 170 40 CD 15th

* 1 X-ray fluorescence analysis

* 2 extraction 10 hours with boiling xylene

* 3 measured according to JIS K6760

TO CO K) CD OO

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4 Table 3 Hot weldability *

Peel strength (.kg / 10 mm) 1.0 1 80 ⁰ C 200 ⁰ C Gel content 160 ⁰ C 3.1 Weight % example 5.3 5.4 5.3 1 5.0 4.3 4.7 32 2 3.8 4.0 4.2 71 3 3.2 79 Comparative example 1.8 2.0 1 3.8 4.0 70 2 5.2 5.4 68 3 0

* 4 test method:

Various test strips, each 10 mm wide and 100 mm long, were produced from a sheet 0.5 mm thick. A number of samples each superimposed from two to each other under pressure welded test pieces were, was prepared by each of pairs of the test pieces for 1 minute in a steam ironing machine, on 160, 180 and 200 ⁰ C preheated and then 2 minutes each at a pressure of 6 kg / cm were pressed together. The 90 peel strength of the welded area of each sample thus obtained was measured with the aid of an autograph at a pulling speed of 500 mm / min.

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Examples 4 to 8

Ethylene-vinyltrimethoxysilane copolymers (A) were continuously synthesized by adding a mixture of each Ethylene, vinyltrimethoxysilane and propylene in an autoclave serving as a reaction vessel, which is equipped with a stirrer was equipped and had a fit of 1.51, were introduced and with stirring at a pressure of 2400

2 0

kg / cm and a temperature of 200 C with t-butyl peroxy-

isobutyrate were added as a polymerization initiator. The polymerization conditions and the properties of the copolymers produced are summarized in Table 4.

To 100 parts of each of these copolymers thus obtained, 5 parts of a master batch, the 1 # dibutyltin dilaurate, were added (B) and a certain amount of a propellant based on azodicarbonamide ("Vinyfor DG Nr.5") from Eiwa Kasei Comp. Japan) (C). These substances were in mixed in a roller mill. The color of the mass obtained was then uniform, from which it was concluded that the propellant is also distributed homogeneously over the mixture would have. Crosslinking was not observed during mixing, i.e. the gel content was in all Cases 0. Ji.

The mixture was then brought into film form and, after being removed from the mill, in this state for 10 minutes heated in a Geer oven to a temperature of 190 C and thereby inflated. The results of foaming and the hot glue property of the products thus obtained are shown in Tables 5 and 6.

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Example 9

An expandable mass made of a copoly-ethylene-vinyltrimethoxysilane (A), the dibutyltin dilaurate (B) and a blowing agent (C) were prepared according to the procedure of Example 7 and in a square shape with a side length of 150 mm and 10 mm deep. This mold was 10 min under a

2 O

Pressure of 100 kg / cm and a temperature of 190C between Press plates held. The pressure was then released so that the mass could expand. That achieved Foaming result is shown in Table 5.

Comparative Examples 4 and 5

Two batches of polyethylene ("Yukalon EH-30" manufactured by Mitsubishi Petrochemical Co. Ltd., Japan) having a melt index of 2 g / 10 min and a density of 0.919 g / cm, that is, a low-density polyethylene, were two different Batches of vinyltrimethoxysilane added, each in an amount of $ 2, based on the amount of the corresponding polyethylene batch. The two batches of vinyltrimethoxysilane contained 0.06 and 0.1 %, respectively, of dicumyl peroxide in dispersed form. Each of the mixtures obtained in this way was ^{subjected to the graft polymerization at an extrusion temperature of 200 °} C. in an extruder with a diameter of 50 mm and an L / D ratio of 24.

The two vinylsilane-polyethylene graft copolymers obtained in this way (hereinafter referred to as graft polymer A and graft polymer B) had a melt index of 1.6 g / 10 min and a silane content of $ 0.5 (graft polymer A) or a melt index of 1, 3 g / 10 min and a silane content of 0.7 f (graft polymer B).

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Then, following the procedure outlined in Examples 4 to 8, a mixture of the vinylsilane-polyethylene graft copolymer, dibutyltin dilaurate, and a blowing agent was prepared from each of the graft polymers A and B, and each expandable mixture was heated in a G- eer oven brought to a temperature of 190 C to froth. The aforementioned expandable masses were already subject to partial crosslinking during their processing in the roller mill, as indicated by their gel content of 17 and 32 % , respectively.

The foaming results and the hot melt properties of the products thus obtained are shown in Tables 5 and 6.

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Table 3 polymerization conditions and

Properties of the copolymers formed.

\ pressure Polymerization conditions Ethylene
supply Vinyl-
silane
supply Propy
len-
supply Initi
ator-
supply Conver
sion Properties of the
Copolymers * 2
Vinyl silane
salary toCopolymeres A
σ
^ Copolymer B
KJ
^ Copolymer C 2
kg / cm Tempe
rature kg / h g / h Lit / h g / h % *1
Enamel
index Weight% 2400
2400
2400 ° c 43
43
43 13th
25th
130 600
550
400 1.6
1 »7
2.2 15th
15th
15th g / 10 min 0.05
0.10
0.50 220
220
220 1.0
1.0
1.0

* 1 test method: JIS K6760

* 2 X-ray fluorescence analysis

K) CJD

CD OO CO

Table 5 Foam Results

Mixing ratios: a and b based on a + b, c based on a.

r ^ BelBplei a -P —Ι
Copolymer Graft 4th s I 6th 7th 8th 9 Comparison "
4th example
5 + J A. polymer A H
3 B. B. 91% - - - - - - - CO
(U C. - 99.8% 91% 70% - - - - C7> pi
I. Propellant - - - - 91% 91% - - C. b catalyst N
+ J basic mix - - - - - - 91% - ω
CO C. υ
cn Expanding - _ _ _ - - _ 91% co C. availability O
co Q)
(O 9% 0.2% 9% 30% 9% 9% 9% 9% OO CQ
• 3 Cell structure OO
c *> 5% 5% 5% 5% 5% 5% 5% 5% O apparent OO density ** * * ** * * *** **** K> OO Gel content same same same same same same unequal - moderate moderate moderate moderate moderate moderate moderate 0.06S ₅ 0.75 0.060 0.021 0-061 0.060 0.076 dimension g / cm not possible 23% 46 48 47 78 75 51 73

Note: All quantitative percentages are in% by weight.

very good

Well

not good (blowholes present)

very bad (not to be called an expanded structure)

K) CD NJ cn OO

Table 6 example 3 el content the foamed 18O ⁰ C Structure 4th Weight % Hot glue measure W) Hot glue property 6th 16O ⁰ C 100 200 ⁰ C C. 8th 23 100 Comparison 48 100 95 100 example 4 78 90 100 60 20th 100 51 VJl 95

Four square steel plates each with a side length of 50 mm and 2 mm thickness were placed in three Geer ovens for 5 minutes, which were set to temperatures of 160, 180 and 200 C had been set - see Table 6. The four panels from each oven were immediately after each on the surface of samples of the four foamed structures according to Examples 4, 6 and 8 or according to Comparative Example 4 applied and 30 seconds. pressed on. The steel plate composite obtained was then left and foamed structure cool naturally. The temperature at which each steel plate was heated was regarded as the heat adhesion temperature, and the state of adhesion at that Thermal adhesion temperature was examined for each foamed structure. So in table 6 is the hot glue measure an index that shows the state of adhesion between the steel plate and the foamed Structure reproduces, namely the percentage based on the size of the detected when joining Adhesion surface - the surface area of the foamed structure that will adhere to the steel plate remains when the foamed structure is peeled from the adhered steel plate.

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Examples 10 to 12

Ethylene-vinyltrimethoxysilane-vinyl acetate copolymers were continuously synthesized by introducing in each case a mixture of ethylene, vinyltrimethoxysilane, vinyl acetate and propylene as a chain transfer agent into an autoclave, which served as a reaction vessel, was equipped with a stirrer and had a capacity of 1.5 1 had. Was then at a pressure of 2400 kg / cm and with stirring to a temperature of 209-222 ⁰ C t-butylperoxy isobutyrate as a polymerization initiator was added. The polymerization conditions and the properties of the copolymers formed are summarized in Table 7.

Each of the copolymers thus formed was then brought into film form with the aid of a steam press. Every the resulting film was immersed in a 10 wt. ^ ige solution of dibutyltin dilaurate in xylene and then 1 day under Maintained water at 70 C, whereby the copolymers were brought to three-dimensional crosslinking. The properties of the films are shown in Table 8.

In addition, 5% of a base mixture consisting of 1% by weight of dibutyltin dilaurate and 99% of a low-density polyethylene was added to each of the copolymers. Each of these mixtures was ^{kneaded for 5 min at 120 °} C. and then pressed to form a film 0.5 mm thick. Each of these films was immersed in water at 70 ° C. for one day
Bring about copolymers.

^{immersed in water at 70 °} C. for a long time in order to cross-link the

Test pieces 10 mm in width and 100 mm in length were prepared from each of these crosslinked copolymer films. Ever two identical test pieces were placed on top of each other, and the end portion of the folded pieces was placed across theirs

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Welded width, namely 2 minutes by means of a steam press under a pressure of 6 kg / cm after the test pieces were heated at 120, 140 and 180 C for 1 minute, respectively. The 90 peel strength of each of the welded test pieces was determined by means of an autograph with a peeling speed determined from 500 mm / min at room temperature. The results are summarized in Table 9.

Be isp i el

The procedure of Examples 10-12 was repeated, but vinyl acetate was replaced by methyl acrylate, so that a Ethylene-methylaerylate-vinyltrimethoxysilane copolymer was formed. This was brought into film form and then networked. The properties of the film were determined, and the results are shown in Tables 7 to 9.

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Table 7 polymerization conditions and

Properties of the copolymers formed

O CO CO

at
game Polymerization conditions pressure Tempe
rature Ethylene
supply * 4
VA or
MA-
supply Vinyl-
silane
supply Propy
len-
supply Initi
ator-
supply Conver
sion Properties of the
Copolymers *1
Melting
index VA or
MA-
salary Vinyl silane
salary 10 2
kg / cm ⁰ C kg / h kg / h g / h Lit / h g / h % g / 10 min Weight% Weight% 11 2400 220 32 VA5.6 52 150 0.8 12th 3.0 14th 0.15 12th 2400 218 32 VA8.0 54 40 0.7 12th 3.2 18th 0.15 13th 2400 215 32 VA8.0 125 80 0.8 12th 3.1 18th 0.50 2400 220 32 MAO. 6th 43 440 1.1 12th 3.4 13th 0.15

* 1 Test method: Japanese Industrial Standards JIS K 6760 * 2 Infrared absorption spectrum analysis * 3 X-ray fluorescence analysis

* 4 VA: vinyl acetate

MA: methyl acrylate

to

00

CD K) cn OO

Table 8 Mechanical properties

*1
Tear- '
strength Tensile elongation * 2
Bending
strength * 3
warmth
deformation Gel content ⁴ Example\ kg / cm % kg / cm % Weight% 10 235 610 680 58 56 11 240 650 510 61 56 ; ¹² · 240 530 490 26th 78 13th 235 620 720 60 58

Table 9 Hot weldability "

example Peel strength (kg / 10 mm) at: 140 ⁰ C 160 ⁰ C 180 ⁰ C 10
11
12th
13th 120 ⁰ C 6.5
6.6
6.1
6.4 6.7
6.5
6.4
6.7 6.8
6.7
6.3
6.5 6.2
6.3
5.8
6.1

Note: * 1 test method: JIS K 6760 * 2 test method: ASTM D 747

* 3 The heat deformation was determined as follows: In an oil bath at 120 ⁰ C, a flat test piece of 2 mm thick and 10 cm square kg charged with 3, and the deformation after one hour was determined.

* 4 The gel content was determined by extraction with boiling xylene for 10 hours.

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ORIGINAL INSPECTED

Examples 14-17

For each of the in Examples 10 - copolymer represented 13 were 5% by weight of a basic mixture of 1 wt% of dibutyltin dilaurate and 99 wt ^ low-density polyethylene added and each of the mixtures thus obtained was processed into a glass film of 50 u thickness... with a blow extruder (40 mm diameter, L / D = 24, extrusion temperature 150 C, and blow ratio 1.5). Each of the films thus produced was placed in a chamber kept constant at a temperature of 40 ° C and for 1 week a relative humidity of 80 fi was kept. The copolymers were able to crosslink.

Each film was subjected to a weld test by placing two pieces of the film on top of one another and using a heat

Seal apparatus having hot plate under a pressure of 2 kg / cm 1 lake to a temperature of 120 ° C, 140 ° C, "160 ⁰ C and 180 C were maintained. Test strips were taken respectively from the thus joined pieces of 2 cm in width and 10 The test strips were examined for 90 ° peel strength with the aid of an autograph, the peeling rate being 500 ml / min. The results are summarized in Table 10.

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Table 10 Heat Sealability

Example peel strength ( g / 20 mm) at; Gel content

12O ⁰ C 14O ⁰ C 160 ⁰ C 18O ⁰ C wt. %

14 1300 1400 1450 1450 56

15 1350 1400 1450 1400 56

16 1250 1300 1400 1400 78

17 1350 1400 1450 1450 58

Examples 18-20

For each of the copolymers have been prepared by a method as explained in Examples 1 to 3 were 5 wt.% Of a master batch added the tin dilaurate dibutyl of 1 wt. #, And 99 wt.% Of polyethylene of low Density existed. Each of the mixtures thus obtained became a tubular film of 60 γ. Thick blown, an extruder being used as the extruder, which had a screw with full flight depth. The diameter was 40 mm, the L / D ratio was 24, the extrusion temperature was 170 ° C., and the blowing ratio was 1.5 ×. Each of the films thus obtained was kept in a chamber kept at 40 ° C. and 80% relative humidity for one week bring about the crosslinking of the copolymer. The results are shown in Tables 11 and 12.

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Table 11 Heat Sealability *

Example of heat sealability
(g / 20 mm) at:

16O ⁰ C

180 ^° C, 200 ^° C

Vinylsilane content wt.

Gel content

18 1450 1550 16

19 HOO 1500 1550

20 1350 1450 1550

0.05 0.54 0.7

29 63 72

Annotation:

* 1 The heat sealability was determined as follows: From that to be examined, a thickness of 60 μ having film, test strips 20 mm wide and 100 mm long were prepared. Two of these strips were superimposed, and both were together with Using a heating rod heat sealing machine connected to each other by placing 1 see across their width under one Pressure of 1 kg / cm were exposed to a hot rod temperature of 160, 180 or 200 ° C. The so generated Specimens were on theirs by means of an autograph at a peeling speed of 500 ml / min 90 ° peel strength tested.

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Table 12

Tensile strength and elongation at break *

23 ° C 8O ⁰ C example Strength elongation Strength elongation kg / cm % kg / cm ² %

18th 210 650 60 520 19th 225 600 85 480 20th 225 450 95 400

Note: * Test method: JIS K6760

Example 21

A copolymer of ethylene and vinyltrimethoxysilane was continuously synthesized by adding a mixture of 43 kg / h Ethylene, 190 g / h vinyltrimethoxysilane and 400 l / h propylene introduced as a chain transfer agent into an autoclave with a capacity of 1.5 l and stirred at 2.4 g / h " t-Butylperoxyisobutyrat added as a polymerization initiator and at a temperature of 220 C under a pressure of 2400 kg / cm was implemented. The product had a melt index of 1 g / 10 min and a vinylsilane content of 0.75 wt. It was almost odorless.

To the copolymer, low density polyethylene $ 5 wt. ^, Based on the copolymer, of a basic mixture of 1 wt.% Dibutyltin dilaurate and 99 wt. Added. Further, low density polyethylene ("Yukalon ZF-30" manufactured by Mitsubishi Petrochemical Co. Ltd., Japan) was used.

909883/0828

having a melt index of 1 g / 10 min and a density of 0.920 g / cm2 added in an amount of 5% by weight based on the total weight of the copolymer and the low density polyethylene. The mixture obtained in this way was blown to a film 60 μm thick, the extruder having a full flight depth 40 mm in diameter at L / D = and the extrusion temperature 170 ° C. and the blowing ratio 1.5. The film obtained in this way was kept for 1 week in a chamber which was kept constant at a temperature of 40 ^° C. and a relative humidity of 80 % , so that the copolymer could crosslink.

Another portion of the same mixture of copolymer, dibutyltin dilaurate and low density polyethylene, as it had been processed by the above processes into a blown film, was 7 minutes at 120 - 125 ⁰ C milled on a roll mill and formed into a press sheet. ^{This was then immersed in hot water at 100 °} C. for 1 day in order to bring about crosslinking of the copolymer.

Example 22

To the obtained according to Example 21 mixture of copolymer and dibutyltin dilaurate the same low density polyethylene was further added as in Example 21, namely, in an amount of 10% by weight of the total amount of copolymer and low density polyethylene.

As in Example 21, the mixture was processed into a blown film on the one hand and a press film on the other, which was then subjected to crosslinking of the copolymer.

Example 2 5

To the mixture of copolymer and dibutyltin dilaurate obtained by following the procedure of Example 21, was added

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here the same low-density polyethylene as in Example 21 added, but in an amount of 30 wt. ^, "based on the total amount of copolymer and low density polyethylene.

As in Example 21, the mixture was made into blown film or Pressed film processed, and the products were then subjected to the crosslinking of the copolymer.

Example 24

Example 23 was repeated, but here the amount was of the low density polyethylene 50% by weight of the total amount of the copolymer and low density polyethylene.

Example 25

The procedure was repeated as in the previous examples, but the low-density polyethylene was used in an amount of 70 wt. #, based on the total amount of copolymer and low density polyethylene.

Weldability, heat resistance and mechanical Behavior, namely tear strength and elongation at break, of the crosslinked products according to Examples 21 to 25 are in Table 13 given.

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O CO OO OO

O OO N> OO

*1
GeI-
salary Table 1 3 180 ⁰ C 200 ⁰ C g / 2 cm 1350 1500 1500 * 3
Warmth
formation * 4
Tear resistance and
Elongation at break strain example Weight% * 2
Heat seal strength 1400 1500 1550 % strength % 21st 70 160 ⁰ C 1450 1500 1600 26th 2
kg / cm 480 22nd 68 1500 1600 1600 30th 225 550 23 59 1550 1600 1600 41 225 610 24 48 49 225 630 25th 25th 62 220 640 215

Note: * 1 see footnote * 4 to table 9.

* 2 The sealability was determined as follows: Two pieces of film of 60 μ in thickness were superposed and by means of a heat sealing device with hot plate at a sealing temperature of 160 ⁰ C 180 ⁰ C and 200 ⁰ C under a pressure of 2 kg / cm 1 lake. warmed; a test strip 2 cm wide and 10 cm long was made from the heat-sealed film, with the heat-sealed area extending the full width. This test piece was then examined to determine the 90 ° peel strength with a Schopper device at a peeling speed of 500 mm / min.

* 3 see footnote * 3 to table 9.

* 4 The elongation was determined according to the Japanese industrial standard JIS Z 1702 certainly.

U)

CD

to

CD OO OO O

Examples 26 to 31

Two types of ethylene vinyl trimethoxysilane copolymers were continuously produced by each mixing a mixture of Ethylene, vinyltrimethoxysilane and propylene as chain transfer agents was introduced into an autoclave used als_ reaction vessel, which was provided with a stirrer and had a capacity of 1.5 liters. After adding t-Butyl peroxyisobutyrate as a polymerization initiator was carried out with stirring at a pressure of 2400 kg / cm and a temperature of 220 C. The polymerization conditions and the properties of the copolymers obtained are shown in Table 14.

Each of the copolymers was immersed in the form of pellets (small cylindrical compacts) for 1 minute in xylene containing dissolved dibutyltin dilaurate by weight , and then kept in water at 100 ° C. for one day to effect crosslinking of the copolymer. Each of the three-dimensionally crosslinked copolymers was extracted for 10 hours with boiling xylene, resulting in a gel content of 54 and 75% by weight, respectively.

To another sample of the one prepared as described above Copolymers a certain amount of a base mixture of 1 wt. $ Dibutyltin dilaurate and polyethylene was lower Density ("Yukalon EH-3Q" manufactured by Mitsubishi Petrochemical Co. Ltd., Japan) and a certain amount of kaolin clay with an average particle size of 1.9 u added. The mixture was made using a double axis extruder of 40 mm diameter, L / D = 30, with a Deformation temperature of 170 ° C pressed into strands. Gel content and appearance of the strands after extrusion were set.

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Films were pressed from these strands and these were immersed in water at 100 ° C. for 1 day in order to crosslink the Bring about copolymers. Each film was examined for its thermal deformation.

Table 15 shows more details. Examples 32 and __33

The production of the strands, the determination of the gel content and evaluations of the appearance of the strands after extrusion were made in the same manner as in Examples 26 to 31, but calcium carbonate was used with an average particle size of 0.04 μ instead of the kaolin clay.

Each of the compacted strands of the films was immersed for 1 day in water of 100 G ^0, to the crosslinking of the copolymers bring about. The hardness of each film was determined.

The results are shown in Table 16. Examples 34 and 35

The procedure according to Examples 26 to 31 was followed, but gypsum hemihydrate with an average particle size of 6 μ was used instead of kaolin clay. The gel content and appearance of the strands were determined.

The results are summarized in Table 17.

It is also pointed out that the ¹ × term "heat sealing" used in the above is understood within the context of the Anglo-Saxon language use.

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Table 14

co

(0 CO OO

O OO

OO

pressure Polymerization conditions Ethylene
supply Vinyl-
silane
supply Propy
len-
supply Initi
ator-
supply Conver
sion Properties of the
Copolymers * 2
Vinyl silane
salary V 2
kg / cm Tempe
rature kg / h g / h Lit / h g / h % *1
Enamel
index Weight% Copolymer ^ 2400
2400 ⁰ C 43
43 25th
130 550
400 1.7
2.2 15th
15th g / 10 min 0.10
0.51 A.
B. 220
220 1.0

Note: * 1, * 2 - see note. * 1, * 2 in table 1.

U)

TO CD IV) CO OO Ca) O

Table 15

example Composition% by weight Copoly-
meres (al
based
on (a)
+ (C) A. 26th 27 28 29 30th 31 B. 89 69 40 - - - Graft
polyme
res - - - 89 69 40 Catalyst reason
mixture related
on (a) - - - - - - Caolin clay
based on
(a) + (c) 5 5 Ul 5 5 5 *1
Gel content immed
bar after extrusion,
Weight% 11 31 60 11 31 60 Appearance of the
Strand 0 0 0 0 0 0 * 2
Thermal deformation Well Well Well Well Well Well 56 45 24 23 18th 11

Annotation:

* 1, * 2: see footnote to Table 9.

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292683Q

Table 16

example Composition% by weight Copolymer (a)
based on
(a) + (C) A. Basic catalyst mixture
related to (a) 32 33 B. CaCOo based on
(a) ί (C) 69 - Graft Gel content immediately
after extrusion, wt.% - 69 Appearance of the strand - - hardness 5 5 31 31 O O Well Well 54 54

Table 17

Composition% by weight example A. Basic catalyst mixture
related to (a) 34 35 Copolymer (a)
based on
(a) + (C) B. Gypsum hemi-hydrate covered
on (a) + - (c) 69 - Graft Gel content immediately
after extrusion, wt.% - 69 Appearance of the strand - - 5 5 31 31 Q 3 Well pacify.

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Claims (1)

Patent attorney Dipl.-C'.cm. F. Shrinkage D-5; £ 0 Düren Patent Attorney Dr. Werner Hassler D-5CS0 Lüdenscheid Applicant: Misubishi Petrochemical Company Limited Tokyo / Japan 2.7.1979
A 79 128 Claims 1. Crosslinkable polyethylene plastic compound, characterized by a content of a copolymer of one unit
Ethylene and a unit of an ethylenically unsaturated SilanverMndung, wherein the proportion of the unit of the ethylenically unsaturated silane compound is 0.001 to 15 wt.%, And a catalyst for the silanol condensation. 2. Plastic compound according to claim 1, characterized in that
that the copolymer further contains a unit of a copolymerizable with the ethylene and the ethylenically unsaturated silane compound monomer in an amount up to 40 wt.%, based on the weight of the resulting copolymer. 903883/0828 3 · Plastic mass according to claim 1 or 2, characterized in that it further comprises a blowing agent in an amount of 0.2 to 30 wt.%, Based on the total amount of the copolymer and the blowing agent. 4. The plastic composition according to claim 1 or 2, characterized in that it further comprises a polyolefin in an amount up to 70 wt.%, Based on the total amount of the polyolefin and the copolymer, the proportion of the unit of the ethylenically unsaturated silane compound to the total amount is sourced from polyolefin and copolymers. 5. Plastic compound according to claim 1 or 2, characterized in that it further contains an inorganic filler in an amount of up to 60 wt. $ , Based on the total amount of the copolymer and the inorganic filler. 6. Plastic compound according to claim 1 or 2, characterized in that that it is in film or sheet form. 7. Plastic compound according to claim 1, characterized in that the ethylenically unsaturated silane compound of the formula CH ₂ = CHSi (OZ) ₃ corresponds to, wherein Z is a hydrocarbon group with 1 to Means carbon atoms. 909883/0828