PT100835A - METHOD FOR SYNTHESIS OF A RETICULATED, WHITE OR CLEAR POLYMER CONTAINING HALOGENEUM - Google Patents

Description

74 299 ΕΑη: ΑΜΗ Ρ9139 -2-

The present invention relates to white or clear thermally stable polymers containing cross-linked halogen and to a process for producing them. There are several processes for crosslinking halogen-containing polymers, including PVC. Among the interesting processes that have appeared in recent years we can mention processes where organosilanes are used as crosslinking agents. DE 3719151 discloses the use of organosilanes, especially mercapto-silanes (e.g., mercaptopropyltrimethoxysilane (I)) as crosslinking agents for halogen-containing polymers, especially for the PVC homopolymer. The crosslinking is done as follows: First the trimethoxysilane (I) is grafted onto the polymer chain and this should preferably be done by a standard process such as composition, extrusion or rolling. (CH 2 CH 3) 3 CH 2 CH 3 CH 2 CH 2 CH 3 CH 2 CH 3 CH 2 CH 2 CH 3 CH 2 CH 2 CH 3 is then performed in two steps: By treatment with hot water or steam the alkoxysilanes are hydrolyzed and form silanols. As soon as the silanols are formed they react rapidly with each other and form the crosslinking through the condensation of H 2 O: (CH 2) CH 2 -CH- 74 299 ΕΑη: ΑΜΗ Ρ9139 -3-

/ > CH2 CH2 CH3 /

(CH 2) 3-Si- (OH) 3 + 3 CH 3 OH CH 3 CH 2 CH 3 CH 3 CH 2 CHC

2 (III) -► HC-S- (CH 2) 3-Si (OH) 2 -O- Si - (OH) 2 - (CH 2) 3 -S-CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 -chci = polymer chain)

In Norwegian Patent Application No. 890543 (Patent No. 166189) halogen-containing polymers are used which are comprised of copolymers of halogen containing monomer and glycidyl acrylates. Preferred copolymers are copolymers of vinyl chloride monomer (VCM) and glycidyl methacrylate (GMA). The Norwegian patent application differs first and foremost from application DE 3719151 in that the epoxy group introduced by the glycidyl monomers facilitates the grafting of the organosilanes in the polymer chain. The dominant graft reaction is carried out as follows, a copolymer of VCM and 0.05-10% glycidyl methacrylate being used together with (I):

O O

) II

ch3-c-c-ch2-ch-ch2 + (I) 0

(CH 2) 3-Si- (OCH) 3 () = polymer chain)

74 299 ΕΑη: ΑΜΗ Ρ9139 -4-

In both of the aforementioned patent applications crosslinking occurs after processing by exposing the material to hot water or steam. No. 890543 states that the use of glycidyl copolymers is considerably more effective than the use of the PVC homopolymer, therefore grafting of the organosilane into the polymer is more effective.

Both of these patent applications underline the importance of using lead-based stabilizers so that the cross-linking is effective. An undesirable effect of the combination of the lead stabilizer and the mercapto-silane is that the material turns yellow. This happens at room temperature as soon as the mercapto-silane and the lead stabilizer come into contact with each other. It is therefore plausible that the yellow color is due to the formation of a compound or complex between the lead stabilizer and the mercapto-silane. Nor can the possibility of formation of this compound / complex be a precondition for effective grafting. The yellow color tends to become stronger with the increased addition of mercapto-silane. Coloring limits the usefulness of this crosslinking technique, since even after the addition of large amounts of white pigment, the titanium oxide still remains a yellow shade. This means that the crosslinking process can not be used when whiteness is an important requirement. In addition, the color is unstable with a tendency to change, for example, under the influence of sunlight. It is also difficult to add other dyes, especially those with light colors. The object of the invention is therefore to avoid the disadvantages of the processes described above and to obtain a crosslinked halogen containing polymer and having a white or light color. In certain systems, especially with homopolymers, another objective is to strengthen the network.

These and other objects of the invention are achieved by means of 5-

of the process described below and the invention is characterized and defined by the appended claims. The present invention relates to a process for producing crosslinked, halogen-containing thermally stable white or clear color polymers. Surprisingly it has been found that this polymer can be produced using mercapto-silane, lead stabilizer and a low molecular weight epoxy compound. The low molecular weight epoxy compound reacts with the mercapto-silane and / or the side products which, together with the lead stabilizer, cause the coloring and thus solves the problem. The polymer comprises 30-98% by weight of halogen-containing polymer, 0-60% by weight of plasticizer, 0.05-10% by weight of hydrolysable mercapto-silane, 0.1-10% by weight of stabilizer of lead, 0-4% by weight of lubricant and 0.1-10% by weight of epoxy resin. The halogen-containing polymer may be a homopolymer such as PVC or a copolymer based on halogen-containing polymer and inactive or reactive-reactive comonomers. A copolymer between a halogen containing monomer and a glycidyl-containing acrylate is preferred. The content of glycidyl-containing acrylate is 0.05-10% by weight. Below 0.05 wt% the effect is too weak and above 10% the plimerization is too slow. The mercapto-silane has the general formula: ???????? SH-R'-Si-R "

where: R 1 = a -CH 2 -, -C 2 H 4 - to C 9 H 12, or other non-functional group? R " = a freely chosen non-hydrolyzable group; Y = one or more hydrolyzable groups such as -OCH 3, -OC 2 H 5, -OC 3 H 7, -OC 4 H 9; n = 0, 1, 2.

Compound R " Compound < RTI ID = 0.0 > may be a freely chosen non-hydrolyzable group. Examples of useful groups are -CH2- to C8H17, but the choice of groups in principle is meaningless for the result. The lead stabilizer is a commercially available stabilizer based on, for example, tribasic lead sulfate, tetrabasic lead sulfate, dibasic lead phosphite, dibasic lead carbonate, dibasic lead phthalate or dibasic lead stearate. To achieve an effect must be added more than 0.1%. The upper limit is set according to what is practical and there is no level that can be exceeded. The disadvantages of large additions are: higher expense and higher density. A practical limit is 10% by weight.

Commercial commercial plasticizers are used in amounts up to 60% by weight. Above this limit the mixture can not be handled. Commercial lubricants are used in amounts up to 4% by weight. Higher additions produce a blend that is over-lubricated and therefore difficult to handle. The low molecular weight epoxy compound may for example consist of glycidyl ethers, glycidyl esters, monofunctional or multifunctional glycidylamines, of the linear or cycloaliphatic type. This is added at 0.1-10% by weight. An addition of less than 0.1% has no effect and an addition of greater than 10% produces too large an excess of epoxy resin over the mercapto-silane. In addition, the blend may contain small amounts of the common additives used for this type of product. The invention will be illustrated in more detail in the following examples. In the examples the amounts are expressed in pph (pph = parts per hundred parts of polymer). EXAMPLE 1:

Three different formulas have been produced as seen in

z? 74 299 ΕΑη: ΑΜΗ Ρ9139 -7-

Table 1. Table 1 1 | Formula AI A2 A3 | Homopolymer PVC 100 100 100 | PD 53 53 53 | Chalk 5 5 5 | Interstab LF 36551 5 5 5 | Tetrabasic lead sulphate 3 3 3 | Oxidized polyethene wax2 | Mercaptopropyltrimethoxy- 0.5 0.5 0.5 | silane (I) 3 3 3 | Araldit GY2503 1 _-- 0 1 2 _ 1 = commercial combination of lead stabilizer and lubricant 2 = external lubricant 3 = commercial epoxy resin of diglycerol-bisphenol A type ether, known as DGEBA resin. DOP = dioctyl phthalate.

The formulas were mixed / hot mixed to 110 ° C. They were then laminated at 170 ° C for 5 minutes. The crosslinking was then performed in an autoclave at 110 ° C for two hours. The following analyzes were carried out:

Ael content: measured as the insoluble ratio of polymer to tetrahydrofuran (THF) at room temperature.

Hot hardening: measured as the deformation caused by a load of 0.1 MPa on a sample rod at 200 ° C after 15 minutes and as

The residual deformation 5 minutes after the load has been removed from the sample.

Color: measured visually.

The results of the analyzes are set forth in Table 2:

Table 2: Formula

AI A2 A3

Gel content: 1 | 1 1 0% 1 1 0% | Hot hardening, deformation after 15 minutes 1 | break 1 1 break 1 1 break | Residual deformation | 1 - 1 - | Color | yellow 1 yellow 1 white | | dark 1 1 light 1

L 1

The results of this example show that adding 2 pph of DGEBA resin to a formula with 3% trimethoxysilane (I) can eliminate all yellow color. In the example no crosslinking was given in any of the formulas. A likely reason for this is that the processing conditions are too mild for the mercapto-silane graft in the PVC chain to function. EXAMPLE 2:

Three different formulas were produced according to Table 3. (following Table 3): (a)

Table 3 Γ Formula BI B2 B3 Homopolymer PVC 100 100 100 DOP 35 35 35 Chalk 5 5 5 Interstab LF 3655 5 5 5 Lead sulfate tetrabasic 3 3 3 Oxidized polyethene wax Mercaptopropyltrimethoxy- 0.5 0.5 0.5 silane (I) 3 3 3 Araldit GY250 0 1 2 1_I_I_I-1

The formulas were mixed / hot mixed to 110 ° C and rolled at 190 ° C for 5 minutes. The same analyzes as in Example 1 were made with the results set forth in Table 4:

Table 4 τ r Formula

Gel content:

Heat hardening, deformation after 15 minutes Residual deformation Color BI B2 1 I B3 23% 27% 1 1 I 15% breaking break 1 1 I yellow yellow break 1 1 light dark white 1

J

L

Here, the highest processing temperature probably contributes to the achievement of the graft in the

(I.e.

polymer and therefore for a certain amount of cross-linking. Addition of a small amount of DGEBA resin seems to favor crosslinking. The explanation for this may be that the epoxy resin which, for example, reacted with two mercapto-silanes may form a bridge: CH-; (CH2) 3 -CH2 -CH-CH2-O-Ph-J-Ph-O-CH2 -CH-CH2-CHO

(CH2) 3-S-CH2-CH-CH2-Ph-O-CH2 -CH-CH2-S- CH- (CH2) 3 - (OCH3) 3 (IV)

Considering the low gel content there should be space between the grafted mercapto-silanes, after the reactions of hydrolysis and condensation with two mercaptopropyltrimethoxysilanes (I) grafted in the polymer chain, (IV) can form a bridge therebetween.

With higher epoxy resin contents, the amount of (I) grafted onto the polymer chains is probably reduced because it reacted mainly with the epoxy resin. EXAMPLE 3:

Three different formulas were produced according to Table 5. (following Table 5) 74 299 ΕΑη: ΑΜΗ Ρ9139 -11-

Table 5 1 | Formula C1-C2-C3 | Copolymer (VCM + 1% GMA) 100 100 100 | PD 53 53 53 | Chalk 5 5 5 j Interstab LF 3655 5 5 5 | Tetrabasic lead sulphate 3 3 3 | Oxidized polyethene wax | Mercaptopropyltrimethoxy- 0.5 0.5 0.5 | -silane 3 3 3 | Araldit GY250 0 1 2 1

L

J

The formulas were mixed / hot mixed to 110 ° C. They were then laminated at 170 ° C for 2 hours. The crosslinking was later performed in an autoclave at 110øC for two hours. The same analysis was carried out as in Example 1. The results are shown in Table 6:

Table 6 Formula

Gel content: Hot hardening, deformation after 15 minutes Residual deformation Color

Cl C2 | C3 92% 90% 1 84% 118% 156% | 205% 34% 50% | 90% yellow light yellow | White Example 3 shows that it is possible to produce white material

Which is strongly cross-linked by adding a low molecular weight epoxy compound to the already familiar reaction between the mercapto-silane, the halogen-containing comonomer containing epoxy and the lead stabilizer. The fact that the gel content decreases with the addition of epoxy resin, and that the heat deformation also becomes greater, is most likely a function of the fact that the low molecular weight epoxy compound "robs" mercaptosilane to the epoxy groups linked to the chain. We can not rule out the possibility that the hydrolyzed and condensed type compounds (IV) have a positive effect on hot setting, but are no less effective than if (I) were grafted onto the polymer chains. EXAMPLE 4

Three different formulas were produced according to Table 7.

Table 7

I I I I I | Formula | I 1 Dl D2 D3 1 1 | Copolymer (VCM + 2,5% GMA) | 100 100 100 1 DOP 1 53 53 53 1 G * -z 1 5 5 5 J Interstab LF 3655 | 5 5 5 | Tetrabasic lead sulphate | 3 3 3 | Oxidized polyethene wax | | Mercaptopropyltrimethoxy- | 0,5 0,5 0,5 | -silane | 3 3 3 | Araldit GY250 | 1 1 1_L 0 _ 1 _ 2 _

The formulas were mixed / hot mixed to 110 ° C. They were then laminated at 170 ° C for 5 minutes. The crosslinking was then performed in an autoclave at 110 ° C for two hours.

V

V

5 "

74 299 EAnsAMH P9139 -13-

The same analyzes were carried out as in Example 1. The results are shown in Table 8:

Table 8 I-1-1-1-1 Formula | Dl I | D2 1 I D3 Gel content: 1 | 96% | 92% 1 1 90% Hot hardening, 1 1 deformation after 15 minutes | 37% | 55% 1 67% Residual deformation | 7% 1 14% 1 20% Color | yellow | white 1 white | clear 1 1 1

Example 4 shows that an increase in the amount of epoxy in the polymer chains can produce a white material with a lower content of low molecular weight epoxy resin. This example shows the same tendency as Example 3f since the addition of epoxy resin decreases the gel content and increases the deformation in hot setting. Note that the formulas D 2 and Cl in Example 3 have the same gel content, but D 2 is considerably better in terms of hot setting. The explanation for this is that probably a higher proportion of (I) is bound to the polymer chains. EXAMPLE 5

Three different formulas were produced according to Table 9. (following Table 9) '/ -14- 74 299 ΕΑη: ΑΜΗ Ρ9139

Table 9 I-1 I-1-1 Formula | EI E2 E3 1 Copolymer (VCM + 2,5% GMA) | 100 100 100 PDO | 53 53 53 Chalk | 5 5 5 Interstab LF 3655 | 5 5 5 Tetrabasic lead sulphate | 3 3 3 Oxidized polyethene wax | Mercaptopropyltrimethoxy- | 0.5 0.5 0.5 -silane | 3 3 3 Araldit GY1841 | 1 0 1 2

I_I_I_1_I

Commercial cycloaliphatic epoxy resin.

The formulas were mixed / hot mixed to 110 ° C. They were then laminated at 170 ° C for two hours. The same analyzes were carried out as in Example 1. The results are shown in Table 10:

Table 10 1 | Formula 1 | EI I r E2 | 1 E3 | | Gel content: 1 1 96% 93% | 91% | | Hot hardening, 1 | deformation after 15 minutes I 37% 44% | 58% | | Residual deformation | 7% 12% | 17% | | Color | yellow white | white | 1_ | clear 1 J_1 _1

74 299 ΕΑηίΑΜΗ Ρ9139 -15-

Cycloaliphatic epoxy resins are considered less reactive with mercaptan groups than, for example, diglycidyl ether-based epoxy resins such as those of type D6EBA. Higher gel content and lower deformation than when DGEBA resin is used may be due to the fact that the cycloaliphatic epoxy resin does not compete so well with the polymer-based epoxy groups for (I).

In Examples 3-5 the addition of low molecular weight epoxy resin produced a lighter or white material at the expense of much poorer crosslinking. The epoxy resin in all these experiments was bifunctional and the mercapto-silane was tetrafunctional. Clearly, this was not sufficient to give a positive overall contribution to the mechanical durability of the net in terms of hot setting values. EXAMPLE 6:

Three different formulas were produced according to Table 11.

Table 11 Γ 1

L Formula F1 F2 F3 Copolymer (VCM + 1% GMA) 100 100 100 DOP 53 53 53 Chalk 5 5 5 Interstab LF 3655 5 5 5 Tetrabasic lead sulphate 3 3 3 Oxidized polyethene wax Mercaptopropyltrimethoxy- 5 0.5 -silane 3 3 3 Araldit GY01631 0 _ 1 _ 2 - j

74 299 EAnsAMH P9139 -16-

Commercial tetrafunctional epoxy resin of the glycidyl ether type.

The formulas were mixed / hot mixed to 100 ° C. They were then laminated at 170 ° C for 5 minutes. Crosslinking was done later in an autoclave at 110 ° C for two hours. The same analyzes were carried out as in Example 1. The results are shown in Table 12:

Table 12 Formula | F1 I F2 | F3 I Gel content: 1 | 92% 88% 1 1 79% Hot hardening, 1 1 deformation after 15 minutes | 118% 110% 1 140% Residual deformation | 34% 38% 1 56% Color | yellow yellow | yellow 1 i clear | clear 1

Example 6 shows that the use of tetrafunctional resin gives a contribution to the mechanical durability of the network, at least with the addition of small amounts. The fact that the material turns pale yellow is presumably due to the fact that Araldit 0163 itself has an intense yellow color. The gel content lower than that of Example 3 can be explained by the fact that the epoxy content per unit weight in the tetrafunctional resin is higher than in the DGEBA resin.

In all examples where white material was produced, this only occurred after autoclaving. Prior to autoclaving the material had a light yellow hue. On the other hand, non-epoxy low molecular weight material shows a tendency to develop a stronger yellow color after autoclaving. 74 299 ΕΑη: ΑΜΗ Ρ9139 -17-

With the present invention we have reached a process for producing white or clear crosslinked material using polymers containing halogen, mercapto-silanes, lead stabilizers and low molecular weight epoxy resin. In certain formulas, especially where tetrafunctional resin is used, a positive contribution to the mechanical properties of the network can be achieved.

Claims (10)

74 299 EAn: AMH P9139 -18- ./ W A crosslinked polymer of white or light color characterized in that it consists of 30-98% by weight of halogen-containing polymer, 0-60% by weight of plasticizer, 0.05-10% by weight of hydrolysable mercapto-silane, , 1-10% by weight of stabilizer with lead, 0-4% by weight of lubricant and 0.1-10% by weight of epoxy resin. A halogen containing polymer according to claim 1, characterized in that it contains a low molecular weight epoxy resin, which is mono- to tetrafunctional, of glycidyl ether, glycidyl ester, glycidylamine or the linear or cycloaliphatic type. A halogen containing polymer according to claim 1, characterized in that the halogen-containing polymer is homopolymer of PVC. A halogen containing polymer according to claim 1, characterized in that it is a copolymer between a halogen containing monomer and a glycidyl-containing acrylate. Copolymer according to claim 3, characterized in that it has a glycidyl-containing acrylate content of 0.05-10% by weight. A process for the production of a white or light crosslinked polymer containing halogen using a mercapto-silane of the type SH-R'-Si-R " n where: R 1 = a -CH 2 - - - C 2 H 4 - to C 8 H 16 or other non-functional group; R " = a freely chosen (non-hydrolyzable) group; Y = one or more hydrollable groups such as -OCH 3, -OC 2 H 5, -OC 2 H 5, -OC 2 HH f f = 0, 1 as a crosslinking agent and a lead stabilizer, and wherein the cross-linking is carried out in the presence of moisture after the processing of the polymer, characterized in that a low molecular weight epoxy resin is added to the blend. Process according to claim 6, characterized in that a low molecular weight epoxy resin, which is mono- to tetrafunctional, of glycidyl ether, glycidyl ester, glycidylamine or linear or cycloaliphatic type is used. A process according to claim 6, characterized in that 0.1-10% by weight of epoxy resin is added. A process according to claim 6, characterized in that vinyl chloride is used as the halogen-containing polymer. A process according to claim 6, characterized in that a copolymer of vinyl chloride and glycidyl methacrylate is used. Lisbon, ^ ^ 92 by NORSK HYDRO a.S = 0 0FICIAL AGENT = ATTACHMENT