AU666494B2 - Procedure for synthesis of a white or light-coloured cross-linked halogen containing polymer - Google Patents

Description

OPI DATE 05/04/93 AOJP DATE 10/06/93 APPLN. ID 24749/92 PCT NUMBER PCT/N092/00131 lllll Ill 1111 lll I 1111111 1i11 111111 II I AU9224749 IN I -l-l rA 1 11. 1 U tPCT) (51) International Patent Classification 5 (11) International Publication Number: WO 93/05112 C08L 27/04, 27/06, 63/00 Al C08F 8/42, 8/1206 63/00 A (43) International Publication Date: 18 March 1993 (18.03.93) (21) International Application Number: PCT/N092/00131 (81) Designated States: AU, BR, CA, FI, HU, JP, KR, RU, US, European patent (AT, BE, CH, DE, DK, ES, FR, GB, (22) International Filing Date: 17 August 1992 (17.08.92) GR, IE, IT, LU, MC, NL, SE).

Priority data: Published 913441 3 September 1991 (03.09.91) NO With international search report.

(71) Applicant (for all designated States except US): NORSK HY- 6 64 DRO A.S [NO/NO]; N-0240 Oslo 2 (NO).

(72) Inventor; and Inventor/Applicant (for US only) DAHL, Roger [NO/SE]; Glansbaggeviigen 3, S-444 46 Stenungsund (SE).

(74) Agent: ANDERSON, Elin; Norsk Hydro a.s, N-0240 Oslo 2 (NO).

(54) Title: PROCEDURE FOR SYNTHESIS OF A WHITE OR LIGHT-COLOURED CROSS-LINKED HALOGEN CON- TAINING POLYMER (57) Abstract White or light-coloured cross-linked polymer and a procedure for synthesis of the sai.e. The polymer consists of 30-98 weight percent halogen containing polymer, 0-60 weight percent plasticizer, 0.05-10 weight percent hydrolysable mercaptosilane, 0.1-10 weight percent lead stabilizer, 0-4 weight percent lubricant and 0.1-10 weight percent epoxy resin. The cross-linking is carried out in the presence of moisture after the processing of the polymer.

I

Separate Sheet Sheet 1 Application No.: PCT/N092/00131 a) Having regard to the documents cited in the International Search Report, no objections arise with regard to the novelty or inventive step of the subject matter of the present claims. (Art.33(l)-(3) PCT) b) WO 90/09407 discloses cross-linked halogen containing polymers in which the halogen containing polymer is a copolymer with glycidyl (epoxy)-containing acrylate.

Crosslinking is effected with a hydrolysable mercaptosilane. Novelty is recognised as in the present claims the epoxy functionality is present in a component separate from the halogen containing polymer, namely in an epoxy resin. Inventive step can be recognised as the subject matter now claimed does not appear to be suggested by the disclosure in WO 90/09407 and the present examples demonstrate that the present invention achieves an unexpected reduction in yellowing caused by the presence of lead stabilizer.

c) The abstract relating to JP-A-59 20342 is not considered to be of any real relevance to the subject matter of the present claims because it does not concern a halogen containing polymer composition crosslinked with a hydrolysable mercaptosilane.

d) The subject matter of the present claims is considered to be industrially applicable. (Art.33(4) PCT) The following points are raised under Art.6 PCT.

i) In claim 1, there is no mention of "low molecular weight" as used in claim 6 and the description to refer to the epoxy resin. However, before the term is used in claim 1, it would appear to be necessary that the applicant demonstrates that the term has a well understood meaning in the art as the term is otherwise considered vague.

ii) Claim 6 should be clearly supported at page 4.

i i i i; WO 93/05112 PCr/N092/00131 2 and form silanols. Once the silanols have been formed they quickly react with one another and form the cross link through condensation of H 2 0:

CH

2 -CHC1- (II) 3H20 HC-S-(CH 2 3 -Si-(OH) 3 3 CH 3 0H

CH

2 -CHC1-

(III)

CH

2 -CHC1- 2 (III) HC-S-(CH 2 3 -Si(OH) 2 -O-Si(OH) 2 -(CH2)3-S-CH CH2-CHC1-

CH

2 CHC1-

CH

2 -CHC1polymer chain) In Norwegian Patent Application No. 890543 (Patent No. 166189) halogen containing polymers are used which consist of copolymers of halogen containing monomer and glycidyl acrylates. The preferred copolymers are copolymers between vinyl chloride monomer (VCM) and glycidyl methacrylate (GMA).

The Norwegian patent application first and foremost differs from DE 3719151 in that the epoxy group introduced by the glycidyl monomers facilitates the grafting of the organosilanes to the polymer chain. The dominant grafting reaction is assumed to take place as follows, where a copolymer of VCM and 0.05-10% of glycidyl methacrylate are used together with 0 0

CH

3

-C-C-O-CH

2

-CH-CH

2

(I)

0 OH

CH

3

-C-C--CH

2

-CH-CH

2

-S-(CH

2 3 -Si-(OCH)3 =polymer chain) WO93/05112 PCT/N092/00131 3 In both the above-mentioned patent applications the cross-linking takes place after processing by exposing the material to hot water or steam. In NO 890543 it is stated that the use of glycidyl copolymers is considerably more effective than the use of the homopolymer PVC, inasmuch as the grafting of the organosilane to the polymer is more effective.

Both the cited patent applications emphasize the importance of using lead-based stabilizers so the cross-linking will be effective. An undesirable effect of the combination of lead stabilizer and mercaptosilane is that the material turns yellow. This happens at room temperature as soon as the mercaptosilane and lead stabilizer come into contact with each other.

It is therefore likely that the yellow colour comes from the formation of a compound or complex between the lead stabilizer and the mercaptosilane. Nor can the possibility be excluded that the formation of this compound/complex is a precondition of effective grafting. The yellow colour has a tendency to become stronger with increased addition of mercaptosilane.

The colouring limits the usefulness of this cross-linking technique, since even after the addition of large quantities of the white pigment titanium oxide there is still a yellowish tone.

This means that the cross-linking method cannot be used when whiteness is an important requirement. The colour is moreover unstable, showing a tendency to change under the influence of sunlight, for example. It is also difficult to add other colj ours, especially light colours.

iJ The object of the inantion is thus to avod thA disadvantages..

of the methods described above and to obtain a cro inked halogen containing polymer with a white or _it colour. In certain systems, especially with ompolymers, a further objective is to strengthen th etwork.

These and oth objects of the invention are achieved by the proce described below, and the invention is characterized fned by the ccomnin atent claim.

v Ing pol 1 ii ~*~ri -3a It would be desirable to avoid the disadvantages of the methods described above and to obtain a cross-linked halogen containing polymer with a white or light colour. In certain systems, especially with homopolymers, it would be desirable to strengthen the network.

Throughout the description and claims of this specification, the word "comprise" and variations of the word, such as "comprising" and "comprises", are not intended to exclude other additives or components or integers.

i i i ills.

SI i 2 4 The present invention concerns a white or light-colourcd thermostable cross-linked hialoger, containing polymer composition and a Process for produIcing thc sam~c Surprisingly, it wvas foundl( t that this polymer can he p rodluced using- mercaptos iianc, lead stabilizer and a low -mu oecu ar epoxy compound. The low -moleciiar epoxy compound rcacts with thc mercaptos iiaine and/or the by produIcts Which together with thle lead stabilizer cause the colon ring-, and thus renmedies the problem.

The polymer composition comprises 30-98 weight halogen containing polynicr, 0-60 weight% plasticizer, 0. 1-10 weight lead stabilizer, 0-4 weight lubricant, 0. 1-10 weight epoxy resin and 0.05-10 weight hydrohysable mercaptosilane of the general formtila SH-R'Si-R"n

Y(

3 -n) where: R, a -C 2

H

4 uIP to C 3 1-{ 16 or another non-functional group.

R" a f4eely eleee4, non-hydrolysable group Y one or more hydrolysable groups such as -OCH 3 -0C 2

H

5 -0C 3

H

7

C

4

H

9 The group R" can be R fFBO~j.slect@ non-hydrolysable group. Examples of usable grOu~ps are

C-

2 up to C 8 H 17, but the choice of groups in Principle has no significance for thle result.

The low-molecular epoxy Compound may consist ofeg nionofunctional or multifunctional glycidyl ethers, glycidyl esters. glycidyl ainines, or of a l inear or cycloal iphatic type. This is added at 0. 1 weight Ani addition of' less than 0. 1 has no effect and an addition over 10 pr1oduces too great a surplus of epoxy resin in proplortion to the mercaptos ilarie. [In addition tie In i xtutre mlay contain small quantities of' tie ord inary additives used for ti is type of prodUCt.

R R Thle halogen contain ing pol ymer may be I homopolyiner like P'VC, or a copolymer based oil halogen containing pialyiner aiid inactive or reactive coniononiers with r-espect to the cross I inkino~ A\ copol ymer between a halogen containung monomer andi a glyc idyl -contai iiing aIC I-:1 ai is L i. favoured. The content of glycidyl-containing acrylate is 0.05-10 weight Under 0.05 weight the effect is too weak and over 10% the polymerization is too slow.

The invention also concerns a process for production of white or light-coloured cross-linked halogen containing polymer. A mercaptosilane of the above described type is used as cross-liiiking agent, a lead stabilizer is supplied and where 0. 1-10 weight of a low-molecular epoxy resin is added to the mixture.. The cross-linking is carried out in the presence of moisture after the processing of the polymer.

It is preferred to use a low-molecular epoxy resin which is mono- to tetrafunctional, of the glycidyl ether, glycidyl ester, glycidyl amine or linear or cycloaliphatic type.

It is preferably used vinyl chloride or a copolymer of vinyl chloride and glycidyl methacrylate as the halogen containing polymer.

S The lead stabilizer is a freely selected commercial stabilizer based on e.g. tribasic lead sulphate, S tetrabasic lead sulphate, dibasic lead phosphite, dibasic lead carbonate, dibasic lead phthalate or S dibasic lead stearate. To obtain an effect, more than 0.1% should be added. The upper limit is fixed according to whatever is practical, there is no level that cannot be exceeded. The disadvantages of high additions are more expense and higher density. A practical limit is 10 weight Ordinary commercial plasticizers in quantities up to 60 weight are used. Above this limit the mixture cannot be handled. Commercial lubricants are used in quantities up to 4.weight Higher additions produce a mixture which is overlubricated and thus difficult to handle.

n SUBSTITUTE SHEET I ^i Specifically, the present invention provides a process for production of white or light-coloured cross-linked chlorine containing polymer composition, comprising 30-98 weight halogen containing polymer, 0-60 weight plasticizer, 0.1-10 weight lead stabilizer, 0-4 weight lubricant, 0.1-10 weight of a low molecular weight epoxy resin and 0.05-10 weight hydrolysable mercaptosilane of the general formula: SH-R'-Si-R"n Y(3-n) where: R' a -CH 2 2

H

4 up to CaH 16 or other non-functional group, R" a non-hydrolysable group, Y one or more hydrolysable groups such as -OCH 3

-OC

2

H

5

C

3

H

7 S: OC 4

H

9 and n 0, 1,2 i as cross-linking agent and a lead stabilizer, and wherein the cross-linking is carried out in the presence of moisture after the processing of the polymer.

The invention will be clarified in more detail in the following examples. In the examples the quantities are expressed in pph (pph parts per 100 parts of Spolymer).

S 4 WO 93/05112 PCT/N092/00131 EXAMPLE 1: Three different formulas were produced as in Table 1.

Table 1 Formula Al A2 A3 PVC Homopolymer 100 100 100 DOP 53 53 53 Chalk 5 5 Interstab LF 36551 5 5 Tetrabasic lead sulphate 3 3 3 Oxidized polyethene wax 2 0.5 0.5 Mercaptopropyl trimethoxysilane 3 3 3 Araldit GY250 3 0 1 2 1 commercial lead stabilizer and lubricant combination 2 external lubricant 3 commercial epoxy resin of diglycidyl ether-bisphenol A type, known as DGEBA resin.

DOP dioctyl phthalate The formulas were mixed/hot-mixed up to 1100 C. They were then rolled at 1700 C for 5 mins. The cross-linking was then carried out in an autoclave at 1100 C for two hours. The following analyses were carried out: Gel content: Hot-set: Measured as the insoluble proportion of polymer in tetrahydrofuran (THF) at room temperature.

Measured as the deformation caused by a load of 0.1 MPa on a sample rod at 2000 C after mins., and as the residual deformation 5 mins.

after the load has been removed from the sample.

Colour Measured visually i WO 93/05112 PCT/N092/00131 The results of the analyses are shown in Table 2: Table 2: Fo:r ula Al A2 A3 Gel content: 0 0 0 Hot-set: Deformation after 15 mins.: break break break Residual.deformation: Colour: dark light white yellow yellow The results in this example show that addition of 2 pph of DGEBA resin to a formula with 3pptrimethoxysilane can eliminate all yellc colour. In the example no cross-linking has arisen for any formula. One probable reason for this is that the processing conditions were too mild for the grafting of mercaptosilane to the PVC chain to work.

EXAMPLE 2: Three different formulas were produced as in Table 3.

Table 3 Formula Bl B2 B3 PVC Homopolymer 100 100 100 DOP 35 35 Chalk 5 5 Interstab LF 3655 5 5 Tetrabasic lead sulphate 3 3 3 Oxidized polyethene wax 0.5 0.5 Mercaptopropyl trimethoxysilane 3 3 3 Araldit GY250 0 1 2

I

I

-I WO 93/05112 PCr/N092/00131 The formulas were mixed/hot-mixed up to 1100 C and rolled at 190 0 C for 5 mins. The same analyses were conducted as in Example 1, with the results shown in Table 4: Table 4 Formula B1 B2 B3 Gel content: 23 27 15 Hot-set: Deformation after 15 mins.: break break break Residual deformation: Colour: dark light white yellow yellow Here the higher processing temperature probably contributed to the achievement of grafting to the polymer chains an? thus a certain amount of cross-linking. Addition of a small quantity of DGEBA resin appears to favour the cross-linking. The explanation of this could be that epoxy resin, for example, which has reacted with two mercaptosilanes can form a bridoa: O CH 3

O

2 SH-(CH 2 3 -Si-(OCH 3 )3 CH 2

-CH-CH

2 -O-Ph-C-Ph-O-CH 2

-CH-CH

2 CH3 OH CH 3

OH

S(OCH

3 3 -Si-(CH2) 3

-S-CH

2

-CH-CH

2 -O-Ph-C-Ph-O-CH 2

-CH-CH

2

-S-

CH

3

(CH

2 3 -Si-(OCH 3 3

(IV)

Since in view of the low gel content there must be space between the grafted mercaptosilanes, after hydrolysis and condensation reactions with two mercaptopropyl trimethoxysilanes grafted to the polymer chain, (IV) can form a bridge between these.

-i t

IY!JX

i WO 93/05112 PCT/N092/00131 9 At higher contents of epoxy resin the amount of grafted to the polymer chains is probably reduced because it has mostly reacted with the epoxy resin instead.

EXAMPLE 3: Three different formulas were produced as in Table Table Formula Cl C2 C3 Copolymer (VCM 1% GMA) 100 100 100 DOP 53 53 53 Chalk 5 5 Interstab LF 3655 5 5 Tetrabasic lead sulphate 3 3 3 Oxidized polyethene wax 0.5 0.5 Mercaptopropyl trimethoxysilane 3 3 3 Araldit GY250 0 1 2 The formulas were mixed/hot-mixed up to 1100 C. They were then rolled at 1700 C for two hours. The cross-linking was later carried out in an autoclave at 110 0 C for two hours. The same analysis as in Example 1 was done. The results appear in Table 6: Table 6 Formula Cl C2 C3 Gel content: 92 90 84 Hot-set deformation after 15 118 156 205 mins.: Residual deformation: 34 50 90 Colour: yellow light white yellow n u, I, L, /2 ~alI~J I 'I i ill i WO 93/05112 PCT/N092/00131 Example 3 shows that it is possible to produce white material which is strongly cross-linked by adding a low-molecular epoxy compound to the already familiar reaction between mercaptosilane, epoxy-containing halogen containing comonomer and lead stabilizer. The fact that the gel content decreases through addition of epoxy resin and that the deformation by heat also becomes greater is very probably a function of the fact that the low-molecular epoxy compound "steals" mercaptosilane from the epoxy. groups bonded in the chain. We carnot exclude the possibility that hydrolysed and condensed compounds of type (IV) have a positive effect on the hot-set, but it is no less effective than if were grafted to the polymer chains.

Example 4 Three different formulas were produced as in Table 7.

Table 7 Formula D1 D2 D3 Copolymer (VCM 2.5% GMA) 100 100 100 DOP 53 53 53 Chalk 5 5 Interstab LF 3655 5 5 Tetrabasic lead sulphate 3 3 3 Oxidized polyethene wax 0.5 0.5 Mercaptopropyl trimethoxysilane 3 3 3 Araldit GY250 0 1 2 The formulas were mixed/hot-mixed up to 1100 C. They were then rolled at 1700 C for 5 mins. The cross-linking was later done in an autoclave at 1100 C for two hours. The same analyses as in Example 1 were carried out. The results appear in Table 8: r tr L Big I OR OWL.m WO 93/05112 PCT/N092/00131 Table 8 Formula D1 D2 D3 Gel content: 96 92 90 Hot-set deformation after mins.: 37 55 67 Residual deformation: 7 14 20 Colour: light white white yellow Example 4 shows that an increase of the amount of epoxy in the polymer chains can produce a white material with lower lowmolecular epoxy resin content. The example shows the same tendency as Example 3, inasmuch as addition of epoxy resin decreases the gel content and increases the hot-set deformation. One can note that the formulas D2 and C1 in Example 3 have the same gel content, but D2 is considerably better in terms of hot-set.

The explanation of this is probably that a higher proportion of is bonded in the polymer chains.

Example Three different formulas were produced as in Table 9.

Table 9 Formula El E2 E3 Copolymer (VCM 2.5% GMA) 100 100 100 DOP 53 53 53 Chalk 5 5 Interstab LF 3655 5 5 Tetrabasic lead sulphate 3 3 3 Oxidized polyethene wax 0.5 0.5 Mercaptopropyl trimethoxysilane 3 3 3 Araldit CY184 1 0 1 2 1 commercial cycloaliphatic epoxy resin.

I I 'ti i i WO 93/05112 PCI/N092/00131 12 The formulas were mixed/hot-mixed up to 1100 C. They were then rolled at 1700 C for two hours. The same analyses as in Example 1 were carried out. The results appear in Table Table Formula El E2 E3 Gel content: 96 93 91 Hot-set deformation after mins.: 37 44 58 Residual deformation: 7 12 17 Colour: light white white yellow Cycloaliphatic epoxy resins are considered less reactive with mercaptan groups than for example diglycidyl ether-based epoxy resins like those of the DGEBA type. The higher gel content and the lower deformation than when DGEBA resin is used may be due to the fact that the cycloaliphatic epoxy resin does not compete as well with the polymer-based epoxy groups for In Examples 3-5 the addition of low-molecular epoxy resin has produced a lighter or white material at the expense of a rather poorer cross-linking. The epoxy resin in all these experiments has been difunctional, and the mercaptosilane has been tetrafunctional. This has clearly not been sufficient to make an overall positive contribution to the mechanical durability of the network in terms of hot-set values.

c. I c I p* I c rC i

.J

i i;i I I -Ul~asc.~1~U~Cii?3UI~ WO 93/05112 PCT/N092/00131 Example 6: Three different formulas were produced as in Table 11.

Table 11 Formula F1 F2 F3 Copolymer (VCM 1% GMA) 100 100 100 DOP 53 53 53 Chalk 5 5 Interstab LF 3655 5 5 Tetrabasic lead sulphate 3 3 3 Oxidized polyethene wax 0.5 0.5 Mercaptopropyl trimethoxysilane 3 3 3 Araldit DY0163 1 0 1 2 1 Commercial tetrafunctional epoxy resin of glycidyl ether type.

The formulas were mixed/hot-mixed up to 1000 C. They were then rolled at 170 0 C for 5 mins. The cross-linking was later done in an autoclave at 110 0 C for two hours. The same analyses as in Example 1 were carried out. The results appear in Table 12: Table 12 Formula F1 F2 F3 Gel content: 92 88 79 Hot-set deformation after mins.: 118 110 140 Residual deformation: 34 38 56 Colour: yellow light light yellow yellow i Ik

F

WO 93/05112 PCr/N092/00131 14 Example 6 shows that the use of a tetrafunctional resin makes a contribution to the mechanical durability of the network, at least with additions of small quantities. The fact that the material turns light yellow is presumably due to the fact that Araldit 0163 itself is an intense yellow colour. The lower gel content than in Example 3 can be explained by the fact that the epoxy content is higher per weight unit in the tetrafunctional resin than in the DGEBA resin.

In all examples where white material has been produced, it has only happened after autoclaving. Before autoclaving the material had a light yellow tone. On the other hand, material with no low-molecular epoxy content exhibits a tendency to develop a stronger yellow colour after autoclaving.

With the present invention we have arrived at a method of producing white or light-coloured cross-linked material using halogen containing polymers, mercaptosilanes, lead stabilizers and a low-molecular epoxy resin. In certain formulas, especially when tetrafunctional epoxy resin is used, a positive contribution to the mechanical properties of the network can be achieved.

Claims (10)

1. White or light-coloured cross-linked polymer composition, comprising 30-98 weight halogen containing polymer, 0-60 weight plasticizer, 0.1-10 weight lead stabilizer, 0-4 weight lubricant, 0.1-10 weight of a low molecular weight epoxy resin and 0.05-10 weight hydrolysable mercaptosilane of the general formula: SH-R'-Si-R"n Y(3-n) where: R' a -CH 2 2 H 4 up to C 8 H 16 or other non-functional group, R" a non-hydrolysable group, Y one or more hydrolysable groups such as -OCH 3 -OC 2 H 5 -OC 3 H 7 OC 4 H 9 and n 0,1,2,

2. White or light-coloured cross-linked polymer composition according to claim 1, wherein the low-molecular weight epoxy resin is mono- to tetrafunctional, of the glycidyl ether, glycidyl ester, glycidyl amine or linear or cycloaliphatic type.

3. White or light-coloured cross-linked polymer composition according to claim 1 or 2 wherein the halogen containing polymer is PVC homopolymer.

4. White or light-coloured cross-linked polymer composition according to claim 1 or 2, wherein the halogen containing polymer is a copolymer between a halogen containing monomer and a glycidyl-containing acrylate.

White or light-coloured cross-linked polymer composition according to claim 4, wherein the content of glycidyl-containing acrylate is 0.05-10 weight IL_ -r -16-

6. Process for production of white or light coloured cross-linked chlorine containing polymer composition, comprising 30-98 weight halogen containing polymer, 0-60 weight plasticizer, 0.1-10 weight lead stabilizer, 0-4 weight lubricant, 0.1-10 weight of a low molecular weight epoxy resin and 0.05-10 weight hydrolysable mercaptosilane of the general formula: SH-R'-Si-R"n t I r i I ~I II u Y(3-n) where: R' a -CH 2 -yC 2 H 4 up to C 8 H 16 or other non-functional group, R" a non-hydrolysable group, Y one or more hydrolysable groups such as -OCH 3 -OC 2 H 5 -OC 3 H 7 OC 4 H 9 and n 0,1,2 as cross-linking agent and a lead stabilizer, and wherein the cross-linking is carried out in the presence of moisture after the processing of the polymer.

7. Process according to claim 6, wherein the low molecular weight epoxy resin is mono- to tetrafunctional, of the glycidyl ether, glycidyl ester, glycidyl amine or linear or cycloaliphatic type.

8. Process according to claim 6 or 7, wherein the halogen containing polymer is polyvinyl chloride.

9. Process according to claim 6 or 7, wherein the halogen containing polymer is a copolymer of vinyl chloride and glycidyl methacrylate. White or light-coloured cross-linked polymer composition substantially as hereinbefore described with reference to any one of the examples. -o 1IJ ~C~O ORKVAPP24749,DOC The halogen containing polymer ,may be a homlopolymier like PIVC, or a copol yier based on halogen contaninig polymer and inactive or reactive coluonomers wid respcct to (lie cross.linkin g. N J A copolyiner between a Ihalogen containing monomer and a glycidyl-containing aciviate is INTERNATIONAL SEARCH REPORT International Application No PCT/NO 92/00131 1. CLASSIFICATION OF SUBJECT MATTER (if several classification symbols apply, indicate all) 6 According to International Patent Classification (IPC) or to both National Classification and IPC C 08 L 27/04, 27/06, 63/00, C 08 F 8/42, 8/12 II. FIELDS SEARCHED Minimum Documentation Searched 7 Classification System Classification Symbols C 08 L; C 08 F Documentation Searched other than Minimum Documentation to the Extent that such Documents are Included in Fields Searched 8 SE,DK,FI,NO classes as above III. DOCUMENTS CONSIDERED TO BE RELEVANT" Category* Citation of Document, 11 with indication, where appropriate, of the relevant passages 12 Relevant to Claim No. 13 A WO, Al, 9009407 (NORSK HYDRO A.S) 1-10 23 August 1990, see the whole document A Questel, Derwent, 84-065110, C84-027810, Mitsui 1 Toatsu Chem Inc.: "Weather resistant vinylA chloride resin compsns. contain organo-zinc cpds., epoxyA resins and organo phosphorus cpds., J59020342 A 840202 DW8411, J87051980 B 871102 DW8747 SSpecial categories of cited documents:

10 T later document published after the international filing date docuiment defining the general sate of the art which is not or priority date and not in conflict with the application but A" dcunsent deininge npear a l ttean o thheart which is not ted to understand the principle or theory underlying the considered to be of particular relevance invsntion earlier document but published on or after the international filing date bX' document of particular relevance, the claimed invention cannot be considered novel or cannot be considered to "L documpnt which may throw doubts pn priority claim(s) or involve an inventive step which is cited to establish the publication date of another citation or other special reason (as specified) oY' document of particular relevance, the claimed invention Sr cannot be considered to involve an inventive step when the document referring to an oral disclosure, use, exhibition or document is combined with one or more other such do:u- other erring disclosure, use, exhibition or ments, such combination being obvious to a person skilled in the art. document publishe prior to the international filing date butf te s e p t later than the priority date claimed document member of the same patent family IV. CERTIFICATION Date of the Actual Completion of the International Search Date of Mailing of this International Search Report 17th August 1992 18 -12- 1992 International Searching Authority Signature o Authorized Officer Sofia Nikolopoulou SWEDISH PATENT OFFICE :orm PCiTISAT (second sheet) (.las ary 1985) L~ i r- C NY SUBSTFFUTE SHEET k I -1 l-14, ANNEX TO THE INTERNATIONAL SEARCH REPORT ON INTERNATIONAL PATENT APPLICATION NO.PCT/NO 92/00131 This annex lists the patent family members relating to the patent documents cited in the above-mentio) ed international search report. The members are as contained In the Swedish Patent Office EDP file on 02/12/92 The Swedish Patent Office is in na way liable for these particulars which ame merely given for the purpose of information. Patent document Publication Patent family Publication cited in search report Tdate member(s) date WO-Al- 9009407 90-08-23 AU-fl- 5083790 90-09-05 CA-A- 2046282 90-08-09 CN-A- 1045268 90-09-12 EP-A- 0456746 91-11-21 JP-T- 4503368 92-06-18