DE2512952A1 - PLASTICATED VINYL CHLORIDE POLYMER - Google Patents

Description

PATENT LAWYERS

DR.-ING. H. FINCKE DIPL-ING, H. BOHR DIPL.-ING. S. STAEGER

Patent attorneys Dr. Find »■ Bohr ■ Stoeoe * · ■ Munich 5 ■ MOlWroft ·

β M-iNCMEN β. March 24, 1975 MOlLntraB 31 Remote call: (089) 26 6OiO telegram! Claim · Munich Telex: 523903 claim d

mopp.no. 23717 - Dr P / v

Please indicate in the answer

Case A-3O3-O / D

M & T INTERNATIONAL B.V. The Hague / Netherlands

"Plasticized Vinyl Chloride Polymer"

Priority: March 25, 1974 - USA

The invention relates to plastisols, which are vinyl chloride polymers contain, which stabilizes against discoloration and degradation caused by the action of heat are.

The invention also relates to a method of improvement the thermal stability, the plasticized vinyl

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Vanmcbonk monks, account 420404

27044-102

Chloride polymer compositions have been imparted by organic esters of phosphorous acid.

It is known that triorganophosphites of the general formula P (OR) _7. , Wherein R is an alkyl or aryl radical, impart useful thermal stability to vinyl chloride polymers. US Pat. No. 2,867,594 states that mixed alkyl aryl phosphites are particularly suitable for this purpose. This patent also states that mixtures containing the phosphites and an organic acid salt of an alkali metal or alkaline earth metal can be used in conjunction with other known stabilizers, including organic salts of cadmium, zinc or tin.

The use of combinations of organophosphites or other auxiliary stabilizers with certain reaction products of stinic acids for the purpose of improving the thermal stability of vinyl chloride polymers is in US Pat U.S. Patent 3,413,284. A number of patents, including GB-PS 1,180,398, describe the expediency of adding organophosphites to organotin mercaptides or organotin ninercaptoic acid esters for the purpose of improving the thermal stability of vinyl chloride polymers. The resulting mixture of polymer and Stabilizers along with other additives, including plasticizers, improve impact resistance Substances, lubricants and pigments are mixed together to form a homogeneous composition of substances. In many In cases, the mixing is carried out by means of a roller grinder or extruder. This is the case with the polymer samples described in CA-PS 910,538

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where it is stated that certain organophosphites improve the thermal stability of vinyl chloride polymers, which has been given to them by monoorganotin derivatives of mercapto acid esters. From experimental results reported in the aforementioned Canadian patent are given, it can be seen that the beneficial effect of phosphite is limited to Monoorganotin compounds. Polymer fabric compositions, which the corresponding diorganotin compounds, such as dibutyltin-SjS'-bisiisooctylmercaptoacetate), contain a decrease rather than an increase in thermal stability when a phosphite is added.

Surprisingly, it has now been found that when a plasticized vinyl chloride polymer composition containing a phosphite as a primary stabilizer is not subjected to sufficient shear treatment in the molten state, the addition of between 0.1 and 1 %, based on the weight of the composition, of certain Organotin compounds, the resistance to discoloration at temperatures of 150 ⁰ C and higher increases considerably. The concentration of organotin compound is between 3 and 45%, based on the combined weight of the phosphite and the organotin compound.

The invention now relates to an improved plasticized vinyl chloride polymer composition which essentially comprises the following ingredients:

1) a vinyl chloride homopolymer or a copolymer in which at least 50 % of the repeating units are derived from vinyl chloride and the

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Rest of the repeating units being derived from one or more ethylenically unsaturated compounds which are interpolymerizable with vinyl chloride;

2) based on the weight of this material composition, between 5 and βθ % of a plasticizer selected from the group consisting of esters / on carboxylic acids, in which the acid and alcohol residues of the carboxylic acid ester contain between 2 and 20 carbon atoms _s trialkyl, triaryl and mixed Arylalkyltriester of phosphoric acid, esters derived from benzoic acid and oligomers of alkylene diols which 2 to 5 repeating units contain, epoxidized esters of unsaturated fatty acids _s esters of Trimellithsäurej chlorinated paraffin hydrocarbons and liquid polyester _A which are derived from aliphatic dicarboxylic acids and Diols &bisites;

3) based on the weight of the composition of matter, between 0.5 and 5% of an organic ester of a phosphorous acid _s where these esters correspond to the general formula P (OR ¹ ), or P (OR ¹ ) ₂ (OR ² ), in which R ¹ and R ² are both selected from the group consisting radicals from alky!, which contains 1 to 20 carbon atoms, s j, cycloalkyl _s aralkyl ₉ aryl ,, alkaryl radicals and hydrogen atoms under eggs, provided that the number of hydrogen atoms 0 or 1 is »

The improvement is based on the presence of 0.1 and 1% _t, based on the weight of the substance composition, of an organotin compound, according to the general formula

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/-1

3 3 ff 3 β "4 3

[R ₂ SnSR C _v ] S, R ₃ SnSR COR or R ₃ Sn

^k OR ⁴ S O

al a "4 R Sn (SR COR ) _a

where m corresponds to the integer 1, 2 or 3 and Y denotes a radical which is selected from the group below Formulas

-SR ⁴ , 0
• ι
-OCR ⁴ , 3
-SR O
OR R ⁴ O O
OCCH ₂ CH-COR,
t O
It
-OCR O
dd
COR ⁴ , O
•1
-OCCH = C S- O
Il O
Il
HHfiOR ⁴ and O
ti
IHC 0-; R ^ and R both individually

are selected from the group consisting of the alkyl radicals, which contain between 1 and 20 carbon atoms,

5 cycloalkyl, aralkyl, aryl and alkaryl radicals, R a

Is methylene or ethylene and R is an alkylene radical containing between 1 and 8 carbon atoms, with the proviso that the organotin compound represents between 3 and 45 % of the total amount by weight of the organotin compound and the organic ester of phosphorous acid.

The stabilizer compositions according to the invention improve the resistance of plasticized Vinyl chloride polymers oppose thermal degradation if these do not meet the high levels the shear stresses which occur when the polymers are processed with calender rolls or under high pressure by relatively small ones

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Openings are pressed, as they are in the usual extruders and injection molding machines.

The phosphites or esters of phosphorous Skure, which are used in the present stabilizer compositions, preferably correspond to the general formula (R 0), P or (R ¹ O) ₀ (RO) P, wherein R ¹ and

R are individually selected from alkyl radicals, which contain between 1 and 20 carbon atoms, unsubstituted phenyl radicals and phenyl radicals which have a or contain two alkyl radicals as substituents, these alkyl radicals each between 1 and 20 carbon

1 2
contain atoms. Either R, R or both can contain a hydroxyl or alkoxy group as a substituent.

Suitable phosphites are:

Triphenyl phosphite diphenylisodecyl phosphite bis (p-nonylphenyl) phenyl phosphite Phenyldiisodecyl phosphite ■ (p-methoxyphenyl) diisodecyl phosphite p-Hydroxyphenyldiisodecyl phosphite p-Nonylphenylbis (hydrogenated bisphenol A) phosphite

Tetrakis (p-nonylphenyl) polypropylene glycol (PPG) 425 diphosphite

Bis (p-nony! Phenyl) PPG 425 phosphite 1-naphthyldiisodecyl phosphite
2-naphthyl diisodecyl phosphite
p-Cyclohexylphenyldiisodecyl phosphite bis (isooctyl) p-nonylphenyl phosphite

Triphenyl phosphite, diphenyl isodecyl phosphite, triisodecyl

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phosphite and diisodecylphenyl phosphite are used in the present stabilizer compositions particularly preferred.

The phosphite is the main stabilizing component of the present compositions of matter, and the proportion thereof is between 0.2 and 5%, based on the weight of the composition of matter. The degree of heat stabilization is significantly increased when the phosphite is combined with certain mono-, di- and triorganotin compounds in concentrations as low as they are usually considered to be ineffective because they do not produce substantial heat stability in the absence of the phosphite. An amount between 0.1 and 1 % of the organotin compound based on the weight of the polymeric composition is useful. If more than about 1 % of the organotin compound is used, little, if any, effect is achieved. Concentrations between 0.1 and 0.5 % are preferred. The organotin compound increases the length of time that the polymer composition can be exposed to elevated temperatures without discoloration to the extent that the composition is no longer practical.

Organotin compounds, which are suitable in connection with phosphite, the stabilizer substance according to the invention Forming compositions generally correspond to the following formulas

SR ⁵ 0

R * s / I, [RiSnSR ³ C ⁷ JS or I & nSRC

\ C = ⁰ V * ι

OR

O! υ

R Sn (SR C ') a

5098 ^ 0/1081 M) R

In these formulas, the symbols R, R, Y and m are at corresponding points in the present description explained.

A class of suitable compounds can be broadly defined as mono-, di- and triorganotin derivatives of mercaptans, mercapto acids and mercapto acid esters, the organotin compound by replacing a hydrogen / sulfur or hydrogen / oxygen bond with a tin-sulfur or a tin-oxygen bond has been formed. A second class of suitable organotin compounds are mono-, di- and triorganotin carboxylates, whereby the acid residue is derived from monocarboxylic acids, which contain between 2 and 20 carbon atoms. Optionally, the acid part of the molecule can be the remainder of a dicarboxylic acid, such as maleic, fumaric or adipic acid or a half ester of a dicarboxylic acid. Remnants of half-esters of maleic acid 0 0

Il Il

derived from the formula -OCCH = CHCOCgH ₁₇ are particularly preferred.

The following are mentioned as radicals R ⁵ and Y of the formula f ^ ^SnY 4_ _ra given above:

1) alkyl radicals - methyl, ethyl, n-propyl, isopropyl, the isomeric butyl, hexyl, 2-ethylhexyl, octyl, Decyl, dodecyl and eicosanyl residuesj

2) aryl radicals - phenyl, naphthyl;

3) Cycloalkyl radicals - cyclopentyl, cyclohexyl, cyclooctyl;

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4) aralkyl radicals - benzyl, ß-phenylethyl;

5) Alkaryl radicals - ToIy1, ο-, m- or p-xylyl.

4 4

1) a mercaptan radical -SR, where R is selected from

the same group as R;

2) a mercapto acid ester residue -SR c / or a mercapto

0 \) R ⁴

"5 4

acid residue -OCR ^ S-, where R has the meaning given above and R ^ is a methylene or ethylene radical. This class includes alkyl and aryl esters of mercaptoacetic acid and mercaptopropionic acid in addition to the free acids;

"4 4

3) a residue of a monocarboxylic acid -OCR, where R is selected from the same group as R, i.e. a The remainder is from acetic, propionic, stearic, lauric, benzoic, naphthoic or phenylacetic acid, one of the isomeric methylbenzoic acids or the mixture of fatty acids such as are present in tall oil, a By-product of the paper-making process from wood pulp;

4) a residue of a half ester of a saturated or ethylenically unsaturated dicarboxylic acid, e.g. maleic or Adipic acid, the alcohol residue of the ester containing between 1 and 20 carbon atoms; Examples for such half esters are isopropyl maleate, isooctyl maleate, lauryl maleate, stearyl maleate, benzyl maleate, Cyclohexyl maleate and lauryl adipate;

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ο ο

5) a residue of a diester of thioapfeic acid R OC-CH-CH ₉ COR,

S bonded to the sulfur atom; '

0 0

it H

6) a residue of maleic acid -OC-CH = CH-CO- or another Dicarboxylic acid.

The stabilizer compositions according to the invention are suitable for use with plastisols which contain vinyl chloride polymers. If here from "vinyl chloride polymers" the question is, both homopolymers of vinyl chloride and mixed polymers are understood, where the majority of the repeating units are derived from vinyl chloride and the remainder Units are derived from one or more ethylenically unsaturated monomers, which with vinyl chloride can be copolymerized. Suitable mixed polymers are vinylidene chloride, olefinic hydrocarbons, such as Ethylene and propylene, esters of unsaturated acids, such as the lower alkyl esters of acrylic, methacrylic and maleic acids, and vinyl esters of saturated acids such as vinyl acetate.

In addition to vinyl chloride polymer and stabilizers, the compositions of matter of the invention also contain nor a plasticizer for the polymer in an amount of between 5 and 60?, based on the weight of the Composition of matter. Vinyl chloride polymers of suitable intrinsic viscosity (between 0.5 and 1.6, measured as a 0.2 iige solution in cyclohexane at 30 ° C) are of Naturally made of rigid and fragile materials. By combining the polymer with a suitable plasticizer is it possible to obtain a plastisol that is

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temperature is solid, semi-solid or liquid. If desired, an organic solvent can be added to the plasticized polymer can be added to give an organosol. The resulting plastisol or Organosol can easily be made into shaped objects by casting or molding. Plasticized Vinyl chloride polymers can be used as covering or encasing compounds for a large number of metallic and non-metallic base materials are used. Covering compounds for textiles is just one of the numerous uses for these materials. The plasticized polymers are applied to the textile fabric in liquid form by dipping, brushing and spreading or spray applied. Plasticized polymers, in a finely divided solid form, the known as powder coatings can be applied by placing the polymer particles in a stream of air are suspended and a heated base is immersed in the suspended particles. Some the particles touch the heated surface and melt to form a well-adhering coating. Other known Working methods for applying powder coatings, including electrostatic spraying, can can also be used. Regardless of the method used in each case, the one with the covering will be provided Base material is usually heated to melt the polymer particles and thus create a well-adhering film or coating to surrender.

Among the classes of known plasticizers for vinyl chloride polymers include esters derived from aromatic or aliphatic dicarboxylic acids and monohydric alcohols, which both have between 6 and 20 carbon atoms

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contain. Representative plasticizers are dioctyl phthalate, dioctyl adipate and dioctyl sebacate. Other Plasticizers are alkyl, aryl and mixed alkylaryl triesters of phosphoric acid, such as triphenyl phosphate; Esters of benzoic acid with oligomers of alkylenediols, such as dipropylene glycol dibenzoate, epoxidized esters of unsaturated acids such as butyl epoxystearate, lower Alkyl esters of trimellitic acid, chlorinated paraffinic hydrocarbons, which are between 30 and 70 Gew.-JS contain chlorine, and liquid polyester, which derived from aliphatic dicarboxylic acids and diols.

The stabilized compositions of matter according to the invention can, if desired, contain one or more materials which contain volatile organic solvents (including ketones, primary Alcohols and liquid hydrocarbons with 1 to 12 carbon atoms), pigments such as titanium dioxide, antioxidants, such as hindered phenols, lubricants ■ including paraffin and waxes, fillers, such as calcium carbonate or kaolin, and viscosity regulating agents such as fused silica, or polymeric glycols, which contain on average between 2 and 5 repeating units per molecule. The antioxidants prevent or reduce the degradation of the vinyl chloride polymer or another Component by oxidizing agents, such as the oxygen present in the air. As the viscosity regulator Polyethylene glycols and polypropylene glycols are particularly preferred.

The heat resistance, which by the invention

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Combinations of an organophosphite and organotin compound are imparted to plasticized vinyl chloride polymers, is even further improved if a heavy metal salt, in particular a zinc, cadmium or barium salt of a monocarboxylic acid, which contains between 6 and 12 carbon atoms, is added to the polymer material composition at a concentration of between 0, 5 and 10 % based on the weight of the stabilizer component is incorporated.

The subject matter of the invention is explained in more detail with the following examples, without being restricted thereto. the Parts and percentages in the examples are based on weight.

EXAMPLE 1

The stabilizers were plasticized vinyl chloride polymer compositions of matter incorporated with the following components:

Vinyl chloride homopolymer 100 parts

Dioctyl phthalate 60 parts

epoxidized soybean oil 5 parts

Stabilizer as indicated

The formulations were prepared by gradually adding the total amount of the polymer to 45 parts of dioctyl phthalate was added with stirring. The remaining 15 parts of phthalate ester were then made into the resulting thickness Paste mixed in, after which the epoxidized soybean oil was added. Depending on the number of desired Samples, the respective amount of the received

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A mixture was weighed out and combined with the required amount of the stabilizer while stirring at high speed. The resulting composition of matter was then deaerated under reduced pressure and cast into a film using a scraper. The thickness of the film was between 0.05 and 0.08 cm. The film was then heated to a temperature of 190 ° C. for five minutes in order to fuse the individual polymer particles together. After cooling, the film was cut into square test pieces having a side length of 2.5 J ¹ cm. The samples were placed in an air oven and heated to 205 ° C. for 25 minutes. Samples were removed from the oven at five-minute intervals and assessed for discoloration according to the Gardner Color Scale by observation, the color of the sample being compared with a set of Gardner standard color discs, which were determined according to the depth of the color shade of 1 (water-clear). until 18 (dark brown) were numbered. The color ratings for fabric compositions containing combinations of diphenyl isodecyl phosphite and an organotin compound or the phosphite alone are shown in Table 1. The ratings obtained for samples containing the organotin compound as the sole stabilizer are shown in Table 2.

The organotin compounds used are identified by letters as follows:

A = di-n-butyltin-S, S'-bis (isooctyl mercaptoacetate); used alone 2.0 parts

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B = di-n-butyltin dilaurate; used alone with 2.0 parts and 0.25 parts

C - triphenyltin lauryl mercaptide; used alone with 2.5 parts

D = monobutyltin tris (2-ethylhexoate); used alone with 2.5, 1.0 and 0.25 parts

E = di-n-butyltin bis (isooctyl maleate); used alone with 0.25 parts

P = di-n-butyltin-S, S'-bis (lauryl mercaptopropionate); used alone at 0.25 parts

G = di-n-butyltin-SjS'-bisCdiisooctylthiomaleate); used alone at 0.25 parts

H = butyl tin crystallate (from tall oil fatty acids); used alone with 2.5 parts)

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TABEL

CD OO -fr-CD

Phosphite
(Split up
100 parts
Polymer) Organotin
links
(Split up
100 parts
Polymer) Gardner discoloration after
χ minutes at 205 C
x = 0 5 10 15 1 4th 7th Heat
20 25 13th 2.0 without 0 1 2 5 11 12th ² »5 without 0 0 0 2 7th 8th 1.75 A (0.25) 0 0 2 5 5 9 1.75 B (0.25) 0 0 0 2 7th 5 2.25 C (0.25) 0 0 2 3 it 5 1.75 D (0.25) 0 0 0 1 4th 4th 2.0 D (0.5) 0 0 1 1 3 5 1.5 D (1.0) 0 0 0 2 3 5 2.25 E (0.25) 0 0 0 1 3 4th 2.25 P (0.25) 0 0 0 1 2 4th 2.25 G (0.25) 0 0 0 1 2 3 2.31 H (0.19) 0 2

TABLE 2
Stabilized by organotin compounds without phosphite

link Parts (on
100 parts polymer) Gardner discoloration after
χ minutes at 205 C 5 10 15th Heat 25th x = 0 0 1 3 20th 15th A. 2.0 0 0 4th 12th 13th 17th B. 2.0 0 1 2 12th 14th 17th B. 0.25 0 1 2 2 16 13th C. 2.5 0 0 1 4th 6th 15th D. 2.5 0 1 2 6th 15th 13th D. 1.0 0 1 2 6th 13th 14th D. 0.25 0 1 3 12th 17th E. 0.25 0 1 1 7th 16 16 P. 0.25 0 1 1 9 15th 16 G 0.25 0 1 2 5 14th 13th H 2.5 0 12th

EXAMPLE 2

This example illustrates the improved stabilization provided by the organotin compounds according to the invention when using different phosphates. The samples used to determine the Thermal stability was established and tested as described in Example 1. Every phosphite was alone and in combination with 0.25 parts of monobutyltin-S, S ·, S "-tris (isooctyl mercaptoacetate) examined for 100 parts of polymer. The amount of each phosphite used was equivalent to a content of phosphorus from 0.2 parts to 100 parts of vinyl chloride polymer.

The results are compiled in Table 3 below.

50984 0/1081

TABLE 3

Effect of various phosphites on the heat resistance when using monobutyltin-SjS ¹ , S "-tris (isooctyl mercaptoacetate)

Phosphite Parts (on lüO
Parts polymer) Gardner discoloration after heating
χ minutes at 205 C
χ = 0 5 10 15 20 25 Diphenylisodecyl
phosphite 2.25
2.25 0 0 0 0 13 (with organotin compound)
0 1 3 6 9 13 (without organotin compound) Phenyldiisodecyl
phosphite 2.6
2.6 0 0 0 0 13 (with organotin compound)
0 1 2 3 8 11 (without organotin compound) Triisodecyl
phosphite 3.0
3.0 0 0 0 0 1 4 (with organotin compound)
I.
0 1 1 3 13 16 (without organotin compound) Triphenyl
phosphite 1.85
1.85 0 0 0 0 3 5 (with organotin compound)
0 1 2 6 14 16 (without organotin compound)

VO

Concentration of phosphite equivalent to 0.2 parts of phosphorus

cn ro

CD cn

EXAMPLE 3

The experiments described in Example 2 were repeated using 0.25 parts of dibutyltin bis (isooctyl maleate) as an organotin compound. The results are summarized in Table 4 below.

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TABLE 4

Effect of various phosphites on the heat resistance when using dibutyltin bis (isooctyl maleate)

on ο co oo * · » ο

ο oo

Phosphite Parts (to 100
Parts polymer) Gardner discoloration after
χ minutes at 205 C
x = 0 5 10 15 1 4th 8th Heat
20 25 14th Triphenyl phosphite 1.85 0 1 2 5 12th 15th Triisodecyl phosphite 3.00 0 1 2 5 11 12th Phenyldiisodecyl
phosphite 2.60 0 1 3 6th 7th 14 · Diphosphite 4.20 0 1 3 12th 11 17th without
(only 0.25 parts
Organotin compound 0 16

* Diphosphite = tetrakis (nonylphenyl) polypropylene glycol 425 diphosphite (phosphorus content

4.5 i)

IVJ

cn ro

CD

cn

From Examples 1 to 3 and Tables 1 to 4

it can be seen that by the organotin compound

an improved resistance to discoloration is achieved.

EXAMPLE 4

This example demonstrates that it is not an improvement or a decrease, but rather a Increase in heat resistance is achieved when the weight ratio of phosphite to organotin compound is less than 1: 1.

The samples were prepared and tested as described in Example 1. The organotin compounds used consisted of A) dibutyltin-SjS'-bistisooctyl mercaptoacetate) and B) dibutyltin di (isooctyl maleate). The phosphite used was diphenylisodecyl phosphite. The concentrations of the two stabilizer components and the Gardner color values obtained in the experiment are summarized in the following table 5, with all parts based on weight and based on 100 parts of vinyl chloride polymer.

TABLE 5

Thermal stability for compositions of matter with a ratio of phosphite to organotin of less than 1: 1

Organotin
link
(Parts) Parts
Phosphite X Gardner discoloration after
χ minutes at 205 C
= 0 5 10 15 0 0 1 Heat
20th A (2.25) 0.25 0 0 0 1 2 A (1.5) 1.0 0 0 0 1 2 A (2.5) 0 0 1 1 2 1 B (2.25) 0.25 0 12th

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EXAMPLE 5

In this example it is demonstrated that the heat resistance of vinyl chloride polymers by the invention Stabilizer compositions is not observed when the polymers are subjected to high shear stresses as is the case with extrusion or injection molding.

Into the mixing vessel of a Brabender Plasticorder mixing device a sample of 55 g of the following composition was introduced:

Vinyl chloride homopolymer 100 parts

Dioctyl phthalate (plasticizer) ^ 5 parts

epoxidized soybean oil 5 parts

Stabilizer (as indicated) 1 part

The contents of the mixing vessel were ^{heated to 190 °} C. and the rotational speed of the rotors was set to 200 revolutions per minute. The amount of torque required to maintain a constant engine speed of 200 revolutions per minute was plotted as a function of time. As the polymer melted, the torque decreased to a level which remained fairly constant until the polymer began to decompose and cross-link, at which point the plunger deflection increased rapidly. The time that had elapsed to this sudden rise in the curve due to polymer degradation is given as the time of mass disintegration in the following table.

The phosphite and organo

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- 21 »-

Tin compounds were diphenylisodecyl phosphite and dibutyltin-SjS ¹ -bis (isooctyl mercaptoacetate).

Parts * ' phosphite

Parts
Organotin time to
Decay (minutes) link 1 46 0 36 0.75 38 ■ 0.25 26th 0.1. 30th

0.25 0.75

Parts per 100 parts by weight of polymer

These test results show that the stability achieved by the addition of phosphite is adversely affected by the addition of an organotin compound in the amount according to the invention if excessive shear treatment occurs.

Claims : 509840/1081

Claims (5)

PATENT CLAIMS 1. Improved plasticized vinyl chloride polymer composition consisting of 1) a vinyl chloride homopolymer or copolymer wherein at least 5.0 % of the repeating units are derived from vinyl chloride and the remainder of the repeating units are derived from one or more ethylenically unsaturated compounds which are copolymerizable with vinyl chloride; 2) between 5 and 60? By weight of the composition of matter of a plasticizer for vinyl chloride polymers j 3) between 0.5 and 5% *, based on the weight of the composition of matter, of an organic ester of phosphorous acid, namely an ester of the general formulas P (OR ¹ ), or P (OR K (OR ² ), in which R ¹ and R are both selected from the group consisting of alkyl radicals containing between 1 and 20 carbon atoms, cycloalkyl, aralkyl, aryl, alkaryl radicals and hydrogen atoms, with the proviso that the number of hydrogen atoms is 0 or 1, characterized in that the mass with respect to the weight of the same 0.1 to 1 % of an organotin compound 509840/1081 using the general formula O 3 0 "3 S - R « ] S, R ^ SnSR ⁵ COR ⁴ or R ₂ Sn ^ I SO 0 ^y • Il R ³ Sn (SR ⁵ COR ⁴ ), contains, wherein m denotes the integer 1, 2 or 3 and Y is a radical of a formula from the group consisting of 0 0000 "Q It H ₄ » » ₄ -SR ⁴ -OCR ⁴ , -SR ³ C ^ ₄ , R ⁴ OCCH ₂ CH-COR , -OCR COR, \ 0R ^f S- OO OO "4 3 4 -OCCH = CHCOR and -OCCH = CHCO-; R- * and R both selected are from the group consisting of alkyl radicals containing between 1 and 20 carbon atoms, Cycloalkyl, aralkyl, aryl and alkaryl radicals and 5 6 R is a methylene or ethylene radical and R is an alkylene radical having 1 to 8 carbon atoms inclusive provided that the organotin compound comprises between 3 and 45 percent of the combined weight of the organotin compound and the organic ester of phosphoric acid. 2. The composition of matter according to claim 1, characterized in that that the phosphite is selected from the group consisting of triphenyl phosphite, diphenylisodecyl phosphite, Triisodecyl phosphite, phenyl diisodecyl phosphite, and tetrakis (nonylphenyl) polypropylene glycol 425 diphosphite. 509840/1081 3. The composition of matter according to claim 1, characterized in that that the vinyl chloride polymer is a homopolymer. 4. Substance composition according to claim 1, characterized in that the combined concentration of the ester and the organoζin compound is between 1.5 and 2.5 % . 5. A composition of matter according to claim 1, characterized in that the organotin compound is selected from the group consisting of butyltin-S, S ¹ , S "-tris (isooctylmercaptoacetate), dibutyltin-S, S'-bis (isooctylmercaptoacetate), dibutyltin dilaurate, dibutyltin bis (2-ethylhexoate), dibutyltin bis (isooctyl maleate), dibutyltin-S, S'-bis (isooctylmercaptopropionate), dibutyltin-S, S ¹ -bis (thiomaleate) and triphenyltin S-lauryl mercaptide. 50984D / 10