DE2340953A1 - FIRE-RETARDANT, RUBBER MODIFIED STYRENE RESIN COMPOSITIONS - Google Patents

Description

Dr. F. Zumsieln son. Dr. E. A3smann
Dr. R. Koenlgsberger - Dlpl.-Phys. R. Holzbauer - Dr. F. Zumsteln Jun,

PATENT LAWYERS

TELEPHONE: COLLECTIVE NO. 225341 8 MUNICH 2.

TELEX 529979 BRÄUHAUSSTRASSE 4

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CHECK ACCOUNT:
MUNICH 91139-809. BLZ 7OOK3O8O

BANK ACCOUNT: BANKHAUS H. AUFHAUSER '

ACCOUNT NO. 397997. BLZ 7OO 306 OO

97 / Li
RC-1262-M200

DART INDUSTRIES INC ₄ , Los Angeles, Calif., USA

Fire-retardant, rubber-modified styrene resin compounds

. Subsidence.

The invention relates to a fire retardant composition having good impact strength, heat resistance and good melt flow. It contains (1) a rubber-modified styrene resin, (2) at least one halogenated polyolefin, (3) an inorganic fire retardant and (4) a halogenated, aliphatic hydrocarbon. It was found that
the addition of (4) to a mixture of (1), (2) and (j5) leads to synergistic improvements in the melt flow and flame retardant properties of the mixture without impairing the physical properties, in particular the impact strength.

The invention relates to rubber-modified styrene resin compositions, and especially fire retardant, mixed.

409810/1066

Compositions or mixed compositions.

From the prior art it was known that by incorporating certain additives into thermoplastic, flammable polymers fire retardant compositions can be obtained. The known Fire retardants include inorganic and organic compounds such as antimony oxide, chlorinated polyethylene, etc. In general, an inorganic and an organic fire retardant are used together. Such additives often have to be used in Combination or alone are added in such large amounts that they lead to undesirable properties in the obtained Compositions lead and often impair the properties inherent in the thermoplastic matrix. These problems are special severe if the matrix is a mixture, as mixtures of polymers are made to measure to maintain certain physical properties such as high impact strength and heat resistance.

Typical mixing problems include the following: The fire retardant property alone can be effected by that large amounts of halogen-containing materials are incorporated, but addition of large amounts destroys them Impact strength and moldability (measured on the basis of the dimensional stability and the melt flow of the mixture). If lesser amounts are used to maintain physical properties, the amount will be insufficient to be fire retardant Properties. Furthermore, large amounts of halogenated materials add significantly to the cost of the mixtures.

Accordingly, it is an object of the present invention to provide a fire retardant, to provide rubber-modified styrene resin systems, v / obei an easily moldable mixture of satisfactory impact strength can be obtained.

409810/1066

According to the invention it was found that by adding a halogenated aliphatic hydrocarbon to a mixture of a rubber-modified styrene resin, an inorganic fire retardant and a halogenated polyolefin form a composition having excellent fire retardant properties and a superior melt flow which is suitable for molding is excellently suitable, the impact resistance and the heat distortion temperature of the original Mixture is maintained.

The essential components of the mixture according to the invention should be present in the following amounts:

1. about 25 to about 80% rubber modified styrene resin,

2. about 10 to about 50% by weight of halogenated polyolefin,

3. about 2 to about 20 weight percent inorganic fire retardant and

4. about 2 to about 20 wt .-? 6 halogenated aliphatic Hydrocarbon.

As stated above, the content of the rubber modified one varies Resin within the broad range of about 25 to 80% by weight of the mixture, and the concentration should advantageously be between about 50 and about 70% by weight.

By the term "rubber modified styrenic resin" is meant any of unsubstituted or substituted styrenes and Resin derived from natural or synthetic rubbers. These resins include the impact-resistant styrenes, I-ethyl methacrylate / butadiene / styrene resins (MBS), acrylonitrile / Butadiene / styrene resins (ABS) and their mixtures. The definition also includes, for the purpose of the invention, mixtures of any of the foregoing resins with other compatible resins such as e.g. mixtures of MBS or ABS with styrene / acrylonitrile copolymers (SAN), wherein the SAN is incorporated into the mixture in order to increase the flexural strength and the flowability

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" ⁴ " 7340953

raise. The compatible resin can be present in the total mixture in amounts ranging from about 5 to about 70 weight percent. The techniques used to make the above resins are known and do not form the subject of the present invention. However, if ABS is used as a component of the inventive blend , it should preferably have been made by either an emulsion or a Hassen bulk suspension technique to ensure a moldable composition.

The halogenated polyolefin resin in amounts ranging from 10 to 50 wt -. Is used% of the mixture is generally a resin which .- contains% halogen up to about 70 percent by about 10, the preferred range being between 20 to 60 weight .- ^ o lies. This resin can be polymerized by post-halogenation (preferably in solution, although a slurry halogenation is also possible) of a suitable hydrocarbon resin, such as homopolymers or copolymers of Oc -olefins or dienes, or by addition polymerization of a suitable mono-ethylenically unsaturated halogenated hydrocarbon monomer, or by copolymerization of suitable amounts of halogenated hydrocarbons S and hydrocarbon monomers can also be used. The preferred halogens are chlorine and bromine and the preferred hydrocarbon resins are c ^ The most preferred are the chlorinated polyethylenes having a melt viscosity of 10,000 to 30,000 poises, determined at 190 ° C. The processes for preparing the above compounds are generally known and do not form part of the present invention the invention.

In order to optimize the impact strength and processability, it is preferred that two such halogenated polyolefins together can be used in the mixture, one being from about 10 to about 50-3 halogen and the other from about 40 to about 70 / o halogen

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7340 9 53

contains. The relative amounts of each of the foregoing halogenated polyolefins should be such as the average Halogen content between about 20 and about 60% by weight, based on the total amount of halogenated polyolefins, and the range from about 25 to about 40 is most preferred Weight-50.

The inorganic fire retardants can be inorganic oxides, hydrates or salts such as aluminum hydrate or antimony oxide. Of special The antimony, barium, bismuth and zinc borates are of interest. These compounds can be used alone or in combination can be used in the mixtures according to the invention in amounts in the range from 2 to about 15% by weight.

The halogenated aliphatic hydrocarbon, in a concentration of about 2 to about 20 wt -.% Is used in the mixture should be one that has durchsdnittlich 18 to 36 carbon atoms per molecule. The preferred halogen is chlorine, although bromine and fluorine can also be used. The halogen content of the aliphatic hydrocarbon should be at least 40% by weight, and. it should preferably range from about 50 to about 80 weight percent. The halogenated aliphatic hydrocarbon is not limited to any specific isomeric composition. A preferred material is a chlorinated hydrocarbon containing between about 50 to 80% chlorine and having an average of about 18 to 24 carbon atoms.

The mixtures can also contain up to 15% by weight of the usual additives, including fillers, stabilizers, lubricants, pigments etc.

The mixture according to the invention can be produced by that first the components are mixed dry, and then the dry mixture of an intensive mechanical

U 0 9 8 1 0/1 0 S 6,

7340953

Machining at elevated temperatures above the softening point the resins advantageously with the aid of compounding rolls, but preferably with a Banbury mixer or is subjected by screw extrusion through perforated disks, and that processing is continued until a uniform mixture is obtained. When the viscosity properties of the resins differ noticeably, it is desirable to mix any additives into the halogenated polyolefin resin, before adding the base resin and other modifying additives for the formulation is done.

It has been found that a mixture of the foregoing three components, i.e. a mixture of rubber modified styrene resin, halogenated polyolefin resin and inorganic Fire retardant, although fire retardant, not fire resistant was enough to pass the Underwriters Laboratory, Inc. (UL) rigorous vertical flammability tests (vertical flammability tests) UL-94 on a 0.158 cm (i / i6 ") basis Poor flow properties. By adding the halogenated aliphatic hydrocarbon component of the present invention to the Mixture, an unexpected synergistic effect was obtained on the mixture, resulting in a composition with a very high melt flow (there was an increase from about 20 to about 70 with an average increase of about 30 units observed) and with excellent fire protection (the UL-94 test has now been passed) while maintaining the impact properties of the original mixture.

The invention is explained in more detail on the basis of the following illustrative examples and comparative examples in the examples All parts and percentages relate to <_is weight, unless otherwise stated. The various test values mentioned in the examples are illustrated in Table I below.

BAD OBiGlNAL 409810/10 66

7340953

Table I.

A. Melt flow at 190 ° C, 21.6 kg (ASTM D-1238-52T) _

B. Impact strength ^{50 (cm} j (it-lbs / inch)

Izod impact test, ASTH D-256-Gate end / Dead end

C. Tensile Strength at Yield Point / "kg / cm (-psiJf7-ASTM D63S

D. Tensile Strength at Failure / 50.8 cm / min (20 in./min.) At 23 ° C7 in kg / cm ² (psi). ASTM D-638-56T

E. Dimensional stability (C) ASTM D-648

F. Flammability - UL-94 / 1/4 "(0.835 cm) rod_7

G. 'Flammability - (ASTM D-635-56T)

H. Flexural Strength at Limit (at Yield) / kg / cm (psi) __ 7

ASTM D-790
I. Flexural Modulus at Limit X 105 / kg / cm ² * 22.8 ° C (psi-73 ° F) _7

ASTM D-740

Comparative example 1

A mixture was prepared containing 32.5 parts by weight of a suspension-polymerized ABS resin (69% styrene, 23% acrylonitrile, 8% butadiene), 32.5 parts SAN (about 72% styrene and 28% Acrylonitrile), 20 parts of a chlorinated one commercially available from Dow Chemical Company under the tradename CPE 3614 Polyethylene with a content of 36 wt .-% chlorine, 15 parts a chlorinated polyethylene having a chlorine content available from the Dow Chemical Company under the tradename MX 2243.25 of 43% by weight and 4 parts of antimony oxide. The mixture also contained about 3 parts of stabilizers (mixture of lead stabilizer and pentaerythritol) and 1 part of lubricants (mixture axis magnesia stearate and bisstearamide). It is not to guess that the presence or absence of stabilizers and

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Lubricant affects the properties of the mixed materials. The mixture was made by dry blending the Components during about 20 Hin. and mixing the mixture in a Banbury mixer for 2 minutes at 135-140 ° C. Molded or extruded samples of the formulation were then prepared and tested with the results in Table II summarizes.

Comparative example 2

Using the same technique as Comparative Example 1, the mixture of Comparative Example 2 was prepared! Their composition differed from that of the example in that 15 parts of CPE 3614 were used instead of 20 parts; 20 parts MX 2243.25 instead of 15 parts and 3 parts antimony oxide instead of 4 parts. The test results are summarized in Table II.

Example 3

A mixture was prepared according to Example 1 with the exception that 4 parts of stabilizers were used instead of 3 parts and 3 parts of antimony oxide were used instead of 4 parts. Further the mixture of this example contained 5 parts of one from Imperial Chemical Industries under the trade name Chlorez 700 HI-IP available chlorinated aliphatic hydrocarbon, the average of 18 to 24 carbon atoms per Γ · ο-lekül and had a content of about 70% chlorine. the analytical results are summarized in Table II.

Example 4

This mixture was made on the same track as that of Example 1 with the following differences: 30 parts of CPE 3614 were used and the other chlorinated polyethylene LiX 2243.25 was omitted. Dar composition;

BATH ORIGINAL

A09810 / 1066

10 parts of Chlorez 700 HMP were also added. The results obtained from the analyzes of the test samples are in Table II summarized. The comparison of Examples 3 and 4 with Comparative Examples 1 and 2 shows that the combination consists from retention of impact strength, high melt flow and ability to pass UL-94 test cannot be achieved if the halogenated aliphatic hydrocarbon is omitted.

Example 5

The mixture of this example was prepared according to the procedure of Example 3 with the following differences: the ABS resin was a suspension polymerized resin containing about 68% styrene, 23% acrylonitrile and 9% butadiene, the amount of Chlorez 700 HMP was increased to 10 parts and those of the stabilizers and lubricants to 7 and 2 parts, respectively. The test results are summarized in Table II.

Example 6

The mixture of Example 6, which was mixed according to Example 1, contained 65 parts of the ABS from Example 5, 20 parts of CPE 3614, 15 parts MX 2243.25, 3 parts antimony oxide, 10 parts Chlorez 700 HMP, 6 parts stabilizers and 1 part lubricant. The test results are summarized in Table II.

Example 7

Using the same procedure as in the previous examples, a mixture was prepared consisting of 10 parts of an emulsion polymerized ABS containing about 35.5 % styrene, 14.5% acrylonitrile and 50% diene; .55 parts of the SAN of Example 1; 20 parts of a chlorinated polyethylene available from Dow Chemical Company under the trade name MX 2243.37 having a chlorine content of 36? A, 15 parts

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MX 2243.25, 5 parts of antimony oxide, 10 parts of Chlorez 700 HMP, 4 parts stabilizers and 2 parts lubricants. The test results obtained from samples of this composition are summarized in Table II.

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Table II Summary of the test results

example 1 2 3 not
burning .. 4 VJ! 6th 0.1652
(2.36) _7th Melt flow at 1900 ° C, 21.6 kg 22.0 22.5 31.8 557.1
(7930) 39.9 70.1 59.0 45.3 Lzod impact strength, stretch
limit f— -η
), 30 (cm) .0 _D 453 (kp;) / _{ft lt} "/ _in ) 9.8 / 7.8 9.3 / 7.4 9.4 / 7.0 9 0.1925
(2.75) , 4 / 7.1 7 , 2 / 6.4 10.1 / 9.0 3.6 / 1.8 2.4 (cm) L "J * ■ *
O
ίΟ 2ugfe stigk.bd stretch limit
kg / cm2 (psi) 387
(5500) 380
(5400) 387
(5500) 366.7
(5210) - - 341
(4850) 810 High strength in the event of failure -
kg / cm2 (psi) 323
(4600) 316
(45ΟΟ) 309 ^
(4400) 309.7
(4410) - - 280.1
(3980) ο Dimensional stability C 95.2 95.5 94.7 96.3 87.5 85.8 90 cn
cn Flammability-UL-94 SH-1 not
passed not persistent
passed. the passed
the passed
the - passed
the passed
the Flammability ASTM D 635-56T not
burning not
burning not
burning - not
burning 3iegefestigk.bd limit
(at yield) - kg / cm ² (psi) 541.7
(7710) 541
(7700) 525.6
(7480) 461.2 419.2
(656Ο) (5960) 489.2
(6960) 3 bending module bd limit
(at yield) - kg / cm2 (psi) 0.1855
(2.65; 0.1827
(2.61) 0.1771
(2.53) 0.1869
. (2.67) 0.1911
(2.73)

-C- CD CD

Claims (8)

Claims (1) about 25 ms about 80 weight percent of a rubber modified styrene resin; (2) about 10 to about 50 weight percent of at least one halogenated Polyolefins; (3) about 2 to about 20 weight percent of an inorganic fire retardant; and (4) about 2 to about 20 weight percent of a halogenated aliphatic Hydrocarbon with an average of 18 to 36 carbon atoms per. Molecule and one Halogen content of at least 40% by weight. 2. Composition according to claim 1, characterized in that the rubber-modified styrene resin is ABS. 3. Composition according to claim 1, characterized in that the rubber-modified styrene resin is a mixture of ABS and SAN , the concentration of SAN, based on the total composition, being between 5 and about 70% . 4. Composition according to claim 1, characterized in that that the halogenated polyolefin is a chlorinated polyethylene having a melt viscosity at 190 ° C between about 1,000 and about 30,000 poises, which is about 10 to contains about 70 each chlorine. 5. Composition according to claim 1, characterized in that the inorganic fire retardant is antimony oxide. 409810/1066 6. Composition according to claim 1, characterized in that that the halogenated aliphatic hydrocarbon is a chlorinated hydrocarbon with an average of 18 Ms 24 carbon atoms per molecule and a chlorine content of about 50 Ms is about 80 wt .- ^. 7. Composition according to claim 1, characterized in that that the concentration of the rubber-modified styrene resin is in the range between 50 and about 70% by weight. 8. Composition according to claim 1, characterized in that that two halogenated polyolefins are present, one of which about 10 Ms about 50% halogen and the other about 40 Ms contains about 7Ο5δ halogen, and the relative Amounts of each of the halogenated polyolefins are such that the average halogen content based on the total weight of the halogenated polyolefin is between 20 and about 60% by weight, 409810/1066