WO1995013319A1 - Saccharin containing polyamide moulding compositions - Google Patents

Saccharin containing polyamide moulding compositions Download PDF

Info

Publication number
WO1995013319A1
WO1995013319A1 PCT/GB1994/002424 GB9402424W WO9513319A1 WO 1995013319 A1 WO1995013319 A1 WO 1995013319A1 GB 9402424 W GB9402424 W GB 9402424W WO 9513319 A1 WO9513319 A1 WO 9513319A1
Authority
WO
WIPO (PCT)
Prior art keywords
composition
moulding
saccharin
nylon
polyamide
Prior art date
Application number
PCT/GB1994/002424
Other languages
French (fr)
Inventor
Richard Stuart Williams
Richard Scott Barnes
Original Assignee
T & N Technology Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by T & N Technology Limited filed Critical T & N Technology Limited
Publication of WO1995013319A1 publication Critical patent/WO1995013319A1/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K5/00—Use of organic ingredients
    • C08K5/0008—Organic ingredients according to more than one of the "one dot" groups of C08K5/01 - C08K5/59
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K5/00—Use of organic ingredients
    • C08K5/36—Sulfur-, selenium-, or tellurium-containing compounds
    • C08K5/45—Heterocyclic compounds having sulfur in the ring
    • C08K5/46—Heterocyclic compounds having sulfur in the ring with oxygen or nitrogen in the ring

Definitions

  • This invention is concerned with mo lding compositions which contain a polyamide, e.g. nylon 6 or nylon 66, and is especially concerned with such compositions which contain a filler, eg magnesium hydroxide as a flame retardant.
  • a polyamide e.g. nylon 6 or nylon 66
  • a filler e.g magnesium hydroxide as a flame retardant.
  • Polyamides such as nylons, are widely used for moulding components and, for some moulding applications, is mixed with a flame-retardant so that the moulded component exhibits flame retardant characteristics.
  • Such applications include electrical lamp-holders, and switch housings.
  • Magnesium hydroxide is a flame retardant which has been suggested for use with nylon. This material, when subjected to a flame, decomposes endothermically with the liberation of water. Nylon containing magnesium hydroxide has, however, been found to be difficult to mould because of its high melt viscosity and, furthermore, it is found that the mouldings have obvious surface defects which render them unacceptable commercially. Such surface defects manifest themselves by the appearance of white patches on the surface of the moulding. Various attempts have been made to overcome this problem but without achieving complete success. The most successful previous attempt known to the applicants involves the addition of organic sulphonamide to the moulding composition (see GB 2,237,573A) but even this has not achieved total success.
  • the invention provides a moulding composition containing a polyamide characterised in that the composition also contains saccharin.
  • a moulding composition according to the invention is found to produce mouldings with reduced surface defects. Furthermore, the composition is found to produce mouldings with increased tensile strength which is important, especially for snap-fit mouldings. The composition is also found to be easier to mould making it possible to mould compositions with higher concentrations of fillers.
  • Saccharin is not known to the Applicants to have been used as an additive to moulding compositions but is, of course, well-known as an artificial sweetener.
  • the saccharin provides 1 to 10 per cent by weight of the composition.
  • about 2.5 per cent of saccharin is found to result in saleable mouldings, ie with an acceptable level of surface detects, and 5 per cent was found to result in substantially no discernable surface defects.
  • the polyamide may be nylon 6, nylon 66, nylon 6.12, nylon 6.10 or another suitable polyamide.
  • the composition may also comprise a flame-retardant, eg magnesium hydroxide which may be present in 45 to 65 per cent by weight of the composition, or if a lower standard of flame-retardancy is acceptable, the percentage may be 20 to 45.
  • a flame-retardant eg magnesium hydroxide which may be present in 45 to 65 per cent by weight of the composition, or if a lower standard of flame-retardancy is acceptable, the percentage may be 20 to 45.
  • the composition may contain different fillers, for example, a ferromagnetic material such as strontium ferrite.
  • the composition may also contain reinforcing fibres, e.g. glass fibres, which may be present in up to 35% by weight depending on the amount of magnesium hydroxide or other filler which is present.
  • the first illustrative moulding composition was a formulation of 40 parts nylon 6, 60 parts magnesium hydroxide (Magnifin H5) , 0.3 parts calcium stearate (as a mould lubricant), 2.5 parts saccharin, and 25 parts glass fibre (all parts by weight).
  • the composition was injection moulded into test discs which were subjected to tests in comparison with a comparison composition of the same formulation but with the saccharin omitted.
  • the discs made from the comparison composition had very noticeable surface defects in the form of white marks covering the surface. It was considered that mouldings made from the comparison composition would have been unsaleable as their appearance would have been unacceptable to a customer.
  • the discs moulded from the first illustrative composition had noticeable surface defects but these were far less marked than in the comparison composition. It was considered that mouldings made from the first illustrative composition would have been acceptable to customers.
  • the discs made from the comparison composition gave a mean burn time of 3.6 seconds which is within acceptable limits.
  • a tensile strength test gave an average value of 120
  • an elongation at break test gave a value of 1.1%.
  • a flexural strength test gave a value of 199.
  • the mean burn time was 2.0 seconds (considerably better)
  • the tensile strength was 142
  • the elongation at break was 1.36%
  • the flexural strength was 223.
  • the first illustrative composition out-performed the comparison composition.
  • the first illustrative composition was also easier to mould.
  • the second illustrative composition was the same as the first except that 5 parts by weight of saccharin were included. Discs injection moulded from the second illustrative composition were found to have no discernable surface defects in the form of white marks. The above- mentioned tests were repeated for the second illustrative composition. The mean burn time was measured as 1.8 seconds, the tensile strength as 150, the elongation at break as 1.39%, and the flexural strength as 231.
  • the first and the second illustrative compositions were both easier to mould, ie required less injection force, than the comparison composition.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Compositions Of Macromolecular Compounds (AREA)

Abstract

A moulding composition contains a polyamide, e.g., nylon 6 or nylon 66, and, optionally, a filler such as magnesium hydroxide which acts as a flame-retardant. In order to reduce surface defects in the moulding, the composition also contains saccharin.

Description

SACCHARIN CONTAINING POLYAMIDE MOULDING COMPOSITIONS
This invention is concerned with mo lding compositions which contain a polyamide, e.g. nylon 6 or nylon 66, and is especially concerned with such compositions which contain a filler, eg magnesium hydroxide as a flame retardant.
Polyamides, such as nylons, are widely used for moulding components and, for some moulding applications, is mixed with a flame-retardant so that the moulded component exhibits flame retardant characteristics. Such applications include electrical lamp-holders, and switch housings.
Magnesium hydroxide is a flame retardant which has been suggested for use with nylon. This material, when subjected to a flame, decomposes endothermically with the liberation of water. Nylon containing magnesium hydroxide has, however, been found to be difficult to mould because of its high melt viscosity and, furthermore, it is found that the mouldings have obvious surface defects which render them unacceptable commercially. Such surface defects manifest themselves by the appearance of white patches on the surface of the moulding. Various attempts have been made to overcome this problem but without achieving complete success. The most successful previous attempt known to the applicants involves the addition of organic sulphonamide to the moulding composition (see GB 2,237,573A) but even this has not achieved total success.
It is an object of the present invention to provide a moulding composition containing a polyamide which produces mouldings which are substantially free of surface defects of the type referred to.
It is a further object of the invention to provide a moulding composition containing a polyamide and magnesium hydroxide which produces mouldings which are substantially free of surface defects of the type referred to.
The invention provides a moulding composition containing a polyamide characterised in that the composition also contains saccharin.
A moulding composition according to the invention is found to produce mouldings with reduced surface defects. Furthermore, the composition is found to produce mouldings with increased tensile strength which is important, especially for snap-fit mouldings. The composition is also found to be easier to mould making it possible to mould compositions with higher concentrations of fillers.
Saccharin is not known to the Applicants to have been used as an additive to moulding compositions but is, of course, well-known as an artificial sweetener.
Preferably, the saccharin provides 1 to 10 per cent by weight of the composition. In some compositions, about 2.5 per cent of saccharin is found to result in saleable mouldings, ie with an acceptable level of surface detects, and 5 per cent was found to result in substantially no discernable surface defects.
The polyamide may be nylon 6, nylon 66, nylon 6.12, nylon 6.10 or another suitable polyamide.
The composition may also comprise a flame-retardant, eg magnesium hydroxide which may be present in 45 to 65 per cent by weight of the composition, or if a lower standard of flame-retardancy is acceptable, the percentage may be 20 to 45. The composition may contain different fillers, for example, a ferromagnetic material such as strontium ferrite. The composition may also contain reinforcing fibres, e.g. glass fibres, which may be present in up to 35% by weight depending on the amount of magnesium hydroxide or other filler which is present.
There now follows a detailed description of moulding compositions which are illustrative of the invention.
The first illustrative moulding composition was a formulation of 40 parts nylon 6, 60 parts magnesium hydroxide (Magnifin H5) , 0.3 parts calcium stearate (as a mould lubricant), 2.5 parts saccharin, and 25 parts glass fibre (all parts by weight). The compositionwas injection moulded into test discs which were subjected to tests in comparison with a comparison composition of the same formulation but with the saccharin omitted.
The discs made from the comparison composition had very noticeable surface defects in the form of white marks covering the surface. It was considered that mouldings made from the comparison composition would have been unsaleable as their appearance would have been unacceptable to a customer. The discs moulded from the first illustrative composition had noticeable surface defects but these were far less marked than in the comparison composition. It was considered that mouldings made from the first illustrative composition would have been acceptable to customers.
In a flammability test, the discs made from the comparison composition gave a mean burn time of 3.6 seconds which is within acceptable limits. A tensile strength test gave an average value of 120, an elongation at break test gave a value of 1.1%. A flexural strength test gave a value of 199. These tests were repeated using the discs made from the first illustrative composition. The mean burn time was 2.0 seconds (considerably better) , the tensile strength was 142, the elongation at break was 1.36%, and the flexural strength was 223. Thus, in all the tests, the first illustrative composition out-performed the comparison composition. The first illustrative composition was also easier to mould.
The second illustrative composition was the same as the first except that 5 parts by weight of saccharin were included. Discs injection moulded from the second illustrative composition were found to have no discernable surface defects in the form of white marks. The above- mentioned tests were repeated for the second illustrative composition. The mean burn time was measured as 1.8 seconds, the tensile strength as 150, the elongation at break as 1.39%, and the flexural strength as 231.
The first and the second illustrative compositions were both easier to mould, ie required less injection force, than the comparison composition.

Claims

A moulding composition containing a polyamide characterised in that the composition also contains saccharin.
A moulding composition according to Claim 1, characterised in that the saccharin comprises 1 to 10 per cent by weight of the composition.
A moulding composition according to either one of claims 1 and 2, characterised in that the polyamide is nylon 6.
A moulding composition according to either one of claims 1 and 2, characterised in that the polyamide is nylon 66.
A moulding composition according to any one of Claims 1 to 4, characterised in that the composition also comprises a flame-retardant.
A moulding composition according to claim 5, characterised in that the flame-retardant is magnesium hydroxide.
A moulding composition according to any one of claims 1 to 4, characterised in that the composition also comprises a ferromagnetic material.
A moulding composition according to any one of Claims 1 to 7, characterised in that the composition also contains reinforcing fibres.
A component moulded from a moulding composition according to any one of claims 1 to 8.
PCT/GB1994/002424 1993-11-10 1994-11-04 Saccharin containing polyamide moulding compositions WO1995013319A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9323133.0 1993-11-10
GB9323133A GB2283746A (en) 1993-11-10 1993-11-10 Moulding compositions containing a polyamide

Publications (1)

Publication Number Publication Date
WO1995013319A1 true WO1995013319A1 (en) 1995-05-18

Family

ID=10744916

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1994/002424 WO1995013319A1 (en) 1993-11-10 1994-11-04 Saccharin containing polyamide moulding compositions

Country Status (2)

Country Link
GB (1) GB2283746A (en)
WO (1) WO1995013319A1 (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DD271334A1 (en) * 1988-04-04 1989-08-30 Leuna Werke Veb STABILIZER AND FLAME PROTECTION FOR POLYAMIDE

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DD271334A1 (en) * 1988-04-04 1989-08-30 Leuna Werke Veb STABILIZER AND FLAME PROTECTION FOR POLYAMIDE

Also Published As

Publication number Publication date
GB9323133D0 (en) 1994-01-05
GB2283746A (en) 1995-05-17

Similar Documents

Publication Publication Date Title
US4552912A (en) Flame retardent polyamide compositions
USRE30402E (en) Self-extinguishing polyamide compositions
US5378750A (en) Flame-retardant polyamide molding compounds
AU7747000A (en) Flame-retarded polyphenylene ether composition and method of making same
EP1121388A1 (en) Polyamide composition stabilized with copper complexes and organic halogen compounds
US4105621A (en) Thermoplastic polyamide composition
US5990270A (en) Amorphous, transparent polyamide compositions and articles having reduced flammability
AU722048B2 (en) Polypropylene molding composition containing an antistatic agent and having low-fogging properties
US4548972A (en) Flame retardant polyamide compositions
US5942584A (en) Flame-retardant polyamides
WO1995013319A1 (en) Saccharin containing polyamide moulding compositions
DE60029009T2 (en) FLAME-PROTECTED POLYAMIDE RESIN COMPOSITION AND ELECTRICAL COMPONENTS THEREOF USED
AU3151000A (en) Flame-proofed molding materials
WO1995028439A1 (en) Moulding compositions containing a polyamide
EP1200516B1 (en) An aromatic polyamide compositions for molding
GB2301105A (en) Moulding compositions containing a polyamide
EP0426243B1 (en) Polyamide moulding compositions
EP0576951B1 (en) Flame retardant polyamide moulding compositions
GB2274109A (en) Moulding compositions containing nylon
US6204314B1 (en) Film retardant polyamide resin composition
US3730939A (en) Flame retardant polyamide compositions containing certain sulfanilamides
CA2025372A1 (en) Flame retardant nylon molding resins with improved physical properties
DE19702993B4 (en) Use of an additive combination consisting of zinc sulfide and melamine or its derivatives
CA2277081A1 (en) Flame resistant nylon elastomers
JPS6312661A (en) Polyamide composition

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): CA FI JP NO US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE

121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: CA