GB1594817A - Non-discolouring glass fibre size - Google Patents

Description

(54) NON-DISCOLORING GLASS FIBER SIZE (71) We, OWENS-CORNING FIBERGLAS CORPORATION, a corporation organised and existing under the laws of the State of Ohio, United States of America, of Fiberglas Tower, Toledo, Ohio, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a non-discoloring glass strand sizing.

In one of its more specific aspects, this invention pertains to sizings for glass fibres used for incorporation in polyamides.

Glass fibre reinforced polyamides, such as nylon, are presently being injection molded into many articles in the automotive and appliance industry. To obtain the best improvement in properties, the composition with which the glass fibre is sized must be compatible with the polyamides.

It is known that polyurethanes based on aromatic diisocyanates provide sizes having outstanding adhesion between glass and polyamides. However. such sizes have a tendency to discolor laminates produced from the resulting glass-fibre reinforced nylons, the laminates not possessing a white color but rather a green or brown discoloration.

A large number of these polyurethanes are based on toluene derivatives such as toluene diisocyanate. an aromatic diisocyanate the use of which results in discolored laminates.

It has now been discovered that sizes suitable for use on glass fibres incorporated in polyamides can be produced by employing therein polyurethanes based on aliphatic or cycloaliphatic diisocyanates. The employment of the latter materials largely eliminates such discoloration while not adversely affecting the quality of the finished product.

According to this invention, there is provided a glass fibre size composition comprising an aqueous mixture of (1) a latex emulsion of a thermoplastic polyurethane produced by the chain extension of an NCOterminated prepolymer prepared by the reaction of an aliphatic or cycloaliphatic diisocyanate with a polyalkylene ether polyol, (2) an organo-silane coupling agent, and optionally (3) a lubricant.

Also, according to this invention, there are provided glass fibers, at least a portion of the surface of which is in contact with a residue produced by the removal of water from an aqueous composition as defined above, and a polyamide resin containing such fibres.

This invention also provides polyamide resins reinforced with glass fibres sized with the size composition of this invention.

A particularly suitable thermoplastic polyurethane latex emulsion based on aliphatic or cycloaliphatic diisocyanates, employable in this invention, is designated X1042H, commercially available from BASF Wyandotte, Wyandotte, Michigan. U.S. Patents Nos. 3,401,133 and 3,563,943 described in detail the preparation of latex emulsions of this type.

The polyurethane latex emulsion will be employed in the size preferably in an amount within the range of from 3 to 20 parts per 100 parts by weight of the size composition.

Any suitable coupling agent comprising an organo silane can be employed. Preferably an organo silane such as gamma-aminopropyltrimethoxysilane will be used. A suitable coupling agent of this type is designated At 100 available from Union Carbide.

The coupling agent will be employed in the size preferably in an amount within the range of from 0.2 to 4 parts per 100 parts by weight of the size.

Any suitable lubricant can be employed. A preferred lubricant is the cationic condensation product of dimethylaminopropylamine and pelargonic acid. This material will preferably have a specific gravity of about 1, a viscosity of about 500 cps. at 25"C and a pH (5% aqueous solution) of from 5.5 to 7. A preferred lubricant of these characteristics is available from Emery Industries as Emerstat 6665. Another suitable lubricant is an amide substituted polyethyleneamine such as Emery 6717 available from Emery Industries.

The lubricant may be employed in the size in an amount up to about 5 parts per 100 parts by weight of the size.

The size of this invention is prepared by conventional methods such as described below. It can be applied to any glass fibers conventionally employed as molding compound reinforcement, being applied during the forming operation such that the fibers possess, upon drying, a solids content preferably within the range of from about 0.3 to about 2.0 weight percent based upon loss on ignition.

The best mode for carrying out the invention is demonstrated by the following examples.

EXAMPLE I This example demonstrates the preparation of approximately 100 gallons of a size composition of this invention.

About 40 gallons of demineralized water were added to a main mix tank.

About 8 pounds of gamma-aminopropyltrimethoxysilane (Union Carbide Al 100) ('Union Carbide' is a Registered Trade Mark) were mixed with about 10 gallons of demineralized water in a first premix kettle until the resulting solution was clear (about 10 minutes) and the solution was introduced into the contents of the main mix tank.

About 65 pounds of thermoplastic poly urcthane latex emulsion (X1042H) were mixed with about 20 gallons of deniineral- ized water in a second premix kettle for about 10 minutes and the resulting mixture was introduced into the contents of the main mix tank.

The contents of the main mix tank after complete mixing (about 15 minutes) had a solids content of about 4.7 weight percent and a pH of about 9.

The size prepared in the above manner was applied to individual glass fibers at conventional application methods and rates such that the strand solids, on drying, amounted to about 0.6 weight percent.

EXAMPLE II This example demonstrates the preparation of approximately 100 gallons of a size composition of this invention.

About 25 gallons of demineralized water were added to a main mix tank.

About 8.3 pounds of gamma-aminopropyltrimethoxysilane (Union Carbide A 1100) were mixed with about 20 gallons of demin eralized water in a first prefix kettle until the resulting solution was clear (ahout 10 minutes) and the solution was introduced into the contents of the main mix tank.

About 45.9 pounds of thermoplastic polyurethane latex emulsion (X1042H) W(.rt mixed with about 20 gallons of demineralized water in a second premix tank for about 10 minutes and the resulting mixture was introduced into the main mix tank.

About 8.3 pounds of lubricant (Emery 6665) were mixed with about 10 gallons of demineralized water in a third premix kettle for about 10 minutes and the resulting mixture was introduced into the main mix tank.

The contents of the main mix tank after complete mixing (about 10 minutes) had a solids content within the range of from about 2.5 to about 4.5 weight percent and a pH within the range of from about 9 to about 10.

The size prepared in the above manner was applied to individual glass fibers at conventional application methods and rates such that the strand solids, on drying, amounted to about 0.6 weight percent.

EXAMPLE 111 This example demonstrates the preparation of a molded article reinforced with glass fibers sized with the size composition of Example 1.

The size composition of Example I was applied to 816 "E" glass fibers having diameters of from about 0.00050 to about 0.00055 inch at forming using a roll-type applicator.

The sized fibers were collected in the form of a strand. The strand was wound into a forming package and dried for about 16 hours at about 235"F. The strand solids, on drying, amounted to about 0.6 weight percent.

Fifty forming packages of the sized strand were placed on a creel and the strands from the fifty packages were brought together through guide eyes to form a roving package which was then cured for about 6 hours at 235 F. The roving was withdrawn from the roving package and chopped into approximately d inch length fibers.

About 3 parts by weight of chopped fibers were placed in a drum tumbler with about 7 parts by weight of nylon 6,6 having a melting index of 2 and a molecular weight of about 100.000. The resulting mixture was then placed in a 2 inch Pridex Machine Screw Extruder and electrically heated to about 540"F. The mixture was extruded into 1/8 inch diameter cylindrical rods which were introduced into a Cumberland Pelletizer to form i inch long pellets. The pellets were, in turn, fed into an injection molding machine at a temperature of about 550"F and formed into a standard ASTM D-638 dog bone test sample.

The test sample was white in color and found to have a tensile strength of about 26,000 psi., a modulus of elasticity of 1.2 x 106 psi. and an IZOD notched impact strength of 3.0 ft. pounds/inch.

WHAT WE CLAIM IS: 1. An aqueous size composition for glass fibres comprising: (a) a latex emulsion of a thermoplastic polyurethane produced by the chain extension of an NCO-terminated prepolymer prepared by the reaction of an aliphatic or cycloaliphatic diisocyanate with a polyalkylene ether polyol, and (b) an organo-silane coupling agent.

2. A composition according to claim 1 which includes a lubricant.

3. A composition according to claim 2 in which said lubricant is a cationic condensation product of dimethylaminopropylamine and pelargonic acid.

4. A composition according to claim 2 or claim 3 in which said lubricant is employed in said aqueous composition in an amount up to 5 parts per 100 parts by weight of the aqueous composition.

5. A composition according to any preceding claim in which said silane coupling agent is gamma-aminopropyltrimethoxysilane.

6. A composition according to any preceding claim in which said silane coupling agent is employed in said aqeuous composition in an amount within a range of from'0.2 to 4 parts per 100 parts by weight of the aqueous composition.

7. A composition according to any preceding claim in which said polyurethane latex emulsion is included in an amount within a range of from 3 to 20 parts per 100 parts by weight of the composition.

8. A glass fibre size composition substantially as herein described with reference to the Examples.

9. Glass fibres having at least a portion of their surfaces in contact with the residue formed by the removal of water from an aqueous size composition according to any

Claims (1)

1. preceding claim.

   10. Sized glass fibres substantially as herein described with reference to Example III.

   Il. A polyamide resin containing glass fibers according to claim 9 or claim 10.