	US 7,449,243 B1
	Glass yarns, composite thereof, method for making same and reinforcing glass composition
Sophie Creux, La Motte Servolex (France); Michel Leclercq, La Motte Servolex (France); and Pascal Fournier, Chambery (France)
Assigned to Vetrotex France S.A., Chambery (France)
Appl. No. 10/129,265 PCT Filed Oct. 31, 2000, PCT No. PCT/FR00/03038 § 371(c)(1), (2), (4) Date Sep. 30, 2002, PCT Pub. No. WO01/32576, PCT Pub. Date May 10, 2001.
Claims priority of application No. 99 13836 (FR), filed on Nov. 04, 1999.
Int. Cl. B32B 17/06 (2006.01); C03C 13/00 (2006.01); B29C 53/00 (2006.01)

U.S. Cl. 428—426 [428/36.3; 501/35; 501/55; 501/68; 501/155; 264/13; 264/164; 65/126]

24 Claims

1. Reinforcing glass yarn, the composition of which comprises the following constituents, within the limits defined below, expressed in percentages by weight:


	SiO₂	54.5 to 58%
	Al₂O₃	12 to 15.5%
	SiO₂+ Al₂O₃	70 to 73%
	CaO	17 to 25%
	MgO	0 to 5%
	RO = CaO + MgO	21 to 28%
	R₂O = Na₂O + K₂O + Li₂O	up to 2%
	TiO₂	less than 1%
	Fe₂O₃	less than 0.5%
	B₂O₃	up to 3%
	F₂	less than 1%

and such that the ratio R1=Al₂O₃/CaO is less than 0.7, and when SiO₂is greater than 57% the amount of boron oxide B₂O₃is greater than 2%,

wherein the composition further satisfies the criterion:

2.35<R2=(SiO₂+Al₂O₃)/(RO+R₂O+B₂O₃)<2.70,

a T (log 2.5) of at least 1300° C.,

its liquidus temperature is less than or equal to 1200° C.,

and its fiberizing temperature range is greater than 100° C.