CA1036436A - Surface treatment of glass fibers for reinforcing hydraulic cements - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

Aqueous solutions containing a phosphorus-oxy acid, for example phosphoric acid, or a salt, for example, a phos-phate, or a salt of titanium, zirconium or hafnium are used to form a deposit or coating on the surfaces of glass fibers.
Such coatings may be formed by immersing the glass fiber in the solution at an elevated temperature. The coating enhances the alkali corrosion resisting properties of the glass fiber, and the surface-treated glass fibers are particularly useful as a reinforcement in aqueous hydraulic cement mixtures for imparting into the cured or hardened products made therefrom, a physical strength which is stable with the elapse of time.

Description

~ 36~36 This invention relates to a procedure for surface-treating glass fibers to coat them with a phosphorus-oxy acid or salt, or hydrous metal oxides to enhance and improve cement-alkali corrosion resisting properties of the glass fibers, more especially the inven-tion is concerned with the reinforcement of aqueous hydraulic cements with such fibers and the resulting hardened cements.
In the past, considerable effort has been devoted to glass fibers for use with aqueous hydraulic cement mixtures such as concrete, mortar and plaster containing Portland cement, lime, water glass and the like in order to enhance the physical strength of the hardened products made from these materials.
Such a hardened concrete, mortar or plaster is known to be more durable with elapse of time when the glass fibers incorporated therein as reinforcement have more resistance to corrosion by alkaline substances such as calcium hydroxide, magnesium hydroxide~ potassium hydroxide and sodium hydroxide, and the like. These alkaline substances are prominent in aqueous ~ hydraulic cement mixtures, and, therefore, will be hereinafter referred to by the all inclusive term "cement alkali". Parti-cularly in the case of Portland cement, some of khe calcium hydroxide remains in the form of a dispersed aqueous solution in the matrix of the hardened Portland cement for a consider-able length of time even after the aqueous hydraulic cement mixture has been hardened completely. For this reason, during such a length of time, the dispersed aqueous calcium hydroxide solution continues to corrode the surfaces of the glass fibers incorporated in the hardened cement product and decreases the ultimate physical strength of the product.
As far as glass material itself is concerned, it has heretofore been found that zirconia (ZrO2) is an effective ~.
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ingredient for improving the cement alkali corrosion resisting property of glass. Therefore, most glass materials which are so-called "cement-alkali resisting glass" contain zirconia.
Satisfactory lmprovements are generally obtained with a zirconia content ranging from 4% to 10% on a weight basis.
In the case of glass fibers, however, the increased surface area produces an increase in the susceptibility to corrosion by cement-alkali, so that it is necessary to-increase the con-tent of zirconia to more than 10%, and, in extreme cases, to as high as 20% to impart a sufficient alkali-corrosion resist-ing property thereto. On the other hand, increasing the zirconia content not only renders the resulting glass compo-sitions unsuitable for the melting operation, but also in-creases the frequency of end breakages of fibers in the spin-ning operation because of increase in the liquidus temperature of the glass compositions. In the manufacture of glass fibers, therefore, it is almost impossible to employ glass compositions containing more than 10% by weight of zirconia for the purpose of spinning glass fibers from the melt thereof economically.
qlhe present invention provides a novel method of enhancing and improving the alkali corrosion resis-ting property of glass fibers without the necessity of complicated procedures.
The invention further provides aqueous treating solu-tions which are adapted for coating glass fibers.
Still further there is provided glass fibers which have been provided with an adherent coating or deposit of a phosphorus-oxy acid, for example, phosphoric acid; a salt of a phosphorus-oxy acid, for example, a phosphate; or a hydrous metal oxide, which coating or deposit is effective to inhibit the alkali-corrosion of the glass fibers, B

36~36 The invention further provides glass fibers suitable for addition to concrete, mortar and like cementitious mixtures which impart to the hardened or cured products made therefrom a physical strength and stability against alkali corrosion.
The invention further provides hardened cements reinforced with glass fibers and improvements in the production of such cements wherein the resistance of the fibers to alkali-corrosion is improved.
According to the invention there is provided in a method for reinforcing aqueoushydrauliccement wherein glass fibers are incorporated into the cement, the improvement which comprises applying to the glass fibers an aqueous solution of at least one compound selected from the group consisting of phosphorus-oxy acids, alkali metal salts of phosphorus-oxy acids, zirconium salts, titanium salts, and hafnium salts to form a deposit on said fibers effective to inhibit alkali-corrosion of the fibers prior to incorporating the fibers in the cement.
According to another aspect of the invention there is provided a hardened hydraulic cement reinforced with glass fibers, said fibers having an alkali-corrosion inhibiting deposit thereon of at least one material selected from the group consisting of a phosphorus-oxy acid, an alkali metal salt of a phosphorus-oxy acid, zirconium oxide, titanium oxide and hafnium oxide.
As examples of the aqueous treating solutions pre-ferably useable in the present invention, mention may be made of phosphoric acid solutions, metaphosphoric acid solutions, pyrophosphoric acid solutions as illustrating phosphorus-oxy acids, sodium phosphate solutlons and potassium phosphate B

~36~36 solutions as illustraring salts of phosphorus-oxy acids, titanium tetrachloride solutions, titanic sulfate solutions, zirconium tetrachloride solutions, zirconium nitrate solutions, -~ zirconyl nitrate solutions, zirconium sulfate solutions, hafnium sulfate solution, hafnium tetrachloride solutions, mixed solutions of titanium salt solutions and hafnium salt solutions, mixed solutions of titanium salt solutions and zirconium salt solutions, and mixed solutions of zirconium salt solutions and hafnium salt solutions. The concentrations of phosphate ions, titanium ion, zirconium ion and hafnium ion are not particularly limited. Concentrations of less than 10% by weight are preferred. Beneficiating concentrations are in the order of about 1% by weight.
In accordance with the present invention, glass B ~

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~l~36~3~
fibers made from soda lime glass compositions and ylass fibers made from glass compositions containing zirconia in a relatively small amount are treated with aqueous treating solutions by various methods. A preferred method is to immerse the glass fibers in the aqueous treating solution.
The treating temperature and time are dependent upon the concentration of the aqueous treating solution. The treatment at a temperature of 80-95C for about 2 hours is preferred.
As the treatment temperature is decreased by 10C, the treating time is increased by about 100% to effect an equi-valent result~
Specific examples of the aqueous treating solutions of the invention are shown hereinbelow.

SOLUTIONS A, B and C
As typical examples of water soluble zirconium salts useable in the invention, mention may be made of zirconium tetrachloride, zirconium oxynitrate dihydride and zirconium sulfate tetrahydride. These salts are capable of hydrolyzing in aqueous solutions at elevated temperatures to precipitate the desired insoluble hydrous oxides or mixtures of such oxides onto the immersed glass fiber.
Using these salts, aqueous treating solutions A, B and C
are prepared, solutions Al and A2 containing 3% and 5fi by weight of ZrC14 and having pH values of 0.71 at 15 C and 0.49 at 15.5 C respectively; solutions Bl and B2 containing 3%
and 5% by weight of ZrO(NO3)2 and having pH values of 1.22 at 19.5C and 1~03 at 13C respectively, and solutions Cl and C2 containing 3% and 5% by weight of Zr(SO4)2 and having pH
values of 0.95 at 14C and 0.75 at 15.55C respectively.

SO ~TIONS D and E
Aqueous treating solutions D1, D2 and D3 containing 1.0%, 3.0% and 5.0% by weight of titanium tetrachloride TiC14 and having pH values of 1.04, 0.69 and 0.38 at 15C respectively;
and aqueous treating solutions El, E2 and E3 containing 1.0%, 3.0% and 5.0% by weight of titanic sulfate Ti(So4)2 and haviny pH values of 1.12, 0.89 and 0.39 at 15C respectively.
SOLUTION F
Aqueous treating solutions Fl, F2 and F3 containing 0.15%, 0.5% and 3.0% by weight of hafnium tetrachloride HfC14 and having pH values of 2.17, 1.70 and 0.88 at 15C respec-tively.
SOLUTION G
Aqueous treating solutions Gl through G5 containing mixtures of zirconium tetrachloride and hafnium tetrachloride in the following weight percent concentrations and having the following pH values Gl G2 G3 G4 G5 -ZrC14 2.0 1.5 1.0 0.5 0 HfC14 0 0.5 1.0 1.5 2.0 pH(15 C) 0.81 0.83 0.90 0.93 0.92 SOLUTIO~ H
Aqueous treating solutions Hl through H5 containing mixtures of titanium tetrachloride and zirconium tetrachloride in the following weight percent concentrations having the following pH values.

Hl H2 H3 H4 H5 TiC14 0 0.5 1.0 1.5 2.0 ZrC14 2.0 1.5 1.0 0.5 0 pH(15 C) 0.71 0.73 0.68 0.60 0.50 ~36~3~
SOLUTION I
Aqueous treating solutions ll through15 containing mixtures of titanium tetrachloride and hafnium tetrachloride in the following weight percent concentrations and having the following pH values ll 12 13 14 ~5 TiC14 O 0.5 l.0 1.5 2.0 HfCl4 2.0 1.5 l.0 0.5 0 ~ pH(15 C) 0.75 0.68 0.65 0.61 0.57 SOLUTION J
Aqueous treating solutions Jl through J7 containing 0.1%, 0.5%, 1.0%, 3.0%, 5.0%, 7.0% and 10% by weight of phosphoric acid and having pH values of 2,31, 1.79, 1.62, 1.41, 1.29, 0.99 and 0.87 at a temperature of 15C.
The following examples are submitted to illustrate the uti.lity and the property of the coatings deposited by the above-mentioned aqueous treating solutions of the invention.
Example 1.
A number of soda-lime glass fiber specimens, each specimen consisting of a bundle of twenty glass fibers of 50cm long were immersed in the aqueous treating solutions A, B and C individually in a vertical position at a depth of about lOcm under the level of solution with heating to 80C for 2 hours.
After that, the treated fibers were well washed with water and dried in air to obtain fibers having a zirconium oxide coating deposited thereon.
The ability of the zirconium oxide coating deposited by the solutions A, B and C of this invention to resist cor~osion is shown by the results of the following cement alkali corrosion test. In this test,a cement alkali solution having a '1(~36~3G
pH value of from 12 to 14 was prepared in such a manner that a suspension of l.OI~g of Portland cement in 3.5 liters of water is allowed to stand for 24 hours and then the supernatant fluid was filtrated. The coatéd portions of the glass fibers were immersed again in the cement alkali solution in a vertical position at a depth of about lOcm under the level of solution in a stainless steel beaker heated in boiling water for 2.5 hours. Each of the twenty glass fibers were cut off in a length of lOcm from the opposite ends to obtain two tensile test lq segments, one of which had not been treated with the aqueous solution of the invention as well as the cement alkali solution, and the other of which had been surface-treated with the aqueous solution of the invention and then -treated with the cement alkali solution. Using these forty test segments per specimen for each aqueous treating solution, the load W in gram required to break the fiber segment and the diameter D in millimeter of the fiber at the break point were measured and recorded in the following Table I. The Table I also gives the tensile strength E in I~g/mm2 which is defined by the ollowing equation:

E = _ 4W
~D2 10-3 The cement-alkali corrosion resistance improvement F may be estimated by the following formula:

F C-B
B
(wherein B represents the tensile strength of the untreated fiber and C represents the tensile strength of the treated fiber.) The results of the cement-alkali corrosion test, summarized in Table I, indicate that the aqueous zirconium salt solutions A, B and C of the invention enhance the alkali corrosion resisting property of soda-lime glass fibers.

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Example II: ~36~36 Using an aqueous titanium chloride solution Dl, two soda-lime glass fiber specimens prepared by cutting a bundle of twenty glass fibers having diameters ranging from 14 microns to 26 microns and a length of lOOcm into two equal length parts were surface-treated at 90C for 2 hours by being immersed in a vertical position at a depth of lOcm under the level of solution.
me surface-treated glass fiber specimens were washed with water and dried in air. Each of the twenty glass fibers of one of the 10~ specimens was cut off in a length of lOcm from the opposite ends to obtain twenty surface-treated glass fiber segments and twenty untreated glass fiber segments. Using these segments, the tensile tests were carried out in the manner described with respect to Example I. Average values are given in Table IIa.
Next, the surface-treated portions of the twenty glass fibers of the other specimen were dipped in a vertical position at a depth of lOcm under the level of the cement-alkali solution oE Example I heated to 90C for 2.5 hours. Then the treated glass fibers were removed from the solution and washed with water.
After dried in a desiccator for 24 hours, each of the twenty glass fibers was cut off in a length of lOcm from the opposite ends to obtain two segments, one of which had been treated with the aqueous solution as well as the cement alkali solution, and the other had not been treated with the both solutions.
Using these segments, the tensile tests were carried out in the manner described with respect to Example 1. Average values are given in Table IIb. me results of the surface treatment and cement-alkali corrosion test, summarized in Tables IIa and IIB indicate that a hydrous titanium oxide coating is effective to enhance the cement alkali corrosion resisting property of the glass fibers.

~1~36~3~
Using solutions D2, El and E2, the same surface txeatment and cement alkali corrosion test as above were carried out~ The results are summarized in Tables IIa and IIb.
Table IIa Befoxe Corrosion Test - - L d Tensile FiberInitial Final oa Streny2h diameter g (Kg/mm ) (~) Soln, pH _ _ Blank Treated Blank Treated Blank Treateo D1 1.04 1.41 22.86 24.19 63.78 67.85 21.19 21.23 D2 0.69 0.69 20.52 21.09 68.70 70.22 19.68 19.87 ; ~ 0.38 0.39 25.96 32.03 81.09 100.18 20.14 20.10 El 1.12 1.10 19.20 22.68 59.31 75.09 19.82 19.54 E2 0.89 0.80 19.78 25.34 61.24 72.44 20.53 20.59 E3 0.39 0.39 27.28 28.08 84.22 88.53 20.31 20.18 Table IIb After Corrosion Test . _ .. ~
Tensile strength Fiber Solution Load (g) _ (Kg/mm2) Diameter (~) Blanlc Treated Blank Treated Blank Treated . ..
Dl 20.02 25.68 59.76 76.65 20.69 20.55 D2 25.52- 33.64 70.44 90.82 21.49 21.73 D3 27.52 28.14 86.59 88.48 20.05 20.19 El 20.26 21.16 61.41 64.57 20.15 20.26 E2 22.37 26.13 66074 79.87 20.63 20.36 ~3 23.89 28.28 83.42 92.44 19.10 19.70 . . _ lQ36~3~
Example III
Using a series of aqueous treating solutions F, soda-lime glass fibers were surface -treated and subjected to the cement alkali corrosion test in the manner described with respect to Example II. The results, surnmarized in Table III, indicate that the hydrous hafnium oxide coatings deposited by the aqueous solutions F of this inven-tion are effective to enhance the cement-alkali corrosion resisting property of soda-lime glass fibers provided therewith.
Table IIIa Before Corrosion Test : Soln Initial Pinal Load (g) Tensile Fiber diam~ter . pH pH _ _ _ _ (I~g/mm2) (~ ) Blank Treated Blank Treated Blank Treated . . .
Fl2.17 1.84 26.91 31.69 66.17 76.73 22.&3 23.06 F21.79 1.60 18.48 20.60 61.15 68.43 19.69 19.59 F30.88 0.71 30.15 39.52 85.04 110.30 21.26 21.36 .__ .~ . ~ ' Table IIIb After Corrosion Test _ . . .. _ .__ .
Load (g) Tensile strength Fiber diameter Soln. (Kg/mm2) (~ ) - ~a~~~ ~ Blank Treated Blank Treated Fl 21.57 26.13 61.37 77.50 21.16 20.74 F2 22.59 25.49 66.64 74.99 20.61 20.71 F3 28.77 31 D 38 92.46 98.08 19.88 20.11 . ........... . _ . .. ..
Example IV.
Using a series of aqueous treating solutions F, glass fibers containing 8% by weight of zirconia were surface treated and subjected to -the cement alkali corrosion tes-t in the manner described with respect to Example II. The results, summarized in Table IV, indicate that the hydrous hafnium oxide coatings deposited by the aqueous solutions F of thls invention are effective to enhance the cement-alkali corrosion resisting property of zirconia containing glass fibers provided therewith.
Table IVa Before Corrosion Test ~ ............. _ .. __ Initial Final Load (g) Tensile Fiber diameter Soln. P~ pH Blank Treated (Kq/mm2) Blank Treated . _ _.
Fl 2.17 2,40 18.08 27.71 66.61 95.42, 18.56 19.16 10F2 1.79 1.60 19.45 35.32 61.75 115.74 19.74 19.99 ¦F3 ¦0.88 10.84 119 42 35.85 ¦ 69.76 125.68 11I 88 19.07 Table IVb After Corrosion Test . _ . ..

Soln~ Load (g) Tensile Fiber diameter _ Blank Treated Blank Treated Blank Treated Fl 18.67 28.34 67.36 98.96 18.77 18.98 F2 21.03 37.42 69.96 128.46 19.25 19.64 20 F3 23.12 26.57 72,63 81.48 19.99 20.22 . _ . _ ...
Example V
Using two series of aqueous treating solutions D and E, zirconia containing glass fibers were surface treated and subjected to the cement alkali corrosion test in the manner described with respect to Example II. The results, summarized in Table V, indicate that the hydrous titanium oxide coatings deposited by the aqueous solutions D and E of this invention are effective to enhance the cement alkali corrosion resisting property of zirconia containing glass fibers provided therewith.

1(~36~36 Table Va Before Corrosion Test __ Tensile Fiber diameter Initial Final Load (g) Strength Soln. pH p~I Blank Treated (KCJ-/-mm2) _ Blank Treated . .. , __ .
Dl 1.22 0.50 21.79 38.30 69.01 127.87 18.92 19.44 D2 0.69 0.37 24.89 31.49 87.57 106.56 19.00 19.44 D3 0.33 0.38 23.87 35.70 71~22 106.28 20.57 20.79 i . . _ El 1.12 1.08 21.51 25.82 78.92 97.60 18.52 18.26 E2 0.89 0.80 20.65 29.88 76.44 109.00 18.53 18.81 E3 0.38 0.38 21.53 30.50 71.63 99.28 19.71 19.72 Table Vb After Corrosion Test Tensile strength F~
Load (g) (Kg/mm2) (~l) Solu-tion __ .
Blank Treated Blank Treated Blank Treated _,_ - - . _ . . .. _ Dl 19.77 28.5874.35 107.45 18.51 18.61 D2 19.36 25.2667.79 88.03 19.06 19.10 D3 25.37 35.0980.19 112.14 19.97 20.04 __ . ~ __ .
El 18.47 23,4968.60 82.14 18.45 18.67 E2 24.14 25.3681.63 118.64 19.37 19.61 E3 26.64 30.0584.57 95.87 19.97 20.02 Example VI
Using a series of aqueous treatiny solutions G, soda-lime glass fibers were surface treated and subjected to the cement alkali corrosion test in the manner described with respect to Example II. The results, summarized in Table VI, indicate that the zirconium and hafnium oxide coatings deposited by the aqueous solutions G of this invention are effective to enhance the cement ~(~36~36 alkali corrosion resisting property of soda lime glass fibers resisting property of soda lime glass fibers provided therewith.

Table VIa Before Corrosion Test _ _ . _ .
Tensile Initial Final Load (g) Streng-th F'iber diameter Soln. (I~g/mm2) ( ~) ___ __ _ _ . _ __ .__ _ . ._ _ ~ pH pH Blank Treated Blank Treated Blank Treated ~ ._ .. _ .......... ._ _ . . .__ Gl 0.81 0.80 18.31 29.33 59.16 96.47 19.73 19.71 G2 0.83 0.80 17.80 22.26 58.87 80.12 19.64 19.38 G3 0.90 0.75 18.30 26.23 50.27 73.75 21.49 21.40 G4 0.93 0.86 15.04 20.67 55.40 75.59 18.67 18.66 G5 0.92 0.89 24.62 2 ~ 66.78 74.42 21.74 21.44 .

Table VIb After Corrosion Test . . ., Tenslle L Strength Fiber diameter Solution oad (g) (I~a/mm2) (~ ) . . ~_ . . _ .
Blank Treated Blank Treated Blank Treated . , ........ .. _ Gl 23.18 26.69 63.94 71.54 21.44 21.49 G2 16.23 22.43 53.73 73.27 19.80 19.75 G3 20.75 33.33 53.46 88.20 22.13 21.92 G4 22.86 25.96 59.22 69.99 22.09 21.66 G5 21.70 32.03 55.75 81.92 22.39 22.34 Example VII
Using a series of aqueous treating solutions G, glass fibers containing 10% by weight of zirconia were surface treated and subjected to the cement alkali corrosion test in the manner described with respect to Example II. The results, summarized in 3~ Table VII, indicate that the hydrous zirconium and hafnium oxide coatings deposited by the aaueous solutions G of this invention are effective to enhance the cement alkali corrosion resisting property of zirconia containing glass fibers provided therewith.

` `` 1~36~36 Table VIIa Before Corrosion Test - Initlal Final Load (g) Tensile Fiber Soln. . s~gn~mh/2) diameter (~) P~ p~ Blank Treated Blank Treated Blank Treated . . ..... _ Gl 0.81 0.80 25.00 28.41 78.21 84.09 20.02 20.48 : G2 0.83 0.84 26.60 31.70 83.32 108.92 20.12 19.89 G3 0.90 0.87 20.97 27.51 73.07 97.50 18.57 19.00 G4 0.93 0,72 20.48 30.04 76.17 111.59 18.57 18.43 G5 0.95 0.81 25.24 27.53 90,46 101.57 18.82 18.61 Table VIIb After Corrosion Test Tensile S-trength Fiber Diameter Load (g) (I~g/mm2) (~) Solution _ Blank Treated Blank Treated Blank Treated ._ Gl 27.33 27.73 82.73 86.28 20.46 20.23 G2 25.06 30.91 85.94 100.35 19.35 19.78 G3 17.34 25.13 68.37 98.23 17.99 18.17 G4 20.31 30.51 72.62 ~0.18 18.76 18.74 _ _17.82 29.80 6a.30 109.63 18.24 18.71 Example VIII
Using a series of aqueous treating solutions H, glass fibers containing 7% by weight of zirconia were surface treated and subjected to the cement alkali corrosion test in the manner described with respect to Example II. The results, summarized in Table VIII, indicate that the hydrous titanium and zirconium oxide coatings deposited by the aqueous solutions H of this invention are effective to enhance the cement alkali corrosion resisting property of æirconia containing glass fibers provided therewith.

1(~36~3~i Table VIIIa Before Corrosion Test ¦ ~Initial ~i~aI Load (g) ¦ Tensile Fiber , oln. ___ _ (Kg/mm2) ~pH pH Blank Treated Blank Treated Blank Treated . _ .. .. .. _ .. _ . _ : 1 0.75 0.66 26.26 26.63 88.16 127.61 19.57 19.16

2 0.68 0.74 26.27 31.94 88.98 108.97 19.23 19.23 G3 0.65 0.59 28.72 38.29 96.88 129.73 19.27 19.33 10 G4 0.61 0.50 19.89 29.82 77.41 111.63 17.94 18.00 0.57 0.40 19.08 21.94 87.66 99.46 16.35 16.81 . Table VIIIb After Corrosion Test Load (g) Tensile strength Fiber diameter Solution (I~g/mm2) (~) Blank treatëd Blank Trèated '' Blank''''Trea-ted' '''' ~' .. ___ ..... _ _ _ Hl 25.57~33.12 88.20 117.91 19.14 18.94 EI2 24.47 31.30 83.10 106.96 19.32 19.27 H3 24.46 25.65 92.62. 99.75 18.11 18.12 ¦

H4 24.31 27.78 104.05 115.59 17.27 17.34 H5 26.52 28.31. 96.31 103.98 18.88 18.72 .... ..._ .._. . .
Example IX
Using a series of aqueous treating solutions I, glass fiber scontaining 7% by weight of zirconia were surface treated and subjected to the cement alkali corrosion test in the manner described with respect of Example II. The results, summarized in Table IX, indicate that the hydrous titanium and hafnium oxide coatings deposited by the aqueous solutions I of this invention are effective to enhance the cement alkali corrosion resisting property of zirconia containing glass fibers provided therewith.

~Q36~36 Table IXa Before Corroc ion T~st Inltlal Final Tenslle Fiber , ~ Strength diameter Soln. pH pH Load ~gJ (Kg/mm2) (~) Blank Treated Blank Treated Blank Treated __ ___ Il 0.75 0.77 19.06 33.71 73.01 120.75 18.56 18.83 I2 0.68 0.49 23.44 30.32 86.51 109.68 18.50 18.79 I3 0.65 0.46 22.48 27.94 83.86 105.67 18.54 18.34 I4 0.61. 0.45 20.32 22.75 73.86 86.81 18.77 18.36 I5 0.57 0.43 20.49 30.49 71.69 100.53 19.11 19.59 _ _ . __ Table IXb After Corrosion Test _ Load (g) Tensile strength Fiber Solution . _ (Kg/mm2) diameter (~) Blank Treated Blank Treated Blank Treated .
Il 22.91 27.73 97.36 114.77 17.47 17.66 I2 23.07 29.94 79.51 104.48 19.21 19.33 I3 23.64 27.68 88.33 106.29 18.59 18.41 . I4 26.05 35.76 93.72 121.89 18.90 19.25 IS 3~.06 38.14 114.00 133.82 19.51 19.07 --Example X
Using a series of aqueous treating solutions H, soda-lime glass fibers were surface treated and subjected'to the cement alkali corrosion test in the manner described with respect to Example II. The result~, summarized in Table X, indicate that the hydrous tltanium and zirconium oxide coatings deposited by the aqueous solutions H of this invention are e~fective to enhance the cement alkali corrosion resisting property of soda-lime glass fibers provided therewith.

Table Xa Before Corrosion Test _ _ . ................ . . ~
Tens1le Fiber Initial Final Load (g) Strength Diameter ; Soln. pH pH .. (Kg/mm2) (~) --1 .__ . _ Blank Treated Blank Treated Blank Treated _ ~ _ . .. _ _ , __ Hl 0.73 0.69 22.12 24.59 65.55 74.06 20.80 20.50 H2 7.71 0.79 20.72 21.19 62.73. 62.60 20,66 20.76 H3 0.68 0.51 24.75 29.03 62.77 74.61 22.45 22.22 H4 0.60 0.40 20.34 24.36 62.66 75.16 20.42 20.26 HS O 50 0 45 30.74 36.84 78.88 92.90 22.24 22.52 Table Xb After Corrosion Test _ Tensile Fiber Diameter Load (g) Strength (~) Solution (K~/mm2) .. . Blank Treated Blank Treated Blank Treated ._. _ Hl 22.74 25.91 64.45 70.66 21.36 21.38 20 H2 19.69 20.72 64.71 66.80 19.35 19.70 H3 22.62 24.66 68.08 75.52 20.59 20.38 H4 21.02 24.81 56.21 68.53 21.71 21.60 . 16.95 24.83 61.34 85.39 18.76 19.22 __ Example XI
Using a series of aqueous treating solutions I, soda-lime glass fibers were surface treated and subjected to the cement alkali corrosion test in the manner described with respect to Example II. The results, summarized in Table XI, indicate that the hydrous titanium and hafnium oxide coatings deposited by the aqueous treating solutions H of this invention are effective to enhance the cement alkali corrosion resistIng property of soda-lime glass fibers provided therewith.

~LQ36436 Table XIa Before Corrosion Test _ Tensile Fiber Initial Final Load (g) Strength diameter . Soln l (Kg/mm2) (~) pH pH Blank Treated Blank Treated Blank Treated _ .. . .
Il 0.77 0.77 28.69 34.23 74.53 86.85 22.18 22.37 I2 0.68 0.49 23.34 25.83 60.62 66.82 22.18 21.89 I3 0.61 0.46 19.30. 20.44 55.73 59.13 20.82 20.99 I4 0.60 0.~5 16.24 21.02 50.95 71.02 19.93 19.55 I5 0.57 0.43 27.82 36.50 70.93 95~4 22.45 22.21 Table XIb After Corrosion Test . ............. ..

Solution Load ~g) Tensile s2trength Fiber diameter Blank Treated Blank Treated Blank Treated __ . . _ .
Il24.73 27.34 60.99 68.05 22.66 22.61 I218.39 23.18 60.00 73~79 19.81 20.03 I321~58 25.27 65.54 77.57 20.42 20.50 I424.85 28.78 64.14 78.95 22.03 21.69 I518.33 30.59 50.56 85.42 21.40 21.30 ... .. _. ... __ Example XII
Using a series of aqueous treating solutions J, soda-lime glass fibérs were surface treated and subjected to the cement alkali corrosion test in the manner described with respect to Example II. The results~ summarized in Table XII, indicate that the phosphate coatings deposited by the aqueous treating solutions J of this invention are effective to enhance the cement alkali corrosion resisting property of soda-lime glass fibers provided therewith.

1~36~;~6 TableXIIa Before Corrosion Test . . _ . . _ _ .................. . . _ . _ __ Initial Final Load (g) Tensile Fiber Soln. (Kg/mm2) diameter pH pH _ _ _ _ Blank Treated Blank Treated Blank Treate~

.' . _ _, Jl 2.31 2.31 19.84 22.20 64.35 83.65 19.88 19.73 J2 1.79 1.78 24.58 29.56 56.99 70.65 23.35 23.44 J3 1.62 1.58 27.32 28.08 74.13 74.98 21.69 21.96 J4 1.41 1.30 23.74 26.44 57.16 62.74 23.20 23.18 '~ J5 1 29 1.19 20.79 22.32 66.00 69.34 20.12 20.52 -Table XIIb After Corrosion Test _ _ _ Load (g) Tensile strength¦ Fiber So~ution (Kg/mm2) diameter (~) . ~
Blank Treated Blank Treated Blank Treated Jl 20.35 26.18 55.00 70.63 21.66 21.57 J2 19.54 27.30 51.01 71.79 21.89 21.82 J3 25.53 34.10 60.35 80.89 23.07 23.23 J4 23.64 27.31 53.06 64.64 23.80 23.27 _~ 27.17 30.03 69.54 78.91 21.31 21.91 Example XIII
Using a series of aqueous treating solutions J, glass fibers containing 7% by weight of zirconia were surface treated and subjected to the cement alkali corrosion test in the manner described with respect to Example II.~ The results, summarized in Table XIII, indicate that the phosphate coatings deposited by the aqueous solutions J of this invention are effective to enhance the cement alkali corrosion resisting property of zirconia contain-ing glass fibers provided therewith.

l~J36~36 Table XIIIa Before Corrosion Test _ . __ _ Soln. Initial Final Load (g) strength diameter P~ pH (Kg/mm2) (~) _ _ Blank Treated Blank Treated Blank Treated J3 1.63 1.58 22.29 26.10 81.36 94.57 18.61 18.67 J4 1.41 1.32 23.21 24.05 93.71 95.60 17.78 17.86 J5 1.29 1.20 21.76 25.05 85.51 97.41 17.89 18.18 J6 0.99 0.99 23.29 41.66 72.85 129.98 20.24 20.24 J7 0.89 0.89 24.72 29.08 83 25 98.55 19.42 19.37 Table XIIIb After Corrosion Test _ .

Solution Load (g) Tensi e Strength Fiber diameter Blank Treated Blank Treated Blank Treated . _ ~
J3 22.21 25.8090.14 102.66 17.74 17.94 J4 20.17 25.5681.53 98.07 17.80 18.04 J5 16.87 27.4767.11 113.80 18.07 17.64 J6 19.29 28.9663.33 97.27 19.65 19.52 J7 26.09 27.0484.60 84.30 19.89 20.27 .

Claims (22)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:-

1. In a method for reinforcing aqueous hydraulic cement wherein glass fibers are incorporated into the cement, the improvement which comprises applying to the glass fibers an aqueous solution of at least one compound selected from the group consisting of phosphorus-oxy acids, alkali metal salts of phosphorus-oxy acids, zirconium salts, titanium salts, and hafnium salts to form a deposit on said fibers effective to inhibit alkali-corrosion of the fibers prior to incorporating the fibers in the cement.

2. A method according to claim 1, wherein said fibers are immersed in said solution at a temperature of 80 to 95°C.

3. A method according to claim 1 or 2, wherein said glass fibers contain zirconia.

4. In a method for reinforcing aqueous hydraulic cement wherein glass fibers are incorporated into the cement, the improvement which comprises immersing said glass fibers in an aqueous solution of a zirconium salt and forming a deposit of zirconium oxide on said fibers prior to incorporating the fibers in the cement.

5. In a method for reinforcing aqueous hydraulic cement wherein glass fibers are incorporated into the cement, the improvement which comprises immersing said glass fibers in an aqueous solution of a titanium salt and forming a deposit of titanium oxide on said fiber prior to incorporating the fibers in the cement.

6. In a method for reinforcing aqueous hydraulic cement wherein glass fibers are incorporated into the cement, the improvement which comprises immersing said glass fibers in an aqueous solution of a hafnium salt and forming a deposit of hafnium oxide on said fibers prior to incorporating the fibers in the cement.

7. A method according to claim 4, 5 or 6, wherein said oxide deposit is formed at a temperature of 80 to 95°C.

8. A method according to claim 4, 5 or 6, wherein said glass fibers contain zirconia and said fibers are immersed in said solution at a temperature of 80 to 95°C.

9. In a method for reinforcing aqueous hydraulic cement wherein glass fibers are incorporated into the cement, the improvement which comprises immersing said glass fibers in an aqueous mixed solution of salts of at least two metals selected from the group consisting of zirconium, titanium and hafnium, and forming a deposit of oxides of said at least two metals on said fibers prior to incorporating the fibers in the cement.

10. A method according to claim 9, wherein said solution is a mixed solution of a zirconium salt and a hafnium salt.

11. A method according to claim 9, wherein said solution is a mixed solution of a titanium salt and a zirconium salt.

12. A method according to claim 9, wherein said solution is a mixed solution of a titanium salt and a hafnium salt.

13. A method according to claim 10, 11 or 12, wherein said oxide deposit is formed at a temperature of 80 to 95°C.

14. A method according to claim 10, 11 or 12 wherein said glass fibers contain zirconia and said fibers are immersed in said solution at a temperature of 80 to 95°C.

15. In a method for reinforcing aqueous hydraulic cement wherein glass fibers are incorporated into the cement, the improvement which comprises immersing said glass fibers in an aqueous solution of a phosphorus-oxy acid or an alkali metal salt thereof at a temperature from 80 to 95°C prior to incor-porating the fibers in the cement.

16. A method according to claim 15, wherein said fibers contain zirconia.

17. A method according to claim 15 or 16, wherein said solution comprises an acid selected from the group consisting of phosphoric acid, metaphosphoric acid and pyrophosphoric acid.

18. A hardened hydraulic cement reinforced with glass fibers, said fibers having an alkali-corrosion inhibiting deposit thereon of at least one material selected from the group consisting of a phosphorus-oxy acid, an alkali metal salt of a phosphorus-oxy acid, zirconium oxide, titanium oxide and hafnium oxide.

19. A hardened cement according to claim 18, wherein said deposit comprises at least one metal oxide selected from the group consisting of zirconium oxide, titanium oxide and hafnium oxide.

20. A hardened cement according to claim 18, wherein said deposit comprises two metal oxides selected from the group consisting of zirconium oxide, titanium oxide and hafnium oxide.

21. A hardened cement according to claim 18, wherein said deposit comprises at least one phosphorus-oxy acid selected from the group consisting of phosphoric acid, meta-phosphoric acid and pyrophosphoric acid.

22. A hardened cement according to claim 19, 20 or 21 wherein said glass fibers contain zirconia.