JPS5939386B2 - Glass fiber surface treatment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for surface treatment of glass fibers for imparting alkali resistance and the like to the glass fibers.

Recently, silicon oxide (Si) has been added to mortar, concrete, etc.
O2), calcium oxide (Cab), magnesium oxide (MgO), boron oxide (B203), sodium oxide (
Glass long fibers and short fibers containing Na20), potassium oxide (K2O), aluminum oxide (A1203), and lithium oxide (L l20 ) as main components are mixed to improve the strength and resistance of the cement formation, such as bending strength and compressive strength. Efforts are being made to improve impact resistance.

The thinner the thickness of the glass fibers, the higher the tensile strength and other strengths, and the higher the bending strength, the higher the strength of the cement. Recommended.

By the way, glass fibers having the above composition have a pH of
It has acid resistance in a wide range of acidic ranges from pH 2 to 6, but does not have alkali resistance in an alkaline range from pH 9 to 12. 20. For alkaline earth metal oxides such as MgO and Na2O. Alkali metal oxides such as L120 are Ca(OH)2. Mg(OH)2
．． NaOH.

The glass fibers are dissolved as KOH and LiOH, resulting in a disadvantage that the strength of the glass fibers, especially the tensile strength, deteriorates.

In particular, in the case of thin glass fibers with a large surface area, the surface area that comes into contact with the alkaline components of cement increases, resulting in significant deterioration.

Recently, as mentioned above, as a method of imparting alkali resistance to glass fibers that do not have alkali resistance, zirconium oxide (ZrO2) is added to conventional glass fibers using SiO2, Ca.
O2Mg02B203. 5 for Na2O, Al2O3
A method of mixing ~25% by weight has been proposed.

However, if the amount of ZrO2 mixed is less than 10% by weight, glass fibers with sufficient alkali resistance cannot be obtained.

On the other hand, when the amount of ZrO2 mixed in is 10 to 25% by weight, glass fibers with a certain degree of alkali resistance can be obtained, but it is not only extremely difficult to dissolve the raw material mixture during glass fiber production, but also Even if it is, the liquidus temperature of the molten glass increases, resulting in a significant deterioration in spinning efficiency, inability to form glass fibers efficiently, and increased equipment costs.

Therefore, when ZrO2 is mixed in an amount of 10% by weight or more, in order to eliminate the above-mentioned drawbacks, alkali metal oxides such as Na2O and Li2O may be added as a flux, or CaO2
Alkaline earth metal oxides such as MgO and BaO, and B2O
The melting point is lowered by Go and other aluminum group substances in No. 3, but when the former alkali metal oxide is added, weathering occurs in the air and in aqueous solution, and the alkali components are eluted. As a result, the strength of the glass fiber decreases, and on the other hand, when the latter alkaline earth metal oxide is added, the acid resistance decreases significantly, making it impossible to put it into practical use.

The present invention was made in order to solve the above-mentioned drawbacks, and an object of the present invention is to provide a glass fiber having excellent alkali resistance, abrasion resistance, dispersibility, weathering resistance, water resistance, acid resistance, flexibility, and bondability. With the goal.

That is, the glass fiber according to the present invention was surface-treated with a mixture of an aqueous solution containing at least one of zinc hexafluorosilicate, magnesium hexafluorosilicate, and lithium hexafluorosilicate and an emulsion of various resins to form an alkali-resistant protective coating. Thereafter, the surface is further treated with the above emulsion to form a resin coating.

The present invention will be explained in detail below.

First, zinc hexafluorosilicate (ZnSiF6), magnesium hexafluorosilicate (MgSiF6), lithium hexafluorosilicate (L l 2 S t Fa
) or a mixture thereof with 2 to 98 parts by weight of an aqueous solution of 2 to 80% by weight, preferably 10 to 30% by weight, and styrene-
Methyl acrylate copolymer, styrene-ethyl acrylate copolymer, polyvinyl acetate resin, polyvinylidene chloride resin, ethylene-vinyl acetate copolymer resin, styrene-
10 to 50 of resin such as butadiene copolymer and fluororesin
A mixture of 2 to 98 parts by weight of emulsion is prepared.

This mixture was mixed with SiO2゜Al2O3, MgO, Cab,
BaO, 20. Li2O.

Glass long fibers or short fibers with no alkali resistance made of appropriate combinations of Fe2O3, TiO2, etc., or glass long fibers or short fibers with low alkali resistance (hereinafter referred to as glass fibers) made by blending 25% by weight or less of ZrO2 with the above glass fibers. The glass fibers are surface-treated using a dipping method, spraying method, coating method, etc. to form an alkali-resistant protective coating of 20 to 50 μm on the surface of the glass fibers.

The above mixture may optionally contain alkali-resistant reinforcing inorganic compounds such as zirconium oxide and zirconium tetrachloride; plasticizers such as dioctyl phthalate and dibutyl phthalate; inorganic fillers such as calcium carbonate and silica; and pigments such as titanium oxide. ;Solvents such as benzene, xylene, toluene;
Appropriate materials such as surfactants such as cationic surfactants and nonionic surfactants can be added.

Next, the glass fibers surface-treated as described above are treated with styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, polyvinyl acetate resin, polyvinylidene resin, ethylene-vinyl acetate copolymer, and styrene-methyl acrylate copolymer. A 10 to 50% by weight emulsion of a resin such as a butadiene copolymer or a fluororesin is further surface-treated by an appropriate method such as dipping, spraying, or coating, and a 20 to 50% emulsion is applied onto the alkali-resistant protective coating. A resin coating of 30 μm is formed.

As described above, according to the surface treatment method of the present invention, a protective film having excellent alkali resistance is formed on the surface of the glass fiber, and the resin film further formed on this alkali-resistant protective film improves the protection film. is protected, the glass fibers surface-treated by the method of the present invention not only have excellent alkali resistance, but also have good abrasion resistance, dispersibility, weathering resistance, water resistance, flexibility, and bonding properties. It has characteristics such as gender.

Therefore, the glass fibers surface-treated by the method of the present invention are well dispersed in mortar, concrete, or plastic, and molded articles with homogeneous properties are formed.

In addition, glass fibers have good alkali resistance and abrasion resistance, so they can be blended into mortar, concrete, or plastic without being damaged. objects and plastic moldings are formed.

Furthermore, since it has good flexibility and bondability, a cement molded product that does not cause problems such as cracks can be formed.

Furthermore, the practical effect of forming a molded product with high strength with a small amount of fibers is also achieved.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples.

[Example 1] First, a sample having the following composition, average fineness 12.8μ, length 15
A strand of 400 twisted glass fibers of stage 0 was prepared.

SiO
A mixture of 50 parts by weight of 10% by weight Zn Si F6 aqueous solution was prepared, and the glass fibers were immersed in this mixture for 10 minutes at room temperature and dried at 120°C.

The amount of salt-containing resin adhered is approximately 30%, and the coating thickness is approximately 23μ.
Met.

Next, it was further immersed in the above emulsion for 10 minutes, and
Dry at 0°C.

The total coating thickness was 53μ.

In order to examine the alkali resistance of the glass fibers surface-treated in this manner, the following two types of tests were conducted.

■ Mortar mixing - Cement extract immersion test @ Concrete mixing - Cement extract immersion test ■ Mortar mixing - Cement extract immersion test Mortar with the following mixing ratio is kneaded using a tilting mixer.

Portland cement 320kg/m river sand5. Om
Less than 960 〃Water
128// Next, the surface-treated glass fibers were added and kneaded for 3 minutes, and then the glass fibers were taken out and washed with water and dried.

Next, a cement extract with a pH of 12.3 (mixed with 100 parts by weight of Portland cement and 200 parts by weight of water)
After 1 hour of stirring, the supernatant liquid was filtered.

) for a predetermined time at 80°C.

Thereafter, the glass fibers were taken out, washed with water and dried, and the alkali-resistant protective coating and resin coating attached with chloroform were dissolved and removed, and the tensile strength of the glass fibers was measured using an autograph.

The results are shown in Table 1. ■Concrete mixing - Cement extract immersion test Mix concrete with the following mixing ratio using a tilting mixer.

Portland cement 320kg/m' fine aggregate5.
0 mrtt or less 840//Coarse aggregate 25mtI
g lower 971 // water
179 Next, the surface-treated glass fibers were added and kneaded for 3 minutes, and then the glass fibers were taken out, washed with water, and dried.

Next, the same treatment as in (2) was carried out, and the tensile strength of the glass fibers was measured.

The results are shown in Table 2.

[Comparative example]

As a comparative example, the tests (1) and (2) in Example were conducted on glass fiber containing 25% zirconium oxide, and its tensile strength was measured.

The results are shown in Tables 1 and 2.

[Example 2] Exactly the same treatment was carried out except that a 10% by weight Mg SiFa (large aqueous salt) aqueous solution was used in place of the 10% by weight Z n S + Fa aqueous solution in Example 1. The alkali resistance was investigated.

The results are shown in Tables 3 and 4.

[Example 3] Exactly the same treatment was performed except that a 10% by weight Li5IFa (trihydrate) aqueous solution was used instead of the 10% by weight Z n S IF 6 aqueous solution in Example 1, and the same alkali resistance was investigated. did.

The results are shown in Tables 5 and 6.

As is clear from the data listed in the table above, it can be seen that the glass fibers surface-treated according to the present invention have better alkali resistance than the so-called alkali-resistant glass fiber containing zirconium oxide of the comparative example.

It was also found that the resin coating effectively protects the glass fiber surface against external forces received during mortar or concrete mixing (collision with coarse aggregate, fine aggregate, etc.). Glass fiber reinforced concrete (GR
C) It is also suitable for manufacturing products.

Claims (1)

[Claims] 1 Glass fibers were surface-treated with a mixture of an aqueous solution containing at least one of zinc hexafluorosilicate, magnesium hexafluorosilicate, and lithium hexafluorosilicate and a resin emulsion to form an alkali-resistant protective coating on the surface of the glass fibers. A method for surface treatment of glass fibers, characterized in that the surface is then treated with an emulsion of the resin to form a resin coating on the protective coating.