HK1143569A - Thermally resistant fiber glass - Google Patents

Description

Heat-resistant glass fiber

The quality of the glass and glass fibers used to reinforce the composite material is important to the strength of the composite material (e.g., high-tech sandwich components, GFK). Glass fibers vary greatly in their physicochemical properties. Only glass fibers with excellent physicochemical properties are used for the demanding composite materials. The chemical composition of these glass fibers is shown in table 1.

Table 1: composition of glass fibers.

E-glass (E ═ electricity: (a)Elecric)) is an aluminoborosilicate glass with a low content of alkali metal oxides (< 2 mass%) and with good electrical insulating properties.

E-glass fibers are particularly suitable for producing printed circuits and for reinforcing plastics. The heat resistance (defined as the transition temperature) of E-glass is not satisfactory, being less than 680 ℃.

A big disadvantage of E-glass is the low acid resistance (class 4 acid resistance). These E-glasses are described in particular in patents US 3876481, US 3847627, US 2334961, US 2571074, US 4026715, US 3929497, US 5702498, EP 0761619 a1, US 4199364 and US 3095311.

R-glass (R ═ resistance:)Resistance)) is an alkaline earth (Erdalkali) aluminosilicate glass. The transition temperature and softening point of this glass are about 730 ℃ and about 950 ℃, respectively. Similar glasses, such as "Supremax" -glass, can be used as thermometer glasses due to their low coefficient of expansion.

R-glass fibers are used in applications where mechanical and thermal requirements are high. R-glass fibers have a relatively high tensile strength even at elevated temperatures.

ECR glass (ECR ═ corrosion-resistant E-glass (E: (a) corrosion-resistant glass: (b))E-Glass Corrosion ROisstant)) is a boron-free alumino-calcia silicate glass (alumino-kalsilikatglas) with a low content of alkali metal oxides, such a glass being described for example in DE 69607614T 2. ECR-glass fiber has high acid resistance and good mechanical propertyMechanical and electrical properties.

It is used for the reinforcement of high-demand plastics.

As described in US 5789329The glass is a modified ECR glass, has a very low content of alkali metal oxides and has improved physicochemical properties. This type of fiber has a long-term temperature resistance of about 740 ℃.

S-glass (S ═ strength: (S:)Strength)) is a magnesium aluminum silicate glass. This is a special glass developed for high mechanical demands, in particular at elevated temperatures (WO 02/042233A 3), whose Al content is greater than that of the glass₂O₃The content is more than 10Mol percent. Further high temperature glasses are described in US 2571074, US 3847627 and US 4542106.

Table 2 shows a comparison of the properties of the best type of glass fibers with E-glass.

Table 2: characteristics of the selected glass fiber

As shown in table 2, the S-glass fibers have comparatively best mechanical properties. The chemical resistance and heat resistance of these fibers are also very good.

The conventional S-glass is a magnesium aluminum silicate glass, a special glass developed for high mechanical demands, in particular at elevated temperatures.

Such MgO-Al₂O₃-SiO₂Ternary system glasses, although easily vitrified, solidify, have a tendency to crystallize and phase separate during subsequent heat treatment.

When S-glass is subjected to temperature, MgO and Al are precipitated₂O₃The silicate glass liquid droplet phase of (a) and (b) crystallizes. This is a major disadvantage of conventional S-glass and products made therefrom.

In addition, MgO-Al₂O₃-SiO₂It is also possible in particular to crystallize mullite 3Al in the ternary system₂O₃·2SiO₂Forsterite 2 MgO. SiO₂Spinel MgO-Al₂O₃Cordierite 2 MgO.2Al₂O₃·5SiO₂And periclase MgO.

The phase separation and crystallization process can lead to substantial reduction in fiber strength, embrittlement, and fiber breakage (transverse fragmentation). The temperature alternation resistance of S-glass fibers is also unsatisfactory. Another great disadvantage of S-glass fibers is the relatively high price. In addition, this fiber type is only suitable for a few fields.

Another type of fiber used for high-demand plastic reinforcement is made of boron-freeGlass fibers made of glass.

Glass fibers, although having lower strength than S-glass and lower heat resistance, have a comparatively very small tendency to crystallize.

To produce glass fibers, glass according to a predetermined batch composition is melted in a furnace. The glass melt is supplied to the discharge opening (Bushing) via an outlet and feed channel (Feeder).

The discharge openings, which are usually made of noble metal alloys (mostly Pt/Rh alloys), are fiber-forming units (zerfaseungseinheit), in which the actual spinning process takes place. The discharge opening has a plurality of nozzles (Tips) from which the filaments are drawn and, if possible, bundled.

The quality of the glass melt is critical to the spinning process. Only a completely homogeneous melt without glass production defects is allowed to be processed during the drawing process. The presence of stones, gypsum in the melt is particularly detrimental to the spinning process or completely hinders the spinning process because of the high amount of yarn hot brittle fracture that occurs.

The spinning process can only be performed within a certain temperature range, i.e. between the so-called upper and lower temperature limits, and the optimum stability of the spinning process is reached when log η ≈ 3.0 (unit of η: dPas). At the lower temperature limit of the drawing process, the mass flow in the nozzle decreases with increasing viscosity. The tension in the drawing bulb (Ziehzwiebel) increases dramatically due to the high tensile forces. Due to the high tensile stress during drawing at the lower temperature limit, some distortion and network defects will be "frozen" into the filaments. This leads in particular to a severe reduction in the fibre strength and to a hindrance of the spinning process. The high draw force of the high viscosity glass melt and the melt liquid pressure in the tap hole may cause the nozzle bottom to deform. In the process of drawing at the lower temperature limit, the duration of the process of restarting spinning after thermal embrittlement is long, which is not favorable for the production efficiency of glass fibers.

When the spinning process is carried out at the upper temperature limit, the nozzle edge (the end face of the nozzle) is heavily wetted. This produces a "dead zone" of flow in the drawing bulb, in which the glass melt has a relatively long residence time, and there is the risk of nucleation. As the temperature increases during drawing, the drawing ball will become larger and the cooling time will become longer. And thus is susceptible to dust, water vapor and reactive gases. This leads in particular to a reduction in strength, in particular if the spinning process is carried out under conditions of very high air humidity.

Drawing at or above the upper temperature limit can destabilize the spinning process. Any minor disturbances (e.g., vibration or oscillation) on the drawing drum (ziehtortromel) typically cause vibrations in the drawing bulb, which can cause rapid thermal embrittlement of the fibers. The improvement of the surface tension of the glass has a stabilizing effect on the spinning process. The drawing speed can be increased compared to glass having a lower surface tension. The surface tension of the glass melt can also be influenced by changing the glass composition.

Fiber cooling is particularly important in the glass fiber production industry. The drawn glass fiber must be cooled from the spinning temperature to below the glass transition temperature at an extremely rapid rate over a distance of about 30 mm. The cooling rate is for example about 200 deg.c/cm (20000 deg.c/m) or about 1000 deg.c/ms. The faster and stronger the cooling rate, the more likely it is to "freeze" the glass state, and the better the mechanical properties of the glass fiber will be. In addition, the drawn glass fibers must be intensively cooled in the region of the drawing bulb and below the drawing bulb by means of Cooling combs (Cooling fingers) or by means of Cooling tubes (Cooling Tube). In order to intensify the cooling process of the glass fibers, for example, a water nozzle may be additionally installed below the discharge hole. The water sprayed on the glass filaments not only has a cooling effect, but also reduces the static electricity on the fibers in particular.

In the indirect melt process, a spinning aid (e.g., a diol or polyglycol) is typically used. The gas-phase spinning aid is introduced into the drawing ball and the fiber-forming zone. The spinning aid, in addition to cooling the fibers, also increases the surface tension on the drawing bulb, prevents or greatly reduces the static charge of the glass filaments, and forms a first protection of the surface of the initial glass fiber.

Insufficient and/or uneven fiber cooling can affect the discharge orifice runnability and the quality of the drawn glass fibers.

The aim of the invention is to develop and to provide the market with novel textile glass fibers which not only do not have the disadvantages of the known textile fibers, but also have excellent thermal stability. The novel fibers do not have a strong tendency to crystallize adversely to mechanical properties even when subjected to a temperature action for a long period of time. The glass fiber production costs should be significantly reduced compared to similar fiber types without negatively impacting the glass physicochemical properties.

In addition, the use of the novel fibers should increase the efficiency of production as glass fibers for industrial mass production.

It is also an object of the present invention to develop a composite material which not only has excellent physicochemical properties, but also contributes to significantly improving the mechanical properties of a composite material comprising such novel fibers. The glass fibers should not only have a low density, but also have a high tensile strength and elongation. These novel fibers should have excellent resistance to temperature cycling and low bending sensitivity.

The heat resistance of the glass filaments should in particular be greater than about 750 ℃.

The glass used to produce the fibers should have the following chemical resistance:

hydrolysis resistance grade 1 (< 0.1 cm)³0.01N HCl)

Acid resistance grade 1 (< 0.7 mg/dm)²)

Alkali resistance of grade 2 (< 175 mg/dm)²)。

This object is achieved according to the invention by the features of claim 1.

The dependent claims 2 to 8 are advantageous embodiments of the heat-resistant glass fiber according to the invention, but are not limited thereto.

According to the invention, the glass used for the heat-resistant glass fibers is particularly required to have the following properties:

high chemical resistance:

hydrolysis resistance grade 1 (< 0.1 cm)³0.01N HCl)

Acid resistance level 1 (< 0.7 mg/dm)²)

Alkali resistance is less than or equal to grade 2 (< 175 mg/dm)²)。

Heat resistance, temperature resistance in particular > 750 ℃,

low loss of tensile strength, in particular < 50%, when left at temperatures in particular > 750 ℃ for at least 24 hours,

good dielectric properties, i.e. a dielectric constant at 1MHz of up to 6.5,

high resistance to temperature reversal, i.e. at least no transverse fragmentation of the 10 μm fibres when quenched from 300 ℃ to room temperature.

After a number of experiments and tests, it has surprisingly been found that: the desired glass fiber properties can be achieved if the glass fibers are produced from glass having the following composition:

SiO₂-62.0 to 66.0 mass%

A1₂O₃-14.0 to 16.4 ″

TiO₂-0.8 to 1.2 ″

CaO-10.0 to 12.0 ″)

MgO-4.0 to 6.0 ″)

ZnO-0.8 to 1.5 ″)

Na₂O+K₂O+Li₂O-0.2 to 0.6 ″)

CeO₂-0.2 to 0.5 ″

TeO₂+HfO₂+La₂O₃-less than 0.5 ″)

In the case of this glass composition, the physicochemical properties of the glass fiber are quite outstanding.

According to a preferred embodiment of the glass according to the invention, the glass has the following composition:

SiO₂-64.6% by mass

Al₂O₃ - 16.0″

TiO₂ - 1.0 ″

Fe₂O₃ - 0.1 ″

CaO - 11.2″

MgO - 4.8 ″

ZnO - 1.2 ″

Na₂O+K₂O+Li₂O - 0.5 ″

CeO₂ - 0.3 ″

TeO₂+HfO₂+La₂OA₃ - 0.3 ″

The object of the invention is furthermore achieved by a method for sizing heat-resistant glass fibres having the features of claim 9.

The dependent claims 10 to 12 give advantageous embodiments of the heat-resistant glass fibre according to the invention, but are not limited thereto.

The object of the invention is also achieved by a sized glass fiber having the features of claim 13.

Example 1

Glasses having the following compositions were prepared in a laboratory melting apparatus:

SiO₂-64.6% by mass

Al₂O₃ - 16.0 ″

TiO₂ - 1.0 ″

Fe₂O₃ - 0.1 ″

CaO - 11.2″

MgO - 4.8 ″

ZnO - 1.2 ″

Na₂O+K₂O+Li₂O - 0.5 ″

CeO₂ - 0.3 ″

TeO₂+HfO₂+La₂O₃ - 0.3 ″

The novel glass has a transition temperature of 770 ℃ and a softening temperature of 972 ℃. The fiberization Point (η -viscosity in dPas) defined as log η ═ 3 is approximately 1400 ℃. The spun roving fiber drawn from the melt and sized with the size of the present invention has a monofilament tensile strength of 4000 MPa.

The results of the research carried out on this new type of fiber are surprising, in that the fibers made with the glass composition according to the invention have an excellent drawing behaviour compared to the well known high temperature fibers such as R-glass fibers, ECR-glass fibers, advontex-glass fibers. The fibers of the present invention have an elongation of 5%.

The fibers made of this glass must be sized with a special size (Sizing) in order to have, very prominently, particularly good physicochemical properties in resin-containing composites. Only glass fibers compatible with the polymer matrix ensure excellent physicochemical properties of the reinforced plastic (GFK).

Numerous tests have shown that if the fibres according to the invention are sized to give a roving fibre using a size consisting of the following components, these fibres and the composites produced therewith have particularly excellent mechanical properties:

a)2.0-4.0 mass% of polyvinyl acetate-ethylene copolymer

b) 0.3-0.7% by mass of polyamide amide (Polyamidoid)

c) 0.1-0.3% by mass of a polyvinyl alcohol-polyether mixture

d) 0.1-0.3% by mass of polyolefin wax

e)0.4 to 0.7 mass% of an adhesion promoter (Haftvermitler), and

f) the balance of water was added to 100 mass%.

These characteristics are in particular:

for the fibers:

tensile strength: 4000MPa

Elongation percentage: 5% (+/-0.2%)

Loss of tensile strength after 24 hours at a temperature of 600 ℃: 50 percent of

Modulus of elasticity: 84MPa

For the polyester-containing compound:

tensile strength compared to E-glass: about + 10%

After 3 days exposure in boiling water compared to E-glass: about + 6%.

The glass fibers so sized have excellent integrityElastic and of similar fibre type (e.g. R-glass orGlass) has very good tensile strength (about 4000MPa) and excellent elongation (5%). The novel fiber can ensure the warp and weft to have outstanding anti-slip property and shearability in the weaving process. Composites made with these fibers have excellent strength due to the particularly good compatibility.

For epoxy systems (epoxy matrix), the glass fibers may be sized using a size (PF1) having the following chemical composition:

slurry PF1

1.)CH₃COOH (60%) -0.25% by mass

2.) Apretan 3588 (55%) -3.00% by mass%

3.) Albosilze GL (12.5%) -1.60% by mass%

4.) Arkofil CS (20%) -1.00% by mass%

5.) Polypropylene wax PP-W (30%) -0.40% by mass

6.) A1100-0.50% by mass

7.) Water-93.25% by mass

The slurry mixing process was as follows:

method-mixing Process 100kg

1.) 60kg of water +240g of acetic acid [ CH ] was previously charged₃COOH(60％)]。

2.) use 5.0kg of deionized water +10g of [ CH ]₃COOH(60％)]0.5kg of gamma-aminopropyltriethoxysilane (A-1100) was hydrolyzed. The hydrolysis time was approximately 15 minutes.

3.) adding the hydrolysis solution A-1100.

4.) 3.0kg of vinyl acetate-ethylene copolymer [ Apretan 3588 (55%) ] was stirred with 10kg of water and added to the batch.

5.) 1.6kg of polyamide amide (Polyamidoamid) [ Albosilze GL (12.5%) ] was added to the batch.

6.) 1.0kg of polyvinyl alcohol-polyether [ Arkofil CS (20%) ] was diluted with 6.0kg of water and then added to the batch.

7.) 0.4kg of polypropylene wax dispersion PP-W (30%) was added to the batch.

8.) Add the balance water (12.25kg) +1-2g antifoam (Surfynol 440).

9.) the slurry was agitated and the pH-value was determined.

For the unsaturated polyester resin, for example, a slurry (PF 12) having the following composition can be used:

slurry PF12

1.)CH₃COOH (60%) -0.20 mass%

2.) Apretan 3588 (55%) -2.80% by mass

3.) Albosilze GL (12.5%) -2.00% by mass%

4.) Arkofil CS20 (20%) -2.00% by mass%

5.) wax Michem 42035 (35%) -0.30% by mass

6.) A174-0.50% by mass

7.) water-92.20 mass%.

The slurry mixing process was as follows:

method-mixing Process 100kg

1.) previously charged with 55kg of water +180gCH₃COOH(60％)。

2.) hydrolysis of 0.5kg of gamma-methacryloxypropyltrimethoxysilane (A174) +20g of CH with 3.5kg of hot deionized water₃COOH (60%). The hydrolysis time was about 20 minutes.

3.) add hydrolysis solution A174.

4.) 2.8kg of polyvinyl acetate-ethylene dispersion (Apretan 3588-55%) were added to the batch with stirring with 10kg of water.

5.) 2.0kg of polyvinyl alcohol polyether (Arkofil CS 20-20%) were added to the batch.

6.) 2.0kg of polyamide amide (Albosilze) were added to the batch.

7.) 0.3kg of polyolefin wax (Michem 42035) was added to the batch.

8.) Add the balance water (23.7kg) + about 1g antifoam [ Surfynol 440 ].

9.) the slurry was agitated and the pH-value was determined.

A slurry with a solids concentration of about 2.8 mass% ensures very good fibre wetting by improving the affinity to the plastic matrix and thus contributes to very good strength of the final product (composite).

Example 2

Glass having the following composition was melted in the laboratory:

SiO₂-65.0 mass%

Al₂O₃-15.6 mass%

TiO₂ - 1.0 ″

Fe₂O₃ - 0.1 ″

CaO - 11.0″

MgO - 5.0 ″

ZnO - 1.0 ″

Na₂O+K₂O+Li₂O - 0.5 ″

CeO₂ - 0.4 ″

TeO₂+HfO₂+La₂O₃-0.4 mass%.

The most important fixed point (Fix-Punkt) of the glass of the invention is as follows:

transition temperature 768 deg.C

Softening temperature 970 DEG C

The fiberization temperature (fibersingengtemperature) is 1400 ℃.

Fiberizing Point (log η ═ 3) ═ fiberizing temperature (fiberizing temperature) ═ fiberizing temperature (Zerfaseungstemperature)

The hydrolysis resistance of the glass is 0.03cm³0.01N HCl, grade 2. Acid resistance of glass (ablation rate less than 0.7 mg/dm)²) Is grade 1. Storage stability (mass loss of 102 mg/dm)²) Corresponding to level 2. The tensile strength of a filament of 10 μm diameter drawn from this glass was 3800 MPa. The elongation measured by the tensile test was 5%.

The filaments were sized using size PF 1.

Example 3

Glasses of the present invention having the following composition were prepared in a laboratory melting apparatus:

SiO₂-64.2% by mass

Al₂O₃ - 16.2″

TiO₂ - 1.0 ″

Fe₂O₃ -0.1 ″

CaO -11.6″

MgO -4.6 ″

ZnO -1.2 ″

Na₂O+K₂O+Li₂O -0.5 ″

CeO₂ -0.3 ″

TeO₂+HfO₂+La₂O₃ -0.3 ″

The glass has the following fixing points:

the transition temperature is 775 DEG C

Softening temperature of 975 DEG C

The fiberization temperature is 1390 DEG C

Such a glassHas a hydrolysis resistance of 0.05cm³0.01N HCl, class 1 (according to DIN ISO 719). Acid resistance (value less than 0.7 mg/dm)²Or the alkali precipitation amount (Alkaliabgabe) is 10. mu.g/dm²) Is grade 1. The alkali resistance determined makes it possible to assign the glass to a resistance rating of 2 (mass loss of 100 mg/dm)²)。

Glass fibers were drawn from the glass of the present invention and sized during drawing. PF12 was used as a slurry. The fiber diameter was 10 μm. The monofilament tensile strength was measured to be 4200 MPa. The elongation was 5.0%.

Claims (14)

1. Heat-resistant glass fiber, characterized in that the glass fiber comprises at least

62.0 to 66.0 mass% -SiO₂

14.0 to 16.4' -Al₂O₃

0.8 to 1.2' -TiO₂

10.0 to 12.0' -CaO

4.0 to 6.0' -MgO

0.8 to 1.5' -ZnO

0.2 to 0.6' -Na₂O+K₂O+Li₂O

0.2 to 0.5' -CeO₂

Less than 0.5' -TeO₂+HfO₂+La₂O₃

Wherein the sum of all components of the glass fiber is 100 mass%.

2. The glass fiber according to claim 1, wherein the glass fiber contains Al₂O₃Less than 16.5 Mol-%.

3. The glass fiber according to claim 1, wherein the glass fiber consists of:

64.6% by mass SiO₂

16.0 ″ -Al₂O₃

1.0 ″ -TiO₂

0.1 ″ -Fe₂O₃

11.2 ″ -CaO

4.8 ″ -MgO

1.2 ″ -ZnO

0.5 ″ -Na₂O+K₂O+Li₂O

0.3 ″ -CeO₂

0.3 ″ -TeO₂+HfO₂+La₂O₃。

4. The glass fiber according to any one of claims 1 to 3, wherein CeO₂And TeO₂+HfO₂+La₂O₃The mass ratio of (A) to (B) is 1: 1.

5. The glass fiber according to any one of claims 1 to 3, wherein ZnO and CeO₂The mass ratio of (1) to (2: 1) to (6: 1) (ZnO:)CeO₂＝2∶1～6∶1)。

6. The glass fiber according to any one of claims 1 to 5, wherein Li₂The O content is less than 0.25 mass%.

7. The glass fiber according to claim 1, wherein the glass fiber has at least the following chemical resistance:

hydrolysis resistance K1.1 (< 0.1 cm)³0.01N HCl)

Acid resistance K1.1 (< 0.7 mg/dm)²)

Alkali resistance is less than or equal to K1.2 (< 175 mg/dm)²)。

8. Glass fiber according to any of claims 1 to 6, wherein the glass fiber may be sized with an aqueous slurry having a solids content of 2.0 to 3.0 mass%, the slurry consisting of:

a)2.0-4.0 mass% of polyvinyl acetate-ethylene copolymer

b)0.3-0.7 mass% of polyamide amide

c) 0.1-0.3% by mass of a polyvinyl alcohol-polyether mixture

d) 0.1-0.3% by mass of polyolefin wax

e)0.4-0.7 mass% of an adhesion promoter, and

f) the balance of water was added to 100 mass%.

9. Method for sizing and subsequently heat treating glass fibers according to any of claims 1 to 7, characterized in that the glass fibers are sized with an aqueous size having a solids content of 2.0 to 3.0 mass%, the size consisting of:

a)2.0-4.0 mass% of polyvinyl acetate-ethylene copolymer

b)0.3-0.7 mass% of polyamide amide

c) 0.1-0.3% by mass of a polyvinyl alcohol-polyether mixture

d) 0.1-0.3% by mass of polyolefin wax

e)0.4-0.7 mass% of an adhesion promoter, and

f) the balance of water was added to 100 mass%.

10. The method according to claim 9, characterized in that the aqueous slurry is applied to the glass surface by means of a coater, in particular a godet or a pad coater, and the subsequent heat treatment is carried out in a chamber-type drying oven or a high-frequency dryer after a relaxation time of at least 24 hours.

11. The method according to claim 9, wherein the heat treatment is performed in a chamber type drying furnace or a high frequency dryer at a temperature ranging from 100 to 180 ℃.

12. The method according to any one of claims 9 to 10, wherein Loss On Ignition (LOI) after the heat treatment is 0.2 to 0.8 mass%.

13. Sized glass fibers made according to the method of any of claims 9 to 12.

14. Use of the sized glass fiber of claim 13 as a roving, yarn or plied yarn.