KR102015065B1 - Sizing composition and glass fiber using the same - Google Patents

Abstract

The present invention relates to a sizing composition for glass fibers, a glass fiber coated with the composition and a composite material comprising the same, wherein the sizing composition for glass fibers comprises an amino group-containing alkoxysilane and an azamide group and an amino group-containing alkoxysilane To a coupling agent and a film former.

Description

Sizing composition and glass fiber using same {SIZING COMPOSITION AND GLASS FIBER USING THE SAME}

The present invention relates to a sizing composition for glass fibers, a glass fiber coated with the composition and a composite material comprising the same.

Glass fiber is used in various industries because of its high strength, insulation, non-combustibility, dimensional stability, chemical resistance, etc. Especially, long fiber classified as E-glass has excellent electrical properties and weathering resistance. It is used as a strength reinforcing material for plastics using electrical insulation properties.

Glass fibers generally melt various oxides that form glass, then pull out thin filaments in the form of thin threads through bushings, coat them with a sizing composition, and then spun them into strands. After manufacturing, it is processed into various forms and applied to various fields. The sizing composition serves to focus the filament and impart desired properties to the surface.

In particular, fiberglass strands have been processed in the form of chopped strands and have been used to produce thermoplastic molded articles with the strength of thermoplastics. The thermoplastics molded article is generally obtained by obtaining a resin pellet reinforced with glass fibers through a compounding process, and then injection molding it. In the compounding process, a twin screw extruder is used because of the ease of mixing and productivity of the glass fiber and the resin, wherein a high shear stress in the extruder is applied to the glass fiber. This caused the glass fibers to break during the compounding process, resulting in the final molded article not reaching the level of strength required.

In order to solve this problem, sizing compositions having various compositions have been developed, but the conventional sizing compositions have not improved the compatibility between glass fibers and thermoplastic resins, especially polyamide resins, and mechanical properties of glass fibers to a desired level. There was a limit in improving the mechanical properties of the molded article.

The present invention is to provide a sizing composition for glass fibers that can improve the compatibility of the glass fibers with the polyamide resin and the mechanical strength of the glass fibers.

In addition, the present invention is to provide a glass fiber and a composite material comprising the same coated with the sizing composition described above.

The present invention includes a coupling agent and a film-forming agent comprising an amino group-containing alkoxysilane and an azamide group and an amino group-containing alkoxysilane, wherein the mixing ratio of the amino group-containing alkoxysilane and azamide group and amino group-containing alkoxysilane The sizing composition for glass fibers which has a weight ratio (solid content basis) of this 30: 70-70: 30 is provided.

The present invention also provides a glass fiber coated with the aforementioned sizing composition.

In addition, the present invention provides a composite material including the glass fiber and a thermoplastic resin.

The sizing composition for glass fibers of the present invention is improved adhesion to glass fibers to improve the mechanical properties of the glass fibers, as well as to improve the compatibility of the glass fibers with polyamide resin.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail. However, the present invention is not limited only to the following contents, and each component may be variously modified or optionally mixed as necessary. Therefore, it is to be understood that all changes, equivalents, and substitutes included in the spirit and scope of the present invention are included.

<Sizing Composition for Glass Fibers>

The sizing composition for glass fibers according to the present invention comprises a coupling agent and a film former comprising an amino group-containing alkoxysilane and an azamide group and an amino group-containing alkoxysilane. Hereinafter, the composition of the sizing composition for glass fibers will be described in detail.

Coupling agent

In the sizing composition of the present invention, the coupling agent binds the glass fiber and the film former, and includes an alkoxysilane containing an amino group (hereinafter referred to as 'amino group-containing alkoxysilane'), an azamide group and an amino group. Containing alkoxysilanes (hereinafter, 'azamide group and amino group-containing alkoxysilane'). Thereby, not only the bonding force between the glass fiber and the film former, but also the bonding force between the coating layer of the glass fiber formed of the sizing composition and the polyamide resin can be improved.

Azamid groups and amino group-containing alkoxysilanes have a greater number of amine groups and alkoxy groups compared to amino group-containing alkoxysilanes (eg, gamma -aminopropyltriethoxysilane). Therefore, when an amino group-containing alkoxysilane and an azamide group and an amino group-containing alkoxysilane are used as a coupling agent, the number of alkoxy groups is increased to improve the hydrogen bonding force with the glass fiber interface, and the number of amine groups is further increased. The bonding force between the glass fibers and the film former can be increased. In addition, the azamide group can improve the bonding strength and compatibility between the sizing composition and the polyamide resin, thereby improving the strength of the composite material. In addition, the residual amine groups of the azamide group and the amino group-containing alkoxysilane can form peptide bonds with the carboxyl groups present at the ends of the polyamide to enhance the application properties of the composite material.

On the other hand, when the azamide group and the amino group-containing alkoxysilane alone are used, the coating power for protecting the glass fiber is weaker than that of the amino group-containing alkoxysilane, resulting in greater damage of the glass fiber during the production of the glass fiber and the composite material. There is a problem that the impact strength is lowered.

Therefore, in the present invention, by mixing an amino group-containing alkoxysilane, an azamide group and an amino group-containing alkoxysilane, the strength of the composite material can be improved and the role as a glass fiber coating agent can be enhanced.

In the present invention, by controlling the mixing ratio of amino group-containing alkoxysilane, azamide group and amino group-containing alkoxysilane to 30: 70-70: 30 weight ratio (based on solids), the tensile strength and impact strength of the composite material are simultaneously improved. You can. When the amino group-containing alkoxysilane is used in excess, the bonding strength with the thermoplastic resin is decreased, and when the azamide group and the amino group-containing alkoxysilane is used in the excessive amount, the glass fiber coating power is lowered. The damage may be greater and lower the impact strength of the composite.

The amino group-containing alkoxysilane used in the present invention is not particularly limited as long as it is known in the art, and for example, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane (N-β- (Aminoethyl) -γ-aminopropyltrimethoxysilane), N-β- (aminoethyl) -γ-aminopropyltriethoxysilane (N -β- (aminoethyl) -γ-aminopropyltriethoxysilane, diethylenetriaminopropyltrimethoxysilane, bis- (γ-triethoxysilylpropyl) amine, N- N-phenyl-γ-aminopropyltrimethoxysilane, γ-amino-3,3-dimethylbutyltrimethoxysilane, γ-aminobutyl Such as triethoxysilane (γ-aminobutyltriethoxysilane) Mino trialkoxysilane; γ-aminopropylmethyldiethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N-β- ( Aminoethyl) -γ-aminoisobutylmethyldimethoxysilane (N-β- (aminoethyl) -γ-aminoisobutylmethyldimethoxysilane), γ-aminopropylmethyldimethoxysilane, N-β- (aminoethyl)- amino alkoxysilanes such as γ-aminopropylmethyldiethoxysilane (N-β- (Aminoethyl) -γ-aminopropylmethyldiethoxysilane) and the like, but are not limited thereto. These may be used alone or in combination of two or more thereof.

The azamide group and the amino group-containing alkoxysilane are not particularly limited as long as they are known in the art, and may be an azamide group and an amino group-containing alkoxysilane represented by the following general formula (1).

(In Formula 1,

R ¹ to R ⁵ are the same as or different from each other, and each independently an alkyl group of C ₁ -C ₅ ,

R ⁶ is a C ₃ -C ₁₀ cyclic alkyl group,

R ⁷ is an alkyl group of C ₁ -C ₄ ,

x and y are the same as or different from each other, and each independently an integer of 1 to 4,

n is an integer of 1 to 3).

For example, in Formula 1, R ¹ to R ⁵ may be an ethyl group, R ⁶ is a cyclohexyl group, R ⁷ is an ethyl group, x is 1, y is 4, n may be 3.

In the sizing composition of the present invention, the content of the coupling agent is not particularly limited, and may be, for example, in the range of 5-20% by weight, for example, in the range of 5-15% by weight, based on the total solids of the sizing composition. When the content of the coupling agent is in the above-described range, it is possible to improve the mechanical strength of the final composite material by improving the adhesion with the glass fiber without lowering the compatibility with the polyamide resin.

Film former

In the sizing composition of the present invention, the film former serves to strengthen the focusing between the glass fibers. The film former may comprise polyurethane. Since the polyurethane is structurally similar to the polyamide resin, not only the focusability between the glass fibers, but also the compatibility between the polyamide resin and the glass fibers can be improved.

The polyurethanes can be prepared by methods known in the art, such as addition polymerization reactions between isocyanates containing at least one isocyanate group (-NCO) and an alcohol containing at least one hydroxyl group (-OH).

As said polyurethane, the polyurethane manufactured by reaction of diisocyanate and a polyol can be used. These may be used alone or in combination of two or more thereof.

As the diisocyanate, aliphatic diisocyanate or aromatic diisocyanate may be used. In particular, when aliphatic diisocyanate is used, it is advantageous to improve the strength and dimensional stability of the glass fiber and to improve the discoloration resistance of the composite material.

The aliphatic diisocyanate may be used without particular limitation as long as it is known in the art. Non-limiting examples include dicyclohexylmethane 4,4-diisocyanate (H12MDI), 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (isophorone) diisocyanate, IPDI), trans-1,4-cyclohexyl diisocyanate, norbornene diisocyanate, methylene diisocyanate, dimethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, dipropylether diisocyanate , 2,2-dimethylpentane diisocyanate, 3-methoxyhexane diisocyanate, octamethylene diisocyanate, 2,2,4-trimethylpentane diisocyanate, nonamethylene diisocyanate, decamethylene diisocyanate, 3-butoxyhexane di Isocyanates, 1,4-butylene glycol dipropyl ether diisocyanae , Thiodihexyl diisocyanate, metaxylylene diisocyanate, paraxylylene diisocyanate, tetramethylxylylene diisocyanate, and the like, which may be used alone or in combination of two or more thereof. Among them, dicyclohexyl methane 4,4-diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate and the like are suitable in terms of yellowing resistance, availability and ease of production.

As the polyol, polyester polyol or polyether polyol may be used. In particular, since the polyester polyol has a high intermolecular aggregation energy, mechanical properties such as toughness and hardness of the polyurethane can be improved. Therefore, when using a polyurethane formed using a polyester polyol, it is possible to minimize the occurrence of fuzz due to excellent focusing properties between the glass fibers, it is possible to improve the workability when reinforcing the polyamide resin.

The polyester polyol may be used without particular limitation as long as it is known in the art. Non-limiting examples include ethylene oxide adducts such as diethylene glycol and triethylene glycol; Propylene oxide adducts such as dipropylene glycol and tripropylene glycol; Polytetramethylene ether glycol, and the like.

As the polyester polyol, one obtained by esterification of a low molecular polyol with a dicarboxylic acid or an acid anhydride thereof, or a ring-opening addition reaction of a lactone or a derivative thereof can be used.

Non-limiting examples of the low molecular polyols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propane Diol, 1,4-butanediol, neopentylglycol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2- Methyl-2,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3,5-heptanediol, 1,8-octanediol , 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, cyclohexanedimethanol, cyclohexanediol, trimethylolethane, trimethylolpropane, hexitols, penti Pentitols, glycerin, polyglycerols, pentaerythritol, dipentaerythritol, tetramethylolpropane and the like.

Non-limiting examples of the dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, subberic acid, azelaic acid, sebacic acid, dodecane diacid, 2-methyl succinic acid, 2-methyladipic acid, 3-methyladipic acid, 3-methylpentane diacid, 2-methyloctane diacid, 3,8-dimethyldecane diacid, 3,7-dimethyldecane diacid, phthalic acid, terephthalic acid, Isophthalic acid, naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid, trimellitic acid, trimesic acid, castor oil fatty acid, pyromellitic acid and the like.

Non-limiting examples of the lactones include γ-caprolactone, δ-caprolactone, ε-caprolactone, dimethyl-ε-caprolactone, δ-valerolactone, γ-valerolactone, γ-butyrolactone, and the like. .

The number average molecular weight of the polyester polyol is not particularly limited, and may be, for example, in the range of 1,000-3,000. The hydroxyl value (OH value) of the polyester polyol is not particularly limited, and may be, for example, in the range of 30-120 mgKOH / g.

In the sizing composition of the present invention, the content of the polyurethane is not particularly limited, and may be, for example, in the range of 80-95% by weight, for example, in the range of 85-95% by weight, based on the total solids of the sizing composition. When the content of the polyurethane is in the above-described range, the coating property of the sizing composition may be excellent to improve workability, and the strength and focusing force of the sizing composition may be improved.

additive

The sizing composition of the present invention may further include additives such as lubricants and antioxidants in addition to the above-described coupling agent and film former.

The lubricants impart strength and focus synergistic effects to the sizing composition, and examples thereof include water-soluble lubricants of cationic systems having a polyamide component. The water-soluble lubricant of the cationic system includes fattyamide, sulfonated amine, and the like. The content of the lubricant is not particularly limited and may be, for example, in the range of 0.01-10% by weight based on the total weight of the composition. When the content of the lubricant is in the above-described range, the strength and focusability can be improved without deteriorating the fuzz or apparent specific gravity of the glass fiber.

The antioxidant serves to prevent color fading. Examples of such antioxidants include hypophosphite and the like. The content of the antioxidant is not particularly limited and may be, for example, in the range of 0.01-10% by weight based on the total weight of the composition. When the content of the antioxidant is in the above-described range, it is possible to improve discoloration resistance without lowering the fuzz or apparent specific gravity of the glass fiber, and to reduce the manufacturing cost of the sizing composition.

The sizing composition of the present invention can be used to coat fiberglass in the form of a dispersion or solution obtained by dispersing or dissolving the aforementioned components in a solvent (eg, water) commonly used in the art. Such a sizing composition may improve adhesion to the glass fibers to improve the mechanical properties of the glass fibers, as well as improve the compatibility of the glass fibers with the polyamide resin.

<Glass fiber coated with sizing composition>

The present invention provides a glass fiber coated with the aforementioned sizing composition.

The glass fiber includes a glass fiber substrate and a coating layer formed on part or all of the surface of the glass fiber substrate, and the coating layer is formed by applying and drying the sizing composition, and may be one layer or a plurality of layers.

The sizing composition may protect the glass fiber from friction generated at the contact surface of all the processes through which the glass fiber passes, and may impart compatibility with the polyamide resin to the glass fiber to facilitate bonding between the glass fiber and the resin. In addition, in manufacturing the fiber-reinforced composite material it is possible to prevent the glass fiber from being damaged by the shear force applied to the glass fiber during the compounding process using an extruder.

The glass fiber substrate usable in the present invention is not particularly limited as long as it is known in the art. For example, E-glass, D-glass, S-glass, NE-glass, T-glass, Q-glass and the like, but is not limited thereto. The diameter of such glass fiber substrate is not particularly limited and may be, for example, in the range of 1-50 μm.

The application method of the sizing composition is not particularly limited, and examples thereof include an immersion method, a roll coating method, a die coating method, a gravure coating method, a spray coating method, a flow coating method, and the like, but are not limited thereto. For example, when the sizing composition is applied to the glass fiber substrate through the immersion method, the immersion time may be about 0.5 seconds-1 minutes.

The application amount (usage) of the sizing composition is not particularly limited, and may be, for example, 0.05-10 parts by weight based on 100 parts by weight of glass fiber. When the coating amount of the sizing composition is in the above-described range, the focusing property and workability may be improved without increasing the manufacturing cost, and mechanical properties such as tensile strength and impact strength may be improved.

<Fiberglass strand>

The present invention provides a glass fiber strand comprising a glass fiber coated with the aforementioned sizing composition.

The glass fibers coated with the sizing composition are typically in the form of filaments, where several strands (eg, 4000 pieces) are spun together to form strands. Such strands may be processed into various forms through various processing processes and applied to various fields. For example, the strand may be cut to a certain length (for example, 3-4.5 mm) through chopping and dried to obtain chopped strands. Since the heat strand has good discoloration by heat, and excellent chemical resistance, color, and mechanical strength, it is applied to various electric and electronic products, automobile parts, mechanical parts, etc. together with thermoplastic resins or thermosetting resins such as polyamide resins. Applicable to the field.

<Fiber Reinforced Composites>

The present invention provides a fiber reinforced composite material comprising a glass fiber and a thermoplastic resin coated with the aforementioned sizing composition. At this time, the mechanical strength of the thermoplastic resin is strengthened by the glass fiber, the mechanical strength of the composite material can be improved. Such composites can be processed into various forms and applied to a variety of fields, such as airplane parts, ship parts, automotive parts, sporting goods, electrical and electronic products, and the like.

The thermoplastic resin is not particularly limited as long as it is known in the art, and examples thereof include polyamide. Since polyamide has excellent compatibility with glass fibers coated with the sizing composition, the mechanical strength of the composite material can be further improved.

The mixing ratio of the glass fiber and the thermoplastic resin is not particularly limited, and may be, for example, a weight ratio of 30: 70-50: 50. When the mixing ratio of the glass fiber and the thermoplastic resin is the aforementioned ratio, mechanical properties such as tensile strength and impact strength may be further improved.

Hereinafter, the present invention will be described in detail with reference to Examples, but the following Examples are merely illustrative of one embodiment of the present invention, and the scope of the present invention is not limited by the following Examples.

Example 1-5 and Comparative Example 1-4

Each component was mixed according to the composition shown in Table 1 below to prepare a sizing composition (solid content: 7.5%) of Example 1-5 and Comparative Example 1-4. In Table 1, the content unit of each component is the weight percent of the total weight of the composition, and Table 2 shows the content of each component based on the solids content of the sizing composition, and each component content unit is the total weight of the solids in the sizing composition. Weight percent.

[ Experimental Example . Property evaluation]

The sizing compositions of Example 1-4 and Comparative Example 1-4 prepared above were coated on the glass fiber formed through the bushing using an applicator roller, and the coated glass fiber was cut to form a chopped strand. Glass fiber was produced. The glass fibers were mixed with polyamide at a weight ratio of 3: 7, and then injected at 240 to prepare a reinforced polyamide composite material. Physical properties of the prepared polyamide composite were measured as shown below, and the results are shown in Table 3 below.

<Property evaluation method>

(1) Tensile strength: measured according to ASTM D 638 test method

(2) Impact strength: measured according to ASTM D 256 test method

As a result of the experiment, Examples 1-4 used γ-aminopropyltriethoxysilane or silylated polyazamide alone (Comparative Examples 1 and 2) and silylated with γ-aminopropyltriethoxysilane. The impact ratio and the tensile strength of the polyazamide were higher than that of the case where the mixing ratio of the polyazamide was used in the range of 30: 70-70: 30 (based on the solid content) (Comparative Examples 3 and 4). Thus, it was confirmed that the sizing composition for glass fibers of the present invention can improve the mechanical properties of the polyamide resin by mixing two specific alkoxysilanes in a specific range.

Claims (7)

A sizing composition for glass fibers comprising a film forming agent and a coupling agent,
The coupling agent,
Amino group-containing alkoxysilane,
An azamide group and an amino group-containing alkoxysilane,
A sizing composition for glass fibers in which the mixing ratio of the amino group-containing alkoxysilane, azamide group, and amino group-containing alkoxysilane is 30: 70-70: 30 weight ratio (based on solids). delete The sizing composition for glass fibers according to claim 1, wherein the azamide group and the amino group-containing alkoxysilane are represented by Chemical Formula 1.
[Formula 1]

In Chemical Formula 1,
R ¹ to R ⁵ are the same as or different from each other, and each independently an alkyl group of C ₁ -C ₅ ,
R ⁶ is a C ₃ -C ₁₀ cyclic alkyl group,
R ⁷ is an alkyl group of C ₁ -C ₄ ,
x and y are the same as or different from each other, and each independently an integer of 1 to 4,
n is an integer from 1 to 3. The sizing composition for glass fibers according to claim 1, comprising 80-95 wt% of the film former and 5-20 wt% of the coupling agent, based on the total solids of the sizing composition for glass fibers. Glass fiber coated with the sizing composition as described in any one of Claims 1, 3, or 4. The composite material containing the glass fiber and thermoplastic resin of Claim 5. The composite material of claim 6, wherein the thermoplastic resin comprises a polyamide-based resin.