Sizing composition and glass fiber using same

Abstract

The present invention relates to a sizing composition for a glass fiber, a glass fiber surface-treated with the sizing composition, and a polypropylene composite material comprising the glass fiber as a reinforcing material.

Description

Sizing composition and glass fiber using the same

[0001] The present invention relates to a sizing composition for glass fiber, glass fiber surface-treated with the sizing composition, and a polypropylene composite material comprising the glass fiber as a reinforcing material.

[0002]

[0003] To impart superior durability and mechanical properties to polypropylene, polypropylene composite materials containing glass fiber reinforcement are used. The glass fiber reinforcement is manufactured by coating the surface of the glass fiber with a sizing composition, and the sizing composition plays a role in increasing the adhesion between the glass fiber and the plastic interface during compounding. Active research and development is being conducted on sizing compositions containing film-forming agents and coupling agents of various compositions to impart superior physical properties to glass fiber. For example, Korean Patent Publication No. 10-2018-0067592 discloses a coating composition for reinforced fibers using a film-forming agent comprising at least one of polyvinylpyrrolidone, polyvinylacetate, and polyurethane.

[0004] Recently, polypropylene resin has been widely used as a material for electric vehicles. Due to the risk of battery fires, various flame-retardant materials for polypropylene have been developed. However, conventional glass fiber-reinforced composites have a problem: when burned, the glass fibers act like candle wicks, reducing their flame retardancy.

[0005] Accordingly, there is a need for development of a sizing composition for glass fiber having excellent mechanical properties and flame retardancy, glass fiber surface-treated with the sizing composition, and a polypropylene composite material including the glass fiber as a reinforcing material.

[0006]

[0007] The present invention provides a sizing composition for glass fiber having excellent mechanical properties and flame retardancy, glass fiber surface-treated with the sizing composition, and a polypropylene composite material comprising the glass fiber as a reinforcing material.

[0008]

[0009] The present invention provides a sizing composition comprising a film-forming agent, a coupling agent, and a flame retardant. Furthermore, the present invention provides a glass fiber strand surface-treated with the aforementioned sizing composition. Furthermore, the present invention provides a polypropylene composite material comprising the aforementioned glass fiber strand and a polypropylene resin.

[0010]

[0011] The present invention provides a sizing composition for glass fibers having excellent mechanical properties and flame retardancy, glass fibers surface-treated with the sizing composition, and a polypropylene composite material comprising the glass fibers as a reinforcing material. The sizing composition according to the present invention exhibits homogeneous flame retardancy, and as a result, provides excellent flame retardancy to a polypropylene composite material to which it is applied. Therefore, the polypropylene composite material of the present invention is suitable for use as a material for electric vehicles, which are vulnerable to fire due to their batteries.

[0012]

[0013] The present invention will be described in detail below. However, it is not limited to the following description, and each component may be modified or selectively mixed as needed. Therefore, it should be understood that all modifications, equivalents, and alternatives included within the spirit and technical scope of the present invention are included.

[0014] The “weight average molecular weight” used in this specification is measured by a conventional method known in the relevant technical field, and can be measured by, for example, the GPC (gel permeation chromatography) method.

[0015]

[0016] Sizing Composition

[0017] The sizing composition according to the present invention comprises a film-forming agent, a coupling agent, and a flame retardant. Furthermore, the sizing composition may further comprise additives commonly used in the relevant technical field, as needed.

[0018]

[0019] film former

[0020] The sizing composition of the present invention includes a film former. The film former strengthens the concentration of glass fibers and controls the physical properties of the final molded product. The film former is selected in consideration of adhesion to the glass fibers, toughness, softness / hardness, heat-induced discoloration, and interfacial adhesion strength with the plastic resin to be reinforced. The film former includes a maleic anhydride polypropylene copolymer (MAPP) and a maleic anhydride polyethylene copolymer (MAPE).

[0021]

[0022] Maleic anhydride polypropylene copolymer (MAPP)

[0023] The above maleic anhydride polypropylene copolymer (MAPP) is a main film forming agent and has excellent compatibility with a polypropylene base resin, thereby improving the mechanical properties of the composite material.

[0024] The above maleic anhydride polypropylene copolymer (MAPP) can be prepared by copolymerizing maleic anhydride with polypropylene. The maleic anhydride may be included in an amount of 1 to 5 wt%, for example, 1 to 2 wt%, based on the total weight of the maleic anhydride polypropylene copolymer (MAPP). If the content of maleic anhydride is less than the above-mentioned range, the aggregation of glass fibers may be reduced, and if it exceeds the above-mentioned range, the strength of the final composite may be reduced. The weight average molecular weight of the polypropylene may be 60,000 to 80,000 g / mol.

[0025] The above maleic anhydride polypropylene copolymer (MAPP) may include a nano clay dispersed maleic anhydride polypropylene copolymer and a nano clay-free maleic anhydride polypropylene copolymer.

[0026] The maleic anhydride polypropylene copolymer having the nano clay dispersed therein can be manufactured by dispersing nano clay in the maleic anhydride polypropylene copolymer emulsion. When the maleic anhydride polypropylene copolymer having the nano clay dispersed therein is combusted, the copolymer is thermally decomposed, and the remaining clay moves to the surface layer and is concentrated to form a barrier, and the hydrophobic substrate of the clay blocks moisture, thereby preventing combustion and enhancing flame retardancy.

[0027] The mixing ratio of the nano clay dispersed maleic anhydride polypropylene copolymer and the nano clay-free maleic anhydride polypropylene copolymer may be 6:4 to 4:6 by weight. If the mixing ratio of the nano clay dispersed maleic anhydride polypropylene copolymer to the nano clay-free maleic anhydride polypropylene copolymer exceeds the above-mentioned range, compatibility with the plastic resin may be reduced, resulting in deterioration of mechanical properties.

[0028] The above nano clay dispersed maleic anhydride polypropylene copolymer (nano clay dispersed MAPP) may be included in an amount of 50 wt% or more, for example, 50 to 70 wt%, based on the total solid weight of the maleic anhydride polypropylene copolymer (MAPP). If the content of the nano clay dispersed maleic anhydride polypropylene copolymer is less than the above-mentioned range, sufficient flame retardancy may not be secured, and if it exceeds the above-mentioned range, mechanical strength may be reduced.

[0029] The above maleic anhydride polypropylene copolymer (MAPP) may be included in an amount of 10 to 50 wt%, for example, 20 to 40 wt%, based on the total solid weight of the sizing composition. If the content of the maleic anhydride polypropylene copolymer (MAPP) is less than the above-mentioned range, compatibility with the composite material may be reduced, and if it exceeds the above-mentioned range, the content of the flame retardant may be reduced, thereby reducing flame retardancy.

[0030]

[0031] Maleic anhydride polyethylene copolymer (MAPE)

[0032] The above maleic anhydride polyethylene copolymer (MAPE) is an auxiliary film former that improves the binding properties of glass fibers and suppresses fluff formation of glass fibers.

[0033] The above maleic anhydride polyethylene copolymer (MAPE) can be prepared by copolymerizing maleic anhydride with polyethylene. The maleic anhydride may be included in an amount of 60 to 90 wt%, for example, 75 to 80 wt%, based on the total weight of the maleic anhydride polyethylene copolymer (MAPE).

[0034] The above maleic anhydride polyethylene copolymer (MAPE) may be included in an amount of 1 to 10 wt%, for example, 1 to 5 wt%, based on the total solid weight of the sizing composition. If the content of the maleic anhydride polyethylene copolymer (MAPE) is less than the above-mentioned range, the binding property may be reduced, resulting in fluffing, and if it exceeds the above-mentioned range, the strength of the final composite may be reduced.

[0035]

[0036] The film forming agent may include the maleic anhydride polypropylene copolymer (MAPP) and the maleic anhydride polyethylene copolymer (MAPE) in a weight ratio of 1:0.03 to 0.2 (based on solid content), for example, 1:0.05 to 0.18 (based on solid content). If the mixing ratio of the maleic anhydride polyethylene copolymer (MAPE) to the maleic anhydride polypropylene copolymer (MAPP) is less than the above-mentioned range, the aggregation of the glass fibers may be reduced, and if it exceeds the above-mentioned range, the mechanical strength and color of the final composite may be inferior.

[0037]

[0038] coupling agent

[0039] The sizing composition of the present invention includes a coupling agent. The coupling agent connects the glass fibers and the film-forming agent, enabling the sizing composition to be coated on the surface of the glass fibers. Any coupling agent commonly used in the relevant technical field may be used without limitation. For example, a conventional organic silane coupling agent may be used.

[0040] Non-limiting examples of usable organosilanes include γ-aminopropyltriethoxysilane, n-trimethoxy-silyl-propyl-ethylene-diamine, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-β-aminoethyl-γ-aminopropyltrimethoxysilane, methyl-trichlorosilane, methyl-trimethoxysilane, γ-mercaptopropyl-trimethoxy-silane, γ-chloropropyl-trimethoxy-silane, vinyl-triethoxy-silane, vinyl-tris-(2-methoxyethoxy)silane, vinyl-triacetoxysilane, octyltriethoxysilane, methyltriethoxysilane, methyltrimethoxysilane, γ-ureidopropyltrimethoxysilane, and the like. These may be used alone or in combination of two or more.

[0041] The above coupling agent may be included in an amount of 5 to 20 wt%, for example 5 to 10 wt%, based on the total solid weight of the sizing composition. If the content of the coupling agent is less than the above-mentioned range, the adhesive strength with the glass fiber may decrease, resulting in a decrease in strength. If the content of the coupling agent exceeds the above-mentioned range, the content of the film forming agent may be relatively reduced, resulting in a decrease in compatibility with the plastic resin to be reinforced, or the color of the final composite may be discolored.

[0042] The film forming agent and the coupling agent may be mixed in a weight ratio of 1:0.1 to 0.33 (based on solid content), for example, 1:0.15 to 0.25 (based on solid content). If the mixing ratio of the coupling agent to the film forming agent is less than the above-mentioned range, the glass fiber binding property may be reduced or the strength of the final composite may be reduced, and if it exceeds the above-mentioned range, the compatibility with the plastic resin may be reduced or the color may be discolored.

[0043]

[0044] Inherent flame retardant

[0045] The sizing composition of the present invention comprises a flame retardant. The flame retardant comprises a water-soluble phosphorus-based flame retardant, a non-halogen-type, water-soluble flame retardant. Phosphorus-based flame retardants generate polyphosphoric acid upon thermal decomposition, which then undergoes esterification and dehydrogenation to form char, thereby blocking the oxygen and heat required for combustion and inhibiting chain reactions through radical capture, thereby imparting flame retardancy. Furthermore, phosphorus-based flame retardants have excellent water resistance and a high decomposition temperature, making them suitable as flame retardants for various resins requiring processing.

[0046] As the above water-soluble flame retardant, cyclic phosphonate, phosphoric acid polymer, triethyl phosphate polymer, etc. can be used.

[0047] The water-soluble phosphorus-based flame retardant may be included in an amount of 30 to 70 wt%, for example, 40 to 60 wt%, based on the total solid weight of the sizing composition. If the content of the water-soluble phosphorus-based flame retardant is less than the above-mentioned range, the flame retardancy-conferring effect may be insufficient, and if it exceeds the above-mentioned range, the content of the film-forming agent may be relatively reduced, thereby deteriorating compatibility with the plastic resin to be reinforced.

[0048] The above film forming agent and the above flame retardant may be mixed in a weight ratio of 1:0.5 to 4 (based on solid content), for example, a weight ratio of 1:0.9 to 3 (based on solid content). If the mixing ratio of the flame retardant to the film forming agent is less than the above-mentioned range, sufficient flame retardancy may not be secured, and if it exceeds the above-mentioned range, the binding property of the glass fiber may be reduced, or the compatibility between the glass fiber and the plastic resin may be reduced.

[0049]

[0050] flame retardant adjuvant

[0051] The sizing composition of the present invention includes a flame retardant additive. The flame retardant additive enhances flame retardancy by preventing dripping during plastic combustion.

[0052] The flame retardant additive may include polytetrafluoroethylene (PTFE). PTFE forms a network structure in which long molecular chains are intertwined with each other, and the PTFE chains can migrate to the composite surface when heated due to the low surface energy of fluorine (F). Due to this physical cross-linking structure, the polypropylene (PP) composite material is well fixed, and the elastic strength is increased during the combustion process, thereby suppressing the drip phenomenon of the combustion sample on the surface.

[0053] The flame retardant additive may be included in an amount of 20 wt% or less, for example, 5 to 15 wt%, based on the total solid weight of the sizing composition. If the content of the flame retardant additive is less than the aforementioned range, the flame retardancy-conferring effect may be insufficient, and if it exceeds the aforementioned range, the content of the film-forming agent may be relatively reduced, thereby deteriorating compatibility with the plastic resin to be reinforced.

[0054] The above-mentioned phosphorus-based flame retardant and the above-mentioned flame retardant auxiliary agent may be mixed in a weight ratio of 1:0.05 to 0.5 (based on solid content), for example, a weight ratio of 1:0.1 to 0.3 (based on solid content). If the mixing ratio of the flame retardant auxiliary agent to the phosphorus-based flame retardant agent is less than the above-mentioned range, dripping may occur during flame retardancy evaluation, and if it exceeds the above-mentioned range, the combustion time may not be sufficiently reduced.

[0055]

[0056] additives

[0057] The sizing composition according to the present invention may further include additives such as lubricants, antioxidants, and viscosity modifiers, as long as the effects of the invention are not impaired. The additives may be added in amounts known in the art, and for example, may be included in an amount of 0.1 to 10 wt%, for example, 0.1 to 3 wt%, based on the total solid weight of the sizing composition.

[0058]

[0059] The sizing composition according to the present invention can be used to coat glass fibers in the form of a dispersion or solution obtained by dispersing or dissolving the above-mentioned components in a solvent (e.g., water) commonly used in the relevant technical field. The method for preparing the sizing composition as an aqueous dispersion or solution is not particularly limited, and a method known in the relevant technical field can be used. For example, a method of adding hot water while stirring each component constituting the sizing composition to emulsify and disperse or dissolve it, a method of heating a mixture of each component constituting the sizing composition to a softening point or higher, and then adding mechanical shearing force using a homogenizer, homomixer, ball mill, etc., while slowly adding water to emulsify the phase, etc.

[0060] In the present invention, for the purpose of improving the operability of the aqueous dispersion or aqueous solution during manufacture or the stability of the aqueous dispersion over time, a conventional organic solvent in the relevant technical field other than water may be added within a range that does not impair the advantages of the aqueous dispersion or aqueous solution.

[0061]

[0062] Glass fiber

[0063] The present invention provides glass fibers, such as glass fiber strands, surface-treated with the aforementioned sizing composition. The glass fiber strands comprise one or more glass fibers whose surfaces are partially or completely coated with the aforementioned sizing composition, and mean a bundle of glass fibers that are gathered and bound by the sizing composition.

[0064] As the glass fiber, any conventional glass fiber known in the relevant technical field can be used without limitation, and the raw material thereof can be at least one of alkali-containing glass, low-alkali glass, and alkali-free glass. Non-limiting examples of usable glass fibers include E-glass, S-glass, A-glass, C-glass, ECR-glass, AR-glass, or mixtures thereof. For example, E-glass long-fiber glass used for reinforcing thermoplastic resins or thermosetting resins can be used. The shape of the glass fiber is not particularly limited, and the fiber length, fiber diameter, etc. can be appropriately adjusted within a range commonly used in the relevant technical field.

[0065] The amount of the sizing composition attached to the glass fiber strand may be 0.1 to 5.0 wt%, for example, 0.5 to 3.0 wt%, based on the total weight (based on solid content) of the glass fiber and the sizing composition. When the amount of the sizing composition attached falls within the above-described content range, excellent binding properties can be provided.

[0066] The method for manufacturing the glass fiber strand according to the present invention is not particularly limited, and conventional methods known in the art can be utilized. For example, molten glass can be spun from a plurality of nozzles installed at the bottom of a bushing, a sizing composition is applied to the spun glass fibers using an applicator or sprayer, the spun glass fibers are wound, and the wound glass fiber bundle is heat-dried at a temperature of 80 to 150°C. At this time, the glass fiber strand can be cut after being wound once, or it can be cut as is without being wound.

[0067] The method for treating glass fibers with the sizing composition is not particularly limited, and for example, methods such as immersion application, roller application, spray application, flow application, and spray application can be used.

[0068] The glass fiber strand of the present invention obtained by converging a plurality of glass fibers as described above can be used in a form selected from among glass chopped strands, glass rovings, glass chopped strand mats, glass roving crosses, etc., depending on the purpose of the polypropylene composite material to be reinforced.

[0069]

[0070] Polypropylene composite material

[0071] The present invention provides a polypropylene composite material comprising the aforementioned glass fiber strand and polypropylene resin.

[0072] The above glass fiber strands are used as reinforcing materials for polypropylene resins. The glass fiber strands may be chopped, continuous, or assembled into rovings for thermoplastic or thermosetting reinforcing applications.

[0073] Any conventional polypropylene resin known in the relevant technical field can be used as the above polypropylene resin without limitation. For example, a commercially available product such as H1500 (LG Chemical) can be used.

[0074] In the polypropylene-reinforced composite material according to the present invention, the glass fiber content may be, for example, 10 to 70 wt%, and in another example, 20 to 50 wt%. If the glass fiber content is below the aforementioned range, durability and mechanical strength may be insufficient, and if it exceeds the aforementioned range, manufacturing costs may become excessively high.

[0075] The method for manufacturing the polypropylene composite material of the present invention is not particularly limited, and various methods known in the art can be utilized. For example, the glass fiber strands can be impregnated with molten polypropylene resin, and, if necessary, chopped using a pelletizer or the like. Furthermore, the polypropylene composite material can be obtained using an injection molding machine. For example, the chopped strands can be blended at 20 to 40 wt% based on the total weight of the polypropylene resin, and melt-mixed at a temperature of 180 to 220°C to manufacture the composite material.

[0076]

[0077] Hereinafter, the present invention will be described in more detail through examples. However, the following examples are intended only to aid understanding of the present invention and are not intended to limit the scope of the present invention in any way.

[0078]

[0079] [Experimental Example 1-19]

[0080] Each sizing composition for each experimental example was prepared by mixing each component according to the composition described in Table 1-5 below.

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088] Film former 1-1: Maleic anhydride polypropylene copolymer (MAPP, Aquacer1870, BYK, NV 35%)

[0089] Film former 1-2: Maleic anhydride polypropylene copolymer (MAPP, Aquacer1860, BYK, NV 35%)

[0090] Film former 1-3: Nano clay dispersed maleic anhydride polypropylene copolymer (nano clay dispersed MAPP, 38RC 1545, BYK, NV 35%)

[0091] Film former 2: Maleic anhydride polyethylene copolymer (MAPE, FGLASS X90, Michelman, NV 40%)

[0092] Coupling agent: Aminopropyletriethoxy silane (NV 62%)

[0093] Flame retardant 1: Phosphoric acid polymer (Cas No 28409-84-9, NV 100%)

[0094] Flame retardant 2: Phosphoric acid polymer with methyloxirane amines (FRH-30, Eastwood, NV 30%)

[0095] Flame retardant 3: AMMONIUM POLYPHOSPHATE (W-APP, Yuil Chemitech, NV 100%)

[0096] Flame retardant 4: Microcrystalline cellulose additive (MCA, Eastwood, NV 100%)

[0097] Flame retardant additive: polytetrafluoroethylene (PTFE 60% dispersion, NV 60%)

[0098] Additive 1: Hypophosphite powder (NV 100%)

[0099] Additive 2: polyacrylamide (C9501, Quingdao chemical, Mw 1 million, NV 100%)

[0100]

[0101] [Physical property evaluation]

[0102] The sizing composition of each experimental example manufactured above was coated on glass fibers formed through a bushing using an applicator roller, and the coated glass fibers were mixed with polypropylene resin (LG H1500) at a weight ratio of 8:2 and injection-molded at 200°C to manufacture a polypropylene composite material (POM pellet). The physical properties of the manufactured polypropylene composite material were measured as presented below, and the results are shown in Table 6-8 below.

[0103]

[0104] Flame retardancy

[0105] Flame retardancy was measured according to UL94.

[0106]

[0107] tensile strength

[0108] Tensile strength was measured according to ISO527-1 / 2.

[0109]

[0110] Flexural strength

[0111] Flexural strength was measured according to ISO178.

[0112]

[0113] Impact strength

[0114] Impact strength was measured according to ISO179 / 1eA.

[0115]

[0116]

[0117]

[0118]

[0119]

[0120] As shown in Table 6-8 above, the sizing compositions of Experimental Examples 1-13 according to the present invention exhibited excellent physical properties across all measured items. On the other hand, the sizing compositions of Experimental Example 14 not including a phosphorus-based flame retardant, Experimental Example 15 not including a flame retardant auxiliary agent, Experimental Examples 16 and 17 not including a phosphorus-based flame retardant and a flame retardant auxiliary agent, Experimental Example 18 in which the mixing ratio of the phosphorus-based flame retardant to the film former is outside the scope of the present invention, and Experimental Example 19 in which the mixing ratio of the flame retardant auxiliary agent to the phosphorus-based flame retardant is outside the scope of the present invention, exhibited generally inferior physical properties compared to the sizing compositions of Experimental Examples 1-13.

[0121]

[0122] The present invention provides a sizing composition for glass fiber having excellent mechanical properties and flame retardancy, glass fiber surface-treated with the sizing composition, and a polypropylene composite material comprising the glass fiber as a reinforcing material.

Claims

1. A sizing composition comprising a film forming agent, a coupling agent, a phosphorus flame retardant and a flame retardant auxiliary agent, The above film forming agent and the above flame retardant are mixed in a weight ratio of 1:0.5 to 4 (based on solid content), A sizing composition in which the above-mentioned flame retardant and the above-mentioned flame retardant auxiliary agent are mixed in a weight ratio of 1:0.05 to 0.5 (based on solid content).

2. A sizing composition according to claim 1, wherein the film forming agent comprises a maleic anhydride polypropylene copolymer (MAPP: maleic anhydride polypropylene copolymer) and a maleic anhydride polyethylene copolymer (MAPE: maleic anhydride polyethylene copolymer) in a weight ratio of 1:0.03 to 0.2 (based on solid content).

3. A sizing composition in which the film forming agent and the coupling agent are mixed in a weight ratio of 1:0.1 to 0.33 (based on solid content) in the first paragraph.

4. In the second paragraph, the maleic anhydride polypropylene copolymer (MAPP) is manufactured by copolymerizing maleic anhydride with polypropylene, Contains 1 to 5 wt% of maleic anhydride based on the total weight of the maleic anhydride polypropylene copolymer (MAPP), A sizing composition having a weight average molecular weight of the polypropylene of 60,000 to 80,000 g / mol.

5. In the second paragraph, the maleic anhydride polypropylene copolymer (MAPP) comprises a maleic anhydride polypropylene copolymer with nano clay dispersed (nano clay dispersed MAPP) and a maleic anhydride polypropylene copolymer without nano clay in a weight ratio of 6:4 to 4:6, A sizing composition comprising at least 50 wt% of a maleic anhydride polypropylene copolymer (NANO clay dispersed MAPP) in which the nano clay is dispersed, based on the total solid weight of the maleic anhydride polypropylene copolymer (MAPP).

6. A sizing composition comprising 60 to 90 wt% of maleic anhydride based on the total weight of the maleic anhydride polyethylene copolymer (MAPE) of the second paragraph.

7. A sizing composition according to claim 2, wherein the flame retardant auxiliary agent comprises polytetrafluoroethylene.

8. A sizing composition comprising, in paragraph 1, 10 to 50 wt% of the maleic anhydride polypropylene copolymer (MAPP), 1 to 10 wt% of the maleic anhydride polyethylene copolymer (MAPE), 5 to 20 wt% of the coupling agent, 30 to 70 wt% of the phosphorus-based flame retardant, and 20 wt% or less of the flame retardant auxiliary agent, based on the total solid content weight of the sizing composition.

9. A glass fiber strand surface-treated with a sizing composition according to any one of claims 1 to 8.

10. A polypropylene composite material comprising the glass fiber strand of paragraph 9 and a polypropylene resin.

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