High-strength low-shrinkage outdoor floor and preparation method thereof

Abstract

The invention relates to an outdoor floor, in particular to a high-strength low-shrinkage outdoor floor and a preparation method thereof. Belongs to the technical field of outdoor floors. A high-strength and low-shrinkage outdoor floor comprises a supporting body and a hard surface layer at least covering the using surface of the supporting body, and the supporting body comprises a polymer matrix and a plurality of reinforced fiber yarns densely distributed in the polymer matrix and approximately parallel to the length direction of the supporting body; and the hard surface layer is made of a silicate-based polymer composite material. Through three innovations of material compounding, structure and function integration and process integration, the problems that a traditional outdoor floor is low in strength, prone to shrinkage and the like are solved, collaborative breakthrough of mechanical properties, environmental stability and functionality is achieved, and the composite floor has remarkable application value in the fields of high-end building outer walls, municipal landscapes and the like.

Description

Technical Field

[0001] This invention relates to outdoor flooring, and more particularly to a high-strength, low-shrinkage outdoor flooring and its preparation method. It belongs to the technical field of outdoor flooring. Background Technology

[0002] Outdoor flooring, as a key functional material in municipal construction, landscaping, and courtyard paving, has its core value in enhancing the structural stability and aesthetic appeal of surface coverings. Natural wood flooring, with its unique natural texture and excellent heat and sound insulation properties, holds a significant advantage in the consumer market. However, its industrial application is constrained by high raw material costs (30%–50% higher than traditional stone) and insufficient dimensional stability due to environmental humidity sensitivity (annual expansion rate can reach 2%–3%), severely limiting its market penetration.

[0003] To address the demands of industry upgrades and the trend of consumption upgrading, the field of materials science is focusing on developing high-performance composite flooring systems. Among these, wood-plastic composites (WPC) have become a research hotspot due to their high designability and resource utilization. The essence of composite flooring lies in overcoming the limitations of single-material performance through multiphase material interface control and structural reconstruction, achieving synergistic optimization of mechanical and functional properties. However, current WPC flooring exhibits significant technical shortcomings in engineering applications:

[0004] Insufficient mechanical properties: The static bending strength is generally lower than 25MPa (ASTM D790 standard), which is difficult to meet the requirements of heavy-duty working conditions;

[0005] Poor wear resistance: abrasion loss reaches 0.15g / 100r (Taber abrasion test), and the surface texture retention period is less than 3 years;

[0006] Poor environmental stability: After thermal cycling test at -30℃ to 80℃, the warpage rate exceeded 0.5%;

[0007] Interface bonding failure: Delamination occurs after long-term use (shear strength attenuation rate > 15% / year).

[0008] The existence of such problems severely restricts the promotion and application of WPC flooring in the field of high-end buildings, and it is urgent to achieve technological breakthroughs through material modification and structural innovation. Summary of the Invention

[0009] This invention addresses the aforementioned problems by proposing an outdoor flooring structural system. It innovatively employs continuous fiber-reinforced thermosetting resin-based composite profiles as the load-bearing matrix, achieving integrated molding of oriented fiber arrangement and structure through a pultrusion process. Building upon this, a functional surface layer is constructed on the profile surface using polymer-modified cementitious materials (PMCM), forming a composite interface structure. This design, through material-structure synergistic optimization, achieves technological breakthroughs in enhanced mechanical properties, optimized dimensional stability, strengthened interfacial bonding, and improved environmental durability. This technology overcomes the limitations of single-material performance, achieving a synergistic improvement in load-bearing capacity, environmental adaptability, and durability, providing an innovative solution for high-end outdoor building materials.

[0010] The technical solution of the present invention to solve the above problems is as follows:

[0011] A high-strength, low-shrinkage outdoor flooring includes a support body and a rigid surface layer covering at least the usable surface of the support body. The support body includes a polymer matrix and a plurality of reinforcing fiber yarns densely distributed within the polymer matrix and arranged generally parallel to the length direction of the support body. The rigid surface layer is made of a silicate-based polymer composite material.

[0012] As a preferred embodiment of the above technical solution, the polymer matrix is ​​made of polyurethane.

[0013] As a preferred embodiment of the above technical solution, in the silicate-based polymer composite material, the polymer is selected from at least one of vinyl acetate and ethylene copolymer emulsion, aqueous polyurethane emulsion, and polyacrylate emulsion.

[0014] As a preferred embodiment of the above technical solution, the formulation of the silicate-based polymer composite material is as follows:

[0015] Polymer emulsion 27~36wt%

[0016] Wood fiber 5~8wt%

[0017] Water-reducing agent 0.1~0.4wt%

[0018] Cellulose ether 0.1~0.4wt%

[0019] The remaining amount of silicate cement.

[0020] As a preferred embodiment of the above technical solution, the formulation of the silicate-based polymer composite material is as follows:

[0021] Vinyl acetate and ethylene copolymer powder 2.47~3.21wt%

[0022] Water 24.7~32.1wt%

[0023] Wood fiber 6.41~6.59wt%

[0024] Water-reducing agent 0.16~0.32wt%

[0025] Cellulose ether 0.16~0.32wt%

[0026] The remaining amount of silicate cement.

[0027] As a preferred embodiment of the above technical solution, the outdoor floor further includes a filler disposed within the cavity of the support body; the filler is made of polyurethane foam; the formula of the polyurethane foam is as follows:

[0028] 3-5 wt% water

[0029] 1-2 wt% dibutyltin dilaurate

[0030] Polyether-modified siloxane 2~3wt%

[0031] Aluminum hydroxide 15~20wt%

[0032] 15-20 wt% glass hollow microspheres

[0033] Remaining amount of polyurethane prepolymer.

[0034] As a preferred embodiment of the above technical solution, the polymer matrix is ​​made of modified polyurethane; the modified polyurethane formulation comprises the following components in parts by weight:

[0035] Component A:

[0036] Polyether polyol 18~20

[0037] Polyester polyol 10~12

[0038] Dimethylolpropionic acid 1~3

[0039] 1,4-Butanediol 4~6

[0040] KH-550 0.5~1.0

[0041] Antioxidant 1010 0.1~0.3

[0042] DMF 20~30;

[0043] Component B:

[0044] TDI 28~36

[0045] HDI 8~12

[0046] Phosphoric acid 0.18~0.36

[0047] Dibutyltin dilaurate 0.08~0.12.

[0048] Another object of the present invention is to provide a method for preparing the above-mentioned outdoor flooring.

[0049] A method for preparing high-strength, low-shrinkage outdoor flooring includes the following steps:

[0050] S1. Guide the multiple strands of reinforcing fiber yarn on the yarn rack with a yarn guide plate, and pass them into the pultrusion die in parallel. Pull them out from the discharge port of the pultrusion die and keep the reinforcing fiber yarn in a taut state.

[0051] S2. The raw materials constituting the polymer matrix are injected into the pultrusion mold using a dispensing machine, submerging the reinforcing fiber yarns in the mold cavity, and then heated and cured.

[0052] S3. The polymer, together with the reinforcing fiber yarn, is extruded from the die opening of a pultrusion die to obtain a semi-finished support profile.

[0053] S4. Solidify the semi-finished support profile to obtain the support body;

[0054] S5. Pull the support body to cooperate with extrusion;

[0055] S6. Adjust at least one of the feeding rate, extrusion rate and traction rate to match these rates so that the external dimensions of the support body meet the requirements.

[0056] S7. Using a scraper, the material prepared according to the silicate-based polymer composite material formula is uniformly coated onto the surface of the support to obtain a semi-finished outdoor floor with a hard surface.

[0057] S8. Use an embossing machine to create wood grain on the hard surface of the application layer;

[0058] S9, online cutting, to produce outdoor flooring.

[0059] As a preferred embodiment of the above technical solution, it further includes the step of applying a polyurethane primer to the surface of the support to be covered before scraping.

[0060] In the above technical solution of this invention, the polyurethane primer is a functional coating material formulated based on polyurethane prepolymer and by adding reactive diluents, catalysts, and additives. It is mainly used for enhancing interfacial adhesion between dissimilar materials and for surface pretreatment of substrates. Its core functions include: 1) improving the adhesion between the polyurethane primer and the substrate (such as concrete, metal, and plastic) through chemical bonding (e.g., the reaction of -NCO with the substrate's -OH) or mechanical intercalation; 2) reducing the surface tension of the system (contact angle <30°) and improving wetting and spreading properties; 3) filling micropores in the substrate and reducing interfacial delamination caused by moisture / oxygen penetration. Isocyanate-terminated polyurethane prepolymers are preferred. For example, Huntsman's ARALDITE® PU 450, with core components: MDI-based polyurethane prepolymer (NCO content 4%~5%), ethylene carbonate diluent, and silane coupling agent.

[0061] As a preferred embodiment of the above technical solution, the method further includes the step of injecting polyurethane foam into the cavity of the outdoor floor.

[0062] In summary, the present invention has the following beneficial effects:

[0063] 1. This invention proposes a composite structure of "reinforced fiber-polymer matrix support + silicate-based polymer hard surface layer", which combines the high strength characteristics of fiber-reinforced composite materials with the low shrinkage stability of cement-based materials, forming a significant structural synergistic effect. The support adopts a continuous fiber-reinforced polyurethane matrix, and the fiber orientation is achieved through pultrusion process. The fiber yarns are arranged parallel to the stretching direction, which can maximize the axial strength of the fibers, improving it by more than 200% compared with traditional WPC flooring. The silicate-based polymer composite material (cement-based) directly coats the surface of the support, forming a "soft base hard shell" structure. The high modulus of the cement-based material can effectively suppress the deformation of the support under load, while the introduction of polymer emulsion significantly improves the surface toughness and avoids brittle cracking.

[0064] 2. The polyurethane matrix has high elongation at break, and the tensile strength of the composite material is significantly improved after fiber reinforcement; the hydration reaction of silicate cement forms a dense structure, and with the help of water-reducing agents, the shrinkage rate can be controlled at 0.03%~0.05%; thus achieving a synergy between high strength and low shrinkage.

[0065] 3. In terms of interface bonding, a polyurethane primer is used to strengthen the interface, which significantly improves the bonding strength between the silicate-based polymer hard surface layer and the reinforcing fiber-polymer matrix support.

[0066] 4. After being catalyzed by dibutyltin dilaurate, the polyurethane matrix forms a cross-linked network structure, which improves its resistance to ultraviolet aging.

[0067] 5. The cavity is filled with polyurethane foam, and the closed-cell structure reduces the thermal conductivity.

[0068] 6. The wood fibers and silicate cement in the hard surface layer form a slightly rough surface, with a wear rate of <0.08g / 100r, thus extending the service life;

[0069] 7. Pultrusion process enables continuous production of the support; scraping method prepares a hard surface layer with thickness uniformity controlled within ±0.2mm; embossing process gives it a wood grain effect (texture depth 0.5~1.0mm), improving its aesthetics; polyurethane foam is foamed in situ within the cavity, which reduces weight and enhances thermal insulation performance.

[0070] 8. In summary, this invention solves the problems of low strength and easy shrinkage of traditional outdoor flooring through three major innovations: material composite, structural and functional integration, and process integration. It achieves a synergistic breakthrough in mechanical properties, environmental stability, and functionality, and has significant application value in high-end building exterior walls, municipal landscapes, and other fields. Detailed Implementation

[0071] This specific embodiment is merely an explanation of the present invention and is not intended to limit the present invention. Any changes made by those skilled in the art after reading the specification of the present invention, as long as they are within the scope of the claims, will be protected by patent law.

[0072] Example 1

[0073] A high-strength, low-shrinkage outdoor flooring comprises a support body and a rigid surface layer covering the usable surface of the support body. The support body includes a polymer matrix and multiple reinforcing fiber yarns densely distributed within the polymer matrix and arranged generally parallel to the length direction of the support body; the rigid surface layer is made of a silicate-based polymer composite material.

[0074] The support is a continuous fiber-reinforced polymer matrix composite material, manufactured through a pultrusion process. The support has a rectangular cross-section with a width of 120 mm and a thickness of 25 mm; internally, two insulating support plates divide the rectangular outline into three smaller rectangles. The reinforcing fiber yarn is glass fiber, with a yarn density of approximately 16 yarns / cm within the support. 2 .

[0075] A hard outer layer, 3.0 mm thick, is directly coated onto the surface of the support. It is made of silicate-based polymer composite material and features low shrinkage and high weather resistance. The surface of the hard outer layer is embossed to form a wood grain pattern with a texture depth of 1.2 mm.

[0076] The preparation method of the above-mentioned outdoor flooring is as follows:

[0077] 1.1 The support fabrication process includes the following steps:

[0078] S1, fiber yarn guidance

[0079] The multiple strands of reinforcing fiber yarn on the yarn rack are led out by the yarn guide plate and passed into the pultrusion die in parallel. They are pulled out from the discharge port of the pultrusion die while keeping the reinforcing fiber yarn in a taut state. The pulling speed is 0.8m / min.

[0080] S2, Polymer matrix injection

[0081] The raw materials constituting the polymer matrix are injected into the pultrusion mold using a dispensing machine, submerging the reinforcing fiber yarns in the mold cavity, and then cured at 120°C.

[0082] S3, Support Profile Extrusion

[0083] The polymer, together with the reinforcing fiber yarn, is extruded from the die of a pultrusion die to obtain a semi-finished support profile.

[0084] S4, Support solidification

[0085] The semi-finished support profile is solidified to obtain the support body;

[0086] S5, Support Traction

[0087] The support body is pulled to match the extrusion speed, and the pulling speed is controlled at 0.8 m / min;

[0088] S6, Size Adjustment

[0089] Adjust the feeding rate, extrusion rate, and traction rate to ensure that the dimensions of the support body meet the requirements.

[0090] 1.2 Hard Surface Preparation Process

[0091] S7, Surface Coating

[0092] Using a scraper, the material prepared according to the silicate-based polymer composite material formula is uniformly coated onto the surface of the support, with the coating thickness controlled at 2.0 mm;

[0093] S8, Surface Embossed

[0094] Using an embossing machine, wood grain patterns are created on hard surfaces.

[0095] S9, Online Cutting

[0096] Outdoor flooring is produced by online cutting according to required dimensions.

[0097] The formulations of the materials used in the aforementioned outdoor flooring are as follows:

[0098] polymer matrix materials

[0099] The polymer matrix is ​​made of polyurethane and uses a two-component system.

[0100] Component A:

[0101] Polyether polyol: 18 parts by weight

[0102] Polyester polyol: 10 parts by weight

[0103] Dimethylolpropionic acid: 2 parts by weight

[0104] 1,4-Butanediol: 5 parts by weight

[0105] KH-550 silane coupling agent: 0.8 parts by weight

[0106] Antioxidant 1010: 0.2 parts by weight

[0107] DMF solvent: 25 parts by weight

[0108] Component B:

[0109] TDI: 28 parts by weight

[0110] HDI: 12 parts by weight

[0111] Phosphoric acid: 0.25 parts by weight

[0112] Dibutyltin dilaurate: 0.1 parts by weight;

[0113] The NCO / OH molar ratio is controlled at approximately 0.95, resulting in approximately 2.0 wt% free hydroxyl groups in the system. This achieves an optimized balance of material properties—significantly improving elongation at break, low-temperature toughness, interfacial bonding strength, and processing fluidity while slightly sacrificing tensile strength and hydrolysis resistance. This makes it particularly suitable for outdoor floor support applications, especially in scenarios requiring high impact resistance and good interfacial bonding.

[0114] The formulation of silicate-based polymer composite materials is as follows: (standard formulation)

[0115] Vinyl acetate and ethylene copolymer powder: 2.8wt%

[0116] Water: 28wt%

[0117] Wood fiber: 6.5wt%

[0118] Water-reducing agent: 0.25wt%

[0119] Cellulose ether: 0.25wt%

[0120] Silicate cement: Balance (62.2 wt%).

[0121] Example 2

[0122] The difference from Example 1 is in step S7.

[0123] S7', Surface Coating

[0124] A polyurethane primer was applied to the surface of the support to be covered at a rate of 0.15 kg / m², with a surface drying time of 18 min. Then, using a scraper, the material formulated according to the silicate-based polymer composite material was uniformly applied to the surface of the support, with a coating thickness controlled at 2.0 mm. The polyurethane primer was Huntsman's ARALDITE® PU450.

[0125] Example 3

[0126] The difference from Example 1 is that it also includes S10.

[0127] S10, Foaming Injection

[0128] Polyurethane foam is injected into the support cavity of the outdoor floor.

[0129] The formula for the polyurethane foam is as follows:

[0130] 4% water

[0131] Dibutyltin dilaurate 1.5%

[0132] Polyether-modified siloxane 2.5%

[0133] 15% aluminum hydroxide

[0134] 20% hollow glass microspheres

[0135] The balance of polyurethane prepolymer is 57 wt%.

[0136] Example 4

[0137] The difference from Example 1 is that the silicate-based polymer composite material formulation is different.

[0138] The formulation of silicate-based polymer composite materials is as follows: (Optimized formulation)

[0139] Water-dispersible adhesive powder of vinyl acetate and ethylene copolymer 2.9wt%

[0140] Water 29.1 wt%

[0141] Wood fiber 6.5wt%

[0142] Water-reducing agent 0.25wt%

[0143] Cellulose ether 0.25wt%

[0144] The remainder is silicate cement (61 wt%).

[0145] Comparative Example 1

[0146] The difference from Example 1 is that the formulation of the polymer matrix is ​​different.

[0147] The polymer matrix is ​​made of polyurethane and uses a two-component system.

[0148] Component A:

[0149] Polyester polyol: 26 parts by weight

[0150] Dimethylolpropionic acid: 2 parts by weight

[0151] 1,4-Butanediol: 5 parts by weight

[0152] KH-550 silane coupling agent: 0.8 parts by weight

[0153] Antioxidant 1010: 0.2 parts by weight

[0154] DMF solvent: 25 parts by weight

[0155] Component B:

[0156] TDI: 32 parts by weight

[0157] Phosphoric acid: 0.25 parts by weight

[0158] Dibutyltin dilaurate: 0.1 parts by weight

[0159] The NCO / OH molar ratio is controlled at approximately 1.23, achieving a moderate optimization of material properties—while slightly improving tensile strength, thermal stability, and hydrolysis resistance, it maintains good elongation at break, interfacial bonding properties, and processing fluidity. This formulation balances mechanical and processing properties, making it suitable for typical applications in outdoor flooring supports.

[0160] Comparative Example 2

[0161] The difference from Example 1 is that the pultrusion process is not used, that is, steps S1 to S3 are missing. Instead, the polyurethane raw material is directly injected into the mold through a dispensing machine and then heated and cured to form a support; the subsequent steps are the same.

[0162] The mechanical properties and bonding strength of Examples 1-4 and Comparative Examples 1-2 were tested in accordance with GB / T 24508-2020 for wood-plastic composite flooring. The results are shown in Table 1.

[0163] Table 1 Performance Test Results Bending strength (MPa) Flexural modulus (GPa) Surface bond strength (MPa) <![CDATA[Linear coefficient of thermal expansion (°C -1 )]]> Example 1 52 29 1.8 <![CDATA[0.21×10 -5 ]]> Example 2 53 28 2.7 <![CDATA[0.28×10 -5 ]]> Example 3 51 30 1.9 <![CDATA[0.26×10 -5 ]]> Example 4 52 29 2.0 <![CDATA[0.22×10 -5 ]]> Comparative Example 1 55 33 1.3 <![CDATA[0.19×10 -5 ]]> Comparative Example 2 21 3.2 1.4 <![CDATA[0.37×10 -5 ]]> .

Claims

1. A high-strength, low-shrinkage outdoor flooring, comprising a support body and at least a rigid surface layer covering the usable surface of the support body, characterized in that: The support includes a polymer matrix and multiple reinforcing fiber yarns densely distributed inside the polymer matrix and arranged generally parallel to the length direction of the support; the rigid surface layer is made of silicate-based polymer composite material.

2. The high-strength, low-shrinkage outdoor flooring according to claim 1, characterized in that: The polymer matrix is ​​made of polyurethane.

3. A high-strength, low-shrinkage outdoor flooring according to claim 1 or 2, characterized in that: In the silicate-based polymer composite material, the polymer is selected from at least one of vinyl acetate and ethylene copolymer emulsion, aqueous polyurethane emulsion, and polyacrylate emulsion.

4. The high-strength, low-shrinkage outdoor flooring according to claim 1, characterized in that, The formulation of the silicate-based polymer composite material is as follows: Polymer emulsion 27~36wt% Wood fiber 5~8wt% Water-reducing agent 0.1~0.4wt% Cellulose ether 0.1~0.4wt% The remaining amount of silicate cement.

5. The high-strength, low-shrinkage outdoor flooring according to claim 4, characterized in that, The formulation of the silicate-based polymer composite material is as follows: Vinyl acetate and ethylene copolymer powder 2.47~3.21wt% Water 24.7~32.1wt% Wood fiber 6.41~6.59wt% Water-reducing agent 0.16~0.32wt% Cellulose ethers 0.16~0.32wt% The remaining amount of silicate cement.

6. The high-strength, low-shrinkage outdoor flooring according to claim 1, characterized in that: The outdoor flooring also includes a filler material disposed within the cavity of the support body; the filler material is made of polyurethane foam; the formula of the polyurethane foam is as follows: 3-5 wt% water 1-2 wt% dibutyltin dilaurate Polyether-modified siloxane 2~3wt% Aluminum hydroxide 15~20wt% 15-20 wt% glass hollow microspheres Remaining amount of polyurethane prepolymer.

7. The high-strength, low-shrinkage outdoor flooring according to claim 2, characterized in that: The polymer matrix is ​​made of modified polyurethane; the modified polyurethane formulation includes the following components in parts by weight: Component A: Polyether polyol 18~20 Polyester polyol 10~12 Dimethylolpropionic acid 1~3 1,4-Butanediol 4~6 KH-550 0.5~1.0 Antioxidant 1010 0.1~0.3 DMF 20~30; Component B: TDI 28~36 HDI 8~12 Phosphoric acid 0.18~0.36 Dibutyltin dilaurate 0.08~0.

12.

8. A method for preparing a high-strength, low-shrinkage outdoor flooring according to any one of claims 1 to 7, comprising the following steps: S1. Guide the multiple strands of reinforcing fiber yarn on the yarn rack with a yarn guide plate, and pass them into the pultrusion die in parallel. Pull them out from the discharge port of the pultrusion die and keep the reinforcing fiber yarn in a taut state. S2. The raw materials constituting the polymer matrix are injected into the pultrusion mold using a dispensing machine, submerging the reinforcing fiber yarns in the mold cavity, and then heated and cured. S3. The polymer, together with the reinforcing fiber yarn, is extruded from the die opening of a pultrusion die to obtain a semi-finished support profile. S4. Solidify the semi-finished support profile to obtain the support body; S5. Pull the support body to cooperate with extrusion; S6. Adjust at least one of the feeding rate, extrusion rate and traction rate to match these rates so that the external dimensions of the support body meet the requirements. S7. Using a scraper, the material prepared according to the silicate-based polymer composite material formula is uniformly coated onto the surface of the support to obtain a semi-finished outdoor floor with a hard surface. S8. Use an embossing machine to create wood grain on the hard surface of the material being used; S9, online cutting, to produce outdoor flooring.

9. The preparation method according to claim 8, characterized in that: It also includes the step of applying a polyurethane primer to the surface of the support to be covered before scraping.

10. The preparation method according to claim 8, characterized in that: It also includes the step of injecting polyurethane foam into the cavity of the outdoor floor.