Single-component polyurethane adhesive, composite material as well as preparation method and application of single-component polyurethane adhesive and composite material

Abstract

The invention discloses a single-component polyurethane adhesive, a composite material and a preparation method and application of the single-component polyurethane adhesive and the composite material, and relates to the technical field of polyurethane adhesives, and the single-component polyurethane adhesive comprises the following raw material components in parts by weight: 30-50 parts of polyester polyol; 10 to 20 parts of polyether polyol; 30 to 70 parts of aromatic diisocyanate; 5 to 10 parts of a chain extender; 0.01 part to 0.1 part of a catalyst; 0.1 to 3 parts of filler; 0.02 to 0.5 part of an auxiliary agent; and 30-50 parts of an organic solvent. The single-component polyurethane adhesive provided by the invention can solve the problems of difficult interlayer bonding and easy interface failure of a composite material, and improves the structural reliability and mechanical properties of the composite material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polyurethane adhesive, in particular to a single-component polyurethane adhesive, a preparation method and application thereof, and a composite material and a preparation method thereof. BACKGROUND

[0002] The multi-layer composite material constructed by polyvinyl chloride (PVC) and traditional materials such as polyester fabric and nylon fabric has the problems of large density, low mechanical strength (insufficient tensile strength and breaking strength), weak puncture resistance and knife-cut resistance, and is difficult to meet the demand for lightweight and high-strength materials in the fields of assault boats, air films, outdoor tents, assault clothes and 3C electronics.

[0003] As a high-performance reinforcing material, the ultra-high molecular weight polyethylene (UHMWPE, referred to as UPE) has a molecular weight of 1 million to 5 million, has the characteristics of low density, ultra-high tensile strength, breaking strength and excellent puncture resistance and knife-cut resistance, and becomes the core reinforcing layer selection of a new generation of composite material. However, the surface energy of UPE is extremely low, which leads to the fact that conventional adhesives cannot realize effective interlayer adhesion between UPE and materials such as PVC, thermoplastic polyurethane elastomer (TPU) and silicone rubber, and the composite material is prone to interfacial failure problems such as delamination and peeling, which seriously restricts the application of UPE in high-performance composite fields such as police protection and outdoor equipment.

[0004] The existing technology faces a double bottleneck, and the performance of the traditional composite system is significantly limited, while the new composite material with UPE as the intermediate layer is limited by the interfacial adhesion technology, and it is difficult to fully exert the mechanical performance advantage. Therefore, developing a high-efficiency adhesive resin system suitable for UPE with extremely low surface energy has become a key technical difficulty to break through the performance bottleneck of the composite material. SUMMARY

[0005] The present application is committed to solving the interlayer adhesion problem between UPE and materials such as PVC, TPU and silicone rubber due to the extremely low surface energy of UPE, overcoming the interfacial failure problems such as delamination and peeling of the composite material in the prior art, realizing the efficient combination of UPE and other materials, and improving the structural reliability and mechanical performance of the composite material.

[0006] To solve the above problems, the first aspect of the present application provides a single-component polyurethane adhesive, the raw material components of which include, in parts by weight: 30-50 parts of polyester polyol; 10-20 parts of polyether polyol; 30-70 parts of aromatic diisocyanate; 5-10 parts of chain extender; 0.01-0.1 parts of catalyst; 0.1-3 parts of filler; 0.02-0.5 parts of auxiliary agent; and 30-50 parts of organic solvent.

[0007] In the above raw material components, the polyester polyol contains strong polar groups such as ester groups in its molecular structure, and can form specific interactions with the molecules of materials such as PVC and TPU, for example, can form dipole-dipole interactions with chlorine atoms in PVC and hydrogen bond effects with urethane groups in TPU. The above effects can effectively compensate for the low interfacial defects of the surface energy of UPE. At the same time, the rigid structure in the molecular structure of the polyester polyol can increase the glass transition temperature (Tg) of the polyurethane network, and endow the adhesive with excellent mechanical properties and heat resistance.

[0008] The molecular main chain of the polyether polyol contains ether bonds, which have low cohesive energy density and low internal cohesive energy, and endow the chain segment with strong movement ability, and still maintain flexibility in low temperature environment. The flexible chain segment can diffuse to the micro defects such as micropores and grooves on the non-polar surface of UPE to form a "flexible winding" physical adsorption structure, thereby reducing the interfacial free energy.

[0009] When the polyether polyol is used in combination with the polyester polyol, the polar interaction can be supplemented while the low temperature flexibility is retained, and the "rigidity-flexibility synergy" interfacial bonding can be achieved.

[0010] The molecular structure of the aromatic diisocyanate has aromatic rings, and the π-π stacking effect between the aromatic rings can enhance the interaction force of the polyurethane chain segment, thereby improving the cohesive strength of the adhesive. At the same time, the rigid aromatic ring skeleton can uniformly transmit external load, reduce local stress concentration at the interface, and reduce the risk of peeling.

[0011] The filler can fill the defects such as micropores and grooves on the surface of the UPE substrate (such as the submicron gap between UPE fibers), and form a "nanopinning" structure after curing, so that the interfacial failure energy is improved by overcoming the hooking force between the particles and the substrate. When subjected to external force, it can act as a rigid stress concentration point to initiate the propagation of microcracks in the adhesive, and energy is consumed through particle-matrix interface debonding and plastic deformation to avoid direct interfacial peeling.

[0012] The organic solvent can reduce the surface tension of the adhesive, so that a uniform thin film is formed on the UPE surface, and air holes and local defects are reduced. The amorphous region of the UPE surface is swollen, and the polyol chain segment penetrates into the amorphous region of the UPE fiber, and a molecular level interlocking structure is formed after curing. At the same time, during the volatilization of the organic solvent, the adhesive gradually changes from a "low viscosity penetration state" to a "high crosslinking solid state", avoiding the accumulation of internal stress caused by rapid curing.

[0013] As can be seen, the one-component polyurethane adhesive of the present application effectively solves the interfacial adhesion problem of ultra-low surface energy UPE and other materials through the synergistic effect of multiple components, provides key technical support for the development of high-performance composite materials, and fundamentally breaks through the technical bottleneck of interfacial adhesion of ultra-low surface energy materials.

[0014] In some preferred embodiments, the polyester polyol comprises a first polyester polyol having a high hydroxyl value and / or a second polyester polyol having a high molecular weight, wherein the first polyester polyol has a hydroxyl value of 100 mgKOH / g~150 mgKOH / g and a number average molecular weight of 800~1000; the second polyester polyol has a hydroxyl value of 30 mgKOH / g~60 mgKOH / g and a number average molecular weight of 2000~4000.

[0015] More preferably, the polyester polyol comprises a first polyester polyol having a high hydroxyl value and a second polyester polyol having a high molecular weight, to achieve a balanced control of crosslinking density and segment flexibility. Specifically, the high hydroxyl value increases the isocyanate reaction sites, forms a more intensive crosslinking network, and improves rigidity and heat resistance; the long chain segment structure of high molecular weight provides excellent flexibility.

[0016] In some preferred embodiments, the polyether polyol has a number average molecular weight of 500~3000.

[0017] To further improve the adhesion, mechanical strength and heat resistance of the adhesive, the mass ratio of the first polyester polyol, the second polyester polyol and the polyether polyol is preferably (1.3~2.3):(0.6~1.4):1.

[0018] In some preferred embodiments, the ratio (n NCO / n OH ) of the number of moles of isocyanate groups (n NCO ) of the aromatic diisocyanate to the total number of moles of hydroxyl groups (n OH ) of the polyester polyol, the polyether polyol is (1.3~2.5):1, specifically, for example, 1.3:1, 1.35:1, 1.4:1, 1.45:1, 1.5:1, 1.55:1, 1.6:1, 1.65:1, 1.7:1, 1.75:1, 1.8:1, 1.85:1, 1.9:1, 1.95:1, 2:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1, or a specific ratio within the range of any two of the above ratios. More preferably, the ratio is (1.3~2):1. Most preferably, the ratio is 1.3:1.

[0019] In some preferred embodiments, the polyester polyol is selected from one or more of polyethylene adipate (PEA), polybutylene adipate, polypropylene adipate.

[0020] More preferably, the polyester polyol is selected from polyethylene adipate and / or polybutylene adipate.

[0021] The polyethylene adipate described above can be selected from PEA-1000, PEA-2000, PEA-3000, PEA-4000, etc. Among them, the number average molecular weight of PEA-1000 is about 1000, and the theoretical hydroxyl value is about 112 mgKOH / g. The number average molecular weight of PEA-2000 is about 2000, and the theoretical hydroxyl value is about 56 mgKOH / g. The number average molecular weight of PEA-3000 is about 3000, and the theoretical hydroxyl value is about 37 mgKOH / g. The number average molecular weight of PEA-4000 is about 4000, and the theoretical hydroxyl value is about 28 mgKOH / g.

[0022] The polybutylene adipate can be selected from polybutylene adipate-800, polybutylene adipate-1000, polybutylene adipate-2000, polybutylene adipate-2500, polybutylene adipate-3000. Among them, the number average molecular weight of polybutylene adipate-800 is about 800, and the theoretical hydroxyl value is about 140 mgKOH / g. The number average molecular weight of polybutylene adipate-1000 is about 1000, and the theoretical hydroxyl value is about 112 mgKOH / g. The number average molecular weight of polybutylene adipate-2000 is about 2000, and the theoretical hydroxyl value is about 56 mgKOH / g. The number average molecular weight of polybutylene adipate-2500 is about 2500, and the theoretical hydroxyl value is about 45 mgKOH / g. The number average molecular weight of polybutylene adipate-3000 is about 3000, and the theoretical hydroxyl value is about 37 mgKOH / g.

[0023] The polypropylene adipate can be selected from polypropylene adipate-1000, polypropylene adipate-2000, polypropylene adipate-3000. Among them, the number average molecular weight of polypropylene adipate-1000 is about 1000, and the theoretical hydroxyl value is about 112 mgKOH / g. The number average molecular weight of polypropylene adipate-2000 is about 2000, and the theoretical hydroxyl value is about 56 mgKOH / g. The number average molecular weight of polypropylene adipate-3000 is about 3000, and the theoretical hydroxyl value is about 37 mgKOH / g.

[0024] More preferably, the polyester polyol includes PEA-1000 and PEA-2000.

[0025] In some preferred embodiments, the polyether polyol is selected from one or more of polypropylene glycol (PPG), polytetramethylene glycol (PTMG), polyoxypropylene triol (POP).

[0026] More preferably, the polyether polyol is selected from polypropylene glycol.

[0027] The polypropylene glycol can be selected from PPG-1000, PPG-1500, PPG-2000, PPG-2500, PPG-3000. The number average molecular weight of PPG-1000 is about 1000, and the theoretical hydroxyl value is about 112 mgKOH / g. The number average molecular weight of PPG-1500 is about 1500, and the theoretical hydroxyl value is about 75 mgKOH / g. The number average molecular weight of PPG-2000 is about 2000, and the theoretical hydroxyl value is about 56 mgKOH / g. The number average molecular weight of PPG-2500 is about 2500, and the theoretical hydroxyl value is about 45 mgKOH / g. The number average molecular weight of PPG-3000 is about 3000, and the theoretical hydroxyl value is about 37 mgKOH / g.

[0028] The polytetramethylene glycol can be selected from PTMG-650, PTMG-1000, PTMG-1400, PTMG-2000, PTMG-3000. The number average molecular weight of PTMG-650 is about 650, and the theoretical hydroxyl value is about 173 mgKOH / g. The number average molecular weight of PTMG-1000 is about 1000, and the theoretical hydroxyl value is about 112 mgKOH / g. The number average molecular weight of PTMG-1400 is about 1400, and the theoretical hydroxyl value is about 80 mgKOH / g. The number average molecular weight of PTMG-2000 is about 2000, and the theoretical hydroxyl value is about 56 mgKOH / g. The number average molecular weight of PTMG-3000 is about 3000, and the theoretical hydroxyl value is about 37 mgKOH / g.

[0029] The polyoxypropylene triol can be selected from POP-1000, POP-1500, POP-2000, POP-2500, POP-3000. The number average molecular weight of POP-1000 is about 1000, and the theoretical hydroxyl value is about 168 mgKOH / g. The number average molecular weight of POP-1500 is about 1500, and the theoretical hydroxyl value is about 112 mgKOH / g. The number average molecular weight of POP-2000 is about 2000, and the theoretical hydroxyl value is about 84 mgKOH / g. The number average molecular weight of POP-3000 is about 3000, and the theoretical hydroxyl value is about 56 mgKOH / g. The number average molecular weight of POP-2500 is about 2500, and the theoretical hydroxyl value is about 67 mgKOH / g.

[0030] More preferably, the polyether polyol comprises PPG-1500.

[0031] In some preferred embodiments, the aromatic diisocyanate comprises toluene diisocyanate (TDI) and / or diphenylmethane diisocyanate (MDI).

[0032] More preferably, the aromatic diisocyanate comprises toluene diisocyanate and diphenylmethane diisocyanate, and the mass ratio (mTDI :m MDI ) is (0.25~1.5):1, specifically, for example, 0.25:1, 0.3:1, 0.35:1, 0.4:1, 0.45:1, 0.5:1, 0.55:1, 0.6:1, 0.65:1, 0.7:1, 0.75:1, 0.8:1, 0.85:1, 0.9:1, 0.95:1, 1:1, 1.05:1, 1.1:1, 1.15:1, 1.2:1, 1.25:1, 1.3:1, 1.35:1, 1.4:1, 1.45:1, 1.5:1, or a specific ratio within a range constituted by any two of the above ratios. More preferably, m TDI :m MDI =1.5:1.

[0033] In some preferred embodiments, the chain extender comprises one or more of ethylene glycol, 1,2-propanediol, 1,4-butanediol (BDO), diethylene glycol, 1,6-hexanediol, neopentyl glycol.

[0034] More preferably, the chain extender comprises 1,4-butanediol.

[0035] In some preferred embodiments, the catalyst comprises one or more of dibutyltin dilaurate, stannous octoate, triethylamine, N,N-dimethylcyclohexylamine, organobismuth catalyst, zinc naphthenate, lead naphthenate.

[0036] More preferably, the catalyst comprises dibutyltin dilaurate (DBDTL).

[0037] In some preferred embodiments, the filler comprises one or more of nano calcium carbonate, talcum powder, kaolin, glass fiber, carbon fiber, nano silicon dioxide, aluminum hydroxide.

[0038] More preferably, the filler comprises nano calcium carbonate.

[0039] In some preferred embodiments, the auxiliary agent comprises a leveling agent, and the leveling agent comprises one or more of an acrylate leveling agent, a silicone leveling agent, a fluorocarbon leveling agent, a cellulose leveling agent.

[0040] More preferably, the auxiliary agent comprises a silicone leveling agent.

[0041] In some preferred embodiments, the organic solvent comprises one or more of ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, cyclohexanone, dichloromethane, tetrahydrofuran, toluene, xylene, propylene glycol methyl ether, propylene glycol methyl ether acetate, dimethylformamide (DMF).

[0042] More preferably, the organic solvent comprises ethyl acetate and dimethylformamide, and the mass ratio of the two is (5-7):(3-5).

[0043] The second aspect of the present application provides a preparation method of the one-component polyurethane adhesive described in any one of the above, which comprises the following steps: S10: preparation of a prepolymer; reacting an aromatic diisocyanate with a polyester polyol and a polyether polyol at a first temperature and a first stirring speed for a first time to obtain a prepolymer, wherein the mass percentage content of isocyanate groups (NCO) in the prepolymer is 2%-5%.

[0044] S11: mixing of a main agent; adding a chain extender, a catalyst and an auxiliary agent to the prepolymer, stirring at a second temperature and a second stirring speed for a second time to obtain a uniformly dispersed main agent mixing system.

[0045] S12: dilution with an organic solvent and addition of fillers; cooling the main agent mixing system to a third temperature, adding an organic solvent and fillers to the main agent mixing system, increasing the stirring speed to a third stirring speed, and stirring for a third time to ensure uniform dispersion, to obtain the one-component polyurethane adhesive.

[0046] When step S10 is performed, the mass percentage content of isocyanate groups in the prepolymer is monitored (titered with di-n-butylamine) to avoid excessive reaction leading to gelation.

[0047] In some preferred embodiments, in step S10, the first temperature is 60°C-90°C, the first stirring speed is 250 rpm-350 rpm, and the first time is 2 hours-5 hours.

[0048] When step S11 is performed, it is preferably performed at low temperature to reduce the occurrence of side reactions (such as excessive generation of urea bonds).

[0049] In some preferred embodiments, in step S11, the second temperature is 50°C-70°C, the second stirring speed is 150 rpm-250 rpm, and the second time is 1 hour-2 hours.

[0050] When step S12 is performed, the fillers can be pre-dispersed in the organic solvent to reduce phase separation caused by excessively high local concentration.

[0051] In some preferred embodiments, in step S12, the third temperature is 50°C or lower, the third stirring speed is 350 rpm-450 rpm, and the third time is 20 minutes-40 minutes.

[0052] In some preferred embodiments, the raw materials used in the above preparation method are strictly dehydrated (moisture content <0.05wt%) before use to avoid reaction with isocyanate groups to generate bubbles.

[0053] In some preferred embodiments, the above preparation method further comprises: step S13, filtering and packaging.

[0054] In some specific embodiments, the single-component polyurethane adhesive obtained in step S12 is filtered with a 200-mesh filter and then sealed and stored to avoid water absorption or contamination by impurities.

[0055] In some preferred embodiments, the sealed light-proof storage at 5℃-25℃ can extend the shelf life to 6 months.

[0056] The third aspect of the present application provides a use of the single-component polyurethane adhesive of any one of the above in the preparation of a composite material.

[0057] The fourth aspect of the present application provides a composite material, comprising: a first material layer comprising a first surface and a second surface arranged oppositely; a second material layer adhered to the first surface of the first material layer through a first adhesive layer; a third material layer adhered to the second surface of the first material layer through a second adhesive layer; wherein the first adhesive layer and the second adhesive layer are both prepared by the coating process of the single-component polyurethane adhesive of any one of the above.

[0058] In some preferred embodiments, the first material layer is a UPE film, and the materials of the second material layer and the third material layer are the same or different and are independently selected from PVC film, TPU film, and silicone rubber film.

[0059] In some specific embodiments, the first material layer is a UPE film; the second material layer is selected from PVC film, TPU film, and silicone rubber film; and the third material layer is selected from PVC film and TPU film.

[0060] In some more specific embodiments, the first material layer is a UPE film; and the second material layer and the third material layer are both PVC films.

[0061] In some more specific embodiments, the first material layer serves as an intermediate layer, the second material layer serves as a surface layer, and the third material layer serves as a bottom layer.

[0062] The fifth aspect of the present application provides a preparation method of a composite material, comprising the following steps: S20: forming a first adhesive layer on the first surface of the first material layer; coating the single-component polyurethane adhesive on the first surface of the first material layer and baking at a fourth temperature for a fourth time to form a first adhesive layer.

[0063] S21: forming a second adhesive layer on the second surface of the first material layer; coating the single-component polyurethane adhesive on the second surface of the first material layer and baking at a fifth temperature for a fifth time to form a second adhesive layer.

[0064] S22: laminating a second material layer and a third material layer on the first material layer with the first adhesive layer and the second adhesive layer; contacting the second material layer with the first adhesive layer and contacting the third material layer with the second adhesive layer at a sixth temperature and a target composite pressure, and continuously pressing at a target linear speed to obtain the composite material.

[0065] In some preferred embodiments, in step S20, the fourth temperature is 100-120°C and the fourth time is 0.5-1.5 minutes.

[0066] In some specific embodiments, in step S20, the first material layer is a UPE film or a UPE grid cloth. When coating the single-component polyurethane adhesive, the first material layer needs to be kept flat and wrinkle-free. After the coating process is completed, the surface is baked in an oven at 110°C for about 1 minute until it is not sticky to the hand, and then it is wound up.

[0067] In some preferred embodiments, in step S21, the fifth temperature is 100-120°C and the fifth time is 0.5-1.5 minutes.

[0068] In some specific embodiments, in step S21, when coating the single-component polyurethane adhesive, the first material layer needs to be kept flat and wrinkle-free. After the coating process is completed, the surface is baked in an oven at 110°C for about 1 minute until it is not sticky to the hand, and then it is wound up. At this time, the surface of the first material layer is basically flat and solvent-free.

[0069] In some preferred embodiments, in step S22, the sixth temperature is 100-130°C, the target composite pressure is 0.1-1.0 MPa, and the target linear speed is 3-5 m / min.

[0070] In some specific embodiments, in step S22, a three-layer laminator is used for the pressing operation. The three-layer laminator can be used with conventional equipment. Generally, the three-layer laminator includes a heating lamination section and a cooling section, wherein the heating lamination section is used for heating the pressing operation, and the cooling section is used for cooling to room temperature for winding.

[0071] In some specific embodiments, in step S22, the second material layer, the third material layer and the first material layer with the first adhesive layer and the second adhesive layer are aligned and placed into a three-layer laminating machine, a set of guide rollers of the three-layer laminating machine is pressed, the temperature of the heating and laminating section is adjusted to 125°C, the length of the heating section is 4 meters, the walking speed is 4 meters per minute, and the laminating operation is performed by a set of laminating rollers. The laminated composite material enters the cooling section for cooling and is wound up.

[0072] Compared with the prior art, the technical scheme of the present application has the following beneficial effects: The single-component polyurethane adhesive of the present application effectively solves the interface bonding problem of ultra-low surface energy UPE and other materials through the synergistic effect of multiple components, overcomes the interface failure problems such as delamination and peeling of the composite material in the prior art, realizes efficient bonding of ultra-low surface energy UPE and other materials, and fully utilizes the excellent mechanical properties and functionality.

[0073] Since UPE has excellent properties such as low density, high tensile strength, high breaking strength, puncture resistance and knife cut resistance, when it is used as a reinforcing structure intermediate layer of a composite material, the composite material can inherit the above-mentioned properties. Therefore, the single-component polyurethane adhesive of the present application is used to realize the compounding of UPE and other functional materials, and the prepared composite material has the advantages of lightweight, high mechanical strength and high peeling strength, and can be widely used in fields such as inflatable boats, air films, outdoor tents, outdoor clothes and 3C electronics.

[0074] The single-component polyurethane adhesive and the preparation method of the composite material of the present application have more excellent performance, simple process and strong operability, and significantly improve the industrial production feasibility. BRIEF DESCRIPTION OF DRAWINGS

[0075] The following drawings describe the exemplary embodiments disclosed in the present application in detail. The same reference numerals in the drawings represent similar structures in several views of the drawings. Those skilled in the art will understand that these embodiments are non-limiting, exemplary embodiments, the drawings are only for the purpose of illustration and description, and are not intended to limit the scope of the present application, and other embodiments can also achieve the same purpose of the invention in the present application. It should be understood that the drawings are not drawn to scale. Among them: Figure 1 The structure schematic diagram of the composite material of some embodiments of the present application. DETAILED DESCRIPTION

[0076] The following will exemplarily give a preparation example of a single-component polyurethane adhesive and a composite material. It should be noted that the number of layers of the composite material can be designed according to actual needs, and here, a composite material with a three-layer structure will be taken as an example to be described.

[0077] Please refer to Figure 1 As shown in the figure, the composite material includes a UPE film 1, a first PVC film 2 and a second PVC film 3, wherein the first PVC film 2 is adhered to the first surface 11 of the UPE film 1 through a first adhesive layer 41, and the second PVC film 3 is adhered to the second surface 12 of the UPE film 1 through a second adhesive layer 42. The thicknesses of the UPE film 1, the first PVC film 2, the second PVC film 3, the first adhesive layer 41 and the second adhesive layer 42 can be 10 microns to 200 microns respectively.

[0078] Unless otherwise specified, the reagents and raw materials used in the following examples can be purchased through commercial channels. The experimental methods without specific conditions are selected according to conventional methods and conditions, or according to the product instructions.

[0079] The sources of raw materials, materials and instruments used in the following examples are as follows: PEA-1000, PEA-2000, PEA-4000 were purchased from Meric; PPG-1500 was purchased from Dow; TDI was purchased from BASF, model number Lupranate T-80; MDI was purchased from Wanhua Chemical, model number MDI-50; BDO was purchased from Sinopec Changcheng Energy Company; dibutyltin dilaurate (DBDTL) was purchased from Beijing Zhengheng Chemical Co., Ltd.; nano-CaCO3 was purchased from Changzhou Calcium Carbonate Co., Ltd.; silicone leveling agent was purchased from BYK, model number BYK 306; ethyl acetate and DMF were purchased from Sinopharm; UPE film was purchased from Suzhou Yilian Road Material Technology Co., Ltd.; PVC film was purchased from Jiangsu Rongfeng New Material Technology Co., Ltd.; three-layer composite machine was purchased from Jinzhida, model number JZD-31.

[0080] Example 1 This embodiment provides a single-component polyurethane adhesive, and the raw material components thereof include: PEA-1000, PEA-2000, PPG-1500, TDI, MDI, BDO, DBDTL, nano-CaCO3, silicone leveling agent, ethyl acetate and DMF mixed solvent. The proportioning of each component can be referred to Table 1 in weight fraction.

[0081] The preparation method of the single-component polyurethane adhesive includes the following steps: (1) Preparation of prepolymer; The TDI, MDI, PEA-1000, PEA-2000 and PPG-1500 are reacted at 60°C under stirring at a speed of 300 rpm for 5 hours to obtain a prepolymer, wherein the mass percentage content of isocyanate groups (NCO) in the prepolymer is 5%.

[0082] (2) mixing of the main agent; The BDO, DBDTL and silicone leveling agent are added to the prepolymer, and stirred at 60°C under stirring at a speed of 200 rpm for 1 hour to obtain a uniformly dispersed main agent mixing system.

[0083] (3) dilution with an organic solvent and addition of fillers; The main agent mixing system is cooled to 50°C, and the mixed solvent in which nano-CaCO3 is pre-dispersed is added to the main agent mixing system, and stirred at a speed of 400 rpm for 30 minutes to ensure uniform dispersion, thereby obtaining the one-component polyurethane adhesive.

[0084] (4) filtration and packaging; After filtration with a 200-mesh filter screen, it is sealed and stored to avoid water absorption or contamination by impurities.

[0085] The embodiment also provides a preparation method of the composite material as shown in Figure 1 The preparation method comprises the following steps: (1) forming a first adhesive layer on a first surface of a UPE film; The UPE film is kept flat and wrinkle-free, the one-component polyurethane adhesive of the embodiment is coated on the first surface of the UPE film by using a blade coating device, and baking is performed at 110°C for 1 minute to form a 50-micron first adhesive layer. The surface is not sticky and is wound up.

[0086] (2) forming a second adhesive layer on a second surface of the UPE film; The UPE film is kept flat and wrinkle-free, the one-component polyurethane adhesive of the embodiment is coated on the second surface of the UPE film by using a blade coating device, and baking is performed at 110°C for 1 minute to form a 50-micron second adhesive layer. The surface is not sticky and is wound up. The surface of the UPE film after coating and drying is basically flat and solvent-free.

[0087] (3) attaching two layers of PVC films to the two surfaces of the UPE film with the first adhesive layer and the second adhesive layer; Keep the UPE film flat and wrinkle-free, align the upper and lower two layers of PVC film with the scraped UPE film, and put them into the three-layer laminating machine. The upper and lower guide rollers are pressed tightly, the temperature of the drying channel is adjusted to 125℃, the length of the drying channel heating section is 4 meters, and the walking speed is 4 meters / minute. When the composite material enters the 4-meter internal drying channel, open the other set of pressing rollers for pressing, and the composite pressure is 0.5 MPa. Open the cooling section and roll up.

[0088] Example 2 The single-component polyurethane adhesive provided in this example has the following differences in raw material components compared to Example 1: m TDI :m MDI =1.5:1. The allocation ratio of each component can be seen in Table 1.

[0089] The preparation method of the single-component polyurethane adhesive and the composite material in this example is the same as that in Example 1.

[0090] Example 3 The single-component polyurethane adhesive provided in this example has the following differences in raw material components compared to Example 1: m TDI :m MDI =0.25:1. The allocation ratio of each component can be seen in Table 1.

[0091] The preparation method of the single-component polyurethane adhesive and the composite material in this example is the same as that in Example 1.

[0092] Example 4 The single-component polyurethane adhesive provided in this example has the following differences in raw material components compared to Example 1: n NCO / n OH =1.3:1. The allocation ratio of each component can be seen in Table 1.

[0093] The preparation method of the single-component polyurethane adhesive and the composite material in this example is the same as that in Example 1.

[0094] Example 5 The single-component polyurethane adhesive provided in this example has the following differences in raw material components compared to Example 1: n NCO / n OH =2:1. The allocation ratio of each component can be seen in Table 1.

[0095] The preparation method of the single-component polyurethane adhesive and the composite material in this example is the same as that in Example 1.

[0096] Example 6 The embodiment provides a single-component polyurethane adhesive, raw material components of which include PEA-4000, PPG-1500, TDI, BDO, DBDTL, nano-CaCO3, a silicone leveling agent, a mixed solvent of ethyl acetate and DMF. The component proportion can be seen from Table 1.

[0097] The preparation method of the single-component polyurethane adhesive comprises the following steps: (1) Preparation of a prepolymer; TDI, PEA-4000 and PPG-1500 are reacted at 90 DEG C and a stirring speed of 300 rpm for 2 hours to obtain a prepolymer, wherein the mass percentage content of isocyanate groups (NCO) in the prepolymer is 2%.

[0098] (2) Mixing of a main agent; BDO, dibutyltin dilaurate and the silicone leveling agent are added into the prepolymer, and the mixture is stirred at 60 DEG C and a stirring speed of 200 rpm for 2 hours to obtain a uniformly dispersed main agent mixture.

[0099] (3) Dilution with an organic solvent and addition of fillers; The main agent mixture is cooled to 50 DEG C, and the mixed solvent in which nano-CaCO3 is pre-dispersed is added into the main agent mixture, and the mixture is stirred at a stirring speed of 400 rpm for 30 minutes to ensure uniform dispersion, thereby obtaining the single-component polyurethane adhesive.

[0100] (4) Filtration and packaging; After filtration with a 200-mesh filter screen, the single-component polyurethane adhesive is sealed and stored to avoid water absorption or impurity pollution.

[0101] The preparation method of the composite material of the embodiment is same as that of Example 1.

[0102] Example 7 The embodiment provides a single-component polyurethane adhesive, raw material components of which include PEA-1000, PPG-1500, MDI, BDO, DBDTL, nano-CaCO3, a silicone leveling agent, a mixed solvent of ethyl acetate and DMF. The component proportion can be seen from Table 1.

[0103] The preparation method of the single-component polyurethane adhesive and the composite material of the embodiment is same as that of Example 1.

[0104] Table 1: Component proportion of Examples 1-7 Comparative Example 1 The comparative example provides a single-component polyurethane adhesive, and compared with Example 1, PPG-1500 is not added in the raw material, and n NCO / nOH and m TDI :m MDI The weight parts of each raw material component are as follows: PEA-1000 30 parts, PEA-2000 15 parts, TDI 20 parts, MDI 30 parts, BDO 10.8 parts, dibutyltin dilaurate 0.05 parts, nano-CaCO3 2 parts, silicone 0.25 parts, and mixed organic solvents of ethyl acetate and DMF 40 parts.

[0105] The one-component polyurethane adhesive and the composite material of the present comparative example were prepared in the same manner as in Example 1.

[0106] Comparative Example 2 The polyurethane adhesive used in the present comparative example was purchased from Huntsman Corporation, and the model number was 737.

[0107] The composite material was prepared in the same manner as in Example 1.

[0108] Viscosity test The viscosity of the polyurethane adhesive of Examples 1-7 and Comparative Examples 1-2 was tested at 25°C and a rotation speed of 50 rpm using a Brookfield DV2T viscometer.

[0109] Curing time test The adhesive of Examples 1-7 and Comparative Examples 1-2 was left to stand in an environment of 25°C and RH 50%, and the surface dry time thereof was tested. According to the ASTM D1640 standard, a polyethylene film was used to lightly touch the film surface, and no thread pulling or adhesion was achieved to reach the surface dry, and the time taken to reach the surface dry was the surface dry time.

[0110] Peeling strength test The 180° peeling strength of the one-component polyurethane adhesive on the PVC / UPE substrate was evaluated according to ASTM D3330, Method A. The test was performed in an environment of 25°C and 50% RH. The PVC substrate and the UPE substrate were each cut into a strip-shaped test piece of 25 mm x 200 mm, the bonding surface to be bonded was wiped with anhydrous ethanol or isopropanol and naturally dried for not less than 10 min. The adhesive was uniformly applied to the bonding surface of the UPE substrate by blade coating, and a 60-80 mm non-bonding area was reserved at the starting end as a guide end, and a 50-micron adhesive layer was formed by baking at 110°C for 1 min. The PVC substrate was attached to the UPE substrate, and the sample was placed in a pressing device, and tested using an Instron 5966 universal material testing machine with a 180° peeling clamp after pressing at 125°C for 5 min at a surface pressure of 0.5 MPa; the test conditions were 180° peeling, an experimental speed of 300 mm / min, and the median value in the stable peeling interval was taken, expressed as N / 25 mm.

[0111] Tensile strength test The one-component polyurethane adhesives of Examples 1-7 and Comparative Examples 1-2 were poured into dumbbell-shaped molds and vacuum degassed to remove internal bubbles, and then removed after baking at 110°C for 1 minute, and carefully demolded after cooling to room temperature to obtain dumbbell-shaped adhesive samples. The test was performed at 25°C, RH 50% using an Instron 5966 universal material testing machine with a tensile speed of 500 mm / min. The specific test method is described in ASTM D412, Method A.

[0112] Table 2. Performance test results As can be seen from Table 2, compared with the commercial polyurethane adhesive (Comparative Example 2), the one-component polyurethane adhesive of the present application can significantly improve the peel strength and mechanical strength of the UPE composite structure, and fundamentally alleviate the bonding bottleneck of the ultra-low surface energy interface.

[0113] Further analysis shows that the peel strength of Example 1 is significantly higher than that of Comparative Example 1 without adding polyether polyol, because Example 1 uses both polyester polyol and polyether polyol. The polar interaction of polyester polyol enhances the interfacial bonding force, and the flexible segment of polyether polyol can disperse stress, and the combination of the two forms a synergistic effect, achieving the common improvement of peel strength and mechanical strength.

[0114] Comparing Comparative Example 1, Example 4 and Example 5, it can be seen that when n NCO :n OH =(1.3-2):1, the one-component polyurethane adhesive has high peel strength and mechanical strength; especially when n NCO / n OH =1.3:1, the peel strength and mechanical strength are as high as 1500 N / 25 mm and 11.2 MPa, respectively.

[0115] And comparing Examples 1-3, it can be seen that when m TDI :m MDI =1.5:1, the one-component polyurethane adhesive has the best comprehensive performance in peel strength and tensile strength.

[0116] The above description of the embodiments is to facilitate the understanding and application of the present application by those of ordinary skill in the art. Those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described herein to other embodiments without having to exert creative labor. Therefore, the present application is not limited to the embodiments described herein, and the improvements and modifications made by those skilled in the art based on the disclosure of the present application without departing from the scope and spirit of the present application are within the scope of the present application.

Claims

1. A one-component polyurethane adhesive, characterized in that, The raw material components include, in parts by weight: Polyester polyol 30-50 parts; Polyether polyol 10-20 parts; Aromatic diisocyanate 30-70 parts; Chain extender 5-10 parts; Catalyst 0.01-0.1 part; Filler 0.1-3 parts; Auxiliary agent 0.02-0.5 parts; Organic solvent 30-50 parts.

2. The one-component polyurethane adhesive according to claim 1, characterized in that In the raw material components: The polyester polyol includes a first polyester polyol and / or a second polyester polyol, wherein the first polyester polyol has a hydroxyl value of 100-150 mgKOH / g and a number average molecular weight of 800-1000; the second polyester polyol has a hydroxyl value of 30-60 mgKOH / g and a number average molecular weight of 2000-4000; preferably, the polyester polyol includes the first polyester polyol and the second polyester polyol, and the mass ratio of the first polyester polyol, the second polyester polyol and the polyether polyol is (1.3-2.3):(0.6-1.4):1; and / or, The polyether polyol has a number average molecular weight of 500-3000; and / or, The aromatic diisocyanate has a molar ratio of isocyanate groups to the total moles of hydroxyl groups of the polyester polyol and the polyether polyol of (1.3-2):

1.

3. The one-component polyurethane adhesive according to claim 1, characterized in that The raw material components satisfy one or more of the following characteristics: (1) The polyester polyol is selected from one or more of polyethylene adipate, polybutylene adipate, polypropylene adipate; preferably, the polyester polyol is selected from polyethylene adipate and / or polybutylene adipate; (2) The polyether polyol is selected from one or more of polypropylene glycol, polytetrahydrofuran diol, polyoxypropylene triol; preferably, the polyether polyol is selected from polypropylene glycol; (3) The aromatic diisocyanate includes toluene diisocyanate and / or diphenyl methane diisocyanate; (4) The chain extender includes one or more of ethylene glycol, 1,2-propanediol, 1,4-butanediol, diethylene glycol, 1,6-hexanediol, neopentyl glycol; (5) The catalyst includes one or more of dibutyltin dilaurate, stannous octoate, triethylamine, N,N-dimethylcyclohexylamine, organic bismuth catalyst, zinc naphthenate, lead naphthenate; (6) The filler includes one or more of nano calcium carbonate, talc, kaolin, glass fiber, carbon fiber, nano silicon dioxide, aluminum hydroxide; (7) The auxiliary agent includes a leveling agent, and the leveling agent is selected from one or more of acrylate leveling agent, silicone leveling agent, fluorocarbon leveling agent, cellulose leveling agent; (8) The organic solvent includes one or more of ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, cyclohexanone, dichloromethane, tetrahydrofuran, toluene, xylene, propylene glycol methyl ether, propylene glycol methyl ether acetate, dimethylformamide.

4. The one-component polyurethane adhesive according to claim 1, characterized in that In the raw material components: The polyester polyol includes PEA-1000 and PEA-2000, and the polyether polyol includes PPG-1500; The aromatic diisocyanate is a combination of toluene diisocyanate and diphenyl methane diisocyanate, and the mass ratio of the two is (0.25-1.5):1; The chain extender comprises 1,4-butanediol; The catalyst comprises dibutyl tin dilaurate; The filler comprises nano calcium carbonate; The auxiliary agent comprises an organic silicon leveling agent; The organic solvent comprises ethyl acetate and dimethylformamide, and the mass ratio of the two is (5-7):(3-5).

5. A process for the preparation of a one-component polyurethane adhesive according to any one of claims 1 to 4, characterized in that The preparation method comprises: reacting aromatic diisocyanate with polyester polyol and polyether polyol at a first temperature and a first stirring speed for a first time to obtain a prepolymer, wherein the mass percentage content of isocyanate groups in the prepolymer is 2%-5%; adding a chain extender, a catalyst and an auxiliary agent to the prepolymer, stirring at a second temperature and a second stirring speed for a second time to obtain a uniformly dispersed main agent mixture system; cooling the main agent mixture system to a third temperature, adding an organic solvent and a filler to the main agent mixture system, increasing the stirring speed to a third stirring speed, and stirring for a third time to obtain the one-component polyurethane adhesive.

6. The method of claim 5, wherein the one-component polyurethane adhesive is prepared by mixing the polyol, the isocyanate, the chain extender, and the catalyst. 5 The preparation method meets one or more of the following conditions: (1) the first temperature is 60-90℃, the first stirring speed is 250-350rpm, and the first time is 2-5 hours; (2) the second temperature is 50-70℃, the second stirring speed is 150-250rpm, and the second time is 1-2 hours; (3) the third temperature is below 50℃, the third stirring speed is 350-450rpm, and the third time is 20-40 minutes.

7. Use of the one-component polyurethane adhesive according to any one of claims 1-4 in the preparation of a composite material.

8. A composite material, characterized by Comprise: a first material layer comprising oppositely arranged first and second surfaces; a second material layer adhered to the first surface of the first material layer through a first adhesive layer; a third material layer adhered to the second surface of the first material layer through a second adhesive layer; wherein the first adhesive layer and the second adhesive layer are both prepared by a coating process through the one-component polyurethane adhesive according to any one of claims 1-4.

9. The composite material of claim 8, wherein, The first material layer is an ultrahigh molecular weight polyethylene film; the materials of the second material layer and the third material layer are the same or different, and are independently selected from polyvinyl chloride film, thermoplastic polyurethane elastomer film, and silicone rubber film.

10. A method of producing a composite material, characterized by, Comprise: coating the one-component polyurethane adhesive according to any one of claims 1-4 on the first surface of the first material layer, and baking at a fourth temperature for a fourth time to form a first adhesive layer; preferably, the fourth temperature is 100-120℃, and the fourth time is 0.5-1.5 minutes; coating the single-component polyurethane adhesive of any one of claims 1 to 4 on the second surface of the first material layer and baking at a fifth temperature for a fifth time to form a second adhesive layer; preferably, the fifth temperature is 100-120℃, and the fifth time is 0.5-1.5 minutes; contacting the second material layer with the first adhesive layer and contacting the third material layer with the second adhesive layer at a sixth temperature and a target composite pressure, and continuously pressing at a target linear speed to obtain the composite material; preferably, the sixth temperature is 100-130℃, the target composite pressure is 0.1-1.0 MPa, and the target linear speed is 3-5 m / min.

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