High-performance weather-resistant yellowing-resistant polyurethane adhesive as well as preparation method and application thereof

Abstract

The invention discloses a high-performance, weather-resistant and yellowing-resistant polyurethane adhesive as well as a preparation method and application thereof. The high-performance, yellowing-resistant and weather-resistant polyurethane adhesive is prepared from the following raw materials in parts by weight: 10 parts of isocyanurate polyol, 18 to 32 parts of isocyanate, 198 to 689 parts of polymer polyol, 37 to 90 parts of polyisocyanate, 26 to 164 parts of plasticizer and 1.3 to 8.2 parts of catalyst. The isocyanate adopted by the invention is aliphatic and / or alicyclic isocyanate and a polymer thereof, no anti-yellowing agent or light stabilizer is added, the problem of yellowing of polyurethane can be thoroughly solved, the high-activity micromolecular isocyanurate polyol reacts with excessive isocyanate, and the yellowing resistance of the polyurethane is improved. Reacting the obtained isocyanate oligomer with excessive polymer polyol under the assistance of a small amount of catalyst, so that the isocyanate is completely reacted to obtain a hydroxyl-terminated polyurethane prepolymer; and reacting with excessive polyisocyanic acid to obtain the weather-resistant and yellowing-resistant polyurethane adhesive with a certain structure, and keeping excellent physical and mechanical properties at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of polyurethane adhesives, and in particular to a high-performance weather-resistant and yellowing-resistant polyurethane adhesive and a preparation method and application thereof. Background Art

[0002] Polyurethane macromolecules contain highly polar urethane groups, which have excellent mechanical properties, as well as corrosion resistance, oil resistance, wear resistance, and aging resistance. They are widely used in electronics, aerospace, transportation, machinery, construction, agriculture, national defense, and other fields. They are a multifunctional polymer material. Polyurethane can be used as an adhesive to bond rubber particles, sand and gravel and other materials to pave a variety of sidewalks, road tracks, and sports venues. After laying, they are directly dried in the open air. They are easy to construct and have excellent performance. They are becoming increasingly popular in indoor and outdoor sports venues such as squares, parks, communities, and stadiums.

[0003] At present, polyurethane adhesives used for sports venues are mainly synthesized from aromatic isocyanates such as toluene diisocyanate (TDI) or diphenylmethane diisocyanate (MDI). Since the isocyanate group in aromatic isocyanates such as TDI and MDI is directly connected to the benzene ring, it is easy to decompose and oxidize to generate quinone-type chromophores through natural aging in light, humidity and heat environments, thereby causing the polyurethane material to change color and turn yellow; especially when laying some light-colored or colorful (such as white, light green, etc.) sports venues, aromatic polyurethane adhesives cannot meet the yellowing resistance requirements.

[0004] In order to improve the yellowing resistance of polyurethane, there are currently two main methods. One is to add a large amount of anti-yellowing agents, light stabilizers, brighteners, etc. This method can only temporarily delay yellowing, and the actual effect is limited; moreover, the large amount of anti-yellowing additives will affect the physical and chemical properties of polyurethane materials. The second is to use aliphatic or alicyclic isocyanates instead of aromatic isocyanates, such as isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (HMDI) or hexamethylene diisocyanate (HDI). The molecular structure of aliphatic or alicyclic isocyanates does not contain aromatic rings, which avoids the problem of yellowing of polyurethane materials, but the reactivity of aliphatic or alicyclic isocyanates is much lower than that of aromatic isocyanates; moreover, the mechanical properties, water resistance, solvent resistance and wear resistance of the prepared polyurethane materials are poor; sports fields paved with polyurethane adhesives based on aliphatic or alicyclic isocyanates are prone to aging and stickiness, low mechanical properties and other problems. Therefore, there is an urgent need to develop polyurethane adhesives for sports venues that are both yellowing-resistant and weather-resistant, while also having excellent mechanical properties to fundamentally solve the problem of yellowing resistance. Summary of the invention

[0005] The main purpose of the present invention is to provide a high-performance weather-resistant and yellowing-resistant polyurethane adhesive and its preparation method and application, so as to solve the problem that the existing polyurethane adhesive cannot have both yellowing resistance and weather resistance while maintaining excellent mechanical properties, thereby fundamentally solving the problem of yellowing resistance.

[0006] To achieve the above-mentioned purpose, the present invention provides a high-performance weather-resistant and yellowing-resistant polyurethane adhesive, which comprises the following raw materials in parts by weight: the high-performance weather-resistant and yellowing-resistant polyurethane adhesive comprises the following raw materials in parts by weight: 10 parts of isocyanurate polyol, 18 to 32 parts of isocyanate, 198 to 689 parts of polymer polyol, 37 to 90 parts of polyisocyanate, 26 to 164 parts of plasticizer and 1.3 to 8.2 parts of catalyst, wherein the isocyanate comprises at least one of aliphatic isocyanate and alicyclic isocyanate; the polymer polyol comprises polycarbonate diol, and the molecular weight of the polycarbonate diol is 2000 to 6000; the polyisocyanate comprises at least one of isocyanate dimer and isocyanate trimer.

[0007] Optionally, the isocyanurate polyol includes at least one of trihydroxyethyl isocyanurate and trihydroxypropyl isocyanurate.

[0008] Optionally, the isocyanate includes at least one of hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, methylcyclohexyl diisocyanate and cyclohexyl diisocyanate.

[0009] Optionally, the polyisocyanate includes at least one of hexamethylene diisocyanate dimer, hexamethylene diisocyanate trimer, dicyclohexylmethane diisocyanate dimer, dicyclohexylmethane diisocyanate trimer, isophorone diisocyanate dimer and isophorone diisocyanate trimer.

[0010] Optionally, the plasticizer includes at least one of dibutyl phthalate and dioctyl phthalate; and / or,

[0011] The catalyst comprises an organic metal compound, and the organic metal compound comprises at least one of stannous isooctanoate, stannous octoate, dibutyltin dilaurate and dibutyltin dichloride.

[0012] The present invention also provides a method for preparing the high-performance weather-resistant and yellowing-resistant polyurethane adhesive as described above, which is used to prepare the high-performance weather-resistant and yellowing-resistant polyurethane adhesive as described above, comprising the following steps:

[0013] S10, vacuum drying 10 parts of isocyanurate polyol at 85-100° C., mixing with 18-32 parts of isocyanate, reacting at 50-70° C. for 2-5 hours, and cooling to obtain polyurethane oligomer A;

[0014] S20, dehydrating 198 to 689 parts of polymer polyol at 95 to 115° C. under reduced pressure, mixing with the polyurethane oligomer A and 0.7 to 4.1 parts of a catalyst, reacting at 65 to 90° C. for 3 to 6 hours, and cooling to obtain a hydroxyl-terminated polyurethane prepolymer B;

[0015] S30, mixing the hydroxyl-terminated polyurethane prepolymer B with 37 to 90 parts of polyisocyanate, reacting at 60 to 85° C. for 3 to 5 hours, and cooling to obtain a polyurethane prepolymer C;

[0016] S40, dehydrate 26 to 164 parts of plasticizer at 95 to 105° C. under reduced pressure, add the polyurethane prepolymer C at room temperature, and add the remaining catalyst; stir and mix evenly, and degas to obtain a high-performance weather-resistant and yellowing-resistant polyurethane adhesive.

[0017] The present invention also proposes a sports field composite material, which includes a high-performance weather-resistant and yellowing-resistant polyurethane adhesive. The high-performance weather-resistant and yellowing-resistant polyurethane adhesive is such as the high-performance weather-resistant and yellowing-resistant polyurethane adhesive described in any one of the above or the high-performance weather-resistant and yellowing-resistant polyurethane adhesive prepared by the preparation method of the high-performance weather-resistant and yellowing-resistant polyurethane adhesive described above.

[0018] The technical solution provided by the present invention comprises the following raw materials in parts by weight: 10 parts of isocyanurate polyol, 18 to 32 parts of isocyanate, 198 to 689 parts of polymer polyol, 37 to 90 parts of polyisocyanate, 26 to 164 parts of plasticizer and 1.3 to 8.2 parts of catalyst. The isocyanate used in the present invention is aliphatic and / or alicyclic isocyanate and polymers thereof, and no anti-yellowing agent or light stabilizer is added, which can completely solve the yellowing problem of polyurethane.

[0019] In the embodiment of the present invention, firstly, a highly active small molecule isocyanurate polyol is used to react with an excess of aliphatic and / or alicyclic isocyanates, which is beneficial to the reaction of low-activity aliphatic and / or alicyclic isocyanates, so that the isocyanurate polyol reacts completely to obtain isocyanate oligomers; then, it reacts with an excess of polymer polyols, assisted by a small amount of catalyst, so that the aliphatic and / or alicyclic isocyanates react completely to obtain a terminal hydroxyl polyurethane prepolymer, thereby avoiding the low activity and incomplete reaction of aliphatic and / or alicyclic isocyanates; then, an excess of polyisocyanates reacts with the terminal hydroxyl polyurethane prepolymer to obtain a polyurethane adhesive. The high-performance weather-resistant and yellowing-resistant polyurethane adhesive prepared by the present invention not only overcomes the problem of insufficient weather resistance of polyurethane adhesives prepared by aliphatic and / or alicyclic isocyanates, but also has excellent mechanical properties. By adjusting the polymerization process and raw materials, on the one hand, the aliphatic and / or alicyclic isocyanates can react completely, which is beneficial to the improvement of the aging resistance and mechanical properties of the polyurethane; on the other hand, a star-shaped polyurethane adhesive prepolymer is designed and synthesized, which presents a stable cross-linked network structure after curing and cross-linking, thereby further improving its weather resistance and mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 This is a process flow chart of an embodiment of the high-performance weather-resistant and yellowing-resistant polyurethane adhesive provided by the present invention.

[0022] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0023] To make the purpose, technical scheme and advantages of the embodiment of the present invention clearer, the technical scheme in the embodiment of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiment, it is carried out according to the normal conditions or the conditions recommended by the manufacturer. If the reagents or instruments used do not specify the manufacturer, they are all conventional products that can be purchased commercially. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes, taking "A and / or B" as an example, including scheme A, or scheme B, or schemes that A and B meet at the same time. In addition, the technical schemes between the various embodiments can be combined with each other, but must be based on the ability of ordinary technicians in the field to achieve. When the combination of technical solutions is contradictory or cannot be achieved, it should be considered that the combination of such technical solutions does not exist, and is not within the scope of protection required by the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present invention.

[0024] At present, there are two main methods to improve the yellowing resistance of polyurethane. One is to add anti-yellowing agents, light stabilizers, etc. Although this method can achieve a certain anti-yellowing effect, it can only temporarily delay the yellowing time, and the actual effect is limited; moreover, adding a large amount of anti-yellowing additives affects the mechanical properties of polyurethane materials. The second is to use aliphatic or alicyclic isocyanates instead of aromatic isocyanates, such as hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate (HMDI) or isophorone diisocyanate (IPDI). Aliphatic or alicyclic isocyanates do not contain aromatic rings in their molecular structure, which fundamentally solves the problem of yellowing of polyurethane materials. However, aliphatic or alicyclic isocyanates do not have the conjugation effect of benzene rings, have low reaction activity, extremely slow reaction rate, and are highly toxic during the production process. Moreover, the mechanical properties, water resistance, and solvent resistance of the prepared polyurethane materials are poor, especially their light aging performance is much lower than that of polyurethane materials prepared from aromatic isocyanates. Sports fields paved with polyurethane adhesives based on aliphatic or alicyclic isocyanates are prone to aging and become sticky, and have poor mechanical properties.

[0025] In view of this, the present invention proposes a high-performance weather-resistant and yellowing-resistant polyurethane adhesive to solve the problem that the existing polyurethane adhesive cannot have both yellowing-resistant and weather-resistant properties while maintaining excellent mechanical properties, thereby fundamentally solving the defect problem of yellowing-resistant polyurethane.

[0026] The invention provides a high-performance weather-resistant and yellowing-resistant polyurethane adhesive. The high-performance weather-resistant and yellowing-resistant polyurethane adhesive comprises the following raw materials in parts by weight: 10 parts of isocyanurate polyol, 18 to 32 parts of isocyanate, 198 to 689 parts of polymer polyol, 37 to 90 parts of polyisocyanate, 26 to 164 parts of plasticizer and 1.3 to 8.2 parts of catalyst, wherein the isocyanate comprises at least one of aliphatic isocyanate and alicyclic isocyanate; the polymer polyol comprises polycarbonate diol, and the molecular weight of the polycarbonate diol is 2000 to 6000; the polyisocyanate comprises at least one of isocyanate dimer and isocyanate trimer.

[0027] The isocyanate used in the present invention is an aliphatic and / or alicyclic isocyanate and its polymer, and no anti-yellowing agent or light stabilizer is added, which can completely solve the problem of yellowing of polyurethane. In the embodiment of the present invention, the proportion of each component is limited, so that the prepared adhesive has better yellowing resistance and weather resistance, and excellent physical and mechanical properties. First, a highly active small molecule isocyanurate polyol is used to react with an excess of aliphatic and / or alicyclic isocyanate, which is beneficial to the reaction of low-activity aliphatic and / or alicyclic isocyanate, so that the isocyanurate polyol reacts completely to obtain isocyanate oligomers; then react with an excess of polymer polyol, assisted by a small amount of catalyst, so that the aliphatic and / or alicyclic isocyanate reacts completely to obtain a terminal hydroxyl polyurethane prepolymer, thereby avoiding the problem of low activity and incomplete reaction of aliphatic and / or alicyclic isocyanates; then an excess of polyisocyanates is used to react with the terminal hydroxyl polyurethane prepolymer to obtain a polyurethane adhesive. The high-performance weather-resistant and yellowing-resistant polyurethane adhesive prepared by the present invention not only overcomes the problem of insufficient weather resistance of polyurethane adhesives prepared from aliphatic and / or alicyclic isocyanates, but also has excellent mechanical properties. By adjusting the polymerization process and raw materials, on the one hand, the aliphatic and / or alicyclic isocyanates react completely, which is beneficial to the improvement of the aging performance and mechanical properties of the polyurethane. On the other hand, the polyurethane adhesive prepolymer with a synthetic star structure is designed to present a stable cross-linked network structure after curing and cross-linking, so that its weather resistance and mechanical properties are further improved.

[0028] Further, the isocyanurate polyol includes at least one of trihydroxyethyl isocyanurate and trihydroxypropyl isocyanurate. It should be noted that the small molecule polyol used in the present invention is isocyanurate polyol. First, the polyol is a rigid ring structure, which helps to improve the mechanical properties and weather resistance of the polyurethane adhesive; second, the polyol has a strong polarity, which enhances the hydrogen bonding and strength of the adhesive; third, the isocyanurate group contained in the polyol has good compatibility with the carbamate group of the polyurethane, further enhancing the physical crosslinking effect of the polyurethane adhesive with a microphase separation structure, and improving the mechanical properties and weather resistance; fourth, the polyol is a triol, and the obtained polyurethane adhesive is a star-shaped structure, which is finally cured and cross-linked into a network structure, which is conducive to improving the aging performance and mechanical properties of the polyurethane adhesive.

[0029] Furthermore, the isocyanate includes at least one of aliphatic isocyanate and alicyclic isocyanate. It should be noted that compared with aromatic isocyanate, aliphatic or alicyclic isocyanate does not contain aromatic rings in its molecular structure and does not have the conjugation effect of benzene rings, and does not have yellowing properties, which completely solves the yellowing property of aromatic polyurethane.

[0030] Specifically, the isocyanate can be hexamethylene diisocyanate, or at least one of dicyclohexylmethane diisocyanate, isophorone diisocyanate, methylcyclohexyl diisocyanate and cyclohexyl diisocyanate. The selected isocyanate is mainly alicyclic isocyanate, which is beneficial to improve the reactivity of isocyanate and also helps to improve the mechanical properties of polyurethane adhesive; at the same time, in order to improve the flexibility of polyurethane adhesive, aliphatic isocyanate hexamethylene diisocyanate can also be selected in whole or in part.

[0031] Furthermore, the polymer polyol includes polycarbonate diol, and the molecular weight of the polycarbonate diol is 2000-6000.

[0032] Specifically, the molecular weight of the polycarbonate diol can be 2000, 4000, 5000 or 6000. Although the hydroxyl groups in the low molecular weight polycarbonate diol are highly active, the resulting polyurethane adhesive has poor flexibility; if the molecular weight of the polycarbonate diol is too high, the reactivity of the hydroxyl groups is low, which is not conducive to the reaction with the low-activity aliphatic / alicyclic isocyanate, and the mechanical strength of the resulting polyurethane adhesive decreases. Therefore, the molecular weight in the range of 2000 to 6000 is selected to take into account both activity and mechanical properties.

[0033] Furthermore, the polyisocyanate includes any one of an isocyanate dimer and an isocyanate trimer.

[0034] Specifically, the polyisocyanate includes at least one of hexamethylene diisocyanate dimer, hexamethylene diisocyanate trimer, dicyclohexylmethane diisocyanate dimer, dicyclohexylmethane diisocyanate trimer, isophorone diisocyanate dimer, and isophorone diisocyanate trimer. In some embodiments of the present application, the polyisocyanate may also contain a mixture of different isocyanate polymers. The polyisocyanate selected in the present invention is a polymer of aliphatic and / or alicyclic isocyanates, does not contain a benzene ring, and the resulting polyurethane adhesive does not yellow; the activity of the isocyanate of the polyisocyanate selected in the present invention is higher than that of the corresponding aliphatic and / or alicyclic isocyanates, which is conducive to the reaction of isocyanate with terminal hydroxyl polyurethane prepolymer to obtain a branched multifunctional terminal isocyanate polyurethane prepolymer, which helps to improve the mechanical properties and aging properties of the polyurethane adhesive. Specifically, its molecular structure is as follows:

[0035]

[0036] Further, the plasticizer includes at least one of dibutyl phthalate and dioctyl phthalate; and / or, the catalyst includes an organic metal compound, and the organic metal compound includes at least one of stannous isooctanoate, stannous octoate, dibutyltin dilaurate and dibutyltin dichloride.

[0037] Specifically, the plasticizer in the present invention can be dibutyl phthalate, dioctanoic acid phthalate, or a mixture of the two. Adding a plasticizer can increase the plasticity of the adhesive, reduce viscosity, and increase fluidity; and the catalyst in the present invention uses an organic metal compound, which helps to increase the reactivity of aliphatic / alicyclic isocyanates with hydroxyl groups and promote the reaction of isocyanates; when the polyurethane adhesive is cured, it helps to increase its wet curing reaction rate, so that the isocyanate end groups in the finally obtained star-shaped polyurethane prepolymer react with water in the air to cure and form.

[0038] The present invention also provides a method for preparing the high-performance weather-resistant and yellowing-resistant polyurethane adhesive as described above, which is used to prepare the high-performance weather-resistant and yellowing-resistant polyurethane adhesive as described above. Figure 1 , Figure 1 The process flow chart of an embodiment of a method for preparing a high-performance weather-resistant and yellowing-resistant polyurethane adhesive of the present invention comprises the following steps:

[0039] S10, vacuum drying 10 parts of isocyanurate polyol at 85-100° C., mixing with 18-32 parts of isocyanate, reacting at 50-70° C. for 2-5 hours, and cooling to obtain polyurethane oligomer A;

[0040] S20, dehydrating 198 to 689 parts of polymer polyol at 95 to 115° C. under reduced pressure, mixing with the polyurethane oligomer A and 0.7 to 4.1 parts of a catalyst, reacting at 65 to 90° C. for 3 to 6 hours, and cooling to obtain a hydroxyl-terminated polyurethane prepolymer B;

[0041] S30, mixing the hydroxyl-terminated polyurethane prepolymer B with 37 to 90 parts of polyisocyanate, reacting at 60 to 85° C. for 3 to 5 hours, and cooling to obtain a polyurethane prepolymer C;

[0042] S40, dehydrate 26 to 164 parts of plasticizer at 95 to 105° C. under reduced pressure, add the polyurethane prepolymer C at room temperature, and add the remaining catalyst; stir and mix evenly, and degas to obtain a high-performance weather-resistant and yellowing-resistant polyurethane adhesive.

[0043] In some embodiments, the preparation method is simple and easy to operate, and the reaction is more complete by adding the reactants in batches.

[0044] S10, vacuum drying 10 parts of isocyanurate polyol at 85-100° C., mixing with 18-32 parts of isocyanate, reacting at 50-70° C. for 2-5 hours, and cooling to obtain polyurethane oligomer A;

[0045] It should be noted that aliphatic / alicyclic isocyanates have low activity, while low molecular weight isocyanurate polyols have high activity; a small amount of highly active isocyanurate polyols are reacted with excess aliphatic / alicyclic isocyanates to completely react the polyols to form oligomers A with isocyanurate as the core and isocyanate groups (-NCO) as the end caps; in some embodiments, the polyurethane oligomer A obtained after the reaction presents a star-shaped structure, and the reaction formula is as follows:

[0046]

[0047] S20, dehydrating 198-689 parts of polymer polyol at 95-115°C under reduced pressure, mixing with the polyurethane oligomer A and 0.7-4.1 parts of catalyst, reacting at 65-90°C for 3-6h, and cooling to obtain hydroxyl-terminated polyurethane prepolymer B; it should be noted that the polymer polyol reacts with isocyanate to form polyurethane, which is the flexible segment of the polyurethane molecular chain, and the rigid segment is carbamate (-NHCOO-). The higher the molecular weight of the polymer polyol, the more the content of the flexible segment, which helps to improve the flexibility of the polyurethane molecule; but if the molecular weight of the polymer polyol is too high, the mechanical properties of the polyurethane adhesive will be reduced; moreover, the higher the molecular weight, the lower the activity of the hydroxyl group of the polymer polyol molecule, and the activity of the terminal isocyanate group of the oligomer A terminated by the aliphatic / alicyclic isocyanate group is also low, and the mutual reaction rate between the two is low and it is difficult to react completely; increasing the temperature can increase the reaction rate, but isomerization reaction will occur.

[0048] In some embodiments, an excess of polymer polyol is added to the polyurethane prepolymer A, supplemented with a small amount of catalyst, and the reaction temperature is adjusted to allow the isocyanate groups in the polyurethane prepolymer A to react completely to obtain a hydroxyl-terminated polyurethane prepolymer B. In some embodiments, the arms of the star-shaped structure are extended after the reaction. The specific reaction formula is as follows:

[0049]

[0050] S30, mixing the hydroxyl-terminated polyurethane prepolymer B with 37 to 90 parts of polyisocyanate, reacting at 60 to 85° C. for 3 to 5 hours, and cooling to obtain a polyurethane prepolymer C;

[0051] It should be noted that the polyisocyanate is an aliphatic and / or alicyclic isocyanate trimer and / or dimer, which has higher activity than the corresponding aliphatic and / or alicyclic isocyanates. The excess isocyanate groups in the polyisocyanate react with the hydroxyl-terminated polyurethane prepolymer B, the molecular chain continues to branch, and the terminal group is an isocyanate group, thereby obtaining a star-shaped polyurethane prepolymer.

[0052] In some embodiments, the reaction formula is as follows:

[0053]

[0054] S40, dehydrate 26 to 164 parts of plasticizer at 95 to 105° C. under reduced pressure, add the polyurethane prepolymer C at room temperature, and add the remaining catalyst; stir and mix evenly, and degas to obtain a high-performance weather-resistant and yellowing-resistant polyurethane adhesive.

[0055] It should be noted that the plasticizer increases plasticity, reduces viscosity, and increases fluidity; the catalyst catalyzes the addition polymerization of isocyanate groups and hydroxyl groups; finally, when the adhesive is used, the isocyanate groups in the obtained star-shaped polyurethane prepolymer react with water in the air to cure (i.e., room temperature curing).

[0056] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments and drawings. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0057] Example 1

[0058] A high-strength, yellowing-resistant and weather-resistant polyurethane adhesive, comprising the following raw materials in parts by mass: 10 parts of trihydroxypropyl isocyanurate polyol, 18 parts of cyclohexyl diisocyanate, 198 parts of polycarbonate diol (molecular weight 2000), 37 parts of hexamethylene diisocyanate trimer, 82 parts of dibutyl phthalate and 4.1 parts of stannous octoate;

[0059] Among them, a method for preparing a high-strength, yellowing-resistant and weather-resistant polyurethane adhesive adopts the component content of Example 1, comprising the following steps:

[0060] S10, drying 10 parts of trihydroxypropyl isocyanurate under vacuum at 100° C., mixing with 18 parts of cyclohexyl diisocyanate, reacting at 60° C. for 3 h, and cooling to obtain polyurethane oligomer A;

[0061] S20, dehydrating 198 parts of polycarbonate diol (molecular weight 2000) at 105° C. under reduced pressure, mixing with the polyurethane oligomer A and 2.1 parts of stannous octoate, reacting at 80° C. for 3 hours, and cooling to obtain a hydroxyl-terminated polyurethane prepolymer B;

[0062] S30, mixing the hydroxyl-terminated polyurethane prepolymer B with 37 parts of hexamethylene diisocyanate trimer, reacting at 75° C. for 4 hours, and cooling to obtain a polyurethane prepolymer C;

[0063] S40, dehydrating 82 parts of dibutyl phthalate at 100° C. under reduced pressure, adding the polyurethane prepolymer C at room temperature, and adding the remaining stannous octoate; stirring and mixing evenly, degassing to obtain a high-performance weather-resistant and yellowing-resistant polyurethane adhesive, and testing its various properties.

[0064] Example 2-16

[0065] Examples 2-16 are similar to Example 1, except that the ratios of the highly weather-resistant and yellowing-resistant polyurethane adhesives are different. Please refer to Table 1 for details.

[0066] Table 1 Components and proportions of high performance yellowing-resistant and weather-resistant polyurethane adhesives of Examples 2-16

[0067]

[0068]

[0069] Comparative Example 1

[0070] The difference from Example 4 is that in step S10, 10 parts of trihydroxypropyl isocyanurate are replaced with 3.1 parts of propylene glycol;

[0071] Comparative Example 2

[0072] The difference from Example 4 is that in step S10, 19 parts of hexamethylene diisocyanate are replaced with 28.3 parts of diphenylmethane diisocyanate;

[0073] Comparative Example 3

[0074] Different from Example 4, in step S10, the amount of hexamethylene diisocyanate used is 17 parts;

[0075] Comparative Example 4

[0076] Different from Example 4, in step S10, the amount of hexamethylene diisocyanate used is 34 parts;

[0077] Comparative Example 5

[0078] The difference from Example 4 is that in step S20, the polycarbonate diol with a molecular weight of 4000 is replaced with a polyether diol with a molecular weight of 4000.

[0079] Comparative Example 6

[0080] Different from Example 4, in step S20, the molecular weight of the polycarbonate diol is 1500.

[0081] Comparative Example 7

[0082] Different from Example 4, in step S20, the molecular weight of the polycarbonate diol is 6500.

[0083] Comparative Example 8

[0084] Different from Example 4, in step S20, the amount of polycarbonate diol with a molecular weight of 4000 is 195 parts;

[0085] Comparative Example 9

[0086] Different from Example 4, in step S20, the amount of polycarbonate diol with a molecular weight of 4000 is 690 parts;

[0087] Comparative Example 10

[0088] Different from Example 4, in step S30, the amount of hexamethylene diisocyanate oligomer is 35 parts;

[0089] Comparative Example 11

[0090] Different from Example 4, in step S30, the amount of hexamethylene diisocyanate oligomer is 92 parts;

[0091] The polyurethane adhesive prepared by the present invention is applied to sports venue composite materials, and its tensile strength (non-permeable surface layer), elongation at break, impact absorption (track and field venue), vertical deformation, and aging resistance are analyzed according to the standard of GB 36246-2018 "Synthetic material surface layer sports venues for primary and secondary schools"; wherein, its aging resistance is subjected to a xenon lamp irradiation test according to the provisions of GB / T 16422.2-2013, and the test conditions are method A, cycle number 1, and after 500 hours of testing, the tensile strength and elongation at break are measured. Its yellowing performance is determined according to the determination of discoloration (yellowing) performance of adhesives in GB / T 39294-2020. The test results of the polyurethane adhesives obtained in the embodiments and comparative examples are shown in Tables 2 and 3, respectively.

[0092] Table 2 Test results of polyurethane adhesive (Example)

[0093]

[0094] From the test results of the embodiment in Table 2, it can be seen that:

[0095] (1) In the comparison of Example 1, Example 2 and Example 3, as the molecular weight of the polycarbonate diol increases, the flexibility of the adhesive increases, and its tensile strength decreases, its elongation at break increases, and its impact absorption and vertical deformation increase before and after aging;

[0096] (2) Compared with Example 2, the diisocyanate in Examples 4, 5, 6, and 7 was changed, and the properties of the obtained polyurethane adhesives were different. The adhesive based on dicyclohexylmethane diisocyanate had better performance before and after aging, and the adhesive based on hexamethylene diisocyanate had a deviation in performance;

[0097] (3) Comparing Example 7, Example 8, and Example 9, different isocyanate trimers have certain effects on the polyurethane adhesive. Among them, the polyurethane adhesive based on dicyclohexylmethane diisocyanate trimer has better performance in all aspects before and after aging; while the polyurethane adhesive based on hexamethylene diisocyanate trimer has poorer performance before and after aging;

[0098] (4) Comparing Example 9, Example 10, and Example 11, as the amount of dicyclohexylmethane diisocyanate trimer increases, the tensile strength of the polyurethane adhesive increases, but the elongation at break and the impact absorption increase first and then decrease, and the vertical deformation decreases; however, if the content of dicyclohexylmethane diisocyanate trimer is too high, the tensile strength, elongation at break, and impact absorption decrease after aging, and the vertical deformation increases;

[0099] (5) Compared with Comparative Example 10, in Comparative Example 12, the trimer of dicyclohexylmethane diisocyanate was replaced by a dimer, and the crosslinking degree of the obtained polyurethane adhesive was weakened, the tensile strength of the adhesive decreased, the elongation at break increased, the vertical deformation increased, and the impact absorption also decreased, but the various performance indicators of the adhesive after aging were inferior to those of Example 10;

[0100] (6) Compared with Example 10, in Example 13, trihydroxypropyl isocyanurate was replaced with trihydroxyethyl isocyanurate, and the tensile strength of the obtained polyurethane adhesive was increased, but its elongation at break and impact absorption were decreased. In particular, the performance indicators of the adhesive after aging were inferior to those of Example 10;

[0101] (7) For Example 13 and Example 14, as the amount of dicyclohexylmethane diisocyanate trimer increased, the tensile strength of the polyurethane adhesive increased before and after aging, but its elongation at break, impact absorption and vertical deformation decreased;

[0102] (8) Comparing Example 14 and Example 15, as the molecular weight of the polycarbonate diol increases, the flexibility of the polyurethane adhesive increases, and its tensile strength decreases before and after aging, while its elongation at break, impact absorption and vertical deformation increase;

[0103] (9) Compared with Example 15, the amount of plasticizer and catalyst used in Example 16 is increased. The catalyst mainly affects the reaction and curing rate; the plasticizer is mainly used to adjust the viscosity and has the effect of increasing flexibility. As the content of plasticizer increases, the mechanical properties and impact absorption of the polyurethane adhesive before and after aging decrease, and the vertical deformation increases.

[0104] The performance of the polyurethane adhesives obtained in Examples 1-16 before and after aging all met the national standards, the color difference ΔE was within 0.15, and they had excellent mechanical properties and weather resistance and yellowing resistance.

[0105] Table 3 Test results of polyurethane adhesive (Comparative Example)

[0106]

[0107]

[0108] In Comparative Example 1, trihydroxypropyl isocyanurate was replaced with propylene glycol, and the mechanical properties and impact absorption of the polyurethane adhesive decreased, and the vertical deformation increased; after aging, all performance indicators did not meet the standards; the color difference ΔE increased, and the yellowing resistance decreased;

[0109] In Comparative Example 2, the aliphatic hexamethylene diisocyanate was replaced with aromatic diphenylmethane diisocyanate. The mechanical strength, elongation at break, impact absorption and vertical deformation before and after aging were better than those of the adhesive prepared with hexamethylene diisocyanate; however, it was prone to yellowing and had a high color difference ΔE after illumination.

[0110] In Comparative Examples 3 and 4, the amount of hexamethylene diisocyanate used is too low, and the curing and crosslinking of the adhesive is insufficient, resulting in reduced mechanical properties and impact absorption, and increased vertical deformation; in particular, after aging, its elongation at break, impact absorption, and vertical deformation do not meet the standards; the amount of hexamethylene diisocyanate used is too high, the rigidity of the adhesive is enhanced, but the toughness is poor, and after aging, its elongation at break and impact absorption do not meet the standards;

[0111] In Comparative Example 5, the polycarbonate diol with a molecular weight of 4000 was replaced with a polyether diol with a molecular weight of 4000, and the mechanical properties of the adhesive decreased, and the vertical deformation increased; although its impact absorption increased, its aging resistance was insufficient, and after aging, its tensile strength, impact absorption and vertical deformation did not meet the standards, and it had a certain yellowing property, and the color difference ΔE increased;

[0112] In Comparative Examples 6 and 7, the molecular weight of the polycarbonate diol is too low, the flexibility of the adhesive is poor, and the elongation at break and impact absorption of the adhesive after aging do not meet the standards; the molecular weight of the polycarbonate diol is too high, although the flexibility of the adhesive is good, its tensile strength is low and the vertical deformation is high, especially the vertical deformation of the adhesive after aging does not meet the standards;

[0113] In Comparative Examples 8 and 9, the amount of polycarbonate diol used is too low, the rigidity of the adhesive is enhanced, but the flexibility is poor, and the aging resistance is insufficient; after aging, the tensile strength of the adhesive decreases significantly, and the elongation at break, impact absorption and vertical deformation do not meet the standards; the amount of polycarbonate diol used is too high, and the curing and cross-linking of the adhesive is insufficient, resulting in a decrease in its mechanical properties and an increase in vertical deformation. After aging, the tensile strength, elongation at break and vertical deformation of the adhesive do not meet the standards;

[0114] In Comparative Examples 10 and 11, the dosage of hexamethylene diisocyanate oligomer is too low, and the curing crosslinking degree of the polyurethane adhesive is insufficient, resulting in reduced mechanical properties and impact absorption and increased vertical deformation; after aging, its tensile strength, elongation at break, impact absorption, and vertical deformation do not meet the standards; the dosage of hexamethylene diisocyanate oligomer is too high, the rigidity of the adhesive is enhanced, but the toughness is poor, and after aging, its elongation at break and impact absorption do not meet the standards;

[0115] It can be seen that among comparative examples 1-11, the polyurethane adhesive prepared by using aromatic isocyanate in comparative example 2 has a large color difference and is prone to yellowing; some or all of the performance indicators of the polyurethane adhesives obtained in other comparative examples before and after aging do not meet the standards.

[0116] The above are only preferred embodiments of the present invention, and do not limit the patent scope of the present invention. For those skilled in the art, the present invention may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the patent protection scope of the present invention.

Claims

1. A high-performance weather-resistant and yellowing-resistant polyurethane adhesive, characterized in that: The high-performance weather-resistant and yellowing-resistant polyurethane adhesive comprises the following raw materials in parts by mass: 10 parts of isocyanurate polyol, 18 to 32 parts of isocyanate, 198 to 689 parts of polymer polyol, 37 to 90 parts of polyisocyanate, 26 to 164 parts of plasticizer and 1.3 to 8.2 parts of catalyst, wherein: The isocyanate includes at least one of an aliphatic isocyanate and an alicyclic isocyanate; The polymer polyol includes polycarbonate diol, and the molecular weight of the polycarbonate diol is 2000-6000; The polyisocyanate includes at least one of an isocyanate dimer and an isocyanate trimer.

2. The high-performance weather-resistant and yellowing-resistant polyurethane adhesive according to claim 1, characterized in that: The isocyanurate polyol includes at least one of trihydroxyethyl isocyanurate and trihydroxypropyl isocyanurate.

3. The high-performance weather-resistant and yellowing-resistant polyurethane adhesive according to claim 1, characterized in that: The isocyanate includes at least one of hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, methylcyclohexyl diisocyanate and cyclohexyl diisocyanate.

4. The high-performance weather-resistant and yellowing-resistant polyurethane adhesive according to claim 1, characterized in that: The polyisocyanate includes at least one of hexamethylene diisocyanate dimer, hexamethylene diisocyanate trimer, dicyclohexylmethane diisocyanate dimer, dicyclohexylmethane diisocyanate trimer, isophorone diisocyanate dimer and isophorone diisocyanate trimer.

5. The high-performance weather-resistant and yellowing-resistant polyurethane adhesive according to claim 1, characterized in that: The plasticizer comprises at least one of dibutyl phthalate and dioctyl phthalate; and / or, The catalyst comprises an organic metal compound, and the organic metal compound comprises at least one of stannous isooctanoate, stannous octoate, dibutyltin dilaurate and dibutyltin dichloride.

6. A method for preparing a high-performance weather-resistant and yellowing-resistant polyurethane adhesive, for preparing the high-performance weather-resistant and yellowing-resistant polyurethane adhesive as claimed in any one of claims 1 to 5, characterized in that: The following steps are involved: S10, vacuum drying 10 parts of isocyanurate polyol at 85-100° C., mixing with 18-32 parts of isocyanate, reacting at 50-70° C. for 2-5 hours, and cooling to obtain polyurethane oligomer A; S20, dehydrating 198 to 689 parts of polymer polyol at 95 to 115° C. under reduced pressure, mixing with the polyurethane oligomer A and 0.7 to 4.1 parts of a catalyst, reacting at 65 to 90° C. for 3 to 6 hours, and cooling to obtain a hydroxyl-terminated polyurethane prepolymer B; S30, mixing the hydroxyl-terminated polyurethane prepolymer B with 37 to 90 parts of polyisocyanate, reacting at 60 to 85° C. for 3 to 5 hours, and cooling to obtain a polyurethane prepolymer C; S40, dehydrate 26 to 164 parts of plasticizer at 95 to 105° C. under reduced pressure, add the polyurethane prepolymer C at room temperature, and add the remaining catalyst; stir and mix evenly, and degas to obtain a high-performance weather-resistant and yellowing-resistant polyurethane adhesive.

7. A composite material for sports fields, characterized in that: The composite material comprises a high-performance weather-resistant and yellowing-resistant polyurethane adhesive, wherein the high-performance weather-resistant and yellowing-resistant polyurethane adhesive is the high-performance weather-resistant and yellowing-resistant polyurethane adhesive as described in any one of claims 1 to 5 or the high-performance weather-resistant and yellowing-resistant polyurethane adhesive prepared by the preparation method of the high-performance weather-resistant and yellowing-resistant polyurethane adhesive as described in claim 6.

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