High-temperature-resistant moisture-cured polyurethane hot melt adhesive as well as preparation method and application thereof

Abstract

The invention relates to a high-temperature-resistant moisture-cured polyurethane hot melt adhesive as well as a preparation method and application thereof. The preparation raw materials of the high-temperature-resistant moisture-cured polyurethane hot melt adhesive comprise the following components in parts by weight: 20-50 parts of bio-based polyol; 180 to 450 parts of polyether polyol; 200 to 450 parts of polyester polyol; 120 to 200 parts of isocyanate; 80 to 150 parts of tackifying resin; and 0.1 to 0.5 part of a catalyst. The moisture-cured polyurethane hot melt adhesive provided by the invention has good weather resistance after being completely cured, can keep relatively good bonding strength in an environment of 80 DEG C, and has the characteristics of high initial bonding strength, quick positioning, universality in winter and summer and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of reactive polyurethane hot melt adhesives, and in particular to a high-temperature resistant moisture-curing polyurethane hot melt adhesive, a preparation method thereof, and applications thereof. Background Art

[0002] As living standards improve, people's demands for a more comfortable living and working environment are increasing. In the field of building decoration, floor performance has attracted much attention. To improve flooring's sound insulation, moisture resistance, and cushioning properties, floor mute mats have been developed, and market demand is rapidly growing.

[0003] Floor soundproofing pads are widely used in various types of buildings, such as residential buildings, commercial office buildings, hotels, etc. They can effectively reduce the transmission of noise between floors and improve the quietness of living and working. At the same time, in some places with high requirements for acoustic environment, such as recording studios and concert halls, soundproofing pads are even more indispensable. At present, common floor soundproofing pad materials on the market include ethylene vinyl acetate copolymer (EVA), electron radiation cross-linked polyethylene foam material (IXPE), chemical cross-linked polyethylene foam material (XPE), etc., which are composed of a mesh independent closed-cell foam structure, have good sound insulation, heat insulation, thermal insulation effects, low water absorption and other characteristics, and meet international environmental standards.

[0004] In the composite process of flooring and soundproofing pads, adhesives play a vital role. Commonly used acrylic adhesives have the characteristics of fast curing speed, wide bonding range, and good weather resistance. However, they emit a pungent odor during the construction process, affecting the health of construction workers. In addition, they have poor flexibility after curing and are prone to cracking when subjected to large external impacts or large deformations, resulting in bonding failure. Moisture-curing polyurethane hot melt adhesive is an environmentally friendly adhesive with excellent adhesion to floors and soundproofing pads of various materials. It has the advantages of being solvent-free, fast curing, high bonding strength, and moderate elasticity. It has been widely used in the bonding of floor soundproofing pads.

[0005] However, current polyurethane adhesives have limitations in terms of high-temperature resistance and adhesion to low-polarity surfaces. For example, they lack heat resistance after curing, significantly reducing bond strength at high temperatures. This can lead to shifting and peeling during summer container transportation. Furthermore, existing polyurethane hot-melt adhesives exhibit poor adhesion to low-polarity materials such as EVA noise-canceling pads, making them difficult to meet market demand.

[0006] Therefore, it is of great significance to design and provide a high-temperature resistant moisture-curing polyurethane hot melt adhesive for floor noise pads that has good bonding performance to low-polarity materials. Summary of the Invention

[0007] To address the above technical issues, the present invention provides a high-temperature-resistant, moisture-curing polyurethane hot-melt adhesive, its preparation method, and its application. While maintaining an odorless appearance and strong positioning capabilities, the moisture-curing polyurethane hot-melt adhesive provided by the present invention also exhibits excellent bonding properties and temperature resistance for low-polarity materials. This satisfies the market demand for environmentally friendly, high-performance adhesives, provides technical support for industrial production, and promotes the development of the floor muffler industry.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a high-temperature resistant moisture-curing polyurethane hot melt adhesive. The raw materials for preparing the high-temperature resistant moisture-curing polyurethane hot melt adhesive include the following components in parts by weight:

[0010]

[0011] The present invention designs raw materials for preparing high-temperature resistant moisture-curing polyurethane hot melt adhesive. Through the coordination of various components, a high-temperature resistant moisture-curing polyurethane hot melt adhesive is prepared, which maintains odorlessness and strong positioning ability while also having excellent bonding performance and temperature resistance to low-polarity materials.

[0012] Furthermore, the present invention, by adding bio-based polyols to the moisture-curing polyurethane hot melt adhesive system, can not only significantly improve the initial adhesion strength and T-peel strength of the resulting moisture-curing polyurethane hot melt adhesive, but also enable it to obtain excellent high temperature resistance, thereby enabling it to have suitable strength in high temperature tests without significant attenuation. At the same time, by compounding bio-based polyols with polyether polyols, polyester polyols, tackifying resins, isocyanates and catalysts in proportion, it is possible to obtain a moisture-curing polyurethane hot melt adhesive with low odor, high transparency and good stability (can be stored at 5-30°C for 6 months). It can maintain excellent bonding strength at 80°C, and has the characteristics of high initial adhesion strength, fast positioning and universality in winter and summer, and can be better used in the bonding of low-polarity material floor silent pads.

[0013] The present invention controls the amount of bio-based polyols in the raw materials for preparing high-temperature, moisture-curing polyurethane hot melt adhesives within a specific range, and utilizes the stability and high wettability brought by the aromatic rings or long carbon chain structures in the bio-based polyols to produce a high-temperature, moisture-curing polyurethane hot melt adhesive with excellent overall properties, including high initial tack strength, bonding performance, and heat resistance. If the amount of bio-based polyols used is too small, the bonding strength and high-temperature resistance of the resulting high-temperature, moisture-curing polyurethane hot melt adhesive will be weakened; if the amount of bio-based polyols used is too large, the initial tack of the resulting high-temperature, moisture-curing polyurethane hot melt adhesive will be reduced, resulting in increased shrinkage of the electrostatic pad after bonding.

[0014] It should be noted that the low-polarity material in the present invention refers to a material with low molecular polarity and a dielectric constant of 2.3-3.5, such as ethylene vinyl acetate copolymer (EVA, dielectric constant of 2.5-3.5), electron radiation cross-linked polyethylene foam material (IXPE, dielectric constant of 3.0-3.3), and chemically cross-linked polyethylene foam material (XPE, dielectric constant of about 2.3).

[0015] The weight proportions of the bio-based polyol in the raw materials for preparing the high-temperature resistant moisture-curing polyurethane hot melt adhesive provided by the present invention can be 20 parts, 25 parts, 30 parts, 35 parts, 38 parts, 40 parts, 45 parts, 48 parts or 50 parts, as well as specific values between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the said range.

[0016] The weight proportions of the polyether polyol can be 180 parts, 200 parts, 280 parts, 250 parts, 300 parts, 350 parts, 400 parts, 435 parts or 450 parts, as well as specific values between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the range.

[0017] The weight proportions of the polyester polyol can be 200 parts, 230 parts, 250 parts, 280 parts, 300 parts, 320 parts, 350 parts, 380 parts, 400 parts, 420 parts or 450 parts, as well as specific values between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific points included in the range.

[0018] The weight percentage of the isocyanate can be 120 parts, 130 parts, 140 parts, 150 parts, 160 parts, 170 parts, 180 parts, 190 parts or 200 parts, as well as specific points between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the range.

[0019] The weight percentage of the tackifying resin can be 80 parts, 90 parts, 100 parts, 110 parts, 120 parts, 130 parts, 140 parts or 150 parts, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values included in the range.

[0020] The weight percentage of the catalyst can be 0.1 part, 0.15 part, 0.2 part, 0.25 part, 0.3 part, 0.35 part, 0.4 part, 0.45 part or 0.5 part, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values included in the range.

[0021] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0022] As a preferred technical solution of the present invention, the weight proportion of the bio-based polyol is 25-45 parts, for example, it can be 25 parts, 28 parts, 30 parts, 32 parts, 35 parts, 38 parts, 40 parts or 45 parts, as well as specific values between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the said range.

[0023] The present invention further optimizes and controls the weight proportion of bio-based polyol in the raw materials for preparing high-temperature resistant moisture-curing polyurethane hot melt adhesive to 25-45 parts, thereby further regulating the mass ratio of bio-based polyol to components such as polyether polyol and polyester polyol, thereby further improving the comprehensive performance of high-temperature resistant moisture-curing polyurethane hot melt adhesive.

[0024] As a preferred technical solution of the present invention, the viscosity of the bio-based polyol at 25°C is 350-550 cPs, for example, it can be 350 cPs, 380 cPs, 400 cPs, 420 cPs, 450 cPs, 480 cPs, 500 cPs, 520 cPs or 550 cPs, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values included in the said range.

[0025] By controlling the viscosity of the bio-based polyol at 25° C. within a relatively low range, the present invention can effectively reduce the viscosity of the polyurethane system in a moisture-curing polyurethane hot melt adhesive, thereby reducing the operational difficulty during production and use and increasing the wettability of the colloid, thereby improving its bonding performance.

[0026] Preferably, the hydroxyl value of the bio-based polyol is 45-320 mg KOH / g, for example, 45 mg KOH / g, 50 mg KOH / g, 80 mg KOH / g, 100 mg KOH / g, 150 mg KOH / g, 200 mg KOH / g, 250 mg KOH / g, 280 mg KOH / g, 300 mg KOH / g or 320 mg KOH / g, as well as specific values between the above points. Due to space limitations and for the sake of brevity, the present invention does not exhaustively enumerate the specific values included in the above range.

[0027] Preferably, the bio-based polyol includes any one of castor oil polyol, soybean oil polyol or cashew nut shell liquid polyol, or a combination of at least two thereof, and more preferably cashew nut shell liquid polyol.

[0028] The structure of the bio-based polyol of the present invention has long aliphatic side chains or aromatic rings. The long aliphatic side chains can achieve good substrate wettability for low-polarity substrates, thereby improving the initial adhesion strength and bonding performance of the resulting moisture-curing polyurethane hot melt adhesive; the aromatic ring can improve the bonding performance and high temperature resistance of the resulting moisture-curing polyurethane hot melt adhesive, and also affect its appearance transparency. Furthermore, the bio-based polyol of the present invention is preferably a cashew nut shell oil polyol, which has both long aliphatic side chains and aromatic rings in its structure, and can make the resulting moisture-curing polyurethane hot melt adhesive have better initial adhesion strength, bonding performance and high temperature resistance and other comprehensive properties. Compared with non-bio-based polyols such as polyoxypropylene glycol, the addition of bio-based polyols in the present invention not only has better initial adhesion strength, but is also more excellent in terms of high temperature resistance and solvent resistance.

[0029] As a preferred technical solution of the present invention, the polyether polyol includes any one of polyethylene glycol ether, polyoxypropylene glycol or polytetramethylene ether glycol, or a combination of at least two thereof.

[0030] As a preferred technical solution of the present invention, the polyester polyol includes any one of amorphous polyester polyol, crystalline polyester polyol or liquid polyester polyol, or a combination of at least two of them.

[0031] Preferably, the polyester polyol is a combination of an amorphous polyester polyol, a crystalline polyester polyol and a liquid polyester polyol.

[0032] The polyester polyol in the present invention is preferably a combination of an amorphous polyester polyol, a crystalline polyester polyol and a liquid polyester polyol, which can further improve the comprehensive performance of the moisture-curing polyurethane hot melt adhesive.

[0033] Preferably, the mass ratio of the amorphous polyester polyol, the crystalline polyester polyol and the liquid polyester polyol is 1:(0.8-2):(1-2.5), wherein (0.8-2) can be 0.8, 1, 1.2, 1.4, 1.6, 1.8 or 2, and (1-2.5) can be 1, 1.2, 1.4, 1.6, 1.8, 2.0, 2.3 or 2.5, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values included in the range.

[0034] By controlling the mass ratio of amorphous polyester polyol, crystalline polyester polyol, and liquid polyester polyol, the present invention significantly improves the transparency, adhesive properties, and high-temperature resistance of the resulting moisture-curing polyurethane hot melt adhesive. This ensures that even at high temperatures, the T-peel strength does not significantly decrease. The liquid polyester polyol improves wettability, thereby enhancing adhesive performance, while the amorphous polyester polyol and crystalline polyester polyol enhance colloid cohesion, thereby increasing heat resistance. By controlling the mass ratio of the three within a specific range, the resulting moisture-curing polyurethane hot melt adhesive achieves a good balance between initial tack, heat resistance, and final bond strength, achieving excellent overall performance requirements. When the content of polyester polyol is fixed, when the content of amorphous polyester polyol or crystalline polyester polyol is too high, the open time of the colloid is short and may cause the final bonding effect to deteriorate, while when its content is too low, the cohesive force of the colloid is too low, causing the silent pad to shrink; when the content of liquid polyester polyol is too high, the initial adhesion of the colloid decreases, and when its content is too low, the wettability of the colloid is insufficient, resulting in poor final bonding strength.

[0035] Preferably, the hydroxyl value of the amorphous polyester polyol is 30-120 mg KOH / g, for example, 30 mg KOH / g, 40 mg KOH / g, 50 mg KOH / g, 60 mg KOH / g, 70 mg KOH / g, 80 mg KOH / g, 90 mg KOH / g, 100 mg KOH / g, 110 mg KOH / g or 120 mg KOH / g, as well as specific values between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the range.

[0036] Preferably, the amorphous polyester polyol includes any one or a combination of at least two of ethylene glycol / butylene glycol / diethylene glycol / adipic acid copolymer, butylene glycol / phthalic anhydride copolymer, neopentyl glycol / phthalic anhydride copolymer or diethylene glycol / trimethylolpropane / adipic acid copolymer.

[0037] It should be noted that the ethylene glycol / butylene glycol / diethylene glycol / adipic acid copolymer in the present invention refers to a copolymer of ethylene glycol, butylene glycol, diethylene glycol and adipic acid, the butylene glycol / phthalic anhydride copolymer refers to a copolymer of butylene glycol and phthalic anhydride, the neopentyl glycol / phthalic anhydride copolymer refers to a copolymer of neopentyl glycol and phthalic anhydride (such as Asahikawa Chemical FLP-PA1000N), and the diethylene glycol / trimethylolpropane / adipic acid copolymer refers to a copolymer of diethylene glycol, trimethylolpropane and adipic acid.

[0038] Preferably, the hydroxyl value of the crystalline polyester polyol is 18-54 mg KOH / g, for example, it can be 18 mg KOH / g, 20 mg KOH / g, 25 mg KOH / g, 30 mg KOH / g, 35 mg KOH / g, 40 mg KOH / g, 45 mg KOH / g, 50 mg KOH / g or 54 mg KOH / g, as well as specific values between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the range.

[0039] Preferably, the crystalline polyester polyol includes any one of polybutylene succinate diol, polybutylene adipate diol, polyhexane adipate diol (such as Asahikawa Chemical FLP-3500H, Asahikawa Chemical XCP-R4500H) or polydecanediol sebacate diol, or a combination of at least two thereof.

[0040] Preferably, the hydroxyl value of the liquid polyester polyol is 53-59 mg KOH / g, for example, it can be 53 mg KOH / g, 54 mg KOH / g, 55 mg KOH / g, 56 mg KOH / g, 57 mg KOH / g, 58 mg KOH / g or 59 mg KOH / g, as well as specific values between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the range.

[0041] Preferably, the liquid polyester polyol comprises phthalic anhydride liquid polyester polyol (such as XCPA-2000HL from Asahikawa Chemical) and / or polyneopentyl adipate diol (such as FLP-2000N from Asahikawa Chemical).

[0042] As a preferred technical solution of the present invention, the isocyanate includes any one of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate or hexamethylene diisocyanate, or a combination of at least two thereof.

[0043] As a preferred technical solution of the present invention, the tackifying resin includes acrylic resin and / or polyurethane elastomer.

[0044] As a preferred technical solution of the present invention, the catalyst includes any one of dibutyltin dilaurate, organic bismuth, triethylenediamine or dimorpholinodiethyl ether, or a combination of at least two thereof.

[0045] As a preferred technical solution of the present invention, the raw materials for preparing the high temperature resistant moisture curing polyurethane hot melt adhesive also include a stabilizer.

[0046] Preferably, the weight proportion of the stabilizer in the raw materials for preparing the high temperature resistant moisture curing polyurethane hot melt adhesive is 0.1-0.5 parts, for example, it can be 0.1 parts, 0.15 parts, 0.2 parts, 0.25 parts, 0.3 parts, 0.35 parts, 0.4 parts, 0.45 parts or 0.5 parts, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values included in the said range.

[0047] Preferably, the stabilizer comprises any one or a combination of at least two of phosphoric acid, polyphosphoric acid, p-toluenesulfonyl isocyanate, sebacic acid, benzoyl chloride or azelaic acid.

[0048] Preferably, the viscosity of the high temperature resistant moisture-curing polyurethane hot melt adhesive at 110-150°C is 8000-20000 mPa·s, wherein 110-150°C can be 110°C, 120°C, 130°C, 140°C or 150°C, and the viscosity can be 8000 mPa·s, 9000 mPa·s, 10000 mPa·s, 12000 mPa·s, 14000 mPa·s, 16000 mPa·s, 18000 mPa·s or 20000 mPa·s, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values included in the range.

[0049] In a second aspect, the present invention provides a method for preparing the high-temperature resistant moisture-curing polyurethane hot melt adhesive as described in the first aspect, the preparation method comprising the following steps:

[0050] Bio-based polyol, polyether polyol, polyester polyol, tackifying resin, optional stabilizer and isocyanate are mixed, subjected to temperature-controlled reaction, and then a catalyst is added thereto and vacuum degassing is performed to obtain the high-temperature resistant moisture-curing polyurethane hot melt adhesive.

[0051] It should be noted that the catalyst added in the present invention is mainly used to accelerate the curing speed of the high temperature resistant moisture curing polyurethane hot melt adhesive after coating, so it needs to be added after the temperature control reaction is completed.

[0052] Preferably, the mixing temperature is 60-100°C, for example, it can be 60°C, 70°C, 80°C, 90°C or 100°C, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values included in the range.

[0053] Preferably, the mixing step further includes a pretreatment step, wherein the pretreatment method includes vacuum dehydrating the bio-based polyol, polyether polyol, polyester polyol, tackifying resin, and optional stabilizer. Preferably, the vacuum dehydration specifically includes: mixing the bio-based polyol, polyether polyol, polyester polyol, tackifying resin, and optional stabilizer and then vacuum dehydrating them for 1-3 hours at 80-160°C and a pressure of -0.08 to -0.1 MPa.

[0054] It should be noted that the order of vacuum dehydration of the raw material components in the vacuum dehydration step of the present invention is not limited. The bio-based polyol, polyether polyol, polyester polyol, tackifying resin and optional stabilizer can be blended and then vacuum dehydrated. Alternatively, the polyether polyol and tackifying resin can be vacuum dehydrated first, and then the bio-based polyol, polyester polyol, tackifying resin and optional stabilizer are added, and vacuum dehydration is continued.

[0055] In the vacuum dehydration step of the present invention, 80-160°C can be 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C or 160°C, -0.08~-0.1MPa can be -0.08MPa, -0.09MPa or -0.1MPa, 1-3h can be 1h, 1.2h, 1.4h, 1.6h, 1.8h, 2h, 2.2h, 2.4h, 2.6h, 2.8h or 3h, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values included in the said range.

[0056] Preferably, the temperature of the temperature-controlled reaction is 90-120°C, for example, it can be 90°C, 95°C, 100°C, 102°C, 105°C, 108°C, 110°C, 112°C, 115°C, 118°C or 120°C, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values included in the range.

[0057] Preferably, the pressure of the temperature-controlled reaction is -0.08 to -0.1 MPa, for example, it can be -0.08 MPa, -0.09 MPa or -0.1 MPa, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values included in the range.

[0058] Preferably, the temperature control reaction time is 1-3h, for example, it can be 1h, 1.2h, 1.4h, 1.6h, 1.8h, 2h, 2.2h, 2.4h, 2.6h, 2.8h or 3h, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values included in the range.

[0059] Preferably, the temperature of the reaction system when the catalyst is added is 70-100°C, for example, it can be 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values included in the range.

[0060] Preferably, the temperature of the vacuum degassing is 70-100°C, for example, it can be 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values included in the range.

[0061] Preferably, the vacuum degassing time is 0.5-2h, which can be 0.5h, 0.8h, 1h, 1.2h, 1.4h, 1.6h, 1.8h or 2h, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values included in the range.

[0062] Preferably, the temperature-controlled reaction and the vacuum degassing are both carried out under stirring conditions; the present invention does not have any special restrictions on the stirring speed, and the speed range commonly used in this field is applicable, illustratively including but not limited to: 30-60r / min, for example, it can be 30r / min, 35r / min, 40r / min, 45r / min, 50r / min, 55r / min or 60r / min, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values included in the range.

[0063] For example, the preparation method of the high temperature resistant moisture curing polyurethane hot melt adhesive specifically comprises the following steps:

[0064] Under conditions of 80-160° C. and a pressure of -0.08 to -0.1 MPa, a bio-based polyol, a polyether polyol, a polyester polyol, a tackifying resin, and an optional stabilizer are mixed and vacuum dehydrated for 1-3 hours to obtain a mixture; after cooling the obtained mixture to 60-100° C., an isocyanate is added thereto, and the mixture is stirred and temperature-controlled reacted at 90-120° C. and -0.08 to -0.1 MPa for 1-3 hours, then cooled to 70-100° C., a catalyst is added thereto, and the mixture is stirred and vacuum degassed at 70-100° C. and -0.08 to -0.1 MPa for 0.5-2 hours before stopping to obtain the high-temperature-resistant moisture-curing polyurethane hot melt adhesive;

[0065] The viscosity of the high temperature resistant moisture curing polyurethane hot melt adhesive at 110-150° C. is 8000-2000 mPa·s.

[0066] The preparation process of the present invention is simple and easy to operate. By precisely controlling process parameters such as reaction temperature, pressure and time, the occurrence of side reactions is reduced, the uniformity of the reaction and the performance stability of the product are effectively improved, and the quality of the obtained product is thereby improved.

[0067] In the present invention, the obtained high-temperature-resistant, moisture-curing polyurethane hot melt adhesive can be discharged and sealed and packaged when the viscosity is between 8,000 and 20,000 mPa·s at 110-150°C to obtain the high-temperature-resistant, moisture-curing polyurethane hot melt adhesive product. The high-temperature-resistant, moisture-curing polyurethane hot melt adhesive provided by the present invention has an appropriate open time (6-18 minutes) and excellent initial tack, which is conducive to improving production convenience, reducing production inconveniences caused by too short an open time, and does not affect initial tack due to too long an open time.

[0068] In a third aspect, the present invention provides a use of the high-temperature resistant moisture-curing polyurethane hot melt adhesive as described in the first aspect in a floor sound-absorbing pad.

[0069] Compared with the prior art, the present invention has at least the following beneficial effects:

[0070] (1) The present invention, by adding bio-based polyols to the polyurethane hot melt adhesive system, can not only significantly improve the initial adhesion strength and T-peel strength of the obtained moisture-curing polyurethane hot melt adhesive, but also enable it to obtain excellent high temperature resistance, thereby enabling it to have suitable bonding strength in high temperature tests without significant attenuation. At the same time, by compounding the bio-based polyols with polyether polyols, polyester polyols, tackifying resins, isocyanates and catalysts in proportion, it is possible to obtain a moisture-curing polyurethane hot melt adhesive with low odor, high transparency and good stability (can be stored for 6 months at 5-30°C). It can maintain excellent bonding strength at 80°C, and has the characteristics of high initial adhesion strength, fast positioning and universal application in winter and summer, and can be better applied to the bonding of low-polarity material floor silent pads.

[0071] (2) The high-temperature resistant moisture-curing polyurethane hot melt adhesive provided by the present invention is applied to floor sound-absorbing pads. After curing for 7 days in an oven at 80°C for 6 hours, its T-peel strength can reach more than 90% of the original strength. At the same time, when bonding sound-absorbing pads made of low-polarity materials such as IXPE and EVA, its T-peel strength can reach more than 50N / cm, and it can be effectively bonded in both winter and summer environments, and has good weather resistance. DETAILED DESCRIPTION

[0072] For the convenience of understanding the present invention, the present invention is given below with examples. It should be understood by those skilled in the art that the examples are only for the purpose of helping to understand the present invention and should not be regarded as specific limitations of the present invention.

[0073] Unless otherwise specified, the raw materials used in the following examples and comparative examples are all commercially available products. Information on some of the raw materials is shown in Table 1.

[0074] Table 1

[0075]

[0076] Example 1

[0077] This embodiment provides a high-temperature resistant moisture-curing polyurethane hot melt adhesive. The raw materials for preparing the high-temperature resistant moisture-curing polyurethane hot melt adhesive include the following components in parts by weight:

[0078]

[0079]

[0080] The preparation method of the high temperature resistant moisture curing polyurethane hot melt adhesive comprises the following steps:

[0081] At 120°C and a pressure of -0.09 MPa, cashew nut shell oil polyol, polyoxypropylene glycol, amorphous polyester polyol 1, crystalline polyester polyol 1, liquid polyester polyol 1, TPU and phosphoric acid are mixed and vacuum dehydrated for 2 hours to obtain a mixture; after the obtained mixture is cooled to 90°C, diphenylmethane diisocyanate is added thereto while stirring, and the temperature is controlled and reacted at 110°C and -0.09 MPa for 2 hours, and then the temperature is cooled to 100°C, dimorpholine diethyl ether is added thereto, and the vacuum degassing is carried out at 100°C and -0.09 MPa for 1 hour and then stopped to obtain the high temperature resistant moisture-curing polyurethane hot melt adhesive.

[0082] Example 2

[0083] This embodiment provides a high-temperature resistant moisture-curing polyurethane hot melt adhesive. The raw materials for preparing the high-temperature resistant moisture-curing polyurethane hot melt adhesive include the following components in parts by weight:

[0084]

[0085]

[0086] The preparation method of the high temperature resistant moisture curing polyurethane hot melt adhesive is the same as that in Example 1.

[0087] Example 3

[0088] This embodiment provides a high-temperature resistant moisture-curing polyurethane hot melt adhesive. The raw materials for preparing the high-temperature resistant moisture-curing polyurethane hot melt adhesive include the following components in parts by weight:

[0089]

[0090] The preparation method of the high temperature resistant moisture curing polyurethane hot melt adhesive comprises the following steps:

[0091] At 80°C and a pressure of -0.08MPa, cashew nut shell oil polyol, polytetramethylene ether glycol, amorphous polyester polyol 2, crystalline polyester polyol 2, liquid polyester polyol 2 and TPU are mixed and vacuum dehydrated for 3 hours to obtain a mixture; after the obtained mixture is cooled to 60°C, diphenylmethane diisocyanate is added thereto while stirring, and the temperature is controlled and reacted at 90°C and -0.08MPa for 3 hours, and then the temperature is cooled to 70°C, dimorpholine diethyl ether is added thereto, and the vacuum degassing is carried out at 70°C and -0.08MPa for 2 hours after stirring to obtain the high temperature resistant moisture-curing polyurethane hot melt adhesive.

[0092] Example 4

[0093] This embodiment provides a high-temperature resistant moisture-curing polyurethane hot melt adhesive. The raw materials for preparing the high-temperature resistant moisture-curing polyurethane hot melt adhesive include the following components in parts by weight:

[0094]

[0095] The preparation method of the high temperature resistant moisture curing polyurethane hot melt adhesive comprises the following steps:

[0096] At 160° C. and a pressure of −0.1 MPa, cashew nut shell oil polyol, polyethylene glycol ether, amorphous polyester polyol 1, crystalline polyester polyol 1, liquid polyester polyol 1, acrylic resin and sebacic acid are mixed and vacuum dehydrated for 1 hour to obtain a mixture; after the obtained mixture is cooled to 100° C., isophorone diisocyanate is added thereto while stirring, and the mixture is stirred for temperature-controlled reaction at 120° C. and −0.1 MPa for 1 hour, then the mixture is cooled to 100° C., dibutyltin dilaurate is added thereto, and the mixture is stirred for vacuum degassing at 100° C. and −0.1 MPa for 0.5 hour and then stopped to obtain the high-temperature resistant moisture-curing polyurethane hot melt adhesive.

[0097] Example 5

[0098] This embodiment provides a high-temperature resistant moisture-curing polyurethane hot melt adhesive, which differs from Example 1 in that the weight of cashew nut shell liquid polyol is adjusted from 30 parts to 20 parts, and the weight of diphenylmethane diisocyanate is adjusted from 180 parts to 178 parts. Other raw materials, weight parts and preparation methods are the same as those in Example 1.

[0099] Example 6

[0100] This embodiment provides a high temperature moisture curing polyurethane cashew nut shell liquid polyol, the weight parts are adjusted from 30 parts to 25 parts, and the weight parts of diphenylmethane diisocyanate are adjusted from 180 parts to 179 parts. The other raw materials, weight parts and preparation method are the same as those in Example 1.

[0101] Example 7

[0102] This embodiment provides a high-temperature resistant moisture-curing polyurethane hot melt adhesive, which differs from Example 1 in that the weight of cashew nut shell liquid polyol is adjusted from 30 parts to 45 parts, and the weight of diphenylmethane diisocyanate is adjusted from 180 parts to 183 parts. Other raw materials, weight parts and preparation methods are the same as those in Example 1.

[0103] Example 8

[0104] This embodiment provides a high-temperature resistant moisture-curing polyurethane hot melt adhesive, which differs from Example 1 in that the weight of cashew nut shell liquid polyol is adjusted from 30 parts to 50 parts, and the weight of diphenylmethane diisocyanate is adjusted from 180 parts to 184 parts. Other raw materials, weight parts and preparation methods are the same as those in Example 1.

[0105] Example 9

[0106] This embodiment provides a high-temperature resistant moisture-curing polyurethane hot melt adhesive. The only difference between this embodiment and Example 1 is that the cashew nut shell liquid polyol is replaced with an equal weight portion of castor oil polyol, and the weight portion of diphenylmethane diisocyanate is adjusted from 180 parts to 185 parts. Other raw materials, weight portions, and preparation methods are the same as those in Example 1.

[0107] Example 10

[0108] This embodiment provides a high-temperature resistant moisture-curing polyurethane hot melt adhesive, which differs from Example 1 in that the cashew nut shell liquid polyol is replaced with an equal weight portion of soybean oil polyol, and at the same time, the weight portion of diphenylmethane diisocyanate is adjusted from 180 parts to 190 parts. Other raw materials, weight portions, and preparation methods are the same as those in Example 1.

[0109] Example 11

[0110] This embodiment provides a high-temperature resistant moisture-curing polyurethane hot melt adhesive, which differs from Example 1 in that the mass ratio of amorphous polyester polyol 1, crystalline polyester polyol 1, or liquid polyester polyol 1 is adjusted from 1:1.4:1.8 to 1:0.5:1.8, i.e., 106 parts by weight of amorphous polyester polyol 1, 53 parts by weight of crystalline polyester polyol 1, and 191 parts by weight of liquid polyester polyol 1. At the same time, the weight of diphenylmethane diisocyanate is adjusted from 180 parts to 174 parts. Other raw materials, weights, and preparation methods are the same as those in Example 1.

[0111] Example 12

[0112] This embodiment provides a high-temperature resistant moisture-curing polyurethane hot melt adhesive, which differs from Example 1 in that the mass ratio of amorphous polyester polyol 1, crystalline polyester polyol 1, or liquid polyester polyol 1 is adjusted from 1:1.4:1.8 to 1:2.5:1.8, i.e., 66 parts by weight of amorphous polyester polyol 1, 165 parts by weight of crystalline polyester polyol 1, and 119 parts by weight of liquid polyester polyol 1. At the same time, the weight of diphenylmethane diisocyanate is adjusted from 180 parts to 186 parts. Other raw materials, weights, and preparation methods are the same as those in Example 1.

[0113] Example 13

[0114] This embodiment provides a high-temperature resistant moisture-curing polyurethane hot melt adhesive, which differs from Example 1 in that the mass ratio of amorphous polyester polyol 1, crystalline polyester polyol 1, or liquid polyester polyol 1 is adjusted from 1:1.4:1.8 to 1:1.4:0.5, i.e., 121 parts by weight of amorphous polyester polyol 1, 169 parts by weight of crystalline polyester polyol 1, and 60 parts by weight of liquid polyester polyol 1. At the same time, the weight of diphenylmethane diisocyanate is adjusted from 180 parts to 172 parts. Other raw materials, weights, and preparation methods are the same as those in Example 1.

[0115] Example 14

[0116] This embodiment provides a high-temperature resistant moisture-curing polyurethane hot melt adhesive, which differs from Example 1 in that the mass ratio of amorphous polyester polyol 1, crystalline polyester polyol 1, or liquid polyester polyol 1 is adjusted from 1:1.4:1.8 to 1:1.4:3, i.e., 65 parts by weight of amorphous polyester polyol 1, 91 parts by weight of crystalline polyester polyol 1, and 194 parts by weight of liquid polyester polyol 1. At the same time, the weight of diphenylmethane diisocyanate is adjusted from 180 parts to 188 parts. Other raw materials, weights, and preparation methods are the same as those in Example 1.

[0117] Comparative Example 1

[0118] This comparative example provides a moisture-curing polyurethane hot melt adhesive, which differs from Example 1 in that the weight of cashew nut shell liquid polyol is adjusted from 30 parts to 10 parts, and the weight of diphenylmethane diisocyanate is adjusted from 180 parts to 177 parts. Other raw materials, weight parts and preparation methods are the same as those in Example 1.

[0119] Comparative Example 2

[0120] This comparative example provides a moisture-curing polyurethane hot melt adhesive, which differs from Example 1 in that the weight parts of cashew nut shell liquid polyol are adjusted from 30 parts to 70 parts, and the weight parts of diphenylmethane diisocyanate are adjusted from 180 parts to 185 parts. The other raw materials, weight parts and preparation methods are the same as those in Example 1.

[0121] Comparative Example 3

[0122] This comparative example provides a moisture-curing polyurethane hot melt adhesive, which is purchased from Asahikawa Chemical XCUR-6106HL.

[0123] Comparative Example 4

[0124] This comparative example provides a moisture-curing polyurethane hot melt adhesive, which differs from Example 1 in that the cashew nut shell liquid polyol is replaced with an equal weight portion of polyoxypropylene glycol (purchased from Wanhua Chemical WANOL C2020, with a weight-average molecular weight of 2000). The other raw materials, addition amounts, and preparation methods are the same as those in Example 1.

[0125] The moisture-curable polyurethane hot melt adhesives obtained in Examples 1-14 and Comparative Examples 1-4 were subjected to performance tests using the following test methods / standards:

[0126] (1) Viscosity: Use a viscometer to test the viscosity, with a speed of 20 rpm, a temperature set to 120°C, and a time detection setting of 15 min. Place the moisture-curing polyurethane hot melt adhesive into a viscosity tube for testing.

[0127] (2) Determination of open time: Moisture-curing polyurethane hot melt adhesive was melted at 120°C for 30 min, and then a 30 cm long, 10 cm wide, and 30 μm thick strip was applied to aluminum foil using a mold. One strip was bonded with a piece of paper every 30 s, and the end time was when the paper strip was completely torn off without damage.

[0128] (3) Initial Adhesion Strength Test: Heat the moisture-curing polyurethane hot melt adhesive to 120°C to melt it. Then, use a mold to pull out a 30cm long, 10cm wide, and 30μm thick adhesive strip on the adhesive surface of the floor. Use a pressure roller to stick an electrostatic mat about 32cm long and 12cm wide on the adhesive surface of the floor. Immediately use a knife to cut out a 10cm long and 2.54cm wide strip. 5 minutes after the bonding is completed, perform a 90-degree peel test at a speed of 3000mm / min on a tensile testing machine. Peel off the cut silent mat strip. The measured peel strength is the initial adhesion of the hot melt adhesive. The unit is N / M or N / cm, the same as the peel strength.

[0129] (4) Shrinkage test: Heat the moisture-curing polyurethane hot melt adhesive to 120°C and melt it. Then, use a mold to pull out a 30 cm long, 10 cm wide, and 30 μm thick adhesive strip on the adhesive surface of the floor. Apply a transverse tensile force of about 80 N to the silent pad. Use a pressure roller to stick the silent pad to the floor to obtain a floor silent pad sample. Immediately use a knife to cut the silent pad in the middle. Observe the shrinkage length of the silent pad from the cut center line at 25°C. Cut the floor silent pad sample from the middle after curing for 7 days with a knife and bake it in an 80°C oven for 6 hours. Observe the shrinkage length of the silent pad from the cut center line.

[0130] (5) Determination of T-peel strength: Samples were prepared and tested in accordance with GB / T 2791-1995. Wood plastic board (WPC) or stone plastic board (SPC) was used as the substrate to test the T-peel strength of moisture-curing polyurethane hot melt adhesive applied to SPC&EVA, SPC&IXPE and WPC&EVA at 25°C. The floor noise pad sample, which had been cured for 7 days at 25°C*65%, was placed in an oven at 80°C and baked for 6 hours. The sample was then taken out of the oven and a 2.54 cm wide strip was cut from the noise pad. The T-peel strength was tested within 1 minute. The WPC board was easily softened at high temperature, so the T-peel strength was tested 5 minutes after it was taken out of the oven.

[0131] The test results are shown in Tables 2 and 3.

[0132] Table 2

[0133]

[0134] Table 3

[0135]

[0136]

[0137] The test results show that:

[0138] (1) It can be seen from Examples 1-14 that the present invention designs the raw materials for preparing the polyurethane hot melt adhesive. Through the coordination of the various components, a high-temperature resistant moisture-curing polyurethane hot melt adhesive with excellent performance can be obtained. The viscosity at 120°C is 9000-18000 mPa·S, the initial adhesion strength is 9.4-27.1 N / cm, the shrinkage film is ≤1.0 mm at 25°C, and the shrinkage film is ≤2.5 mm at 45°C. The T-peel strength measured at 25°C for SPC&EVA, SPC&IXPE and WPC&EVA is higher than 19.8 N / cm, and can reach up to 50 N / cm or more. Moreover, the T-peel strength measured after high-temperature (80°C) baking is still relatively high, and its retention rate is not less than 33%, and can reach more than 90%, showing excellent high-temperature resistance.

[0139] (2) By comparing Example 1 with Examples 5-8 and Comparative Example 1 with Comparative Example 2, it can be seen that the content of bio-based polyols in Comparative Example 1 and Comparative Example 2 exceeds the specific weight range of 20-50 parts of the present invention, and the initial adhesion strength and T-peel strength of the corresponding moisture-curing polyurethane hot melt adhesive are significantly reduced, and the T-peel strength measured after high-temperature (80°C) baking is significantly reduced, and the degree of high-temperature shrinkage is serious; further, by comparing Example 5 and Example 8 with Example 6 and Example 7, it can be seen that the present invention can further increase the initial adhesion strength and peel strength of the moisture-curing polyurethane hot melt adhesive, reduce the degree of shrinkage, improve the high-temperature resistance, and thus improve its comprehensive performance by optimizing the weight proportion of bio-based polyols.

[0140] (3) By comparing Example 1 with Example 9 and Example 10, it can be seen that the bio-based polyol in Example 9 is castor oil polyol, and the appearance of the moisture-curing polyurethane hot melt adhesive obtained is turbid and opaque, and the T-peel strength and the T-peel strength after high-temperature baking are significantly reduced. In Example 10, the bio-based polyol is soybean oil polyol, and the initial adhesion strength of the moisture-curing polyurethane hot melt adhesive obtained is reduced, and the high-temperature shrinkage phenomenon is aggravated. At the same time, the T-peel strength and the T-peel strength after high-temperature baking are also significantly reduced, indicating that the present invention can further improve the initial adhesion strength, bonding performance and high-temperature resistance of the moisture-curing polyurethane hot melt adhesive obtained by preferably using cashew nut shell oil polyol as the bio-based polyol. Further, by comparing Example 1, Example 9, Example 10 with Comparative Example 4, it can be seen that compared with non-bio-based polyols, the addition of bio-based polyols in the present invention can improve the comprehensive performance of the moisture-curing polyurethane hot melt adhesive obtained, especially the high-temperature resistance.

[0141] (4) By comparing Example 1 with Examples 11-14, it can be seen that the mass ratios of amorphous polyester polyol, crystalline polyester polyol and liquid polyester polyol in the polyester polyols of Examples 11-14 all exceed the preferred range of 1:(0.8-2):(1-2.5), and the appearance of the corresponding moisture-curing polyurethane hot melt adhesives obtained are turbid and opaque, and the T-peel strength is reduced, especially the T-peel strength after high-temperature baking is significantly reduced, indicating that the present invention can significantly improve the appearance transparency and high temperature resistance of the obtained moisture-curing polyurethane hot melt adhesive by further optimizing the mass ratios of amorphous polyester polyol, crystalline polyester polyol and liquid polyester polyol in the polyester polyol.

[0142] (5) By comparing Examples 1-14 with Comparative Example 3, it can be seen that the viscosity of the cured polyurethane hot melt adhesive obtained in Comparative Example 3 is 7000 mPa·S at 120°C, the degree of film shrinkage is serious, especially at a high temperature of the adhesive (45°C), and it has an odor and a yellow and turbid appearance. Although its T-peel strength for low-polarity materials is high at room temperature, its T-peel strength is significantly reduced after high-temperature baking, and can only maintain a maximum of 24% of the original T-peel strength, that is, the high-temperature resistance is insufficient. This well illustrates that compared with the existing moisture-curing polyurethane hot melt adhesive, the moisture-curing polyurethane hot melt adhesive provided by the present invention has the comprehensive technical effects of higher viscosity, transparent and odorless appearance, less film shrinkage, and excellent high-temperature bonding performance for low-polarity materials.

[0143] The applicant declares that the above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the scope of protection and disclosure of the present invention.

Claims

1. A high temperature resistant moisture curing polyurethane hot melt adhesive, characterized in that: The raw materials for preparing the high temperature resistant moisture curing polyurethane hot melt adhesive include the following components in parts by weight:

2. The high temperature resistant moisture curing polyurethane hot melt adhesive according to claim 1, characterized in that: The weight proportion of the bio-based polyol is 25-45 parts; Preferably, the bio-based polyol has a viscosity of 350-550 cPs at 25°C; Preferably, the bio-based polyol has a hydroxyl value of 45-320 mg KOH / g; Preferably, the bio-based polyol includes any one of castor oil polyol, soybean oil polyol or cashew nut shell liquid polyol, or a combination of at least two thereof, and more preferably cashew nut shell liquid polyol.

3. The high temperature resistant moisture curing polyurethane hot melt adhesive according to claim 1 or 2, characterized in that: The polyether polyol includes any one of polyethylene glycol ether, polyoxypropylene glycol or polytetramethylene ether glycol, or a combination of at least two thereof.

4. The high temperature resistant moisture curing polyurethane hot melt adhesive according to any one of claims 1 to 3, characterized in that: The polyester polyol includes any one of amorphous polyester polyol, crystalline polyester polyol or liquid polyester polyol, or a combination of at least two thereof; Preferably, the polyester polyol is a combination of amorphous polyester polyol, crystalline polyester polyol and liquid polyester polyol; Preferably, the mass ratio of the amorphous polyester polyol, the crystalline polyester polyol and the liquid polyester polyol is 1:(0.8-2):(1-2.5); Preferably, the hydroxyl value of the amorphous polyester polyol is 30-120 mg KOH / g; Preferably, the hydroxyl value of the crystalline polyester polyol is 18-54 mg KOH / g; Preferably, the liquid polyester polyol has a hydroxyl value of 53-59 mg KOH / g.

5. The high temperature resistant moisture curing polyurethane hot melt adhesive according to any one of claims 1 to 4, characterized in that: The tackifying resin includes acrylic resin and / or polyurethane elastomer.

6. The high temperature resistant moisture curing polyurethane hot melt adhesive according to any one of claims 1 to 5, characterized in that: The catalyst includes any one of dibutyltin dilaurate, organic bismuth, triethylenediamine or dimorpholinodiethyl ether, or a combination of at least two thereof.

7. The high temperature resistant moisture curing polyurethane hot melt adhesive according to any one of claims 1 to 6, characterized in that: The raw materials for preparing the high temperature resistant moisture curing polyurethane hot melt adhesive also include a stabilizer; Preferably, the weight portion of the stabilizer in the raw materials for preparing the high temperature resistant moisture curing polyurethane hot melt adhesive is 0.1-0.5 parts; Preferably, the stabilizer includes any one of phosphoric acid, polyphosphoric acid, diphenyl phosphate or dibutyl phosphate, or a combination of at least two thereof.

8. The high temperature resistant moisture curing polyurethane hot melt adhesive according to any one of claims 1 to 7, characterized in that: The viscosity of the high-temperature resistant moisture-curing polyurethane hot melt adhesive at 110-150° C. is 8000-20000 mPa·s.

9. A method for preparing the high temperature resistant moisture curing polyurethane hot melt adhesive according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: The bio-based polyol, polyether polyol, polyester polyol, tackifying resin, optional stabilizer and isocyanate are mixed and reacted under temperature control, and then a catalyst is added and vacuum degassing is performed to obtain the high temperature resistant moisture curing polyurethane hot melt adhesive; Preferably, the mixing further includes a pretreatment step, wherein the pretreatment method includes vacuum dehydrating the bio-based polyol, polyether polyol, polyester polyol, tackifying resin, and optional stabilizer.

10. Use of the high temperature resistant moisture curing polyurethane hot melt adhesive according to any one of claims 1 to 8 in floor soundproofing pads.

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