A moisture-curing reactive polyurethane hot melt adhesive, its preparation method and application

Abstract

The present invention discloses a moisture-curing reactive polyurethane hot melt adhesive and its preparation method and application. The raw materials for preparing the moisture-curing polyurethane hot melt adhesive, calculated by weight percentage, include the following components: polyether polyol, crystalline polyester polyol, vegetable oil-modified liquid polyester polyol, isocyanate, poly(meth)acrylic resin, catalyst, leveling agent, phosphate ester and antioxidant for preparation. The moisture-curing reactive polyurethane hot melt adhesive of the present invention can effectively improve the wettability of the hot melt adhesive to low surface energy substrates in the field of woodworking PUR, and at the same time overcome the difficulties such as glue stratification and particles caused by the reduced system compatibility due to the addition of low-polarity raw materials.

Description

Technical Field

[0001] The present invention belongs to the technical field of moisture-curing reactive polyurethane hot melt adhesives, and relates to a moisture-curing reactive polyurethane hot melt adhesive, a preparation method thereof, and an application thereof. Background Art

[0002] Due to excellent properties such as being solvent-free, can be used immediately after heating and melting, having high strength after reaction, and not releasing toxic and harmful gases during the reaction, moisture-curing reactive polyurethane hot melt adhesives are widely used in industries such as electronics, textiles, woodworking, household appliances, and automobiles. Traditional organic solvent-based and water-based adhesives have gradually been replaced by reactive hot melt adhesives.

[0003] In the woodworking flat pasting industry, due to the market's sensitivity to price, the shipping prices of domestic pasting factories have been continuously decreasing. In order to compress costs, it is necessary to choose lower-cost substrates. The substrate factory reduces the cost of the substrate (PVC) by not performing a primer treatment on the substrate. At the same time, when the substrate has no primer, its surface tension is low, and ordinary hot melt adhesives are difficult to infiltrate and achieve effective adhesion. Even when corona treatment is performed, problems such as debonding and non-sticking often occur.

[0004] Based on this, if a large amount of low-polarity raw materials are used in the hot melt adhesive formulation, it will lead to poor compatibility of the glue, and adverse conditions such as delamination and particles will occur. Currently, the technology in the woodworking flat pasting field mainly focuses on adding low-polarity substances to reduce the polarity of the glue, so as to achieve the bonding of materials with low surface tension.

[0005] Chinese Patent CN202010227578.6 discloses a polyurethane hot melt adhesive for bonding non-polar materials. Chinese Patent CN202111154134.5 discloses a polyurethane adhesive containing EVA material for adhesion without treatment. Chinese Patent CN201510481187.6 discloses a silane-capped polyurethane prepolymer, which uses silane capping to replace isocyanate group (NCO) capping and is applied in the formulation of polyurethane adhesives, and it is more sensitive to moisture. Most of the moisture-curing polyurethane hot melt adhesives disclosed in the above patents reduce the polar force of the glue by introducing low-polarity raw materials or improve the wettability and adhesion to the substrate by replacing the original isocyanate group with a silane group. However, the introduction of low-polarity raw materials has poor compatibility in high-polarity raw materials such as polyester polyol and polyether polyol, and even some raw materials may precipitate, etc., which easily causes adverse phenomena such as particles and delamination in the glue product; using silane capping to replace isocyanate group not only reduces the final strength, but also the silane is more sensitive to moisture, and it is easy to have situations such as foaming of the final glue layer and decomposition of some capped silanes when encountering water, thus all resulting in unfavorable results for the use of the hot melt adhesive. Summary of the Invention

[0006] In view of the above deficiencies in the prior art, in order to solve the problem that it is impossible to effectively bond substrates with low surface tension in the field of moisture-curing reactive polyurethane hot-melt adhesives, the present invention provides a moisture-curing reactive polyurethane hot-melt adhesive and a preparation method thereof. The present invention also overcomes the difficulties such as glue stratification and particles caused by the reduced system compatibility due to the addition of low-polarity raw materials.

[0007] In the present invention, a non-reactive phosphate ester is introduced into the traditional reactive polyurethane hot-melt adhesive system, which can achieve the wettability of PVC substrates with low surface tension. In addition, the introduction of vegetable oil-modified liquid polyester polyol further improves the wettability of the adhesive layer to the substrate after reaction. At the same time, due to the reaction between the vegetable oil-modified liquid polyester polyol and isocyanate, the compatibility of the final glue is improved, and there is no stratification or the like.

[0008] In order to achieve the above object, the present invention is realized by the following scheme:

[0009] In the first aspect, the present invention provides a moisture-curing reactive polyurethane hot-melt adhesive, and its raw material mass fraction composition includes:

[0010]

[0011] In the present invention, the functionality of the vegetable oil-modified liquid polyester polyol is 2-4, preferably 2-3, and most preferably 2;

[0012] Preferably, the vegetable oil-modified liquid polyester polyol is one or more of poly(adipic acid vegetable glycol ester) diol, poly(succinic acid vegetable glycol ester) diol, poly(sebacic acid vegetable glycol ester) diol, and more preferably 6331 of Kunle Chemistry (number average molecular weight 2000, functionality 2), FH-2130 of Feihang Technology (number average molecular weight 862, functionality 2).

[0013] In the present invention, the crystalline polyester polyol is one or more of poly(hexamethylene dodecanedioate) diol, poly(hexamethylene adipate) diol PHA, poly(butylene adipate) diol PBA with a number average molecular weight of 2000-8000, and is preferably one or more of 7380, 7360, 7361 of Evonik or one or more of XCP-2000H, XCP-3000H, XCP-44 of Asahi Kasei Chemicals.

[0014] In the present invention, the phosphate ester is a phosphate ester with a carbon chain length less than 4, and is preferably one or more of trimethyl phosphate, triethyl phosphate, and tripropyl phosphate.

[0015] In the present invention, the polyether polyol has a molecular weight of 400-4000, preferably 400-2000, and a hydroxyl value of 28-280, preferably 56-280;

[0016] Preferably, the polyether polyol is one or more of polypropylene glycol (PPG) and polytetrahydrofuran glycol (PTMEG), and more preferably is C2004, C2010, and C2020 of Wanhua Chemical.

[0017] In the present invention, the poly(meth)acrylic resin has a number average molecular weight of 10,000 - 150,000, preferably 30,000 - 80,000, and a glass transition temperature of 20 - 80 °C, preferably 40 - 60 °C.

[0018] Preferably, the poly(meth)acrylic resin is BR-106, BR-116, BR-113 of Mitsubishi of Japan, AC1630, AC2740 of Evonik, and B66, B44 of Dow Chemical.

[0019] In the present invention, the isocyanate is selected from one or more of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate, preferably diphenylmethane - 4,4 - diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and isophorone diisocyanate, and more preferably MDI-100F, HMDI, and IPDI of Wanhua Chemical.

[0020] In the present invention, the antioxidant is selected from one or more of phosphite esters or hindered phenols. The phosphite esters are selected from dipentaerythritol diphosphite diisodecyl ester and tris(2,4 - di - tert - butylphenyl) phosphite, and the hindered phenols are selected from pentaerythritol tetra[β-(3,5 - di - tert - butyl - 4 - hydroxyphenyl)propionate] and octadecyl 3-(3,5 - di - tert - butyl - 4 - hydroxyphenyl)propionate; preferably one or more of 168, 1010, and 1076 of Tianjin Rianlon Co., Ltd. One or more of 168, 1010, and 1076.

[0021] In the present invention, the leveling agent is selected from one or more of acrylate esters and organosilicons. The acrylate esters are selected from n - butyl poly(meth)acrylate, isooctyl poly(meth)acrylate, and cyclohexyl poly(meth)acrylate, and the organosilicons are selected from polydimethylsiloxane, polymethylalkylsiloxane, and organically modified polysiloxane; preferably an acrylate ester leveling agent, and more preferably one or more of L-35, L-37, and L-4 of Estron Co., Ltd.

[0022] In the present invention, the catalyst is one or more of organic bismuths, organic tins, and bis - morpholine ethers. The organic bismuths are selected from bismuth neodecanoate, bismuth laurate, and bismuth isooctanoate, the organic tins are selected from stannous octoate, dibutyltin dilaurate, and dibutyltin bis(dodecyl mercaptide), and the bis - morpholine ethers are selected from dimorpholine diethyl ether and dimorpholine dimethyl ether; preferably stannous octoate, HTT9 of Haotai Chemical Co., Ltd., and dimorpholine diethyl ether of BASF Co., Ltd., with the brand number 106。

[0023] In the present invention, a non-reactive phosphate ester is added to the reactive polyurethane hot melt adhesive. Without reducing the compatibility of the system, chloride ions are formed during the thermal degradation of the PVC-based substrate. The chloride ions further complex with the phosphate ester to form a coordination bond, thereby linking the main body of the adhesive layer to the substrate and improving the wettability of the low surface tension substrate. However, the alkyl chain length of the phosphate ester should not exceed 4 carbons. Because the longer the chain segment, the greater the steric hindrance and the weaker the complexation degree.

[0024] Meanwhile, in the present invention, a vegetable oil-modified liquid polyester polyol is further introduced into the reactive polyurethane hot melt adhesive. Due to its surface energy being similar to the main body of the formulation, it has good compatibility. Secondly, because the vegetable oil has a long side chain and a carbon-carbon double bond structure, its polarity is low, and there is a van der Waals force with the low surface tension substrate, further improving the wettability of the low surface tension substrate.

[0025] In a second aspect, the present invention provides a preparation method of the above-mentioned moisture-curing reactive polyurethane hot melt adhesive. The steps include:

[0026] Mix polyether polyol, crystalline polyester polyol, vegetable oil-modified liquid polyester, antioxidant, leveling agent and poly(meth)acrylic resin, dehydrate under vacuum, then add a catalyst, add isocyanate under a nitrogen atmosphere, heat up to 100 - 120 °C, preferably 110 - 120 °C and react for 1 - 5 h, preferably 1.5 - 4 h, then add the phosphate ester and continue to keep warm and react for 0.5 - 2 h, preferably 0.5 - 1 h to obtain the moisture-curing reactive polyurethane hot melt adhesive.

[0027] In the preparation method of the present invention, for the vacuum dehydration, the pressure is -0.09 - -0.1 MPa, preferably -0.095 - -0.098 MPa, the temperature is 130 - 160 °C, preferably 130 - 145 °C, and the time is 2 - 4 h, preferably 2 - 3.5 h; dehydrate until the water content in the system is lower than 300 ppm.

[0028] For the moisture-curing reactive polyurethane hot melt adhesive prepared by the present invention, the NCO content is 1 - 1.8 wt%, preferably 1.1 - 1.7 wt%; the viscosity at 120 °C is 6000 - 20000 mPa·s, preferably 6000 - 13000 mPa·s.

[0029] In a third aspect, the present invention also provides an application of the above-mentioned moisture-curing reactive polyurethane hot melt adhesive as an adhesive. The bonding application fields include but are not limited to the woodworking field. The moisture-curing reactive polyurethane hot melt adhesive of the present invention can effectively improve the wettability of the hot melt adhesive to the low surface energy substrate in the woodworking PUR field.

[0030] Compared with the prior art, the present invention has the following advantages and effects:

[0031] The moisture-curing reactive polyurethane hot melt adhesive of the present invention, through the synergistic effect of vegetable oil-modified liquid polyester polyol and non-reactive phosphate ester with a carbon chain length less than 4, effectively improves the wettability of the hot melt adhesive in the field of woodworking PUR to substrates with low surface energy, and overcomes problems such as glue stratification and particles caused by the reduction of system compatibility due to the addition of low-polarity raw materials. Detailed implementation manners

[0032] The following examples are further descriptions of the present invention, but the actual implementation manners of the present invention are not limited to the following descriptions. At the same time, the parts mentioned in the following examples are parts by mass.

[0033] The source information of the main raw materials used in the examples and comparative examples is as follows. For other raw materials and reagents, unless otherwise specified, they are all obtained through ordinary commercial channels:

[0034] Polypropylene glycol PPG: C2020, C2010D, C2004 of Wanhua Chemical;

[0035] Polyhexamethylene adipate diol PHA: XCP-3000H, XCP-2000H of Asahi Kasei Chemicals;

[0036] Vegetable oil-based polyhexamethylene adipate diol: 6331 of Kunle Chemical, FH-2130 of Feihang Technology;

[0037] Poly(meth)acrylic resin: BR-106 of Mitsubishi Chemical;

[0038] Isocyanate: MDI-100F, HMDI, IPDI;

[0039] Phosphate ester: Trimethyl phosphate, Triethyl phosphate, Trioctyl phosphate of Zhangjiagang Yarui Chemical Industry;

[0040] Antioxidant: 1076;

[0041] Leveling agent: L-35 of Estron;

[0042] Catalyst: DMDEE of BASF 106, Stannous octoate HTT9 of Haotai Chemical Industry.

[0043] The properties of the moisture-curing reactive polyurethane hot melt adhesives prepared in the examples and comparative examples were all tested by general methods. The main methods are as follows:

[0044] (1) Viscosity: Test was carried out using a Brookfield CAP 2000+ cone and plate viscometer, referring to the GB9751 standard. The No. 4 rotor was selected, the temperature was set at 120 °C, and the rotational speed was 50 rpm;

[0045] (2) Holding tack: Under the conditions of 25 °C and 40% RH, two solid wood pieces were overlapped and bonded using hot melt adhesive, the bonding area was 1 cm × 1 cm. After pressing the bonding part with a 3 kg weight for 30 seconds, it was hung in the holding tack test box, a 1 kg weight was hung in the shear direction, and timing started from the hanging moment to record the falling time of the weight;

[0046] (3) Pot life: Test was carried out referring to the ASTM D4497-1994(2004) standard.

[0047] (4) Peel strength of low surface tension PVC substrate: Under the conditions of 25 °C and 40% RH, a PVC film without primer (30 cm long and 2.5 cm wide) was bonded to an untreated PVC substrate through the wet-curing polyurethane hot melt adhesive of the example and the comparative example. The U-shaped peel force was tested after bonding for 1 h / 2 h / 6 h / 24 h. The PVC film without primer and the untreated PVC substrate were shrunk using a Cuiyuan No. 28 dyn pen, and the measured dyn value was less than 28;

[0048] (5) NCO% content of the adhesive: Test was carried out by titration with amine substances referring to the GB / T 12009.4-2016 standard.

[0049] Example 1

[0050] Prepare a wet-curing reactive polyurethane hot melt adhesive, and its raw material composition includes:

[0051] 30 g of polyether polyol: 27 g of polypropylene glycol PPG (Wanhua C2020, Mn is 2000); 3 g of polypropylene glycol PPG (Wanhua C2004, Mn is 400);

[0052] 25 g of crystalline polyester polyol: polyhexamethylene adipate diol PHA (Asahikawa Chemical XCP-3000H, Mn is 3000);

[0053] 25 g of vegetable oil-modified liquid polyester polyol: polyadipic acid vegetable oil diol ester diol (Kunle Chemical 6331, Mn is 2000, functionality 2);

[0054] 25 g of poly(meth)acrylic resin: Mitsubishi BR-106;

[0055] 12 g of isocyanate: MDI-100F;

[0056] 1 g of phosphate ester: trimethyl phosphate;

[0057] 0.3 g antioxidant: 1076;

[0058] 0.03 g leveling agent: L-35;

[0059] 0.025 g catalyst: 0.02 g DMDEE LUPRAGEN N 106, 0.005 g stannous octoate HTT9.

[0060] The steps are as follows:

[0061] Mix polyether polyol, crystalline polyester polyol, vegetable oil-modified liquid polyester, antioxidant, leveling agent and poly(meth)acrylic resin, dehydrate at 130 °C under vacuum of -0.095 MPa for 2 h until the water content is lower than 300 ppm, then add the catalyst, add isocyanate under nitrogen atmosphere, raise the temperature to 110 °C and react for 1.5 h, then add phosphate ester, continue to keep the temperature and react for 0.5 h until the NCO content is 1.1 wt% and the viscosity at 120 °C is 13000 mPa·s to obtain a moisture-curing reactive polyurethane hot melt adhesive.

[0062] Example 2

[0063] Prepare a moisture-curing reactive polyurethane hot melt adhesive, and its raw material composition includes:

[0064] 50 g polyether polyol: 47 g polypropylene glycol PPG (Wanhua C2020, Mn is 2000); 3 g polypropylene glycol PPG (Wanhua C2010D, Mn is 1000);

[0065] 15 g crystalline polyester polyol: poly(hexamethylene adipate) diol PHA (Asahi Kasei Chemicals XCP-2000H, Mn is 2000);

[0066] 10 g vegetable oil-modified liquid polyester polyol: poly(adipic acid vegetable oil diol ester) diol (Feihang Technology FH-2130, Mn is 862, functionality 2);

[0067] 25 g poly(meth)acrylic resin: Mitsubishi BR-106;

[0068] 15 g isocyanate: HMDI;

[0069] 1 g phosphate ester: triethyl phosphate;

[0070] 0.3 g antioxidant: 1076;

[0071] 0.03 g leveling agent: L-35;

[0072] 0.025 g catalyst: 0.02 g DMDEE LUPRAGEN N 106, 0.005 g stannous octoate HTT9.

[0073] The steps are as follows:

[0074] Mix polyether polyol, crystalline polyester polyol, vegetable oil-modified liquid polyester, antioxidant, leveling agent and poly(meth)acrylic resin, dehydrate at 145 °C under vacuum of -0.098 MPa for 3.5 h until the water content is less than 300 ppm, then add the catalyst, add isocyanate under nitrogen atmosphere, raise the temperature to 120 °C and react for 4 h, then add phosphate ester, continue to keep the temperature and react for 1 h until the NCO content is 1.7 wt% and the viscosity at 120 °C is 6000 mPa·s to obtain a moisture-curing reactive polyurethane hot melt adhesive.

[0075] Example 3

[0076] Prepare a moisture-curing reactive polyurethane hot melt adhesive, and its raw material composition includes:

[0077] 40 g polyether polyol: 37 g polypropylene glycol PPG (Wanhua C2020, Mn is 2000); 3 g polypropylene glycol PPG (Wanhua C2004, Mn is 400);

[0078] 20 g crystalline polyester polyol: poly(hexamethylene adipate) diol PHA (Asahi Kasei XCP-2000H, Mn is 2000);

[0079] 17 g vegetable oil-modified liquid polyester polyol: poly(adipic acid vegetable oil diol ester) diol (Feihang Technology FH-2130, Mn is 862, functionality 2);

[0080] 26 g poly(meth)acrylic resin: Mitsubishi BR-106 of Japan;

[0081] 16 g isocyanate: IPDI;

[0082] 1 g phosphate ester: tributyl phosphate;

[0083] 0.3 g antioxidant: 1076;

[0084] 0.03 g leveling agent: L-35;

[0085] 0.025 g catalyst: 0.02 g DMDEE LUPRAGEN N 106, 0.005 g stannous octoate HTT9.

[0086] The steps are as follows:

[0087] Mix polyether polyol, crystalline polyester polyol, vegetable oil-modified liquid polyester, antioxidant, leveling agent and poly(meth)acrylic resin, dehydrate at 140 °C under -0.095 MPa vacuum for 2.5 h until the water content is lower than 300 ppm, then add a catalyst, add isocyanate under a nitrogen atmosphere, raise the temperature to 115 °C and react for 1.5 h, then add phosphate ester, continue to keep warm and react for 0.5 h until the NCO content is 1.3 wt% and the viscosity at 120 °C is 10000 mPa·s to obtain a moisture-curing reactive polyurethane hot melt adhesive.

[0088] Example 4

[0089] Prepare a moisture-curing reactive polyurethane hot melt adhesive, and its raw material composition includes:

[0090] 33 g of polyether polyol: 30 g of polypropylene glycol PPG (Wanhua C2020, Mn is 2000); 3 g of polypropylene glycol PPG (Wanhua C2004, Mn is 400);

[0091] 10 g of crystalline polyester polyol: polyhexylene adipate diol PHA (Asahikawa Chemical XCP-2000H, Mn is 2000);

[0092] 15 g of vegetable oil-modified liquid polyester polyol: poly(vegetable oil adipate) diol (Kunle Chemical 6331, Mn is 2000, functionality 2);

[0093] 25 g of poly(meth)acrylic resin: Mitsubishi BR-106;

[0094] 13 g of isocyanate: HMDI;

[0095] 1.5 g of phosphate ester: triethyl phosphate;

[0096] 0.03 g of antioxidant: 1076;

[0097] 0.03 g of leveling agent: L-35;

[0098] 0.025 g of catalyst: 0.02 g of DMDEE LUPRAGEN N 106, 0.005 g of stannous octoate HTT9.

[0099] The steps are the same as those in Example 1 to obtain a moisture-curing reactive polyurethane hot melt adhesive with an NCO content of 1.5 wt% and a viscosity at 120 °C of 11000 mPa·s.

[0100] Example 5

[0101] Prepare a moisture-curing reactive polyurethane hot melt adhesive, and its raw material composition includes:

[0102] 33 g of polyether polyol: 30 g of polypropylene glycol PPG (Wanhua C2020, Mn is 2000); 3 g of polypropylene glycol PPG (Wanhua C2004, Mn is 400);

[0103] 10 g of crystalline polyester polyol: polyhexylene adipate diol PHA (Asahi Kasei XCP-2000H, Mn is 2000);

[0104] 15 g of vegetable oil-modified liquid polyester polyol: poly(vegetable oil adipate) diol (Kunle Chemical 6331, Mn is 2000, functionality 2);

[0105] 25 g of poly(meth)acrylic resin: Mitsubishi BR-106;

[0106] 13 g of isocyanate: MDI-100F;

[0107] 1 g of phosphate ester: trioctyl phosphate;

[0108] 0.03 g of antioxidant: 1076;

[0109] 0.03 g of leveling agent: L-35;

[0110] 0.025 g of catalyst: 0.02 g of DMDEE LUPRAGEN N 106, 0.005 g of stannous octoate HTT9.

[0111] The procedure is the same as in Example 1 to obtain a moisture-curable reactive polyurethane hot melt adhesive with an NCO content of 1.5 wt% and a viscosity of 11000 mPa·s at 120 °C.

[0112] Comparative Example 1

[0113] Referring to the preparation method of Example 1, the difference is only that: no phosphate ester is added, and other operations remain unchanged, to obtain a hot melt adhesive.

[0114] Comparative Example 2

[0115] Referring to the preparation method of Example 2, the difference is only that: an equal amount of phosphoric acid is added instead of the phosphate ester, and other operations remain unchanged, to obtain a hot melt adhesive.

[0116] Comparative Example 3

[0117] Referring to the preparation method of Example 3, the difference is only that: no vegetable oil-modified polyester polyol is added, and other operations remain unchanged, to obtain a hot melt adhesive.

[0118] Comparative Example 4

[0119] Referring to the preparation method of Example 4, the difference is only that: no phosphate ester and vegetable oil-modified polyester polyol are added, and other operations remain unchanged, and a hot melt adhesive is prepared.

[0120] Comparative Example 5

[0121] The commercially available reference product is: the moisture-curing polyurethane hot melt adhesive commercially available from Wanhua Chemical 6241.

[0122] Performance tests of the moisture-curing reactive polyurethane hot melt adhesives prepared in Examples 1-5 and Comparative Examples 1-5:

[0123] The specific operation is as follows: at 25°C and 40% RH, a PVC film without primer (30 cm long and 2.5 cm wide) is adhered to an untreated PVC substrate through the moisture-curing polyurethane hot melt adhesives of the examples and comparative examples, and the U-shaped peel strength is tested after 1 h / 2 h / 6 h / 24 h of adhesion. The PVC film without primer and the untreated PVC substrate are shrunk using a Dyne pen No. 28 from Cuiyuan, and the measured Dyne value is less than 28;

[0124] The performance test results are shown in Table 1:

[0125] Table 1 Performance test results of examples and comparative examples

[0126]

[0127] Table 2 Surface tension test results

[0128]

[0129]

[0130] As can be seen from Table 1, the moisture-curing reactive polyurethane hot melt adhesives prepared in Examples 1-5 all have good adhesion and wettability to the PVC film with low surface tension. At the same time, in Comparative Example 1, it was found that the force value increased slowly after 2 hours and the force value decreased after 6 hours, and there was no glue layer on the substrate. It is proved that adding phosphate ester can improve the wettability of the glue layer to the PVC substrate with low surface tension.

[0131] Compared with Example 1, after adding 1 part of phosphoric acid in Comparative Example 2, the subsequent curing speed of the NCO group was seriously affected, and the force value also decreased. Therefore, in this invention, phosphoric acid cannot replace phosphate ester in the formula.

[0132] Compared with Examples 1-5, the force value after adhesion in Example 5 was slightly lower. Although trioctyl phosphate increased the steric hindrance due to the presence of octyl groups, resulting in a weakened van der Waals force effect, the force value after 24 hours was still better than that of Comparative Example 6.

[0133] Compared with Examples 1-5, the force value attenuation occurred 6 hours after lamination in Comparative Example 3. Although the phosphate ester played a complexing role with the low surface tension PVC substrate, the lack of introduction of poly (adipic acid vegetable oil diol) diol ultimately led to... This also confirms the synergistic effect of vegetable oil polyester polyol and phosphate ester in this patent, and neither of them can be absent.

[0134] Compared with Examples 1-4, the force value attenuation occurred 2 hours after lamination in Comparative Example 4, proving that if neither phosphate ester nor vegetable oil-modified polyester polyol is used, the wettability of the surface tension PVC substrate is even worse.

[0135] As can be seen from Table 2, from the test results of surface energy, the surface energy of the main body of the formulation is similar to that of poly (adipic acid vegetable oil diol) diol, proving that there will be no abnormality in compatibility, while the surface energy difference is relatively large without the introduction of vegetable oil-modified polyester polyol.

[0136] The present invention illustrates a moisture-curable polyurethane hot melt adhesive and its preparation method through the above examples, but the present invention is not limited to the above examples, that is, it does not mean that the present invention must rely on the above examples to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent substitution of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A moisture-curing reactive polyurethane hot melt adhesive, characterized in that, The raw material mass composition includes: 10 - 50 parts of polyether polyol; 10 - 30 parts of crystalline polyester polyol; 5 - 30 parts of vegetable oil-modified liquid polyester polyol; 20 - 30 parts of poly(meth)acrylic resin; 10 - 30 parts of isocyanate; 0.5 - 2 parts of phosphate ester; 0.01 - 0.8 parts of antioxidant; 0.01 - 0.1 parts of leveling agent; 0.01 - 0.5 parts of catalyst; The phosphate ester is a phosphate ester with a carbon chain length less than 4.

2. The moisture-curing reactive polyurethane hot melt adhesive according to claim 1, wherein The raw material mass composition includes: 30 - 50 parts of polyether polyol; 15 - 25 parts of crystalline polyester polyol; 10 - 25 parts of vegetable oil-modified liquid polyester polyol; 25 - 28 parts of poly(meth)acrylic resin; 12 - 20 parts of isocyanate; 1 - 1.5 parts of phosphate ester; 0.1 - 0.4 parts of antioxidant; 0.03 - 0.08 parts of leveling agent; 0.02 - 0.1 parts of catalyst.

3. The moisture-curing reactive polyurethane hot melt adhesive according to claim 1, characterized in that, The functionality of the vegetable oil-modified liquid polyester polyol is 2 - 4.

4. The moisture-curing reactive polyurethane hot melt adhesive according to claim 3, characterized in that The functionality of the vegetable oil-modified liquid polyester polyol is 2 - 3.

5. The moisture-curing reactive polyurethane hot melt adhesive according to claim 4, wherein, The functionality of the vegetable oil-modified liquid polyester polyol is 2.

6. The moisture-curing reactive polyurethane hot melt adhesive according to claim 1, characterized in that, The vegetable oil-modified liquid polyester polyol is one or more of poly(adipic acid vegetable glycol ester) diol, poly(succinic acid vegetable glycol ester) diol, poly(sebacic acid vegetable glycol ester) diol.

7. The moisture-curing reactive polyurethane hot melt adhesive according to claim 6, wherein The vegetable oil-modified liquid polyester polyol is 6331 of Kunle Chemistry, FH-2130 of Feihang Technology.

8. The moisture-curing reactive polyurethane hot melt adhesive according to claim 1, wherein The crystalline polyester polyol is one or more of poly(hexamethylene adipate) diol, poly(adipic acid hexanediol ester) glycol PHA, poly(adipic acid butanediol ester) glycol PBA with a number average molecular weight of 2000 - 8000.

9. The moisture-curing reactive polyurethane hot melt adhesive according to claim 8, wherein The crystalline polyester polyol is one or more of 7380, 7360, 7361 of Evonik or XCP-2000H, XCP-3000H, XCP-44 of Asahi Kasei Chemicals Corporation. 7380, 7360, 7361 or one or more of XCP-2000H, XCP-3000H, XCP-44 of Asahi Kasei Chemicals Corporation.

10. The moisture-curing reactive polyurethane hot melt adhesive according to claim 1, wherein, The phosphate ester is selected from one or more of trimethyl phosphate, triethyl phosphate, tripropyl phosphate.

11. The moisture-curing reactive polyurethane hot melt adhesive according to claim 1, characterized in that, The poly(meth)acrylic resin has a number average molecular weight of 10000 - 150000 and a glass transition temperature of 20 - 80 °C.

12. The moisture-curing reactive polyurethane hot melt adhesive according to claim 11, wherein The number average molecular weight is 30000 - 80000 and the glass transition temperature is 40 - 60 °C.

13. The moisture-curable reactive polyurethane hot melt adhesive according to claim 1, characterized in that, The poly(meth)acrylic resin is BR-106, BR-116, BR-113 of Mitsubishi of Japan, AC1630, AC2740 of Evonik, B66, B44 of Dow Chemical.

14. The moisture-curing reactive polyurethane hot melt adhesive according to claim 1, characterized in that, The polyether polyol has a molecular weight of 400 - 4000 and a hydroxyl value of 28 - 280; The isocyanate is selected from one or more of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate.

15. The moisture-curing reactive polyurethane hot melt adhesive according to claim 14, characterized in that, The polyether polyol has a molecular weight of 400 - 2000 and a hydroxyl value of 56 - 280.

16. The moisture-curing reactive polyurethane hot melt adhesive according to claim 14, wherein The isocyanate is selected from diphenylmethane - 4,4 - diisocyanate, diphenylmethane - 2,4 - diisocyanate, polyphenyl polymethylene polyisocyanate.

17. The moisture-curable reactive polyurethane hot melt adhesive according to claim 16, characterized in that, The isocyanate is selected from MDI-100F, HMDI, IPDI of Wanhua Chemical.

18. The moisture-curing reactive polyurethane hot melt adhesive according to claim 1, wherein The polyether polyol is one or more of poly(propylene glycol) PPG, poly(tetrahydrofuran ether glycol) PTMEG.

19. The moisture-curable reactive polyurethane hot melt adhesive according to claim 18, characterized in that, The polyether polyol is C2004, C2010, C2020 of Wanhua Chemical.

20. The moisture-curing reactive polyurethane hot melt adhesive according to claim 1, wherein, The antioxidant is selected from one or more of phosphite esters or hindered phenols. The phosphite esters are selected from pentaerythritol diphosphite diisodecyl ester and tris(2,4-di-tert-butylphenyl) phosphite. The hindered phenols are selected from pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate; The leveling agent is selected from one or more of acrylate esters and organosilicons. The acrylate esters are selected from n-butyl poly(meth)acrylate, isooctyl poly(meth)acrylate, and cyclohexyl poly(meth)acrylate. The organosilicons are selected from polydimethylsiloxane, polymethylalkylsiloxane, and organically modified polysiloxane; The catalyst is selected from one or more of organobismuths, organotins, and bismorpholine ethers. The organobismuths are selected from bismuth neodecanoate, bismuth laurate, and bismuth isooctanoate. The organotins are selected from stannous octoate, dibutyltin dilaurate, and dibutyltin bis(dodecyl sulfide). The bismorpholine ethers are selected from dimorpholine diethyl ether and dimorpholine dimethyl ether.

21. The moisture-curing reactive polyurethane hot melt adhesive according to claim 20, characterized in that, The antioxidant is selected from one or more of RIANOX 168, 1010, and 1076 from Tianjin Lyond Chemical Co., Ltd.

22. The moisture-curing reactive polyurethane hot melt adhesive according to claim 20, wherein The leveling agent is selected from acrylate leveling agents.

23. The moisture-curing reactive polyurethane hot melt adhesive according to claim 22, wherein, The leveling agent is selected from one or more of L-35, L-37, and L-4 from Estron Corporation.

24. The moisture-curing reactive polyurethane hot melt adhesive according to claim 20, wherein, The catalyst is stannous octoate and dimorpholine diethyl ether.

25. A method for preparing the moisture-curing reactive polyurethane hot melt adhesive according to any one of claims 1-24, characterized in that the steps Comprising: Mix polyether polyol, crystalline polyester polyol, vegetable oil-modified liquid polyester, antioxidant, leveling agent, and poly(meth)acrylic resin, dehydrate under vacuum, then add the catalyst, add isocyanate under a nitrogen atmosphere, heat up to 100-120 °C and react for 1-5 h, then add phosphate ester, and continue to keep warm and react for 0.5-2 h to obtain a moisture-curing reactive polyurethane hot melt adhesive.

26. The preparation method according to claim 25, characterized in that, Heat up to 110-120 °C and react for 1.5-4 h.

27. The preparation method according to claim 25, characterized in that, Add phosphate ester and continue to keep warm and react for 0.5-1 h.

28. The preparation method according to claim 25, characterized in that, For the vacuum dehydration, the pressure is -0.09--0.1 MPa, the temperature is 130-160 °C, and the time is 2-4 h; dehydrate until the moisture content in the system is lower than 300 ppm.

29. The preparation method according to claim 28, characterized in that, For the vacuum dehydration, the pressure is -0.095--0.098 MPa, the temperature is 130-145 °C, and the time is 2-3.5 h.

30. Use of the moisture-curing reactive polyurethane hot melt adhesive according to any one of claims 1-24 as an adhesive.

31. The application according to claim 30, characterized in that, Suitable for use as an adhesive in the woodworking field.

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