A hydroxyl composition for preparing polyurethane resin and its preparation method and application

Abstract

The invention provides a hydroxy composition for preparing a polyurethane resin, a preparation method and an application thereof. The hydroxy composition comprises a combination of a bio-based dimer acid polyester polyol and a vegetable oil polyol. The ultra-long carbon chain of the bio-based dimer acid polyester polyol is used in combination with the vegetable oil polyol as a multifunctional cross-linking agent, so that the polyurethane resin prepared by using the hydroxy composition has an ultra-soft hand feel and is non-sticky at a low modulus, thereby making the synthetic leather further made by using the polyurethane resin also have a soft and plump hand feel, and also have excellent mechanical properties, rebound performance, hydrolysis resistance and degradability, and will not have a dead wrinkle phenomenon when folded in half for a long time.

Description

Technical Field

[0001] The invention belongs to the technical field of polyurethane, and in particular relates to a hydroxyl composition for preparing polyurethane resin, a preparation method and application thereof. Background Art

[0002] At present, the main materials used for environmentally friendly synthetic leather on the market are two-component solvent-free polyurethane resin and water-based polyurethane resin; among them, although water-based polyurethane resin has begun to be used, its physical properties are poor and it is still difficult to replace the traditional dry and wet process on a large scale; in addition, the mainstream water-based polyurethane adopts the acetone process, and there are still solvents in the preparation process, and the preparation process consumes a lot of energy, while the two-component solvent-free polyurethane resin preparation process only uses ordinary stirring, and there is no need to dry out any solvents and water in the later production, which has great advantages in energy conservation and emission reduction. At the same time, bio-based materials have been greatly developed and applied in recent years. How to apply bio-based materials to the development and application of solvent-free polyurethane synthetic leather and develop ultra-soft solvent-free polyurethane synthetic leather containing bio-based materials will be of great significance.

[0003] CN113699802A discloses a solvent-free polylactic acid bio-based polyurethane synthetic leather, a preparation method and an application thereof. The synthetic leather is composed of an aqueous polyurethane surface layer slurry, a solvent-free polyurethane adhesive layer slurry and a base cloth treated with polylactic acid. The preparation method of the synthetic leather comprises the following steps: coating the aqueous polyurethane surface layer slurry on a release paper and drying to obtain a surface layer composite film; uniformly coating the solvent-free polyurethane adhesive layer slurry on the obtained surface layer composite film, drying, and retaining a certain degree of adhesion of the coating; laminating the base cloth treated with polylactic acid on the obtained adhesive layer, and peeling off the release paper after drying and aging to obtain a solvent-free polylactic acid bio-based polyurethane synthetic leather. The solvent-free polylactic acid bio-based polyurethane synthetic leather prepared by the invention has the advantages of alcohol resistance, hydrolysis resistance, large peeling strength, high room temperature deflection, good wear resistance, and is degradable.

[0004] However, since most solvent-free polyurethane synthetic leathers use an open thin-layer foaming process with a low foaming ratio, the prepared synthetic leather feels stiff. If ordinary polyether materials are used, the modulus will be reduced and the inside of the foaming layer will become sticky. Therefore, it is mainly used in sofa products that do not require high hand feel. At present, most ultra-soft solvent-free polyurethane synthetic leathers have the problem of dead wrinkles.

[0005] Therefore, developing a hydroxyl composition for preparing a polyurethane resin that can produce synthetic leather that is soft to the touch and non-sticky is a technical problem that urgently needs to be solved in the art. Summary of the invention

[0006] In view of the deficiencies in the prior art, the object of the present invention is to provide a hydroxyl composition for preparing a polyurethane resin, and a preparation method and application thereof. The hydroxyl composition introduces a bio-based dimer acid polyester polyol with an ultra-long carbon chain as the main raw material and is matched with a vegetable oil polyol, so that the polyurethane resin prepared by the hydroxyl composition has an ultra-soft feel and is non-sticky at a low modulus, and also has excellent mechanical properties, elasticity, hydrolysis resistance and biodegradability.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a hydroxyl composition for preparing a polyurethane resin, wherein the hydroxyl composition comprises the following components in parts by weight:

[0009] Bio-based dimer acid polyester polyol A 20-85 parts by weight

[0010] 10 to 30 parts by weight of vegetable oil polyol.

[0011] Wherein, the bio-based dimer acid polyester polyol A can be 30 parts by weight, 40 parts by weight, 50 parts by weight, 60 parts by weight, 70 parts by weight or 80 parts by weight.

[0012] The vegetable oil polyol may be 12 parts by weight, 14 parts by weight, 16 parts by weight, 18 parts by weight, 20 parts by weight, 22 parts by weight, 24 parts by weight, 26 parts by weight, 28 parts by weight, etc.

[0013] The hydroxy composition provided by the present invention comprises specific proportions of bio-based dimer acid polyester polyol A and vegetable oil polyol. The bio-based dimer acid polyester polyol A has an ultra-long carbon chain, and thus has excellent hydrolysis resistance, softness and mechanical properties. When used with the vegetable oil polyol as a multifunctional cross-linking agent, the polyurethane resin prepared by using the hydroxy composition can have an ultra-soft hand feel and be non-sticky at a low modulus, thereby solving the problem of stickiness of traditional polyurethane resins as foaming layers at low modulus, and thus making the synthetic leather further prepared by using the polyurethane resin also have a soft and plump hand feel, and also have excellent mechanical properties, rebound performance, hydrolysis resistance and degradability, and will not have a dead wrinkle phenomenon when folded in half for a long time.

[0014] Preferably, the raw materials for preparing the bio-based dimer acid polyester polyol A include small molecule diol A and bio-based dimer acid.

[0015] Preferably, the small molecule diol A includes any one of ethylene glycol, propylene glycol, butylene glycol or hexylene glycol, or a combination of at least two thereof.

[0016] Preferably, the bio-based dimer acid is a bio-based dimer fatty acid.

[0017] Preferably, the bio-based dimer fatty acid is a bio-based dimer fatty acid having no less than 18 carbon atoms (eg, 19, 20, 21, 22, 23, 24 or 25, etc.).

[0018] Preferably, the bio-based dimerized fatty acid comprises bio-based octadecane unsaturated fatty acid dimer.

[0019] Preferably, the preparation method of the bio-based dimer acid polyester polyol A may specifically include the following steps:

[0020] (1) adding bio-based dimer acid, small molecule diol A and a trace amount of catalyst into a reactor, reacting at 140-220° C., controlling the top temperature of the fractionation tower (column) at 100-102° C., removing most of the produced water under normal pressure, and then keeping the temperature at 200-230° C. for 1-2 hours;

[0021] (2) Evacuate the mixture and gradually increase the vacuum degree to remove trace amounts of water and excess small molecule diol A, thereby obtaining the desired bio-based dimer acid polyester polyol A.

[0022] Preferably, the vegetable oil polyol includes any one of castor oil polyol, soybean oil polyol or palm oil polyol, or a combination of at least two thereof, and castor oil polyol is further preferred.

[0023] In the present invention, the castor oil polyol includes castor oil-modified polyol, the soybean oil polyol includes soybean oil-modified polyol, and the palm oil polyol includes palm oil-modified polyol.

[0024] Preferably, the hydroxyl composition further comprises a polyether polyol.

[0025] As a preferred technical solution of the present invention, polyether polyol is also added to the hydroxyl composition. The polyether polyol can be combined with vegetable oil polyol as a multifunctional cross-linking agent, which can further enhance the soft elasticity of the polyurethane resin prepared by using the hydroxyl combination, and can also reduce the viscosity of the hydroxyl composition and reduce the difficulty of processing.

[0026] Preferably, the content of polyether polyol in the hydroxy composition is not higher than 40 parts by weight, for example, 35 parts by weight, 30 parts by weight, 25 parts by weight, 20 parts by weight, 15 parts by weight, 10 parts by weight or 5 parts by weight.

[0027] Preferably, the polyether polyol comprises a bio-based polyether polyol.

[0028] As a preferred technical solution of the present invention, selecting bio-based polyether polyol can further improve the biodegradability of the polyurethane resin prepared by using the hydroxyl composition.

[0029] Preferably, the molecular weight of the polyether polyol is 500-10000, for example, 600, 1000, 2000, 4000, 6000 or 8000.

[0030] Preferably, the hydroxyl composition further comprises a chain extender.

[0031] Preferably, the content of the chain extender in the hydroxyl composition is not more than 2 parts by weight, for example, 1.8 parts by weight, 1.6 parts by weight, 1.4 parts by weight, 1.2 parts by weight, 1 part by weight, 0.8 parts by weight, 0.6 parts by weight, 0.4 parts by weight or 0.2 parts by weight, etc.

[0032] Preferably, the chain extender comprises a small molecule diol B.

[0033] Preferably, the small molecule diol B is a C2-C12 diol, such as a C4, C6, C8 or C10 diol.

[0034] Preferably, the small molecule diol B includes any one of ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol, methylpropylene glycol or hexylene glycol, or a combination of at least two thereof.

[0035] Preferably, the hydroxyl composition further comprises any one of a foaming agent, a leveling agent, a stabilizer or a plasticizer, or a combination of at least two thereof.

[0036] Preferably, the leveling agent comprises silicone oil.

[0037] Preferably, the stabilizer comprises silicone oil.

[0038] Preferably, the blowing agent comprises water.

[0039] Preferably, the silicone oil includes BYK-9565 and / or L-417. The silicone oil is mainly used as a surfactant in the present invention, and can not only reduce surface tension, but also have foam stabilizing, pore opening and leveling effects, and can also prevent the prepared polyurethane resin from having defects such as shrinkage cavities and bubble collapse.

[0040] Preferably, the amount of any one or a combination of at least two of the above-mentioned foaming agent, leveling agent, stabilizer or plasticizer added to the hydroxyl composition is not more than 5 parts by weight, such as 4 parts by weight, 3 parts by weight, 2 parts by weight or 1 part by weight.

[0041] In a second aspect, the present invention provides a method for preparing the hydroxyl composition as described in the first aspect, the preparation method comprising: mixing bio-based dimer acid polyester polyol A, vegetable oil polyol, optionally polyether polyol, optionally chain extender, optionally foaming agent, optionally leveling agent, optionally stabilizer and optionally plasticizer to obtain the hydroxyl composition.

[0042] Preferably, the mixing temperature is 25-60°C, for example, 30°C, 35°C, 40°C, 45°C, 50°C or 55°C.

[0043] In a third aspect, the present invention provides a solvent-free polyurethane resin, wherein raw materials for preparing the solvent-free polyurethane resin include component A and component B, wherein component A includes the hydroxyl composition as described in the first aspect, and component B includes a polyurethane prepolymer.

[0044] Preferably, the mass ratio of component A to component B is 100:(20-100), for example, 100:30, 100:40, 100:50, 100:60, 100:70, 100:80 or 100:90, etc.

[0045] It should be noted that the mass ratio of component A to component B refers to the mass ratio of component A to component B when used, that is, the mass ratio of component A to component B when used to prepare polyurethane resin.

[0046] Preferably, the raw materials for preparing the polyurethane prepolymer include bio-based dimer acid polyester polyol B and diisocyanate.

[0047] Preferably, the raw materials for preparing the polyurethane prepolymer include bio-based dimer acid polyester polyol B and diisocyanate.

[0048] Preferably, the mass content of NCO groups in the polyurethane prepolymer is 5 to 25%, for example, 7%, 9%, 11%, 13%, 15%, 17%, 19%, 21% or 23%, and more preferably 10 to 20%.

[0049] Preferably, the diisocyanate comprises diphenylmethane diisocyanate (MDI) and / or carbodiimide-uretonimine modified MDI (liquefied MDI).

[0050] Preferably, the average functionality of the carbodiimide-uretonimine modified MDI is 2 to 2.2.

[0051] Preferably, the mass percentage of isocyanate groups in the carbodiimide-uretonimine modified MDI is 28-30%, such as 28.5%, 29% or 29.5%.

[0052] Preferably, the B component is obtained by reacting bio-based dimer acid polyester polyol B and diisocyanate.

[0053] Preferably, the reaction is carried out under protective gas protection, more preferably under nitrogen protection.

[0054] Preferably, the reaction time is 3 to 4 h, for example, 3.1 h, 3.2 h, 3.3 h, 3.4 h, 3.5 h, 3.6 h, 3.7 h, 3.8 h or 3.9 h.

[0055] Preferably, the reaction temperature is 60-80°C, for example, 62°C, 64°C, 66°C, 68°C, 70°C, 72°C, 74°C, 76°C or 78°C.

[0056] Preferably, the raw materials for preparing the solvent-free polyurethane further include a catalyst component.

[0057] Preferably, the catalyst component comprises a combination of an organic zinc compound, an organic base and a phenolic compound.

[0058] As a preferred technical solution of the present invention, a combination of organic zinc, organic base and phenolic compounds is used as a catalyst component, and the temperature-sensitive characteristics of the catalyst component and the advantages of extremely high foaming rate and fast gelling speed at high temperature are utilized, and the organic base is adjusted by using a suitable phenolic compound to achieve gelling and foaming balance, breaking through the problem that the foaming rate of the traditional organic tin and common DBU catalyst system in open thin-layer foaming does not exceed 100%, and the catalyst system has a very long open operation time (2 to 10 minutes), which can meet the requirements of continuous production of synthetic leather prepared by solvent-free polyurethane. Even if no additional foaming agent is added to component A, foaming can be achieved by only using a trace amount of water therein, and the foaming rate can reach 100 to 150%, so that the prepared synthetic leather has a soft and plump feel.

[0059] Preferably, the organic zinc includes zinc isooctanoate and / or zinc neodecanoate.

[0060] Preferably, the acidity coefficient of the organic base is not less than 12, such as 12.5, 13, 13.5 or 14.

[0061] Preferably, the organic base includes any one of 1,8-diazabicycloundec-7-ene, 1,5-diazabicyclo[4.3.0]non-5-ene, six-membered bicyclic guanidine or 7-methyl six-membered bicyclic guanidine, or a combination of at least two thereof, and more preferably 7-methyl six-membered bicyclic guanidine.

[0062] Preferably, the phenolic compound comprises phenol.

[0063] Preferably, based on the mass of the component A being 100, the amount of the organic zinc added is 0.025-0.25%, for example, 0.05%, 0.1%, 0.15% or 0.2%.

[0064] Preferably, based on 100% by mass of component A, the added amount of the organic base is 0.01-0.1%, for example, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08% or 0.09%.

[0065] Preferably, the mass ratio of the organic base to the phenolic compound is 1:(0.2-5), for example, 1:0.5, 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4 or 1:4.5, etc.

[0066] In the present invention, in order to facilitate the adding operation, the phenolic compound needs to be compounded with the organic base and first dissolved in the polyether polyol, and the mass percentage of the organic base in the prepared polyether polyol solution is 10%.

[0067] In a fifth aspect, the present invention provides a synthetic leather, wherein the synthetic leather comprises the solvent-free polyurethane resin as described in the third aspect.

[0068] Preferably, the solvent-free polyurethane resin is used as an intermediate layer or a bonding layer of the synthetic leather.

[0069] In a sixth aspect, the present invention provides a method for preparing the synthetic leather as described in the fourth aspect, the preparation method comprising: mixing component A, component B and an optional catalyst component of the solvent-free polyurethane as described in the third aspect, coating the mixture on a release paper, laminating the mixture with a substrate, aging the mixture, and peeling off the release paper to obtain the synthetic leather.

[0070] As a preferred technical solution of the present invention, the mixing method specifically includes: adding the catalyst component to the A component and mixing them evenly, and then adding the B component to react.

[0071] It should be noted that before the actual operation, the A component, the B component and the catalyst component can be kept at a constant temperature of 20 to 40°C.

[0072] Preferably, the substrate comprises any one of knitted fabric, woven fabric, non-woven fabric, microfiber or split leather.

[0073] Compared with the prior art, the present invention has the following beneficial effects:

[0074] (1) The hydroxy composition provided by the present invention comprises specific proportions of bio-based dimer acid polyester polyol A and vegetable oil polyol. The bio-based dimer acid polyester polyol has an ultra-long carbon chain, and is used in combination with the vegetable oil polyol as a multifunctional cross-linking agent. The polyurethane resin prepared by using the hydroxy composition can have an ultra-soft feel and be non-sticky at a low modulus, thereby solving the problem of traditional polyurethane being sticky as a foaming layer at a low modulus. At the same time, it also has excellent mechanical properties, hydrolysis resistance and degradability.

[0075] (2) The synthetic leather made of the solvent-free polyurethane resin prepared from the hydroxyl composition provided by the present invention has a feel similar to that of wet-process leather, and a peel strength of 40 to 52 N / 2.5 cm, which is 20 to 30 N / 2.5 cm compared to the peel strength of the same type of wet-process leather. It also has excellent resilience while having a similar soft feel when wet-processed, and can be folded in half for a long time without any dead wrinkles. DETAILED DESCRIPTION

[0076] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0077] The raw material information involved in the specific implementation of the present invention is as follows:

[0078] Bio-based dimer acid polyester polyol: obtained by reacting bio-based dimer acid (Anqing Hongtai New Materials Co., Ltd., HY-17) with 1,3-propylene glycol, with a molecular weight of 2000;

[0079] Castor oil polyol: derived from refined first-grade castor oil from Guangzhou Chenshi Chemical;

[0080] Palm oil polyol: Maskimi PKF 3000 from Malaysia;

[0081] Polyether polyol: KE-510, molecular weight 4000; FA-703, molecular weight 5000;

[0082] Bio-based polyether polyol: SK Chemical H2000;

[0083] Bio-based polyester polyol: obtained by reacting bio-based succinic acid and 1,3-propylene glycol, with a molecular weight of 2000;

[0084] Leveling silicone oil: BYK-9565;

[0085] Foam-stabilizing silicone oil: Momentive L-417;

[0086] Plasticizer: dioctyl adipate DOA;

[0087] Polyester polyol: Huafeng, polyester PE-7018;

[0088] Carbodiimide-uretonimine modified MDI: Wanhua, MDI-100HL;

[0089] Organotin catalyst: Momentive, Fomrez UL-6;

[0090] Organic bismuth catalyst: bismuth neodecanoate.

[0091] Example 1

[0092] A hydroxy composition for preparing a polyurethane resin comprises the following components in parts by weight:

[0093]

[0094] The preparation method of the hydroxyl composition provided in this embodiment includes: mixing bio-based dimer acid polyester polyol, castor oil polyol, polyether polyol KE-510, ethylene glycol, water, leveling silicone oil, foam stabilizing silicone oil and plasticizer at 30° C. to obtain the hydroxyl composition.

[0095] Example 2

[0096] A hydroxy composition for preparing a polyurethane resin comprises the following components in parts by weight:

[0097]

[0098] The preparation method of the hydroxyl composition provided in this embodiment comprises: uniformly mixing bio-based dimer acid polyester polyol, castor oil polyol, polyether polyol and ethylene glycol, water, leveling silicone oil and foam stabilizing silicone oil at 35° C. to obtain the hydroxyl composition.

[0099] Example 3

[0100] A hydroxy composition for preparing a polyurethane resin comprises the following components in parts by weight:

[0101]

[0102] The preparation method of the hydroxyl composition provided in this embodiment comprises: uniformly mixing bio-based dimer acid polyester polyol, castor oil polyol, polyether polyol and ethylene glycol at 40° C. to obtain the hydroxyl composition.

[0103] Example 4

[0104] A hydroxy composition for preparing a polyurethane resin, which differs from Example 1 only in that no polyether polyol KE-510 is added, the added amount of bio-based dimer acid polyester polyol is 80 parts by weight, and other components, amounts and preparation methods are the same as those in Example 1.

[0105] Example 5

[0106] A hydroxy composition for preparing a polyurethane resin, which differs from Example 1 only in that palm oil polyol is used to replace castor oil polyol, and other components, amounts and preparation methods are the same as those in Example 1.

[0107] Example 6

[0108] A hydroxy composition for preparing a polyurethane resin, which differs from Example 1 only in that bio-based polyether polyol H2000 is used to replace polyether polyol KE-510, and other components, amounts and preparation methods are the same as those in Example 1.

[0109] Comparative Example 1

[0110] A hydroxy composition for preparing a polyurethane resin, which differs from Example 1 only in that conventional polyester polyol (Huafeng Polyester PE-7018) is used to replace the bio-based dimer acid polyester polyol, and other components, amounts and preparation methods are the same as those in Example 1.

[0111] Comparative Example 2

[0112] A hydroxy composition for preparing a polyurethane resin, which differs from Example 1 only in that bio-based polyester polyol is used to replace bio-based dimer acid polyester polyol, and other components, amounts and preparation methods are the same as those in Example 1.

[0113] Comparative Example 3

[0114] A hydroxy composition for preparing a polyurethane resin, which differs from Example 1 only in that castor oil polyol is not added, the addition amount of polyether polyol KE-510 is 50 parts by weight, and other components, amounts and preparation methods are the same as those in Example 1.

[0115] Comparative Example 4

[0116] A hydroxy composition for preparing a polyurethane resin, which differs from Example 1 only in that no bio-based dimer acid polyester polyol is added, the addition amount of polyether polyol KE-510 is 80 parts by weight, and other components, amounts and preparation methods are the same as those in Example 1.

[0117] Application Example 1

[0118] A solvent-free polyurethane resin, the preparation raw materials of which include component A, component B and catalyst component;

[0119] Wherein, component A is the hydroxyl composition obtained in Preparation Example 1;

[0120] The B component is a polyurethane prepolymer in which the mass percentage of NCO groups is 17.5%. The preparation method of the polyurethane prepolymer comprises: reacting 41.5 parts by weight of bio-based dimer acid polyester polyol, 48.5 parts by weight of MDI and 10 parts by weight of carbodiimide-uretonimine modified MDI at 70° C. under nitrogen protection for 3.5 hours to obtain the polyurethane prepolymer;

[0121] The catalyst component is a combination of zinc neodecanoate, MTBD and phenol, the mass ratio of phenol to MTBD is 2:1, based on the mass of component A being 100%, the addition amount of zinc isooctanoate is 0.1%, and the addition amount of MTBD is 0.05%;

[0122] The preparation method of the catalyst component comprises: dissolving phenol and MTBD in polyether polyol KE-510 to prepare a solution (the mass percentage of MTBD is 10%), adding zinc neodecanoate and mixing to obtain the catalyst component.

[0123] Application Examples 2 to 6

[0124] A solvent-free polyurethane resin is disclosed, which differs from Application Example 1 only in that the hydroxyl compositions obtained in Examples 2 to 6 are used to replace the hydroxyl composition obtained in Example 1, and other components, amounts and preparation methods are the same as those in Application Example 1.

[0125] Application Example 7

[0126] A solvent-free polyurethane resin, which differs from Application Example 1 only in that an organic tin catalyst UL-6 is used to replace the catalyst component composed of zinc neodecanoate, MTBD and phenol, and other components, dosages and preparation methods are the same as those in Application Example 1.

[0127] Application Example 8

[0128] A solvent-free polyurethane resin is disclosed, which differs from Application Example 1 only in that an organic bismuth catalyst is used to replace MTBD in the catalyst component, and other components, dosages and preparation methods are the same as those in Application Example 1.

[0129] Application Example 9

[0130] A solvent-free polyurethane resin is different from Application Example 1 only in that the catalyst component does not contain phenol, and other components, dosages and preparation methods are the same as those of Application Example 1.

[0131] Application Example 10

[0132] A synthetic leather, the preparation method of which comprises the following steps:

[0133] (1) adding the catalyst component in Application Example 1 to component A and mixing them evenly, and then adding component B to react, wherein the mass ratio of component A to component B is 100:50, and the amount of the catalyst component is 0.1% zinc isooctanoate, 0.05% MTBD, and 0.1% phenol to obtain a mixed solution;

[0134] (2) firstly, the surface layer resin required by the leather product is coated on the release paper according to the required coating amount, and after drying, the mixed solution obtained in step (1) is coated on the release paper with the surface layer according to the coating amount required by the product, and then preheated at 80-130° C. and quickly bonded with the knitted fabric when it is in the most viscous state, and aged at 100-150° C. for 3-10 minutes, and then cooled and the release paper is removed to obtain the synthetic leather.

[0135] Application Examples 11 to 18

[0136] A synthetic leather, which differs from Application Example 10 only in that the solvent-free polyurethanes obtained in Application Examples 2 to 9 are used to replace the solvent-free polyurethane resin obtained in Application Example 1, and other substances, conditions and preparation methods are the same as those in Application Example 10.

[0137] Comparative Application Examples 1 to 4

[0138] A solvent-free polyurethane, which differs from Application Example 1 only in that the hydroxyl compositions obtained in Comparative Examples 1 to 4 are used to replace the hydroxyl composition obtained in Example 1, and other components, conditions and preparation methods are the same as those in Application Example 1.

[0139] Comparative Application Examples 5 to 8

[0140] A synthetic leather, which differs from Application Example 10 only in that the solvent-free polyurethane resins obtained in Comparative Application Examples 1 to 4 are used to replace the solvent-free polyurethane resin obtained in Application Example 1, and other components, conditions and preparation methods are the same as those in Application Example 10.

[0141] Performance Testing:

[0142] (1) Softness: tested using leather softness tester GT-303;

[0143] (2) Film thickness: Tested with a thickness gauge, the film thickness is the thickness of the final leather product minus the thickness of the cloth;

[0144] (3) Resilience: Fold a piece of synthetic leather with a size of 10 × 10 cm in half, press it with a 5 kg weight at 70 °C for 5 h, and then leave it for 1 h to observe the recovery of the crease.

[0145] (4) Peel strength: tested in accordance with GB / T 1040.3-2006;

[0146] (5) 5-week hydrolysis resistance: After being placed in a constant temperature and humidity chamber (70° C., 95% RH) for 5 weeks, the retention rate of the peel strength before and after aging was tested.

[0147] According to the above test method, the synthetic leather provided by Examples 10 to 18 and Comparative Application Examples 5 to 8 was tested, and the test results are shown in Table 1:

[0148] Table 1

[0149]

[0150] According to the data in Table 1, we can see that:

[0151] (1) The synthetic leather prepared by the solvent-free polyurethane resin in Application Examples 10 to 15 has a thick film thickness, a high softness, and excellent peel strength and hydrolysis resistance. Specifically, the softness is 8 to 9.3, the film thickness is 0.41 to 0.43 mm, the resilience test can fully recover, the peel strength is 40 to 48 N / 2.5 cm, and the peel strength retention rate of the 5-week hydrolysis resistance test is 85 to 91%;

[0152] (2) Compared with Application Examples 16 to 18, the film thickness of the synthetic leather obtained in Application Example 10 is significantly thicker, indicating that the specific catalyst component used in Application Example 10 can effectively improve the foaming ratio of the solvent-free polyurethane resin coating, and has a better foaming effect than the traditional catalyst. The significant increase in the foaming ratio also brings about a significant improvement in softness;

[0153] (3) Compared with Application Example 10, the softness and hydrolysis resistance of the obtained synthetic leather are significantly reduced by replacing other non-dimer acid polyesters in Comparative Application Examples 5-6. This indicates that the solvent-free polyurethane resin prepared by using the bio-based dimer acid polyester polyol provided by the present invention can significantly improve the softness and hydrolysis resistance of the polyurethane resin compared with the common polyester polyol.

[0154] (4) Compared with Application Example 10, the synthetic leather provided by Comparative Application Examples 7-8 has a significant decrease in resilience. In particular, Comparative Application Example 8 does not add bio-based dimer acid polyester polyol, but uses polyether to replace the polyurethane resin obtained by dimer acid polyester, which also has a significant decrease in peel strength.

[0155] The applicant declares that the present invention illustrates a hydroxy composition for preparing polyurethane resin and its preparation method and application through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A solvent-free polyurethane resin, characterized in that: The raw materials for preparing the solvent-free polyurethane resin include component A, component B and a catalyst component; The A component includes a hydroxyl composition; The hydroxyl composition comprises the following components in parts by weight: Bio-based dimer acid polyester polyol A 20-85 parts by weight 10-28 parts by weight of vegetable oil polyol The chain extender is not more than 2 parts by weight; The raw materials for preparing the bio-based dimer acid polyester polyol A include small molecule diol A and bio-based dimer acid; The bio-based dimer acid is a bio-based dimer fatty acid; The bio-based dimer fatty acid is a bio-based dimer fatty acid having no less than 18 carbon atoms; The B component includes a polyurethane prepolymer; The raw materials for preparing the polyurethane prepolymer include bio-based dimer acid polyester polyol and diisocyanate; The diisocyanate includes diphenylmethane diisocyanate and / or carbodiimide-uretonimine modified MDI; The mass content of the NCO group of the polyurethane prepolymer is 5-25%; The catalyst component comprises a combination of organic zinc, an organic base and a phenolic compound.

2. The solvent-free polyurethane resin according to claim 1, characterized in that: The small molecule diol A includes any one of ethylene glycol, propylene glycol, butylene glycol or hexylene glycol, or a combination of at least two thereof.

3. The solvent-free polyurethane resin according to claim 1, characterized in that: The bio-based dimer fatty acid is a bio-based octadecane unsaturated fatty acid dimer.

4. The solvent-free polyurethane resin according to claim 1, characterized in that: The vegetable oil polyol includes any one of castor oil polyol, soybean oil polyol or palm oil polyol, or a combination of at least two thereof.

5. The solvent-free polyurethane resin according to claim 4, characterized in that: The vegetable oil polyol is castor oil polyol.

6. The solvent-free polyurethane resin according to claim 1, characterized in that: The hydroxyl composition also includes a polyether polyol.

7. The solvent-free polyurethane resin according to claim 6, characterized in that: The content of the polyether polyol in the hydroxy composition is not higher than 40 parts by weight.

8. The solvent-free polyurethane resin according to claim 6, characterized in that: The polyether polyol includes a bio-based polyether polyol.

9. The solvent-free polyurethane resin according to claim 8, characterized in that: The molecular weight of the bio-based polyether polyol is 500-10000.

10. The solvent-free polyurethane resin according to claim 1, characterized in that: The chain extender includes a small molecule diol B.

11. The solvent-free polyurethane resin according to claim 10, characterized in that: The small molecule diol B is a C2~C12 diol.

12. The solvent-free polyurethane resin according to claim 10, characterized in that: The small molecule diol B includes any one of ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol, methylpropylene glycol or hexylene glycol, or a combination of at least two thereof.

13. The solvent-free polyurethane resin according to claim 1, characterized in that: The hydroxyl composition further comprises any one of a foaming agent, a leveling agent, a stabilizer or a plasticizer, or a combination of at least two of them.

14. The solvent-free polyurethane resin according to claim 13, characterized in that: The blowing agent includes water.

15. The solvent-free polyurethane resin according to claim 13, characterized in that: The stabilizer includes silicone oil.

16. The solvent-free polyurethane resin according to claim 13, characterized in that: The leveling agent includes silicone oil.

17. The solvent-free polyurethane resin according to claim 1, characterized in that: The preparation method of the hydroxyl composition comprises: mixing bio-based dimer acid polyester polyol A, vegetable oil polyol, optionally polyether polyol, optionally chain extender, optionally foaming agent, optionally leveling agent, optionally stabilizer and optionally plasticizer to obtain the hydroxyl composition.

18. The solvent-free polyurethane resin according to claim 17, characterized in that: The mixing temperature is 25-60°C.

19. The solvent-free polyurethane resin according to claim 1, characterized in that: The mass ratio of component A to component B is 100:(20~100).

20. The solvent-free polyurethane resin according to claim 1, characterized in that: The average functionality of the carbodiimide-uretonimine modified MDI is 2 to 2.

2.

21. The solvent-free polyurethane resin according to claim 1, characterized in that: The mass percentage of isocyanate groups in the carbodiimide-uretonimine modified MDI is 28-30%.

22. The solvent-free polyurethane resin according to claim 1, characterized in that: The B component is obtained by reacting bio-based dimer acid polyester polyol and diisocyanate.

23. The solvent-free polyurethane resin according to claim 22, characterized in that: The reaction is carried out under protective gas protection conditions.

24. The solvent-free polyurethane resin according to claim 23, characterized in that: The reaction was carried out under the protection of nitrogen.

25. The solvent-free polyurethane resin according to claim 22, characterized in that: The reaction time is 3 to 4 hours.

26. The solvent-free polyurethane resin according to claim 22, characterized in that: The reaction temperature is 60-80°C.

27. The solvent-free polyurethane resin according to claim 1, characterized in that: The organic zinc includes zinc isooctanoate and / or zinc neodecanoate.

28. The solvent-free polyurethane resin according to claim 1, characterized in that The acidity coefficient of the organic base is not less than 12.

29. The solvent-free polyurethane resin according to claim 1, characterized in that: The organic base includes any one of 1,8-diazabicycloundec-7-ene, 1,5-diazabicyclo[4.3.0]non-5-ene, six-membered bicyclic guanidine or 7-methyl six-membered bicyclic guanidine, or a combination of at least two thereof.

30. The solvent-free polyurethane resin according to claim 29, characterized in that: The organic base is 7-methyl six-membered bicyclic guanidine.

31. The solvent-free polyurethane resin according to claim 1, characterized in that The phenolic compound includes phenol.

32. The solvent-free polyurethane resin according to claim 1, characterized in that: Based on the mass of the component A being 100%, the amount of the organic zinc added is 0.025-0.25%.

33. The solvent-free polyurethane resin according to claim 1, characterized in that: Based on the mass of the component A being 100%, the amount of the organic base added is 0.01-0.1%.

34. The solvent-free polyurethane resin according to claim 1, characterized in that The mass ratio of the organic base to the phenolic compound is 1:(0.2-5).

35. A synthetic leather, characterized in that: The synthetic leather comprises the solvent-free polyurethane resin as described in any one of claims 1 to 34.

36. The synthetic leather according to claim 35, characterized in that The solvent-free polyurethane resin serves as an intermediate layer or a bonding layer of the synthetic leather.

37. A method for preparing the synthetic leather as claimed in claim 35 or 36, characterized in that: The preparation method comprises: mixing component A, component B and a catalyst component in the solvent-free polyurethane resin according to any one of claims 1 to 34, coating the mixture on a release paper, laminating the mixture with a substrate, aging the mixture, and peeling off the release paper to obtain the synthetic leather.

38. The preparation method according to claim 37, characterized in that: The substrate includes any one of knitted fabric, woven fabric, non-woven fabric, microfiber or split leather.

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