Natural oil-based polyether polyol, preparation method thereof and polyurethane laminated adhesive

Abstract

The invention provides natural oil-based polyether polyol, a preparation method thereof and a polyurethane laminated adhesive, and the preparation method comprises the following step: carrying out polymerization reaction on natural oil substances, small molecular weight polyether polyol and epoxide under the catalysis of a DMC (Dimethyl Carbonate) catalyst to obtain the natural oil-based polyether polyol. The preparation method does not need a post-treatment process, the production cost is low, the synthesis process is simple, the technological process is short, the prepared natural oil-based polyether polyol can replace high-price castor oil, the cost is reduced, and the natural oil-based polyether polyol has better performance indexes and can meet the performance requirements of the high-performance polyurethane laminated adhesive.

Description

Technical Field

[0001] The present invention belongs to the technical field of polyurethane materials, and particularly relates to a natural oil-based polyether polyol, a preparation method thereof, and a polyurethane film laminating adhesive. Background Art

[0002] With the development of the polyurethane film laminating adhesive industry, polyurethane adhesive products have been widely used in many fields such as batteries, packaging, construction, household appliances, and cables. In polyurethane film laminating adhesives, castor oil is an ideal polyol component for adhesives due to its wide source, good environmental friendliness, and excellent performance, and occupies a relatively large market share in polyurethane film laminating adhesives. For example, the raw materials of the polyurethane adhesive disclosed in CN106349450A include combined polyether and polymethylene polyphenyl polyisocyanate, and the combined polyether includes the following components: 40-70 parts of polyether polyol A, 10-20 parts of polyether polyol B, 20-40 parts of castor oil, 50-70 parts of filler, 0.02-0.08 parts of organometallic catalyst, 2-5 parts of fumed silica, 0.5-1 part of dehumidifier, and 0.5-1.5 parts of defoamer; this polyurethane adhesive has good hardness and bonding strength, and the surface is smooth and bubble-free after curing. However, compared with polyether, the price of castor oil is relatively high, resulting in an increase in the raw material cost of polyurethane film laminating adhesives and restricting its application.

[0003] Making natural oils such as castor oil into oil-based polyols is one of the methods to reduce the amount of castor oil in adhesives and lower the raw material cost. For example, the polyurethane adhesive disclosed in CN102559125A includes component A and component B, and component B is prepared from castor oil, diethylene glycol, glycerol, and phthalic anhydride with a molar ratio of 1:4-7:2-5:1-4, and the hydroxyl value is 170-180mg KOH / g; however, the castor oil-based polyester polyol loses some of the soft segment properties provided by castor oil as a polyol, which is not conducive to its application in the polyurethane film laminating adhesive industry. CN115124967A discloses an epoxy-modified vegetable oil-based two-component polyurethane film laminating adhesive, including component A and component B. The preparation raw materials of both components include epoxy-modified vegetable oil-based polyol. The hydroxyl value of the epoxy-modified vegetable oil-based polyol is 110-280mg KOH / g, and the acid value <1mg KOH / g. It is prepared by the ring-opening reaction of an epoxide and vegetable oil acid, and the mass ratio of the epoxide to vegetable oil acid is (150-250):(200-450); the epoxy-modified vegetable oil-based polyol provides a long carbon chain structure, reducing the viscosity of the polyurethane film laminating adhesive and improving the wetting and leveling properties of the adhesive to the substrate, but the activity and bonding performance of the adhesive are somewhat insufficient.

[0004] At present, the typical preparation method of natural oil polyether is to obtain natural oil polyol through transesterification reaction of alcohol and natural oil under the action of an alkaline catalyst, and then obtain natural oil-based polyether polyol through the ring-opening of epoxide catalyzed by an alkali catalyst. However, this method has the following problems: (1) Saponification reaction is likely to occur during the alkali-catalyzed transesterification reaction, producing a large amount of by-products; (2) The polyether polyol prepared by the alkali-catalyzed reaction needs to remove the alkali metal in the product to an ideal range through methods such as neutralization and adsorption. The process is complicated, the production cycle is long, the production cost is relatively high, and there is also polyether loss.

[0005] Therefore, the performance of existing oil-based polyols is insufficient, and the preparation method of natural oil polyether cannot obtain polyol components with good performance that can replace castor oil for polyurethane laminating adhesives. There is an urgent need in the art to develop natural oil-based polyethers with excellent performance and low price to meet the performance requirements of polyurethane laminating adhesives. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a natural oil-based polyether polyol, its preparation method, and a polyurethane laminating adhesive. The preparation method uses natural oil substances and small molecular weight polyether polyols as initiators, and uses a DMC catalyst, which has the characteristics of simple process and low cost. The prepared natural oil-based polyether polyol is used in polyurethane laminating adhesives, which not only reduces the cost, but also makes the polyurethane laminating adhesive have higher activity and more excellent comprehensive performance.

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

[0008] In the first aspect, the present invention provides a preparation method of a natural oil-based polyether polyol, which includes: a natural oil substance, a small molecular weight polyether polyol, and an epoxide are subjected to a polymerization reaction under the catalysis of a DMC catalyst to obtain the natural oil-based polyether polyol.

[0009] In the preparation method provided by the present invention, natural oil substances and small molecular weight polyether polyols are used as initiators, which undergo an epoxy ring-opening polymerization reaction with an epoxide under the catalysis of a DMC catalyst. The catalytic efficiency of the DMC catalyst is high. The preparation method does not require a post-treatment process, has low production cost, a simple synthesis process, and a short process flow. The prepared natural oil-based polyether polyol can replace high-price castor oil, reduce the cost, and the natural oil-based polyether polyol has better performance indicators and can meet the performance requirements of high-performance polyurethane laminating adhesives.

[0010] In particular, in the preparation method provided by the present invention, the natural oil substance and the low-molecular-weight polyether polyol undergo a transesterification reaction in the presence of a DMC catalyst, which has a high reaction efficiency, enabling the natural oil substance originally without hydroxyl groups to have hydroxyl groups, and then undergoing a polymerization reaction to obtain a natural oil-based polyether polyol; the preparation method does not require controlling the feeding order, the process is simpler, and it avoids the saponification reaction of natural oil caused by alkaline catalysts, and no post-treatment is required, resulting in a natural oil-based polyether polyol with higher purity and better performance indicators.

[0011] In the present invention, the term "DMC catalyst" refers to a double metal cyanide complex catalyst, which can be obtained through market channels.

[0012] The following are the preferred technical solutions of the present invention, but do not limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the purpose and beneficial effects of the present invention can be better achieved and realized.

[0013] Preferably, the natural oil substance includes natural oil and / or natural oil derivatives.

[0014] Preferably, the natural oil derivatives include any one or at least two combinations of partially hydrogenated natural oil, epoxidized natural oil, and alkyl esters of natural oil fatty acids.

[0015] Preferably, the natural oil includes animal oil and / or vegetable oil, and further preferably vegetable oil.

[0016] Preferably, the natural oil includes any one or at least two combinations of castor oil, soybean oil, safflower oil, linseed oil, corn oil, sunflower oil, olive oil, rapeseed oil, sesame oil, cottonseed oil, palm oil, rapeseed oil, tung oil, high-oleic safflower oil, high-oleic soybean oil, high-oleic peanut oil, high-oleic sunflower oil, high-oleic rapeseed oil, high-erucic rapeseed oil, fish oil, and further preferably palm oil.

[0017] Preferably, the natural oil substance includes palm oil.

[0018] Preferably, based on the total mass of the natural oil substance, the low-molecular-weight polyether polyol, and the epoxide being 100%, the mass of the natural oil substance is 1-40%, for example, it can be 2%, 5%, 8%, 9%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, or 38%, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range, and further preferably 10-20%.

[0019] In the present invention, the "low molecular weight polyether polyol" as one of the initiators, its "low molecular weight" is relative to the target product, natural oil-based polyether polyol.

[0020] Preferably, the number average molecular weight of the low molecular weight polyether polyol is 300 - 700, for example, it can be 320, 350, 380, 400, 420, 450, 480, 500, 520, 550, 580, 600, 620, 650 or 680, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range. Further preferably, it is 400 - 500.

[0021] Preferably, the functionality of the low molecular weight polyether polyol is 2 - 3.

[0022] In the present invention, the low molecular weight polyether polyol can be a commercially available product or can be prepared by a preparation method known in the art; exemplarily, the preparation method of the low molecular weight polyether polyol includes: polymerizing an initiator with an epoxide (propylene oxide and / or ethylene oxide) to obtain the low molecular weight polyether polyol.

[0023] Preferably, the initiator for preparing the low molecular weight polyether polyol includes any one or a combination of at least two of glycerol, propylene glycol, ethylene glycol, butanediol, dipropylene glycol, diethylene glycol, and trimethylolpropane.

[0024] Preferably, the low molecular weight polyether polyol includes glycerol-based polypropylene oxide polyol, and its number average molecular weight is 300 - 700, further preferably 500.

[0025] Preferably, the epoxide includes any one or a combination of at least two of tetrahydrofuran, ethylene oxide, propylene oxide, epichlorohydrin, 1,2-epoxybutane, and 2,3-epoxybutane. Further preferably, it is propylene oxide.

[0026] Preferably, based on the total mass of the natural oil substance, low molecular weight polyether polyol, and epoxide being 100%, the mass of the low molecular weight polyether polyol is 20 - 70%, for example, it can be 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45%, 48%, 50%, 52%, 55%, 58%, 60%, 62%, 65% or 68%, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range. Further preferably, it is 40 - 55%.

[0027] As a preferred technical solution of the present invention, based on the total amount of the natural oil substance, the small molecular weight polyether polyol and the epoxide being 100%, the mass of the natural oil substance as one of the initiators is 1-40%, preferably 10-20%, and the mass of the small molecular weight polyether polyol as the other initiator is 20-70%, preferably 40-55%; by adjusting the amounts of the initiator and the epoxide, the hydroxyl value and properties of the natural oil-based polyether polyol can be adjusted to reach or exceed the performance indexes of the polyether polyol synthesized by the prior art.

[0028] Preferably, based on the total mass of the natural oil substance, the small molecular weight polyether polyol and the epoxide being 100%, the mass of the DMC catalyst is 20-100 ppm. For example, it can be 30 ppm, 40 ppm, 50 ppm, 60 ppm, 70 ppm, 80 ppm or 90 ppm, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range. Further preferably, it is 30-60 ppm.

[0029] Preferably, the preparation method includes: first mixing the natural oil substance, the small molecular weight polyether polyol and the DMC catalyst, and then optionally performing dehydration treatment, and then adding the epoxide for polymerization reaction to obtain the natural oil-based polyether polyol;

[0030] Preferably, the temperature of the dehydration treatment is 100-170 °C. For example, it can be 105 °C, 110 °C, 115 °C, 120 °C, 125 °C, 130 °C, 135 °C, 140 °C, 145 °C, 150 °C, 155 °C, 160 °C or 165 °C, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range. Further preferably, it is 130-150 °C.

[0031] Preferably, the dehydration treatment method is vacuum dehydration.

[0032] Preferably, the pressure of the dehydration treatment is -0.05 MPa to -0.1 MPa. For example, it can be -0.055 MPa, -0.06 MPa, -0.065 MPa, -0.07 MPa, -0.075 MPa, -0.08 MPa, -0.085 MPa, -0.09 MPa or -0.095 MPa, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0033] Preferably, the dehydration treatment is carried out under stirring conditions.

[0034] Preferably, the time of the dehydration treatment is ≤ 4 h, for example, it can be 0, 0.1 h, 0.2 h, 0.5 h, 0.8 h, 1 h, 1.2 h, 1.5 h, 1.8 h, 2 h, 2.2 h, 2.5 h, 2.8 h, 3 h, 3.2 h, 3.5 h or 3.8 h, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range. Further preferably, it is 1 - 2 h.

[0035] Preferably, the addition (feeding) of the epoxide is carried out under stirring conditions.

[0036] Preferably, the feeding time of the epoxide is 1 - 3.5 h, for example, it can be 1.2 h, 1.5 h, 1.8 h, 2 h, 2.2 h, 2.5 h, 2.8 h, 3 h, 3.2 h or 3.4 h, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range. Further preferably, it is 1.5 - 2 h.

[0037] Preferably, based on the total feeding amount (total amount) of the epoxide being 100%, the feeding rate of the epoxide is 30 - 90% / h. The amount of the epoxide fed per hour is 32%, 35%, 38%, 40%, 42%, 45%, 48%, 50%, 52%, 55%, 58%, 60%, 62%, 65%, 68%, 70%, 72%, 75%, 78%, 80%, 82%, 85% or 88% of the total amount, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range. Further preferably, it is 30 - 90%, and more preferably 40 - 50%.

[0038] Preferably, the feeding temperature of the epoxide is 100 - 170 °C, for example, it can be 105 °C, 110 °C, 115 °C, 120 °C, 125 °C, 130 °C, 135 °C, 140 °C, 145 °C, 150 °C, 155 °C, 160 °C or 165 °C, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range. Further preferably, it is 130 - 150 °C; the feeding process of the epoxide is also accompanied by the progress of the polymerization reaction.

[0039] Preferably, the temperature of the polymerization reaction is 100 - 170°C, for example, it can be 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C, 160°C or 165°C, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range. Further preferably, it is 130 - 150°C.

[0040] Preferably, the pressure of the polymerization reaction is 0.01 - 0.4 MPa, for example, it can be 0.02 MPa, 0.05 MPa, 0.08 MPa, 0.1 MPa, 0.12 MPa, 0.15 MPa, 0.18 MPa, 0.2 MPa, 0.22 MPa, 0.25 MPa, 0.28 MPa, 0.3 MPa, 0.32 MPa, 0.35 MPa or 0.38 MPa, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range. Further preferably, it is 0.15 - 0.25 MPa.

[0041] Preferably, the time of the polymerization reaction after the addition of the epoxide is completed is 0.5 - 3 h, for example, it can be 0.8 h, 1 h, 1.2 h, 1.5 h, 1.8 h, 2 h, 2.2 h, 2.5 h or 2.8 h, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range. Further preferably, it is 1 - 2 h.

[0042] It should be noted that in the preparation method, with the gradual addition of the epoxide, the polymerization reaction starts; after all the epoxide is added, that is, after the addition of the epoxide is completed, the reaction continues (also known as "curing", "aging") for 0.5 - 3 h. Preferably, when the reaction pressure in the system remains unchanged within 20 min, it is considered that the curing is completed and the polymerization reaction is finished.

[0043] Preferably, the pressure of the curing is 0.1 - 0.4 MPa, for example, it can be 0.12 MPa, 0.15 MPa, 0.18 MPa, 0.2 MPa, 0.22 MPa, 0.25 MPa, 0.28 MPa, 0.3 MPa, 0.32 MPa, 0.35 MPa or 0.38 MPa, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range. Further preferably, it is 0.2 - 0.3 MPa.

[0044] Preferably, after the polymerization reaction is completed, it further includes a degassing step; small molecule substances are removed during the degassing process; the small molecule substances include unreacted epoxides, etc.

[0045] Preferably, the pressure for degassing is -0.08 MPa to -0.095 MPa. For example, it can be -0.082 MPa, -0.085 MPa, -0.088 MPa, -0.09 MPa, -0.092 MPa or -0.094 MPa, as well as the specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the range. Further preferably, it is -0.09 MPa to -0.095 MPa.

[0046] Preferably, the time for degassing is 0.25 - 2 h. For example, it can be 0.5 h, 0.8 h, 1 h, 1.2 h, 1.5 h or 1.8 h, as well as the specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the range.

[0047] Preferably, the preparation method includes the following steps:

[0048] First, place the natural oil substance, small molecular weight polyether polyol and DMC catalyst in a reaction device, and carry out vacuum dehydration treatment at 100 - 170 °C under stirring conditions for 0.1 - 4 h;

[0049] Then add an epoxide to the reaction device and carry out a polymerization reaction at 100 - 170 °C under the conditions of 0.01 - 0.4 MPa; the feeding time of the epoxide is 1 - 3.5 h; after the feeding of the epoxide is completed, cure at 100 - 170 °C under 0.1 - 0.4 MPa for 0.5 - 3 h, and the polymerization reaction is completed;

[0050] Then degas at a pressure of -0.08 MPa to -0.095 MPa for 0.25 - 2 h to obtain the natural oil-based polyether polyol;

[0051] Based on the total mass of the natural oil substance, small molecular weight polyether polyol and epoxide being 100%, the mass of the natural oil substance is 1 - 40%, the mass of the small molecular weight polyether polyol is 20 - 70%, and the mass of the DMC catalyst is 20 - 100 ppm.

[0052] In the second aspect, the present invention provides a natural oil-based polyether polyol, which is prepared by the preparation method as described in the first aspect.

[0053] Preferably, the average functionality of the natural oil-based polyether polyol is 2 - 3.

[0054] Preferably, the natural oil content of the natural oil-based polyether polyol is 1-40 wt%, for example, it can be 2 wt%, 5 wt%, 8 wt%, 10 wt%, 12 wt%, 15 wt%, 18 wt%, 20 wt%, 22 wt%, 25 wt%, 28 wt%, 30 wt%, 32 wt%, 35 wt% or 38 wt%, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the specific point values included in the scope of the present invention are not exhaustively listed herein.

[0055] In the present invention, "wt%" represents mass percentage.

[0056] Preferably, the hydroxyl value of the natural oil-based polyether polyol is 140-180 mg KOH / g, for example, it can be 142 mgKOH / g, 145 mg KOH / g, 148 mg KOH / g, 150 mg KOH / g, 152 mg KOH / g, 155 mg KOH / g, 158 mg KOH / g, 160 mg KOH / g, 162 mg KOH / g, 165 mg KOH / g, 168 mg KOH / g, 170 mg KOH / g, 172 mg KOH / g, 175 mg KOH / g or 178 mg KOH / g, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the specific point values included in the scope of the present invention are not exhaustively listed herein.

[0057] Preferably, the acid value of the natural oil-based polyether polyol is < 0.1 mg KOH / g, more preferably < 0.01 mgKOH / g, and even more preferably ≤ 0.008 mg KOH / g.

[0058] In the third aspect, the present invention provides a polyurethane laminating adhesive, which comprises component A and component B;

[0059] Component A includes the following components in parts by mass:

[0060] The natural oil-based polyether polyol described in the second aspect 10-50 parts

[0061] The first polyether polyol 10-50 parts;

[0062] The preparation raw materials of component B include the following components in parts by mass:

[0063] The second polyether polyol 10-50 parts

[0064] Isocyanate 40-80 parts.

[0065] The polyurethane film laminating adhesive provided by the present invention adopts a two-component system, has a low processing temperature, is simple and easy to operate in the preparation process, is environmentally friendly, and has high production efficiency; the natural oil-based polyether polyol is included in the component A, which can replace high-price castor oil, reduce costs, and endow the polyurethane film laminating adhesive with significantly improved viscosity reactivity, higher hardness and tensile strength, and higher peel strength, and has excellent activity, mechanical properties and bonding properties, achieving the effects of low cost and high performance.

[0066] In the component A, the mass part of the natural oil-based polyether polyol is 10-50 parts, for example, it can be 12 parts, 15 parts, 18 parts, 20 parts, 22 parts, 25 parts, 28 parts, 30 parts, 32 parts, 35 parts, 38 parts, 40 parts, 42 parts, 45 parts or 48 parts, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range. Further preferably, it is 20-50 parts.

[0067] The mass part of the first polyether polyol is 10-50 parts, for example, it can be 12 parts, 15 parts, 18 parts, 20 parts, 22 parts, 25 parts, 28 parts, 30 parts, 32 parts, 35 parts, 38 parts, 40 parts, 42 parts, 45 parts or 48 parts, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range. Further preferably, it is 15-40 parts.

[0068] The component B is a prepolymer containing NCO groups obtained by reacting a second polyether polyol with an isocyanate; in its preparation raw materials, the mass part of the second polyether polyol is 10-50 parts, for example, it can be 12 parts, 15 parts, 18 parts, 20 parts, 22 parts, 25 parts, 28 parts, 30 parts, 32 parts, 35 parts, 38 parts, 40 parts, 42 parts, 45 parts or 48 parts, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range. Preferably, it is 20-40 parts.

[0069] The mass part of the isocyanate is 40-80 parts, for example, it can be 45 parts, 48 parts, 50 parts, 52 parts, 55 parts, 58 parts, 60 parts, 62 parts, 65 parts, 68 parts, 70 parts, 72 parts, 75 parts or 78 parts, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range. Preferably, it is 50-70 parts.

[0070] Preferably, the functionality of the first polyether polyol is 2-3.

[0071] Preferably, the number-average molecular weight of the first polyether polyol is 400-6000, for example, it can be 500, 800, 1000, 1200, 1500, 1800, 2000, 2200, 2500, 2800, 3000, 3200, 3500, 3800, 4000, 4200, 4500, 4800, 5000, 5200, 5500 or 5800, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range. Further preferably, it is 400-4000.

[0072] In the present invention, the first polyether polyol can be a commercially available product or can be prepared by a preparation method known in the art; exemplarily, the preparation method of the first polyether polyol includes: a polymerization reaction between an initiator and an epoxide (propylene oxide and / or ethylene oxide) to obtain the first polyether polyol.

[0073] Preferably, the initiator for preparing the first polyether polyol includes any one or a combination of at least two of glycerol, propylene glycol, ethylene glycol, butanediol, dipropylene glycol, diethylene glycol, and trimethylolpropane.

[0074] Preferably, the first polyether polyol is a commercially available product, exemplarily including but not limited to any one or a combination of at least two of C2004, C2020, and F3135 of Wanhua Chemical (Yantai) Rongwei Polyurethane Co., Ltd.

[0075] Preferably, the component A further includes a catalyst.

[0076] Preferably, the catalyst includes an organotin catalyst, further preferably any one or a combination of at least two of dibutyltin dilaurate, stannous octoate, and dibutyltin diacetate, and even more preferably stannous octoate.

[0077] Preferably, based on the total mass of the component A being 100%, the mass of the catalyst is 5-50 ppm, for example, it can be 8 ppm, 10 ppm, 12 ppm, 15 ppm, 18 ppm, 20 ppm, 22 ppm, 25 ppm, 28 ppm, 30 ppm, 32 ppm, 35 ppm, 40 ppm or 45 ppm, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range. Further preferably, it is 10-30 ppm.

[0078] Preferably, the functionality of the second polyether polyol is 2-3.

[0079] Preferably, the number average molecular weight of the second polyether polyol is 300 - 3000, for example, it can be 400, 500, 800, 1000, 1200, 1500, 1800, 2000, 2200, 2500 or 2800, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range. Further preferably, it is 400 - 2000.

[0080] In the present invention, the second polyether polyol can be a commercially available product or can be prepared by a preparation method known in the art; exemplarily, the preparation method of the second polyether polyol includes: a polymerization reaction of an initiator and an epoxide (propylene oxide and / or ethylene oxide, preferably propylene oxide) to obtain the second polyether polyol.

[0081] Preferably, the initiator for preparing the second polyether polyol includes any one or a combination of at least two of glycerol, ethylene glycol, propylene glycol, butylene glycol, dipropylene glycol, and diethylene glycol. Further preferably, it is propylene glycol and / or diethylene glycol.

[0082] Preferably, the second polyether polyol is a commercially available product, exemplarily including but not limited to: any one or a combination of at least two of C2004, C2020, and C2040 from Wanhua Chemical (Yantai) Rongwei Polyurethane Co., Ltd.

[0083] Preferably, the isocyanate is selected from any one or a combination of at least two of aliphatic isocyanates, alicyclic isocyanates, and aromatic isocyanates. Further preferably, it is an aromatic isocyanate.

[0084] Preferably, the isocyanate includes any one or a combination of at least two of toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), 1,5 - naphthalene diisocyanate (NDI), hexamethylene diisocyanate (HDI), methylcyclohexyl diisocyanate (HTDI), 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate (IPDI), p - phenylene diisocyanate (PPDI), p - xylylene diisocyanate (XDI), and tetramethylxylene diisocyanate (TMXDI). Further preferably, it is diphenylmethane diisocyanate (MDI).

[0085] Preferably, the content of the NCO group in the B component is 5 - 30 wt%, for example, it can be 6 wt%, 8 wt%, 10 wt%, 12 wt%, 15 wt%, 18 wt%, 20 wt%, 22 wt%, 25 wt% or 28 wt%, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range. Further preferably, it is 10 - 20 wt%.

[0086] Preferably, the ratio of the molar amount of the NCO groups in Component B to the molar amount of the hydroxyl groups in Component A is (1 - 1.5):1, and for example, it can be 1.05:1, 1.1:1, 1.15:1, 1.2:1, 1.25:1, 1.3:1, 1.35:1, 1.4:1 or 1.45:1, etc.

[0087] Exemplarily, the preparation method of the polyurethane film laminating adhesive comprises:

[0088] Preparing Component A: Mix the natural oil-based polyether polyol, the first polyether polyol and the catalyst evenly according to the formula amount to obtain Component A;

[0089] Preparing Component B: Carry out a prepolymerization reaction on the isocyanate and the second polyether polyol to obtain a prepolymer containing NCO groups, namely Component B;

[0090] Mix Component A and Component B evenly to obtain the polyurethane film laminating adhesive.

[0091] Preferably, the temperature of the prepolymerization reaction is 60 - 100 °C. For example, it can be 65 °C, 68 °C, 70 °C, 72 °C, 75 °C, 78 °C, 80 °C, 82 °C, 85 °C, 88 °C, 90 °C or 95 °C, as well as the specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the range.

[0092] Preferably, the time of the prepolymerization reaction is 1 - 6 h. For example, it can be 1.5 h, 2 h, 2.5 h, 2.8 h, 3 h, 3.2 h, 3.5 h, 3.8 h, 4 h, 4.2 h, 4.5 h, 4.8 h, 5 h or 5.5 h, as well as the specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the range.

[0093] Preferably, after mixing Component A and Component B, it further includes a defoaming step.

[0094] Compared with the prior art, the present invention has the following beneficial effects:

[0095] (1) In the preparation method of the natural oil-based polyether polyol provided by the present invention, natural oil substances and small molecular weight polyether polyols are used as initiators, and they carry out an epoxy ring-opening polymerization reaction under the catalysis of a DMC catalyst, so that the preparation method does not require a post-treatment process, has low production costs, a simple synthesis process, a short process flow, the prepared natural oil-based polyether polyol can replace high-price castor oil to reduce costs, and the natural oil-based polyether polyol has better performance indexes and can meet the performance requirements of high-performance polyurethane film laminating adhesives.

[0096] (2) The polyurethane film laminating adhesive provided by the present invention adopts a two-component system, has a low processing temperature, is simple and easy to operate in the preparation process, is environmentally friendly, and has high production efficiency; by using the natural oil-based polyether polyol, it can replace high-price castor oil, while reducing the cost, making the polyurethane film laminating adhesive have significantly improved viscosity reaction activity, higher hardness, tensile strength, and higher peel strength. Its hardness ≥ 28.8 HA, tensile strength is 3.76 - 5.21 MPa, elongation at break is 880 - 920%, peel strength ≥ 17.5 N / 15 mm, and it has excellent activity, mechanical properties and bonding properties, achieving an excellent balance effect in terms of low cost and high performance. Detailed Embodiments

[0097] The technical solutions of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0098] In the following specific embodiments of the present invention, the materials involved are as follows:

[0099] (1) Natural oil substances

[0100] Palm oil, purchased from COFCO Corporation.

[0101] (2) Small molecular weight polyether polyols

[0102] Wanol R2305, with a number average molecular weight of 500, functionality of 3, hydroxyl value of 335 mg KOH / g, viscosity of 300 mPa·s, Wanhua Chemical (Yantai) Rongwei Polyurethane Co., Ltd.;

[0103] Wanol R2304, with a number average molecular weight of 400, functionality of 3, hydroxyl value of 415 mg KOH / g, viscosity 374 mPa·s, Wanhua Chemical (Yantai) Rongwei Polyurethane Co., Ltd.

[0104] (3) Polyether polyols

[0105] Polyether polyol 1, Wanol F3135, with a number average molecular weight of 4800, functionality of 3, hydroxyl value of 35 mg KOH / g, viscosity of 890 mPa·s, Wanhua Chemical (Yantai) Rongwei Polyurethane Co., Ltd.;

[0106] Polyether polyol 2, Wanol C2020, with a number average molecular weight of 2000, functionality of 2, hydroxyl value of 56 mgKOH / g, viscosity of 350 mPa·s, Wanhua Chemical (Yantai) Rongwei Polyurethane Co., Ltd.;

[0107] Polyether polyol 3, Wanol C2004, with a number average molecular weight of 400, functionality of 2, hydroxyl value of 280 mg KOH / g, viscosity of 70 mPa·s, Wanhua Chemical (Yantai) Rongwei Polyurethane Co., Ltd.;

[0108] (4) Isocyanate

[0109] Diphenylmethane diisocyanate, MDI - 50, MDI - 100, Wanhua Chemical Group Co., Ltd.

[0110] Other reagents not specifically mentioned can be obtained commercially.

[0111] In the following specific embodiments of the present invention, the test methods for various indicators of the natural oil - based polyether polyol are as follows:

[0112] (1) Hydroxyl value: Tested by the method in GB / T 12008.3 - 2009;

[0113] (2) Appearance: Tested by the method in Q / 0600YPU 025 - 2022;

[0114] (3) pH: Tested by the method in GB / T 12008.2 - 2010;

[0115] (4) Acid value: Tested by the method in GB / T 12008.5 - 2010;

[0116] (5) Palm oil content: Calculated based on the feeding amount to obtain the mass content of palm oil in the natural oil - based polyether polyol.

[0117] Example 1

[0118] A natural oil - based polyether polyol A1 and its preparation method, the preparation method comprising the following steps:

[0119] In a 5L stainless - steel autoclave, add 200g of palm oil, 1000g of small - molecular - weight polyether polyol R2305, and 0.1g of DMC catalyst. Replace with nitrogen 3 times. Under a pressure of - 0.09MPa, stir and heat up. When the temperature reaches 150℃, under a pressure of - 0.09MPa, carry out vacuum dehydration for 1h, then pre - add 40g of propylene oxide for initiation. After successful initiation, slowly add a total of 900g of propylene oxide, and the feeding takes 120min in total. Under stirring, carry out the polymerization reaction at 150℃; after the feeding is completed, carry out curing at 150℃ for 1h. If the reaction pressure remains unchanged within 20min, it is considered that the curing is completed. Under a vacuum of - 0.095MPa, degas for 0.5h to remove small - molecule substances, thus obtaining the natural oil - based polyether polyol A1, which is a light - yellow transparent liquid.

[0120] Example 2

[0121] A natural oil-based polyether polyol A2 and its preparation method, the preparation method comprising the following steps:

[0122] In a 5L stainless steel autoclave, add 300g of palm oil, 900g of small molecular weight polyether polyol R2304, 0.1g of DMC catalyst, displace with nitrogen 3 times, under a pressure of -0.09MPa, stir and heat up, heat up to 150°C, under a pressure of -0.09MPa, carry out vacuum dehydration for 1h, then pre-charge 40g of propylene oxide for initiation. After successful initiation, slowly add propylene oxide, a total of 800g is added, and the feeding takes 110min in total. Under stirring, carry out polymerization reaction at 150°C. After the feeding is completed, carry out curing at 150°C for 2h. If the reaction pressure remains unchanged within 20min, it is considered that the curing is completed. Under a vacuum of -0.095MPa, degas for 0.5h to remove small molecular substances, and thus obtain the natural oil-based polyether polyol A2, which is a light yellow transparent liquid.

[0123] Example 3

[0124] A natural oil-based polyether polyol A3 and its preparation method, the preparation method comprising the following steps:

[0125] In a 5L stainless steel autoclave, add 400g of palm oil, 1000g of small molecular weight polyether polyol R2305, 0.1g of DMC catalyst, displace with nitrogen 3 times, under a pressure of -0.09MPa, stir and heat up, heat up to 150°C, under a pressure of -0.09MPa, carry out vacuum dehydration for 1h, then pre-charge 40g of propylene oxide for initiation. After successful initiation, slowly add propylene oxide, a total of 600g is added, and the feeding takes 80min in total. Under stirring, carry out polymerization reaction at 150°C. After the feeding is completed, carry out curing at 150°C for 1h. If the reaction pressure remains unchanged within 20min, it is considered that the curing is completed. Under a vacuum of -0.095MPa, degas for 0.5h to remove small molecular substances, and thus obtain the natural oil-based polyether polyol A3, which is a light yellow transparent liquid.

[0126] Example 4

[0127] A natural oil-based polyether polyol A4 and its preparation method, the preparation method comprising the following steps:

[0128] In a 5L stainless steel autoclave, 500g of palm oil, 950g of small molecular weight polyether polyol R2305, and 0.1g of DMC catalyst were added. After purging with nitrogen three times, while under a pressure of -0.09MPa, the mixture was stirred and heated. When the temperature reached 150°C and under a pressure of -0.09MPa, water was removed under reduced pressure for 1h, and then 40g of propylene oxide was pre-added to initiate the reaction. After successful initiation, propylene oxide was slowly added, with a total of 550g added, and the feeding process took 70 minutes in total. The polymerization reaction was carried out at 150°C with stirring. After the feeding was completed, curing was carried out at 150°C for 1.5h. When the reaction pressure remained unchanged within 20 minutes, it was considered that the curing was completed. Under a vacuum of -0.095MPa, degassing was carried out for 0.5h to remove small molecular substances, and thus natural oil-based polyether polyol A4 was obtained, which is a light yellow transparent liquid.

[0129] The performance indicators of the aforementioned natural oil-based polyether polyol are shown in Table 1:

[0130] Table 1

[0131]

[0132] Application Examples 1-4, Comparative Example 1

[0133] A polyurethane film laminating adhesive comprises Component A and Component B;

[0134] Component A includes the following components by mass parts:

[0135] Natural oil-based polyether polyol 45 parts

[0136] Polyether polyol 1 (F3135) 30 parts;

[0137] Catalyst T9 5ppm;

[0138] The dosage of catalyst T9 is calculated based on the total mass of Component A being 100%, and its mass is 5ppm. The natural oil-based polyether polyols in Application Examples 1-4 are respectively natural oil-based polyether polyols A1, A2, and A3 provided in Examples 1-4. In Comparative Example 1, castor oil with the same mass (hydroxyl value of 161mg KOH / g, brand number 8001-79-4, purchased from Shandong Huian Chemical Co., Ltd.) was used.

[0139] The preparation raw materials of Component B include the following components by mass parts:

[0140]

[0141]

[0142] The preparation method of the polyurethane film laminating adhesive is as follows:

[0143] (1) According to the formulation amount, mix natural oil-based polyether polyol, polyether polyol 1 (F3135) and catalyst T9 at high speed to obtain component A;

[0144] (2) According to the formulation amount, react polyether polyol 2, polyether polyol 3, MDI-100 and MDI-50 at 80 °C for 3 h to obtain component B with an NCO group content of 16 wt%;

[0145] (3) Mix component A and component B at a mass ratio of 75:50 so that the molar ratio of hydroxyl groups in component A to NCO groups in component B is 1:1.4; after mixing evenly, remove air bubbles under vacuum to obtain the polyurethane film laminating adhesive.

[0146] Perform performance tests on the aforementioned polyurethane film laminating adhesive, and the specific contents are as follows:

[0147] (1) Viscosity reaction activity

[0148] The test temperature is 50 °C, and the viscosity of the prepolymer is tested at reaction times of 10 min, 20 min, 30 min, 40 min, and 50 min respectively;

[0149] (2) Film hardness: Film preparation method: Mix component A and component B, where the molar ratio of hydroxyl groups in component A to NCO groups in component B is 1:1.4; pour the mixture into a polytetrafluoroethylene mold with a length × width × thickness of 10 cm × 10 cm × 2 cm and cure for 2 days to obtain a film. The test method is GB / T531.1-2008.

[0150] (3) Tensile strength and elongation at break: The film production method is as described in (2) Film hardness test above. The test method is GB / T 30776-2014.

[0151] (4) Peel strength: The composite film type is PE film, the size of the PE film is 50 cm × 50 cm, the sizing amount is 5 g, and it is tested after curing for two days. Test method: GB / T 8808.

[0152] The test data is shown in Table 2:

[0153] Table 2

[0154]

[0155]

[0156] According to the performance test results in Table 2, it can be seen that the natural oil-based polyether polyol provided by the present invention is used to prepare a polyurethane film laminating adhesive, which can replace high-price castor oil. While reducing the cost, it enables the polyurethane film laminating adhesive to have significantly improved viscosity reactivity, hardness, tensile strength, and peel strength. Compared with the comparative example using castor oil, Application Examples 1-4 have higher viscosity reactivity, a hardness of 28.8-34.1 HA, a tensile strength of 3.76-5.21 MPa, an elongation at break of 880-920%, a peel strength of 17.5-18.3 N / 15 mm, and the mechanical properties and bonding properties are superior to those of the comparative example using castor oil, and the cost is lower.

[0157] The applicant declares that the present invention uses the above embodiments to illustrate the natural oil-based polyether polyol and its preparation method, and the polyurethane film laminating adhesive of the present invention. However, the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments 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, and the selection of specific methods, etc., all fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A preparation method of a natural oil-based polyether polyol, characterized in that, The preparation method includes: a natural oil substance, a low molecular weight polyether polyol, and an epoxide are subjected to a polymerization reaction under the catalysis of a DMC catalyst to obtain the natural oil-based polyether polyol.

2. The preparation method according to claim 1, characterized in that, The natural oil substance includes natural oil and / or natural oil derivatives; Preferably, the natural oil derivatives include any one or a combination of at least two of partially hydrogenated natural oil, epoxidized natural oil, and alkyl esters of natural oil fatty acids; Preferably, the natural oil includes any one or a combination of at least two of castor oil, soybean oil, safflower oil, linseed oil, corn oil, sunflower oil, olive oil, rapeseed oil, sesame oil, cottonseed oil, palm oil, rapeseed oil, tung oil, high oleic safflower oil, high oleic soybean oil, high oleic peanut oil, high oleic sunflower oil, high oleic rapeseed oil, high erucic acid rapeseed oil, fish oil; Preferably, the natural oil substance includes palm oil; Preferably, based on the total mass of the natural oil substance, the low molecular weight polyether polyol, and the epoxide being 100%, the mass of the natural oil substance is 1-40%, more preferably 10-20%; 3. The preparation method according to claim 1 or 2, characterized in that, The number average molecular weight of the low molecular weight polyether polyol is 300-700, preferably 400-500; Preferably, the functionality of the low molecular weight polyether polyol is 2-3; Preferably, the epoxide includes any one or a combination of at least two of tetrahydrofuran, ethylene oxide, propylene oxide, epichlorohydrin, 1,2-epoxybutane, 2,3-epoxybutane, and more preferably propylene oxide; Preferably, based on the total mass of the natural oil substance, the low molecular weight polyether polyol, and the epoxide being 100%, the mass of the low molecular weight polyether polyol is 20-70%, more preferably 40-55%; Preferably, based on the total mass of the natural oil substance, the low molecular weight polyether polyol, and the epoxide being 100%, the mass of the DMC catalyst is 20-100 ppm, more preferably 30-60 ppm.

4. The preparation method according to any one of claims 1 to 3, characterized in that, The preparation method includes: first, the natural oil substance, the low molecular weight polyether polyol, and the DMC catalyst are mixed and then optionally dehydrated, and then the epoxide is added for a polymerization reaction to obtain the natural oil-based polyether polyol; Preferably, the temperature of the dehydration treatment is 100-170 °C, more preferably 130-150 °C; Preferably, the time of the dehydration treatment ≤ 4 h, more preferably 1-2 h; Preferably, the feeding time of the epoxide is 1-3.5 h, more preferably 1.5-2 h; Preferably, the feeding temperature of the epoxide is 100-170 °C, more preferably 130-150 °C; Preferably, the temperature of the polymerization reaction is 100-170 °C, more preferably 130-150 °C; Preferably, the pressure of the polymerization reaction is 0.01-0.4 MPa, more preferably 0.15-0.25 MPa; Preferably, the time of the polymerization reaction after the feeding of the epoxide is completed is 0.5-3 h, more preferably 1-2 h.

5. The preparation method according to any one of claims 1-4, characterized in that, After the polymerization reaction is completed, a degassing step is further included; Preferably, the pressure for degassing is from -0.08 MPa to -0.095 MPa, more preferably from -0.09 MPa to -0.095 MPa; Preferably, the time for degassing is 0.25 - 2 h.

6. The preparation method according to any one of claims 1-5, characterized in that, The preparation method comprises the following steps: Firstly, put the natural oil substance, small molecular weight polyether polyol and DMC catalyst into a reaction device, and carry out reduced-pressure dehydration treatment at 100 - 170 °C under stirring conditions for 0.1 - 4 h; Then add an epoxide into the reaction device, and carry out a polymerization reaction at 100 - 170 °C and 0.01 - 0.4 MPa; the feeding time of the epoxide is 1 - 3.5 h; after the feeding of the epoxide is completed, cure at 100 - 170 °C and 0.1 - 0.4 MPa for 0.5 - 3 h, and the polymerization reaction is completed; Then carry out degassing at a pressure of -0.08 MPa to -0.095 MPa for 0.25 - 2 h to obtain the natural oil-based polyether polyol; Based on the total mass of the natural oil substance, small molecular weight polyether polyol and epoxide being 100%, the mass of the natural oil substance is 1 - 40%, the mass of the small molecular weight polyether polyol is 20 - 70%, and the mass of the DMC catalyst is 20 - 100 ppm.

7. A natural oil-based polyether polyol, characterized in that, The natural oil-based polyether polyol is prepared by the preparation method as described in any one of claims 1 - 6; Preferably, the average functionality of the natural oil-based polyether polyol is 2 - 3; Preferably, the natural oil content of the natural oil-based polyether polyol is 1 - 40 wt%; Preferably, the hydroxyl value of the natural oil-based polyether polyol is 140 - 180 mg KOH / g.

8. A polyurethane film laminating adhesive, characterized in that, The polyurethane film laminating adhesive comprises component A and component B; Component A comprises the following components by mass parts: 10 - 50 parts of the natural oil-based polyether polyol as described in claim 7 10 - 50 parts of the first polyether polyol; The raw materials for preparing component B comprise the following components by mass parts: 10 - 50 parts of the second polyether polyol 40 - 80 parts of isocyanate.

9. The polyurethane film laminating adhesive according to claim 8, wherein, The number-average molecular weight of the first polyether polyol is 400 - 6000, preferably 400 - 4000; Preferably, component A further comprises a catalyst; Preferably, the catalyst comprises an organotin catalyst, more preferably any one or at least two combinations of dibutyltin dilaurate, stannous octoate, and dibutyltin diacetate; Preferably, based on the total mass of component A being 100%, the mass of the catalyst is 5 - 50 ppm, more preferably 10 - 30 ppm.

10. The polyurethane film laminating adhesive according to claim 8 or 9, characterized in that, The number-average molecular weight of the second polyether polyol is 300 - 3000, preferably 400 - 2000; Preferably, the isocyanate is selected from any one or at least two combinations of aliphatic isocyanates, cycloaliphatic isocyanates, and aromatic isocyanates, more preferably aromatic isocyanates; Preferably, the isocyanate includes any one or a combination of at least two of toluene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, hexamethylene diisocyanate, methylcyclohexyl diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate, p-phenylene diisocyanate, p-xylylene diisocyanate, and tetramethylxylene diisocyanate, and diphenylmethane diisocyanate is further preferred; Preferably, the content of the NCO group in the B component is 5-30 wt%, and 10-20 wt% is further preferred; Preferably, the ratio of the molar amount of the NCO group in the B component to the molar amount of the hydroxyl group in the A component is (1-1.5):1.

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