A low temperature resistant and flexible one-component polyurethane resin and preparation method thereof

Abstract

A low-temperature resistant and flexible one-component polyurethane resin and a preparation method thereof, wherein the low-temperature resistant and flexible one-component polyurethane resin comprises the following components in parts by weight: 8-13 parts of isocyanate; 47-59 parts of macromolecular polyol; 15-25 parts of addition modifier; 0.5-1.5 parts of small molecule chain extender; 0.05-0.3 parts of catalyst; and 45-55 parts of solvent. The present invention introduces an addition modifier, which is formed by addition polymerization of terminal hydroxyl polybutadiene, terminal hydroxyl silicone oil and dimethyl diisocyanate under specific conditions. The addition modifier helps to improve the weather resistance, low-temperature flexibility and low-temperature high elasticity of the product, and interacts with other components to enable the low-temperature resistant and flexible one-component polyurethane resin to have excellent weather resistance, low-temperature flexibility and low-temperature high elasticity.

Description

Technical Field

[0001] The invention belongs to the technical field of adhesives, and in particular relates to a low-temperature-resistant and flexible one-component polyurethane resin and a preparation method thereof. Background Art

[0002] Low temperature resistant and flexible one-component polyurethane resin is a type of resin composed of isocyanate-terminated high molecular weight polyurethane and solvent. The resin is coated on the glue point and reacts with water to bond and fix solid parts. The Tg point of the traditional polyurethane adhesive of this glue point is higher than 25℃, which becomes hard and brittle in low temperature environment, causing the bonded parts to crack and fail. This product is suitable for low temperature environment climate and still has excellent toughness and viscoelasticity below zero degrees.

[0003] On the basis of traditional one-component polyurethane resin, through the optimization of synthesis process and formula, by introducing double bond groups and silicon-oxygen bond groups, the weather resistance, low-temperature flexibility and low-temperature high elasticity are further improved, which helps to reduce the failure rate in the production process and improve the low-temperature reliability of the product. Summary of the invention

[0004] The present invention aims at the above-mentioned deficiencies of the prior art and provides a low-temperature resistant and flexible one-component polyurethane resin and a preparation method thereof.

[0005] The specific technical solutions of the present invention are as follows:

[0006] The first object of the present invention is to provide a low temperature resistant and flexible one-component polyurethane resin, comprising the following components in parts by weight:

[0007] 8-13 parts of isocyanate; 47-59 parts of macromolecular polyol; 15-25 parts of addition modifier; 0.5-1.5 parts of small molecule chain extender; 0.05-0.3 parts of catalyst; 42-50 parts of solvent.

[0008] The addition modified body is prepared by addition polymerization of terminal hydroxyl polybutadiene, terminal hydroxyl silicone oil and dimethyl diisocyanate under specific conditions.

[0009] The addition modifier helps to improve the weather resistance, low temperature flexibility and low temperature high elasticity of the product.

[0010] Furthermore, the mass ratio of the terminal hydroxyl polybutadiene:terminal hydroxyl silicone oil:dimethyl diisocyanate is (3.9-4.3):(4-5):2.

[0011] Furthermore, the preparation method of the addition modified body comprises the following steps:

[0012] S1. Dissolve 18-22 parts of hydroxy polybutadiene and 20-24 parts of terminal hydroxy silicone oil in 26-32 parts of ethyl acetate solvent after dehydration, and heat to 35-40°C.

[0013] S2, adding 9-11 parts of dimethyl diisocyanate into the reactor, maintaining constant temperature heating at 80-85°C, stirring and reacting for 1.5-2h under condensation reflux conditions to obtain an intermediate reaction liquid;

[0014] S3. Cool the intermediate reaction liquid to 75-80° C., continue to add 17-21 parts of ethyl acetate solvent, and stir the reaction under condensation reflux conditions for 1.5-2 hours to obtain an addition-modified product with a terminal NCO group.

[0015] The isocyanate is at least one of 2,4-toluene diisocyanate, 2,6-toluene diisocyanate and carbodiimide-modified dimethyl diisocyanate.

[0016] Furthermore, the macromolecular polyol is at least one of polyethylene adipate glycol ester diol, polybutylene adipate glycol ester diol, polyhexanediol adipate-1,6-hexanediol ester diol, polydiethylene adipate glycol-2,2-dihydroxymethylbutanol ester diol, and polytetrahydrofuran diol.

[0017] Furthermore, the small molecule chain extender is at least one of 1,4-butanediol and trimethylolpropane.

[0018] Furthermore, the catalyst is at least one of dibutyltin dilaurate, organic bismuth and organic zinc.

[0019] Furthermore, the solvent is ethyl acetate.

[0020] The second object of the present invention is to provide a method for preparing the above-mentioned low temperature resistant and flexible one-component polyurethane resin, comprising the following steps:

[0021] D1: 47-59 parts of macromolecular polyol and 15-25 parts of addition modified product are put into a four-necked flask and mixed, and then 1.5-2 parts of isocyanate are added, and the mixture is stirred at 75-80°C for 1-2 hours, and 10-12 parts of solvent are added for dilution to obtain soft segment prepolymer A;

[0022] D2: Cool the soft segment prepolymer A obtained in step D1 to 40-50°C, add 0.5-1.5 parts of small molecule chain extender, 6-11.5 parts of isocyanate, 0.05-0.3 parts of catalyst and 30-40 parts of solvent, heat to 75-80°C, stir and react for 1.5-3h to prepare the target product.

[0023] The beneficial effects of the present invention are:

[0024] The present invention introduces an addition modifier, which is formed by addition polymerization of terminal hydroxyl polybutadiene, terminal hydroxyl silicone oil and dimethyl diisocyanate under specific conditions. The addition modifier helps to improve the weather resistance, low temperature flexibility and low temperature high elasticity of the product, and interacts with other components to enable the low temperature resistant and flexible one-component polyurethane resin to have excellent weather resistance, low temperature flexibility and low temperature high elasticity. Implementation

[0025] The principles and features of the present invention are described below in conjunction with examples. The examples are only used to explain the present invention and are not used to limit the scope of the present invention.

[0026] Some of the raw materials used in the present invention are as follows:

[0027] Carbodiimide modified dimethyl diisocyanate (liquefied MDI): industrial grade, Wanhua Chemical Group Co., Ltd.

[0028] Poly(1,6-hexanediol adipate) (CMA-2066): functionality 2, molecular weight 2000 g / mol, Huada Chemical Co., Ltd.

[0029] Polyethylene adipate glycol diol (T-3024): industrial grade, Huada Chemical Co., Ltd.

[0030] Polytetramethylene glycol (PTMG-2000): industrial grade, BASF Group

[0031] 1,4-Butanediol: industrial grade, Sinopharm Chemical Co., Ltd.;

[0032] Hydroxyl-terminated silicone oil: industrial grade, Zimeng Chemical Co., Ltd.

[0033] Hydroxyl-terminated polybutadiene; industrial grade, Tianyuan Aviation Materials;

[0034] Organic bismuth: MB-20, BYK Chemicals. Example 1

[0035] A method for preparing a low-temperature resistant and flexible one-component polyurethane resin comprises the following steps:

[0036] 1. Preparation of addition modified product 1

[0037] S1. Dehydrate 4.09 g of terminal hydroxyl polybutadiene and 4.6 g of terminal hydroxyl silicone oil and dissolve them in 6 g of ethyl acetate solvent, heat to 35-40° C., and mix for 15 minutes.

[0038] S2, add 2g of carbodiimide modified dimethyl diisocyanate into the reactor, keep constant temperature heating at 80-85°C, stir and react for 1.5-2h under condensation reflux conditions to obtain an intermediate reaction liquid;

[0039] S3. The intermediate reaction liquid was cooled to 75-80° C., 4 g of ethyl acetate solvent was added, and the reaction was stirred under condensation reflux for 1.5-2 h to obtain the addition-modified product 1 with a terminal NCO group.

[0040] 2. Preparation of low temperature resistant and flexible one-component polyurethane resin

[0041] D1 4.09g T-3024, 35g CMA-2066, 11.68g PTMG-2000, 20.69g addition modified body 1 were put into a four-necked flask and mixed, and then 2.0g liquefied MDI was added, stirred at 75-80℃ for 1-2h, and 12g solvent was added for dilution to obtain soft segment prepolymer A;

[0042] D2: Cool the soft segment prepolymer A obtained in step D1 to 40-50°C, add 0.9g 1,4-butanediol, 7.9g liquefied MDI, 0.05g catalyst and 33.8g solvent in sequence, heat to 75-80°C and stir to react for 1.5-3h to prepare the target product 1. Example 2

[0043] 1. Preparation of addition modified product 2

[0044] S1. Dehydrate 3.9 g of hydroxy polybutadiene and 5 g of terminal hydroxy silicone oil and dissolve them in 6 g of ethyl acetate solvent, heat to 35-40° C., and mix for 15 min.

[0045] S2, add 2g of carbodiimide modified dimethyl diisocyanate into the reactor, keep constant temperature heating at 80-85°C, stir and react for 1.5-2h under condensation reflux conditions to obtain an intermediate reaction liquid;

[0046] S3. Cool the intermediate reaction liquid to 75-80° C., continue to add 4 g of ethyl acetate solvent, and stir the reaction under condensation reflux conditions for 1.5-2 h to obtain the addition-modified product 2 with a terminal NCO group.

[0047] 2. Preparation of low temperature resistant and flexible one-component polyurethane resin

[0048] D1 4.09g T-3024, 35g CMA-2066, 11.68g PTMG-2000, and 20.9g addition modified body 1 were put into a four-necked flask and mixed, and then 2g liquefied MDI was added, stirred at 75-80℃ for 1-2h, and 12g solvent was added for dilution to obtain soft segment prepolymer A;

[0049] D2: Cool the soft segment prepolymer A obtained in step D1 to 40-50°C, add 0.9g 1,4-butanediol, 7.9g liquefied MDI, 0.05g catalyst and 33.8g solvent in sequence, heat to 75-80°C and stir to react for 1.5-3h to prepare the target product 2. Example 3

[0050] 1. Preparation of addition modified product 3

[0051] S1. Dissolve 4.3 g of hydroxy polybutadiene and 4 g of terminal hydroxy silicone oil in 6 g of ethyl acetate solvent after dehydration, heat to 35-40° C., and mix for 15 min.

[0052] S2, add 2g of carbodiimide modified dimethyl diisocyanate into the reactor, keep constant temperature heating at 80-85°C, stir and react for 1.5-2h under condensation reflux conditions to obtain an intermediate reaction liquid;

[0053] S3, cooling the intermediate reaction liquid to 75-80°C, adding 4 g of ethyl acetate solvent, stirring and reacting under condensation reflux conditions for 1.5-2 h, to obtain the addition-modified product 3 with a terminal NCO group.

[0054] 2. Preparation of low temperature resistant and flexible one-component polyurethane resin

[0055] D1 4.09g T-3024, 35g CMA-2066, 11.68g PTMG-2000, 20.3g addition modified body 1 were put into a four-necked flask and mixed, and then 2.g liquefied MDI was added, stirred at 75-80℃ for 1-2h, and 12g solvent was added for dilution to obtain soft segment prepolymer A;

[0056] D2: Cool the soft segment prepolymer A obtained in step D1 to 40-50°C, add 0.9g 1,4-butanediol, 7.9g liquefied MDI, 0.05g catalyst and 33.8g solvent in sequence, heat to 75-80°C and stir to react for 1.5-3h to prepare the target product 3.

[0057] Comparative Example 1

[0058] A method for preparing a low-temperature resistant and flexible one-component polyurethane resin comprises the following steps:

[0059] 1. Preparation of low temperature resistant and flexible one-component polyurethane resin

[0060] D1: 4.09g T-3024, 35g CMA-2066, 11.68g PTMG-2000, 4.09g hydroxyl-terminated polybutadiene, and 4.6g hydroxyl-terminated silicone oil were mixed in a four-necked flask, and then 4.2g liquefied MDI was added. The mixture was stirred at 75-80℃ for 1-2h, and 24.01g solvent was added for dilution to obtain soft segment prepolymer A;

[0061] D2: Cool the soft segment prepolymer A obtained in step D1 to 40-50°C, add 0.9g 1,4-butanediol, 7.9g liquefied MDI, 0.05g catalyst and 33.8g solvent in sequence, heat to 75-80°C and stir to react for 1.5-3h to prepare the target product 4.

[0062] Compared with Example 1, in Comparative Example 1, hydroxyl-terminated polybutadiene and hydroxyl-terminated silicone oil are directly added to the synthesis reaction, rather than being pre-added and polymerized by hydroxyl-terminated polybutadiene, hydroxyl-terminated silicone oil and liquefied MDI.

[0063] Comparative Example 2

[0064] A method for preparing a low-temperature resistant and flexible one-component polyurethane resin comprises the following steps:

[0065] 1. Preparation of low temperature resistant and flexible one-component polyurethane resin

[0066] D1: 8.18g T-3024, 35g CMA-2066, 11.68g PTMG-2000 and 4.6g terminal hydroxyl silicone oil were mixed in a four-necked flask, and 4.2g liquefied MDI was added. The mixture was stirred at 75-80℃ for 1-2h, and 24.01g solvent was added for dilution to obtain soft segment prepolymer A.

[0067] D2: Cool the soft segment prepolymer A obtained in step D1 to 40-50°C, add 0.9g 1,4-butanediol, 7.9g liquefied MDI, 0.05g catalyst and 33.8g solvent in sequence, heat to 75-80°C and stir to react for 1.5-3h to prepare the target product 5.

[0068] Compared with Comparative Example 1, Comparative Example 2 uses only T-3024 to replace the hydroxy-terminated polybutadiene.

[0069] Comparative Example 3

[0070] A method for preparing a low-temperature resistant and flexible one-component polyurethane resin comprises the following steps:

[0071] 1. Preparation of low temperature resistant and flexible one-component polyurethane resin

[0072] D1: 17.09g T-3024, 35g CMA-2066, 11.68g PTMG-2000, 4.09g hydroxyl-terminated polybutadiene were mixed in a four-necked flask, and 4.2g liquefied MDI was added. The mixture was stirred at 75-80℃ for 1-2h, and 24.01g solvent was added for dilution to obtain soft segment prepolymer A;

[0073] D2: Cool the soft segment prepolymer A obtained in step D1 to 40-50°C, add 0.9g 1,4-butanediol, 7.9g liquefied MDI, 0.05g catalyst and 33.8g solvent in sequence, heat to 75-80°C and stir to react for 1.5-3h to prepare the target product 6.

[0074] Compared with Comparative Example 1, Comparative Example 3 only uses T-3024 in an equal molar amount to replace the terminal hydroxyl silicone oil.

[0075] test

[0076] Tensile test: The resin prepared in the examples and comparative examples was cast on a flat and clean polytetrafluoroethylene plate to form a film, left to stand at room temperature for 2 days to dry, and then dried in a 60°C drying oven for 24 hours. The film thickness was 2 mm. The film was cut into dumbbell shapes.

[0077] The test standard adopts the national standard GB 13022-1991 test method, and the test environment box temperature is -15℃

[0078] Peel strength test: GB / T 2792-2014

[0079] The test results are shown in Table 1:

[0080] Table 1 Test data table of embodiments and comparative examples

[0081] name Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Solid content% 56.3 56.1 56.5 56.4 56.7 66.1 Tensile Strength 11.43 10.76 10.97 7.43 6.58 8.65 Elongation 280 238 252 124 159 76 Peel strength 72 68 65 43 47 29 Hardness / Shore A 35 35 35 37 34 38

[0082] As can be seen from the test results in Table 1, the low-temperature resistant and flexible one-component polyurethane resin in the embodiment of the present invention has excellent low-temperature flexibility and high elasticity at low temperature.

[0083] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A low temperature resistant and flexible one-component polyurethane resin, characterized in that: The invention comprises the following components in parts by weight: 8-13 parts of isocyanate; 47-59 parts of macromolecular polyol; 15-25 parts of addition modifier; 0.5-1.5 parts of small molecule chain extender; 0.05-0.3 parts of catalyst; 42-50 parts of solvent; the addition modifier is prepared by addition polymerization of terminal hydroxyl polybutadiene, terminal hydroxyl silicone oil and diphenylmethane diisocyanate under specific conditions; the mass ratio of the terminal hydroxyl polybutadiene: terminal hydroxyl silicone oil: diphenylmethane diisocyanate is (3.9-4.3): (4-5): 2; the preparation method of the addition modifier comprises the following steps: S1, dehydrate the hydroxyl-terminated polybutadiene and hydroxyl-terminated silicone oil, dissolve them in ethyl acetate solvent, and heat them to 35-40°C; S2, diphenylmethane diisocyanate was added into the reactor, and the mixture was heated at a constant temperature of 80-85°C and stirred for reaction for 1.5-2h under condensation reflux conditions to obtain an intermediate reaction liquid; S3, cooling the intermediate reaction liquid to 75-80° C., continuing to add ethyl acetate solvent, stirring and reacting for 1.5-2 h under condensation reflux conditions to obtain an addition-modified product with a terminal NCO group.

2. The low temperature resistant and flexible one-component polyurethane resin according to claim 1, characterized in that: The isocyanate is at least one of 2,4-toluene diisocyanate, 2,6-toluene diisocyanate and liquefied MDI.

3. The low temperature resistant and flexible one-component polyurethane resin according to claim 1, characterized in that: The macromolecular polyol is at least one of polyethylene adipate glycol diol, polybutylene adipate glycol diol, polyhexanediol adipate-1,6-hexanediol diol, polydiethylene adipate glycol-2,2-dihydroxymethylbutanol diol, and polytetrahydrofuran diol.

4. The low temperature resistant and flexible one-component polyurethane resin according to claim 1, characterized in that: The small molecule chain extender is at least one of 1,4-butanediol and trimethylolpropane.

5. The low temperature resistant and flexible one-component polyurethane resin according to claim 1, characterized in that: The catalyst is at least one of dibutyltin dilaurate, organic bismuth and organic zinc.

6. The low temperature resistant and flexible one-component polyurethane resin according to claim 1, characterized in that: The solvent is ethyl acetate.

7. The method for preparing the low temperature resistant and flexible one-component polyurethane resin according to any one of claims 1 to 6, comprising the following steps: D1 47-59 parts of macromolecular polyol and 15-25 parts of addition modified product are put into a four-necked flask and mixed, and then 1.5-2 parts of isocyanate are added, and stirred at 75-80°C for 1-2h, and 10-12 parts of solvent are added for dilution to obtain soft segment prepolymer A; D2 Cool the soft segment prepolymer A obtained in step D1 to 40-50°C, add 0.5-1.5 parts of small molecule chain extender, 6-11.5 parts of isocyanate, 0.05-0.3 parts of catalyst and 30-40 parts of solvent, heat to 75-80°C and stir for reaction for 1.5-3h to prepare the target product.