A low temperature pressure-changing resin and preparation method thereof

Abstract

The present application relates to the technical field of resin materials, and specifically discloses a low-temperature compression-change resin and a preparation method thereof. A low-temperature compression-change resin comprises the following raw materials in parts by weight: 53‑58 parts of polyester polyol, 8‑9 parts of chain extender, 26‑29 parts of diphenylmethane diisocyanate, and 210‑230 parts of dimethylformamide; the polyester polyol comprises a butanediol polyol and an ethylene glycol polyol in a weight ratio of 1: (1‑1.7); the chain extender comprises a butanediol and ethylene glycol in a weight ratio of 1: (1‑1.4). The low-temperature compression-change resin of the present application can achieve an ideal compression-change effect at 140°C or even 120°C, and the color development after compression-change is uniform.

Description

Technical Field

[0001] The present application relates to the technical field of resin materials, and more specifically, to a low-temperature pressure-changing resin and a preparation method thereof. Background Art

[0002] Resin usually refers to an organic polymer that softens or melts when heated, tends to flow under the action of external force when softened, is solid or semi-solid at room temperature, and can sometimes be liquid.

[0003] Currently, there are dry-process compression resin and wet-process compression resin on the market. Dry-process compression resin is made by adding compression-changing agents to ordinary dry-process polyurethane resin, which changes the color of the leather surface under high temperature and high pressure; wet-process compression resin refers to synthetic leather made by wet process and then subjected to high-temperature pressing to darken the color of the leather surface.

[0004] With respect to the above-mentioned related technologies, the applicant has found that the compression temperature of both dry compression resin and wet compression resin is about 200°C, the color is uneven after compression, and high-temperature compression can easily cause changes in the physical properties of polyurethane resin, or even carbonization. Summary of the invention

[0005] In order to reduce the compression temperature of a compression-changing resin, the present application provides a low-temperature compression-changing resin and a preparation method thereof.

[0006] In a first aspect, the present application provides a low temperature pressure-dependent resin, which adopts the following technical solution:

[0007] A low-temperature compression resin comprises the following raw materials in parts by weight: 53-58 parts of polyester polyol, 8-9 parts of chain extender, 26-29 parts of diphenylmethane diisocyanate, and 210-230 parts of dimethylformamide;

[0008] The polyester polyol comprises a butanediol polyol and an ethylene glycol polyol in a weight ratio of 1:(1-1.7);

[0009] The chain extender includes butanediol and ethylene glycol in a weight ratio of 1:(1-1.4).

[0010] By adopting the above technical scheme, the symmetry of the molecular structure of the synthesized resin can be reduced by compounding butanediol polyols with ethylene glycol polyols as polyester polyols, and the solubility and high temperature resistance of the resin molecules can be improved. In addition, by combining different chain extenders with corresponding polyester polyols, the symmetry of the polyurethane molecules can be further reduced, and the combination of different chain extenders can enable intermolecular interactions between the hard segments of the molecular chain segments, thereby reducing the softening point of the synthesized resin and the pressure change temperature. The ideal pressure change effect can be achieved at low temperatures, and the color development after pressure change is uniform.

[0011] Preferably, the solid content of the low temperature compression resin is 28-33%.

[0012] The solid content of the resin is the content of non-volatile matter in the resin, that is, the amount of the part that forms the dry film. By adopting the above technical solution, the solid content of the resin is regulated. The solid content of the resin can ensure the film thickness within the specified range of this application and achieve the ideal compression effect at a lower temperature; if the solid content is too low, the film formed is thinner. Although compression can be performed at a lower temperature, compression at low temperature will also cause certain damage due to the insufficient thickness of the film; if the solid content is too high, the thickness of the film is too high, which will result in the surface of the film having achieved the compression effect, but the interior of the film has not yet reached it, which will lead to uneven color development.

[0013] Preferably, the viscosity of the low temperature compression resin is 160000-220000 CPS / 25°C.

[0014] The viscosity of the resin has a decisive influence on the performance of the resin. When the resin viscosity is too low, the required film thickness cannot be achieved, and when the resin viscosity is too high, the workability is poor. By adopting the above technical solution, the viscosity of the resin is limited within the scope of this application, which can ensure the film thickness and achieve the ideal pressure change effect at a lower temperature.

[0015] Preferably, 0.05-0.12 parts of silicone oil are also included.

[0016] Silicone oil is an organic silicon material that contains silicon in its molecular structure and has the characteristics of both organic and inorganic compounds. By adopting the above technical solution, silicone oil is added to the resin. On the one hand, silicone oil can improve the bonding force between the resin raw materials, thereby improving the temperature resistance of the synthetic resin; on the other hand, silicone oil can protect the resin, reduce the defects on the resin surface, improve the smoothness of the resin surface, avoid the occurrence of non-uniform surface compression effect caused by surface roughness, and improve the uniformity of the compression effect and the smoothness of the resin surface.

[0017] Preferably, the silicone oil is obtained by grafting trimethylolpropane trioctanoate with silicone oil to obtain trimethylolpropane trioctanoate-modified silicone oil, and the preparation method thereof is:

[0018] Dissolve silicone oil in anhydrous toluene to obtain silicone oil solution; add platinum catalyst to trimethylolpropane trioctanoate, and then fill with protective gas to remove oxygen; then drop the silicone oil solution into the trimethylolpropane trioctanoate, react at 110-120°C for 5-6h, then cool to 70-80°C, add activated carbon for decolorization, and then distill to obtain trimethylolpropane trioctanoate modified silicone oil.

[0019] By adopting the above technical scheme, trimethylolpropane trioctanoate and silicone oil are used as raw materials, and a hydrosilylation reaction occurs under catalysis to synthesize trimethylolpropane trioctanoate modified silicone oil. The introduction of ester bonds into silicone oil improves the compatibility between the resin molecular segments, which is beneficial to improving the uniformity of the resin compression color development; in addition, the elongation at break of the synthetic resin can be improved, and the toughness of the resin can be improved, so that the surface of the resin is not easily damaged during the compression process.

[0020] Preferably, the silicone oil is a modified silicone oil obtained by composite modification of trimethylolpropane trioctanoate-perfluoropolyether, and the preparation method thereof is as follows:

[0021] Perfluoropolyether and antioxidant are added to anhydrous toluene and heated to obtain a mixed solution, and then protective gas is introduced to remove oxygen; a platinum catalyst is then added to the mixed solution for activation, and then trimethylolpropane trioctanoate modified silicone oil is added dropwise, and the mixture is reacted at 90-100°C for 7-8h, and then the temperature is lowered to 70-80°C, activated carbon is added for decolorization, and then distilled to obtain trimethylolpropane trioctanoate-perfluoropolyether composite modified silicone oil.

[0022] The resin molecule is a multi-region polymer, mainly composed of a soft segment and a hard segment. The hard segment includes a diisocyanate and a chain extender, and the soft segment is represented by a polyether or a polyester. By adopting the above technical scheme, the ester-modified silicone oil is further ether-modified to obtain an ester-ether composite modified silicone oil, and fluorine is introduced into the resin molecule. Fluorine has a strong electronegativity and a strong electron-withdrawing ability. The F nucleus has a strong binding force on its extranuclear electrons and bonding electron clouds. The polarizability of the CF bond is low, and the intermolecular force of the polymer containing the CF bond is low, so that the fluorine-containing polymer has a lower surface free energy. Introducing the fluorine-containing polymer into the resin can give the resin film excellent surface properties and improve its low-temperature pressure change effect. In addition, combining fluorine with silicone oil, so that fluorine and silicon are combined and introduced into the resin, can enhance the compounding effect of fluorine and silicon, which is beneficial to enhancing the overall performance of the resin molecule.

[0023] Preferably, the weight ratio of the perfluoropolyether to trimethylolpropane trioctanoate is 1:(2-4).

[0024] By adopting the above technical solution, the ratio of perfluoropolyether to trimethylolpropane trioctanoate is adjusted, thereby adjusting the ester-ether ratio on the silicone oil, which is beneficial to further improve the improvement effect of the silicone oil on the resin.

[0025] In a second aspect, the present application provides a method for preparing a low-temperature pressure-dependent resin, using the following technical solution:

[0026] A method for preparing a low-temperature pressure-changing resin comprises the following steps:

[0027] S1. 25-30% by weight of dimethylformamide, butanediol polyol, butanediol, and 25-30% by weight of diphenylmethane diisocyanate are mixed and heated to obtain a mixture A;

[0028] S2. Add 35-40% by weight of dimethylformamide, ethylene glycol polyol, ethylene glycol, and 35-40% by weight of diphenylmethane diisocyanate to the mixture A and heat to obtain a mixture B;

[0029] S3. Add the remaining isocyanate to the mixture B to react and increase viscosity. During the viscosity increase process, add the remaining dimethylformamide to continuously dilute the reaction mixture to a set solid content to obtain a low-temperature pressure-sensitive resin.

[0030] By adopting the above technical scheme, the step-by-step reaction method is adopted to make the reaction more complete, and the preparation method of the present application is simple and easy to operate, has no special requirements for production equipment, and is suitable for industrial production.

[0031] Preferably, the silicone oil is added in step S1 to obtain mixture A.

[0032] In summary, this application has the following beneficial effects:

[0033] 1. Since the present application adopts a compound of ethylene glycol polyol and butanediol polyol, and cooperates with ethylene glycol and butanediol chain extenders, the symmetry performance of the polyurethane molecule is reduced, and the combination of different chain extenders can make the molecular chain segments and hard segments interact with each other, so that the softening point of the synthesized resin is reduced, and the pressure change temperature is reduced. The ideal pressure change effect can be achieved at 140°C or even 120°C, and the color development after pressure change is uniform.

[0034] 2. In the present application, it is preferred to add silicone oil to the resin and perform ester-ether composite modification on the silicone oil, introduce ester bonds and ether bonds on the silicone oil to improve the compatibility between the resin molecular segments, and introduce fluorine into the resin molecules to give the resin film excellent surface properties, thereby further improving the low-temperature compression deformation effect of the resin. DETAILED DESCRIPTION

[0035] The present application is further described in detail below with reference to the embodiments.

[0036] Preparation examples of raw materials and intermediates

[0037] raw material

[0038] The raw materials in the examples of this application can be obtained from the market:

[0039] The butanediol polyol is poly(1,4-butylene glycol oxalate) with a molecular weight of 1000;

[0040] The glycol polyol is polyethylene adipate, with a molecular weight of 1000;

[0041] Butanediol, ethylene glycol, diphenylmethane diisocyanate, and dimethylformamide were chemically pure;

[0042] The silicone oil is low hydrogen silicone oil, with a hydrogen content of 0.1%;

[0043] The platinum catalyst is H2PtCl6·6H2O;

[0044] Trimethylolpropane trioctanoate analytical grade;

[0045] Perfluoropolyether, brand E10-H;

[0046] The antioxidant is citric acid.

[0047] Preparation Example

[0048] Preparation Example 1

[0049] A trimethylolpropane trioctanoate modified silicone oil, the preparation method of which is as follows:

[0050] Dissolve 1 kg of silicone oil in 3 kg of anhydrous toluene to obtain a silicone oil solution;

[0051] 5×10 -6 1.25 kg of platinum catalyst was added to 2 kg of trimethylolpropane tricaprylate, and then nitrogen was introduced to remove oxygen; then silicone oil solution was added dropwise to the trimethylolpropane tricaprylate, and the reaction was carried out at 110°C for 6 hours, and then the temperature was lowered to 70°C, 0.15 kg of activated carbon was added for decolorization, and then trimethylolpropane tricaprylate modified silicone oil was obtained by vacuum distillation.

[0052] Preparation Example 2

[0053] A trimethylolpropane tricaprylate-perfluoropolyether composite modified silicone oil, the preparation method of which is as follows:

[0054] The silicone oil is a modified silicone oil obtained by composite modification of trimethylolpropane trioctanoate-perfluoropolyether. The preparation method is as follows: 1 kg of perfluoropolyether and 0.03 kg of antioxidant are added to 0.7 kg of anhydrous toluene, the temperature is raised to 70° C., and the mixture is heated to reflux for 1 hour to obtain a mixed solution, and then nitrogen is introduced to remove oxygen; then 4×10 -6 kg of platinum catalyst, heated to 70°C for activation for 3h, then added the trimethylolpropane trioctanoate modified silicone oil obtained in Preparation Example 1, heated to 100°C, reacted for 7h, then cooled to 70°C, added 0.1kg of activated carbon for decolorization, and then distilled to obtain trimethylolpropane trioctanoate-perfluoropolyether composite modified silicone oil;

[0055] At this time, the weight ratio of perfluoropolyether to trimethylolpropane trioctanoate is 1:2.

[0056] Preparation Example 3

[0057] A trimethylolpropane tricaprylate-perfluoropolyether composite modified silicone oil, the preparation method of which is as follows:

[0058] Different from Preparation Example 2, the amount of perfluoropolyether used in Preparation Example 3 is 0.5 kg, and the weight ratio of perfluoropolyether to trimethylolpropane trioctanoate is 1:4.

[0059] Preparation Example 4

[0060] A trimethylolpropane tricaprylate-perfluoropolyether composite modified silicone oil, the preparation method of which is as follows:

[0061] Different from Preparation Example 2, the amount of perfluoropolyether used in Preparation Example 4 is 0.7 kg.

[0062] Preparation Example 5

[0063] A trimethylolpropane tricaprylate-perfluoropolyether composite modified silicone oil, the preparation method of which is as follows:

[0064] Different from Preparation Example 2, the amount of perfluoropolyether used in Preparation Example 5 is 0.3 kg.

[0065] Preparation Example 6

[0066] A trimethylolpropane tricaprylate-perfluoropolyether composite modified silicone oil, the preparation method of which is as follows:

[0067] Different from Preparation Example 2, the amount of perfluoropolyether used in Preparation Example 6 is 2 kg.

[0068] Example

[0069] Examples 1-3

[0070] A low-temperature pressure-changing resin, the preparation method of which is as follows:

[0071] S1. According to the raw material ratio in Table 1, dimethylformamide is divided into three parts by weight: 25%, 35%, and 40%; diphenylmethane diisocyanate is divided into three parts by weight: 25%, 40%, and 35%;

[0072] S2. According to the raw material ratio in Table 1, 25% of dimethylformamide, butanediol polyol, butanediol, and 25% of diphenylmethane diisocyanate were mixed, and the temperature was raised to 70 ° C and heated for 1 h to obtain a mixture A;

[0073] S2. Add 35% of dimethylformamide, ethylene glycol polyol, ethylene glycol, and 40% of diphenylmethane diisocyanate to mixture A, and heat to 70° C. for 1 h to obtain mixture B;

[0074] S3. Add the remaining isocyanate to the mixture B to react and increase viscosity. During the viscosity increase process, add the remaining dimethylformamide to continuously dilute the reaction mixture until the solid content is 28%, thereby obtaining a low-temperature pressure-dependent resin having a resin viscosity of 160,000 CPS / 25°C.

[0075] Table 1 Example 1-3 Raw material ratio table (kg)

[0076]

[0077] The polyester polyol comprises butanediol polyol and ethylene glycol polyol in a weight ratio of 1:1; and the chain extender comprises butanediol and ethylene glycol in a weight ratio of 1:1.

[0078] Example 4

[0079] Different from Example 2, the polyester polyol in Example 4 includes butanediol polyol and ethylene glycol polyol in a weight ratio of 1:1.5.

[0080] Example 5

[0081] Different from Example 2, the polyester polyol in Example 5 includes butanediol polyol and ethylene glycol polyol in a weight ratio of 1:1.7.

[0082] Example 6

[0083] Different from Example 4, the chain extender in Example 6 includes butanediol and ethylene glycol in a weight ratio of 1:1.2.

[0084] Example 7

[0085] Different from Example 4, the chain extender in Example 7 includes butanediol and ethylene glycol in a weight ratio of 1:1.4.

[0086] Example 8

[0087] Different from Example 6, Example 8 also includes 0.05 kg of silicone oil, and the preparation method is as follows:

[0088] S1. Dimethylformamide is divided into three parts by weight: 25%, 35%, and 40%; diphenylmethane diisocyanate is divided into three parts by weight: 25%, 40%, and 35%;

[0089] S2. 25% of dimethylformamide, butanediol polyol, butanediol, 25% of diphenylmethane diisocyanate, and silicone oil were mixed, heated to 70° C. for 1 h to obtain a mixture A;

[0090] S2. Same as Example 6;

[0091] S3. Same as Example 6.

[0092] Example 9

[0093] Different from Example 8, the amount of silicone oil in Example 9 is 0.12 kg.

[0094] Example 10

[0095] Different from Example 8, the amount of silicone oil in Example 10 is 0.2 kg.

[0096] Embodiment 11

[0097] Different from Example 9, in Example 11, an equal amount of trimethylolpropane trioctanoate-modified silicone oil from Preparation Example 1 was used to replace the silicone oil.

[0098] Examples 12-16

[0099] Different from Example 9, in Examples 12-16, the silicone oil was replaced by an equal amount of trimethylolpropane trioctanoate-perfluoropolyether composite modified silicone oil from Preparation Examples 2-6, respectively.

[0100] Comparative Example

[0101] Comparative Example 1

[0102] The difference from Example 1 is that in Comparative Example 1, an equal amount of butanediol polyol is used to replace ethylene glycol polyol.

[0103] Comparative Example 2

[0104] Different from Example 1, in Comparative Example 2, an equal amount of ethylene glycol polyol is used to replace butanediol polyol.

[0105] Comparative Example 3

[0106] Different from Example 1, in Comparative Example 3, ethylene glycol was replaced by an equal amount of butanediol.

[0107] Comparative Example 3

[0108] Different from Example 1, in Comparative Example 3, an equal amount of ethylene glycol was used to replace butanediol.

[0109] Performance testing

[0110] Detection method / test method

[0111] The resins obtained in the examples and comparative examples were tested for their properties:

[0112] Color development evaluation: The pressing temperature was 140℃ and 120℃, and 10 professional technicians scored and evaluated according to the standards in Table 2. The average score was taken as the final score, and the records are shown in Table 3.

[0113] Table 2 Color development evaluation standards

[0114]

[0115] Table 3 Performance test results

[0116]

[0117]

[0118] Combining Examples 1-16 and Comparative Examples 1-4, and in combination with Table 2, it can be seen that the color development effects at compression temperatures of 140°C and 120°C in Examples 1-16 are better than those in Comparative Examples 1-3, which indicates that the resin prepared in the present application can achieve an ideal compression effect at a relatively low temperature.

[0119] Combining Example 1 with Comparative Examples 1-2 and Table 2, it can be seen that in Comparative Examples 1 and 2, both are single polyester polyols, and the color development effects of the compression change at 140°C and 120°C in Comparative Examples 1 and 2 are reduced, especially at 120°C. This shows that the compounding of ethylene glycol polyols and butanediol polyols can reduce the compression change temperature of the resin.

[0120] Combining Example 1 with Comparative Examples 3-4 and Table 2, it can be seen that in Comparative Examples 3 and 4, a single chain extender is used. The color development effects of the compression change at 140°C and 120°C in Comparative Examples 3 and 4 are both reduced, especially significantly reduced at 120°C. This shows that the combination of ethylene glycol and butanediol as a chain extender can reduce the compression change temperature of the resin. This may be because the combination of ethylene glycol and butanediol as a chain extender and the combination of butanediol polyols and ethylene glycol polyols can further reduce the symmetry properties of the polyurethane molecules, and the combination of different chain extenders can cause intermolecular interactions between the hard segments of the molecular chain segments, thereby reducing the softening point of the synthesized resin, reducing the compression change temperature, and achieving an ideal compression change effect at low temperatures, and the color development after compression change is uniform.

[0121] Combining Example 6 with Examples 8-10 and Table 2, it can be seen that the color development effect of the compression change at 140°C and 120°C in Examples 8-10 is better than that in Example 6, which indicates that the addition of silicone oil can further improve the low-temperature compression change color development effect of the resin.

[0122] Combining Example 9 with Examples 11-16 and Table 2, it can be seen that the color development effect of the compression change at 140°C and 120°C in Examples 11-16 is better than that in Example 9, which shows that the low-temperature compression change color development effect of the resin can be further improved by modifying the silicone oil, among which the ester-ether composite modification effect is better.

[0123] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A low temperature pressure-dependent resin, characterized in that: The method comprises the following raw materials in parts by weight: 53-58 parts of polyester polyol, 8-9 parts of chain extender, 26-29 parts of diphenylmethane diisocyanate, 210-230 parts of dimethylformamide, and 0.05-0.12 parts of silicone oil; The polyester polyol comprises a butanediol polyol and an ethylene glycol polyol in a weight ratio of 1: (1-1.7); the chain extender comprises butanediol and ethylene glycol in a weight ratio of 1: (1-1.4); The silicone oil is a modified silicone oil obtained by composite modification of trimethylolpropane trioctanoate-perfluoropolyether, and the preparation method thereof is as follows: Dissolve silicone oil in anhydrous toluene to obtain a silicone oil solution; add a platinum catalyst to trimethylolpropane trioctanoate, and then fill with protective gas to remove oxygen; then drop the silicone oil solution into the trimethylolpropane trioctanoate, react at 110-120°C for 5-6h, then cool to 70-80°C, add activated carbon for decolorization, and then distill to obtain trimethylolpropane trioctanoate modified silicone oil; Add perfluoropolyether and antioxidant to anhydrous toluene and heat to obtain a mixed solution, then fill with protective gas to remove oxygen; then add platinum catalyst to the mixed solution for activation, then drop trimethylolpropane trioctanoate modified silicone oil, react at 90-100°C for 7-8h, then cool to 70-80°C, add activated carbon for decolorization, and then distill to obtain trimethylolpropane trioctanoate-perfluoropolyether composite modified silicone oil; The weight ratio of the perfluoropolyether to trimethylolpropane trioctanoate is 1:(2-4); The method for preparing the low-temperature pressure-changing resin comprises the following steps: S1. 25-30% by weight of dimethylformamide, butanediol polyol, butanediol, 25-30% by weight of diphenylmethane diisocyanate, and a modified silicone oil obtained by mixing and heating trimethylolpropane trioctanoate - perfluoropolyether composite modified to obtain a mixture A; S2. Add 35-40% by weight of dimethylformamide, ethylene glycol polyol, ethylene glycol, 35-40% by weight of diphenylmethane diisocyanate to the mixture A and mix and heat to obtain a mixture B; S3. Add the remaining diphenylmethane diisocyanate to the mixture B to react and increase viscosity. During the viscosity increase process, add the remaining dimethylformamide to continuously dilute the reaction mixture to the set theoretical solid content to obtain a low-temperature pressure-sensitive resin.

2. The low temperature pressure-changing resin according to claim 1, characterized in that: The solid content of the low temperature compression resin is 28-33%.

3. The low temperature pressure-changing resin according to claim 1, characterized in that: The viscosity of the low temperature compression resin is 160000-220000 CPS / 25°C.

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