Unsaturated polyester resin for bonding composite acrylic plate

Abstract

The invention provides unsaturated polyester resin for bonding a composite acrylic plate. The unsaturated polyester resin for bonding the composite acrylic plate is prepared from the following raw materials in percentage by mass: 15 to 30 percent of phthalic anhydride, 5 to 25 percent of maleic anhydride, 0 to 2 percent of dimer acid, 3 to 15 percent of ethylene glycol, 3 to 10 percent of diethylene glycol, 3 to 10 percent of propoxylated bisphenol A, 3 to 15 percent of dicyclopentadiene and 20 to 40 percent of styrene. By adding propoxylated bisphenol A, bisphenol A, propoxy and other groups are introduced into unsaturated polyester resin, so that the adhesive property of the unsaturated polyester resin can be improved; by introducing dicyclopentadiene, the viscosity of the unsaturated polyester resin is reduced, the post-curing process of the unsaturated polyester resin is slowed down, and the adhesive property of the unsaturated polyester resin is improved.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to an unsaturated polyester resin for bonding composite acrylic plates. Background Art

[0002] Acrylic, also known as PMMA or organic glass, is chemically known as polymethyl methacrylate. Acrylic is a plastic polymer material characterized by excellent transparency, chemical stability, weather resistance, ease of dyeing and processing, and an attractive appearance. It is widely used in bathroom products. Composite acrylic sheets are typically bonded to glass fiber cloth using an adhesive. The specific preparation process is as follows: clean the composite acrylic sheet; select an adhesive based on unsaturated polyester resin, apply a layer of adhesive to the surface of the composite acrylic sheet, then apply a layer of glass fiber cloth, allow to cure, and then trim and finish the finished product.

[0003] However, the exothermic peak temperature of existing unsaturated polyester resins is too high, resulting in poor bonding performance to composite acrylic sheets, easy peeling, and even easy to cause deformation, cracking, or changes in the chemical structure of the sheets. Summary of the Invention

[0004] The object of the present invention is to overcome the deficiencies of the prior art and provide an unsaturated polyester resin for bonding composite acrylic panels.

[0005] An unsaturated polyester resin for bonding composite acrylic plates comprises the following raw materials in percentage by mass: 15-30% of phthalic anhydride, 5-25% of maleic anhydride, 0-2% of dimer acid, 3-15% of ethylene glycol, 3-10% of diethylene glycol, 3-10% of propoxylated bisphenol A, 3-15% of dicyclopentadiene, and 20-40% of a diluent.

[0006] Preferably, the unsaturated polyester resin comprises the following raw materials in percentage by mass: 18-25% phthalic anhydride, 10-15% maleic anhydride, 1-2% dimer acid, 8-10% ethylene glycol, 5-8% diethylene glycol, 5-8% propoxylated bisphenol A, 5-10% dicyclopentadiene, and 30-35% diluent.

[0007] Preferably, the unsaturated polyester resin further comprises the following raw materials in percentage by mass: 0.5-2% of hydrazide compound.

[0008] More preferably, in the raw material of the unsaturated polyester resin, the mass percentage of the hydrazide compound is 1-1.5%.

[0009] More preferably, the hydrazide compound includes at least one of adipic acid dihydrazide, oxalic acid dihydrazide, maleic acid dihydrazide, sebacic acid dihydrazide, oxalic acid dihydrazide, and glutaric acid dihydrazide.

[0010] Preferably, the preparation method of the unsaturated polyester resin comprises the following steps:

[0011] S1, mixing phthalic anhydride, maleic anhydride, dimer acid, ethylene glycol, diethylene glycol, propoxylated bisphenol A, dicyclopentadiene and adipic acid dihydrazide to obtain a reaction mixture A;

[0012] S2, heating the reaction mixture A to 150-160° C. and keeping the temperature therefor for 30-60 min, then heating the reaction mixture to 190-210° C. and keeping the temperature therefor for 4-6 h to obtain a reaction mixture B;

[0013] S3. Cooling the reaction mixture B to a temperature not higher than 120° C., adding a diluent, and mixing to obtain the unsaturated polyester resin.

[0014] Further preferably, in step S1, the inert atmosphere includes at least one of nitrogen, argon and helium.

[0015] Further preferably, step S1 specifically comprises: mixing phthalic anhydride, maleic anhydride, dimer acid, ethylene glycol, diethylene glycol, propoxylated bisphenol A and adipic acid dihydrazide, adding dicyclopentadiene dropwise under an inert atmosphere at 120-130° C., and mixing and reacting for 1-3 hours to obtain a reaction mixture A.

[0016] More preferably, in step S1, dicyclopentadiene is added dropwise at a uniform speed, and the addition time is 0.5-2 hours.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The present invention introduces bisphenol A, propoxy groups and the like into the unsaturated polyester resin by adding propoxylated bisphenol A, thereby improving the bonding performance of the unsaturated polyester resin;

[0019] (2) The present invention introduces dicyclopentadiene to appropriately reduce the viscosity of the unsaturated polyester resin, smooth the heat release of the unsaturated polyester resin during the post-curing process, and improve the bonding performance of the unsaturated polyester resin. DETAILED DESCRIPTION

[0020] To better illustrate the purpose, technical solutions, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments. The purpose is to provide a detailed understanding of the content of the present invention, rather than to limit the present invention. All other implementations obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present invention.

[0021] An unsaturated polyester resin for bonding composite acrylic plates comprises the following raw materials in percentage by mass: 15-30% of phthalic anhydride, 5-25% of maleic anhydride, 0-2% of dimer acid, 3-15% of ethylene glycol, 3-10% of diethylene glycol, 3-10% of propoxylated bisphenol A, 3-15% of dicyclopentadiene, and 20-40% of a diluent.

[0022] The present invention introduces bisphenol A, propoxy groups and the like into the unsaturated polyester resin by adding propoxylated bisphenol A, thereby improving the bonding strength of the unsaturated polyester resin. The present invention also introduces dicyclopentadiene to reduce the viscosity of the unsaturated polyester resin, smoothen the post-curing process of the unsaturated polyester resin, and improve the bonding strength of the unsaturated polyester resin.

[0023] For example, in the raw material of the unsaturated polyester resin for bonding composite acrylic panels, the mass percentage of the phthalic anhydride can be 15%, 16%, 18%, 20%, 22%, 25%, 28%, 30% or a range consisting of any two groups of values ​​therein; the mass percentage of the maleic anhydride can be 5%, 7%, 10%, 12%, 15%, 18%, 18.5%, 19%, 19.5%, 20%, 22%, 25% or a range consisting of any two groups of values ​​therein; the mass percentage of the dimer acid can be 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2% or a range consisting of any two groups of values ​​therein; the mass percentage of the ethylene glycol can be 3%, 5%, 8%, 8.5%, 9%, 9.5%, 10%, 12%, 1 5% or a range consisting of any two groups of values ​​therein; the mass percentage of the diethylene glycol can be 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10% or a range consisting of any two groups of values ​​therein, the mass percentage of the propoxylated bisphenol A can be 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10% or a range consisting of any two groups of values ​​therein, the mass percentage of the dicyclopentadiene can be 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%% or a range consisting of any two groups of values ​​therein, and the mass percentage of the diluent can be 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40% or a range consisting of any two groups of values ​​therein.

[0024] In one embodiment, the unsaturated polyester resin comprises the following raw materials in percentage by mass: 18-25% phthalic anhydride, 10-15% maleic anhydride, 1-2% dimer acid, 8-10% ethylene glycol, 5-8% diethylene glycol, 5-8% propoxylated bisphenol A, 5-10% dicyclopentadiene, and 30-35% diluent.

[0025] The inventors have discovered that the addition of dimer acid significantly affects the curing behavior and final properties of unsaturated polyester resins. By adding an appropriate amount of dimer acid, the present invention introduces its long fatty chains (flexible chains) into the unsaturated polyester resin, significantly reducing the exothermic peak temperature and improving the adhesive properties of the unsaturated polyester resin.

[0026] In one embodiment, the unsaturated polyester resin further comprises the following raw materials by mass: 0.5-2% of a hydrazide compound. For example, the mass percentage of the hydrazide compound in the raw materials of the unsaturated polyester resin can be 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, or a range consisting of any two of these values.

[0027] In a preferred embodiment, the mass percentage of the hydrazide compound in the raw material of the unsaturated polyester resin is 1-2%.

[0028] The inventors have found through research that the introduction of an appropriate amount of hydrazide compound can effectively reduce the exothermic peak temperature of the unsaturated polyester resin while improving the bonding performance and heat deformation temperature of the unsaturated polyester resin.

[0029] In a preferred embodiment, the hydrazide compound includes at least one of adipic acid dihydrazide, oxalic acid dihydrazide, maleic acid dihydrazide, sebacic acid dihydrazide, oxalic acid dihydrazide, and glutaric acid dihydrazide.

[0030] In one embodiment, the unsaturated polyester resin comprises the following raw materials in percentage by mass: 18-25% phthalic anhydride, 10-15% maleic anhydride, 1-2% dimer acid, 8-10% ethylene glycol, 5-8% diethylene glycol, 5-8% propoxylated bisphenol A, 1-2% hydrazide compound, 5-10% dicyclopentadiene, and 30-35% diluent.

[0031] In a preferred embodiment, the unsaturated polyester resin comprises the following raw materials in the following weight percentages: 18-25% phthalic anhydride, 10-15% maleic anhydride, 1-1.5% dimer acid, 8-10% ethylene glycol, 5-8% diethylene glycol, 5-8% propoxylated bisphenol A, 1-1.5% hydrazide compound, 5-10% dicyclopentadiene, and 30-35% diluent. When the weight percentages of the components in the raw material formula of the unsaturated polyester resin are within this range, the unsaturated polyester resin exhibits a moderate exothermic peak temperature, better bonding properties, and a relatively high heat distortion temperature.

[0032] In one embodiment, the preparation method of the unsaturated polyester resin comprises the following steps:

[0033] S1, mixing phthalic anhydride, maleic anhydride, dimer acid, ethylene glycol, diethylene glycol, propoxylated bisphenol A, dicyclopentadiene and adipic acid dihydrazide to obtain a reaction mixture A;

[0034] S2, heating the reaction mixture A to 150-160° C. and keeping the temperature therefor for 30-60 min, then heating the reaction mixture to 190-210° C. and keeping the temperature therefor for 4-6 h to obtain a reaction mixture B;

[0035] S3. Cooling the reaction mixture B to a temperature not higher than 120° C., adding a diluent, and mixing to obtain the unsaturated polyester resin.

[0036] In a preferred embodiment, in step S1, the inert atmosphere includes at least one of nitrogen, argon, and helium.

[0037] In a preferred embodiment, step S1 specifically comprises: mixing phthalic anhydride, maleic anhydride, dimer acid, ethylene glycol, diethylene glycol, propoxylated bisphenol A and adipic acid dihydrazide, adding dicyclopentadiene dropwise under an inert atmosphere at 120-130° C., and mixing and reacting for 1-3 hours to obtain a reaction mixture A.

[0038] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0039] Unless otherwise specified, the experimental reagents and instruments involved in the implementation of the present invention are all commonly used ordinary reagents and instruments. Unless otherwise specified, the components and raw materials used in the embodiments and comparative examples of the present invention are all commercially available raw materials, and the components and raw materials used in each parallel experiment are all of the same type.

[0040] Example 1

[0041] The unsaturated polyester resin for bonding composite acrylic sheets according to the present invention is prepared by weighing the raw material components according to Table 1 using the following method:

[0042] S1. Phthalic anhydride, maleic anhydride, dimer acid, ethylene glycol, diethylene glycol, propoxylated bisphenol A, and adipic acid dihydrazide were added to a reaction kettle. Under a nitrogen atmosphere and a stirring speed of 100 r / min, the temperature was raised to 120° C., the temperature was kept constant, and dicyclopentadiene was added dropwise at a uniform rate for 1 hour. After the addition was completed, the temperature was kept constant for 2 hours to obtain a reaction mixture A.

[0043] S2. Under a nitrogen atmosphere and a stirring speed of 100 r / min, the reaction mixture A was heated to 150° C. and kept warm for 30 min, then heated to 200° C. and kept warm for 5 h to obtain a reaction mixture B;

[0044] S3. Under a nitrogen atmosphere and a stirring speed of 100 r / min, the reaction mixture B was cooled to 120° C., styrene was added, and the mixture was mixed to obtain the unsaturated polyester resin.

[0045] Example 2

[0046] The difference between this embodiment and embodiment 1 is that dimer acid is not used in this embodiment, and the mass percentage of phthalic anhydride in the raw material formula of the unsaturated polyester resin provided in this embodiment is 20%, as shown in Table 1.

[0047] Examples 3-5

[0048] The difference between Example 3-5 and Example 1 is that the raw material formula of the unsaturated polyester resin in Example 3-5 is shown in Table 1.

[0049] Example 6

[0050] The difference between this embodiment and embodiment 1 is that dimer acid is not used in this embodiment, and the mass percentage of phthalic anhydride in the raw material formula of the unsaturated polyester resin in this embodiment is 20%, as shown in Table 1.

[0051] Examples 7-12

[0052] The difference between Example 7-12 and Example 1 is that the raw material formula of the unsaturated polyester resin in Example 7-12 is as shown in Table 1.

[0053] Example 13

[0054] The difference between this embodiment and embodiment 1 is that dimer acid and adipic acid dihydrazide are not used in this embodiment. In the raw material formula of the unsaturated polyester resin in this embodiment, the mass percentage of phthalic anhydride is 20%, and the mass percentage of ethylene glycol is 10%, as shown in Table 1.

[0055] Table 1 Raw material formula of unsaturated polyester resin in each embodiment (by mass percentage, unit: %)

[0056]

[0057] Note: “ / ” in Table 1 indicates that the raw material is not included in the raw material formula of the unsaturated polyester resin in the corresponding example.

[0058] Comparative Examples 1-5

[0059] The difference between Comparative Examples 1-5 and Example 1 is that:

[0060] Comparative Example 1 did not use propoxylated bisphenol A, and the mass percentage of ethylene glycol in the raw material formula of the unsaturated polyester resin of Comparative Example 1 was 14%, as shown in Table 2.

[0061] Comparative Example 2 did not use dicyclopentadiene, and the mass percentage of styrene in the raw material formula of the unsaturated polyester resin of Comparative Example 2 was 45%, as shown in Table 2. Step S1 of Comparative Example 2 was: phenolic anhydride, maleic anhydride, dimeric acid, ethylene glycol, diethylene glycol, propoxylated bisphenol A and adipic acid dihydrazide were added to a reaction kettle, and the reaction mixture A was obtained by heating to 120°C and keeping for 3h under the conditions of nitrogen atmosphere and stirring speed of 100r / min.

[0062] Comparative Example 3 did not use propoxylated bisphenol A and dicyclopentadiene, and the mass percentage of ethylene glycol in the raw material formula of the unsaturated polyester resin of Comparative Example 3 was 14%, and the mass percentage of styrene was 45%, as shown in Table 2. Step S1 of Comparative Example 3 was: phenolic anhydride, maleic anhydride, dimeric acid, ethylene glycol, diethylene glycol and adipic acid dihydrazide were added to a reaction kettle, and the reaction mixture A was obtained by heating to 120°C and keeping for 3h under the conditions of nitrogen atmosphere and stirring speed of 100r / min.

[0063] The raw material formula of the unsaturated polyester resin in Comparative Examples 4-5 is shown in Table 2.

[0064] Table 2: Raw material formula of unsaturated polyester resin in each comparative example (in mass percentage, unit: %)

[0065] Raw material name Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Phthalic anhydride 18.5 18.5 18.5 18.5 18.5 Maleic anhydride 15 15 15 15 15 Propoxylated bisphenol A / 5 / 1 5 Ethylene glycol 14 9 14 13 9 Diethylene glycol 5 5 5 5 5 Dicyclopentadiene 10 / / 10 1 Styrene 35 45 45 35 44 Dimer acid 1.5 1.5 1.5 1.5 1.5 Adipic acid dihydrazide 1 1 1 1 1

[0066] Note: " / " in Table 2 means that the corresponding raw material is not included in the raw material formula of the unsaturated polyester resin of the corresponding comparative example.

[0067] In order to further test the performance of the unsaturated polyester resin provided by each of the above examples and comparative examples, the unsaturated polyester resin obtained from the above examples and comparative examples was used as a sample to perform the following tests:

[0068] (1) Exothermic peak temperature (highest peak value): tested according to the method specified in GB / T 7193-2008 standard;

[0069] (2) Heat distortion temperature: tested according to Method A in GB / T1634.2-2019 standard;

[0070] (3) Pulling strength: after the unsaturated polyester resin, the promoter (cobalt isooctoate) and the curing agent (methyl ethyl ketone peroxide) are stirred uniformly according to the weight ratio of 100:0.5:1.5, three composite acrylic plates of the same factory and the same model are coated respectively, the coating thickness is 200 μm, after coating, the three plates are respectively post-cured in a 25℃ environment, during the post-curing, 1g of epoxy AB glue is applied on the preset position of the above-mentioned plate, an aluminum ingot is fixed on the epoxy AB glue, three aluminum ingots are selected and fixed on each plate; after 24h of post-curing, the pulling strength is detected by using an AT-A type pulling tester, and the measured pulling strength is recorded;

[0071] The test results are shown in Tables 3-4.

[0072] Table 3

[0073]

[0074] Table 4

[0075]

[0076]

[0077] It can be seen from Examples 1-13 that the unsaturated polyester resins prepared by the embodiments of the present application have a high heat distortion temperature, the heat distortion temperature is not less than 49.3℃, the exothermic peak temperature is moderate, the bonding performance to the acrylic plate is good, and the pulling strength is not less than 2.71MPa. When the raw material formula of the unsaturated polyester resin is: phthalic anhydride 18-25%, maleic anhydride 10-15%, dimeric acid 1-2%, ethylene glycol 8-10%, diethylene glycol 5-8%, propoxylated bisphenol A 5-8%, hydrazide compound 1-2%, dicyclopentadiene 5-10%, and styrene 30-35%, the comprehensive performance of the unsaturated polyester resin is better, the heat distortion temperature is not less than 52.4℃, the bonding performance to the acrylic plate is better, and the pulling strength is not less than 3.21MPa.

[0078] Compared with Comparative Examples 1-5, the exothermic peak temperature of the unsaturated polyester resin prepared in Example 1 is obviously decreased, the heat distortion temperature is increased, and the bonding performance is significantly improved, which may be due to the introduction of appropriate propoxylated bisphenol A and dicyclopentadiene, which introduces bisphenol A, propoxy and other groups into the unsaturated polyester resin, so that the viscosity of the unsaturated polyester resin is moderate, the exothermic peak temperature is moderate, the exothermic process of the unsaturated polyester resin during post-curing is gentle, and thus the bonding performance of the unsaturated polyester resin is significantly improved.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. An unsaturated polyester resin for bonding composite acrylic sheets, characterized in that: The invention comprises the following raw materials in percentage by mass: 15-30% of phthalic anhydride, 5-25% of maleic anhydride, 0-2% of dimer acid, 3-15% of ethylene glycol, 3-10% of diethylene glycol, 3-10% of propoxylated bisphenol A, 3-15% of dicyclopentadiene and 20-40% of diluent.

2. The unsaturated polyester resin for bonding composite acrylic sheets according to claim 1, wherein: The unsaturated polyester resin comprises the following raw materials in percentage by mass: 18-25% of phthalic anhydride, 10-15% of maleic anhydride, 1-2% of dimer acid, 8-10% of ethylene glycol, 5-8% of diethylene glycol, 5-8% of propoxylated bisphenol A, 5-10% of dicyclopentadiene, and 30-35% of a diluent.

3. The unsaturated polyester resin for bonding composite acrylic sheets according to claim 1, wherein: The unsaturated polyester resin further comprises the following raw materials in percentage by mass: 0.5-2% of hydrazide compound.

4. The unsaturated polyester resin for bonding composite acrylic sheets according to claim 3, wherein: The hydrazide compound includes at least one of adipic acid dihydrazide, oxalic acid dihydrazide, maleic acid dihydrazide, sebacic acid dihydrazide, oxalic acid dihydrazide, and glutaric acid dihydrazide.

5. The unsaturated polyester resin for bonding composite acrylic sheets according to claim 1, wherein: The diluent includes at least one of styrene and α-methylstyrene.

6. The unsaturated polyester resin for bonding composite acrylic sheets according to claim 1, wherein: The preparation method of the unsaturated polyester resin comprises the following steps: S1, mixing and reacting all raw materials except styrene to obtain a reaction mixture A; S2, heating the reaction mixture A to 150-160° C. and keeping the temperature therefor for 30-60 min, then heating the reaction mixture to 190-210° C. and keeping the temperature therefor for 4-6 h to obtain a reaction mixture B; S3. Cooling the reaction mixture B to a temperature not higher than 120° C., adding a diluent, and mixing to obtain the unsaturated polyester resin.

7. The unsaturated polyester resin for bonding composite acrylic sheets according to claim 6, wherein: Step S1 specifically comprises: mixing phthalic anhydride, maleic anhydride, dimer acid, ethylene glycol, diethylene glycol, propoxylated bisphenol A and adipic acid dihydrazide, adding dicyclopentadiene dropwise under an inert atmosphere at 120-130° C., and mixing and reacting for 1-3 hours to obtain a reaction mixture A.

8. The unsaturated polyester resin for bonding composite acrylic sheets according to claim 7, wherein: Step S1: adding dicyclopentadiene dropwise at a uniform speed for 0.5-2 hours.

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