Low-shrinkage acrylic adhesive resin, preparation method thereof and acrylic product using adhesive resin

Abstract

The invention relates to the technical field of acrylic adhesive resin, in particular to low-shrinkage acrylic adhesive resin, a preparation method thereof and an acrylic product using the adhesive resin. Comprising a component A and a component B. The component A comprises, by mass, 100-160 parts of modified unsaturated polyester resin; 40 to 100 parts of PET (Polyethylene Terephthalate) type acrylic adhesive resin; 0.8 part of an accelerant; 20-40 parts of a low shrinkage agent; 1-2 parts of a bonding aid; a component B: 220-240 parts of a filler; the acrylic adhesive resin provided by the invention has the advantages of extremely low contractibility, strong acrylic adhesive property, low heat release and fast curing, is suitable for casting molding, and is suitable for a novel composite manufacturing process for preparing an acrylic product.

Description

Technical Field

[0001] This invention relates to the field of acrylic adhesive resin technology, and in particular to a low-shrinkage acrylic adhesive resin, its preparation method, and acrylic products cast using the adhesive resin. Background Technology

[0002] In the bathroom fixtures market, acrylic bathroom products (bathroom bases, bathtubs, washbasins, etc.) currently occupy half of the market share. Acrylic sheets are characterized by their smooth surface, comfortable feel, warm color, lightweight texture, and rich shapes, but their high production costs have gradually reduced their market competitiveness. Currently, to balance appearance quality, structural strength, and production costs, some manufacturers have begun to try a new composite manufacturing process: First, acrylic (PMMA) thermoplastic sheets are formed into a beautifully designed outer shell using a vacuum forming process. Then, a liquid acrylic adhesive resin system is cast into the internal cavity of this shell. After curing, a solid reinforcing core layer is formed, ultimately resulting in a composite structure product with a high-quality thermoplastic surface and a resin reinforcement inside.

[0003] This composite process combines the excellent surface processing properties of thermoplastics with the flexible structural advantages of resin casting. Compared with pure acrylic casting products, it significantly reduces mold costs and process difficulty; compared with ordinary fiberglass (FRP) products, it significantly improves surface weather resistance, gloss and sensory quality.

[0004] However, this process faces a long-standing and unresolved core technical bottleneck in practical industrial applications: traditional acrylic adhesive resins undergo significant volume shrinkage during curing (linear shrinkage rates typically range from 1.5% to 8%), which leads to a series of serious product defects and quality problems. Furthermore, it is accompanied by high exothermic properties that easily ablate the acrylic sheet, and delamination from the acrylic shell due to poor adhesion after molding.

[0005] Therefore, developing an internally cast reinforcing resin specifically designed for such composite processes, characterized by extremely low curing shrinkage, high mechanical strength, excellent acrylic bonding performance, and process adaptability, has become a key technological requirement for driving the industry toward higher quality and more stable production. Summary of the Invention

[0006] The purpose of this invention is to provide a low-shrinkage acrylic adhesive resin and its preparation method, to solve at least one of the above-mentioned technical problems.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A low-shrinkage acrylic adhesive resin comprises component A and component B, with the following composition by weight: Component A: 100-160 parts of modified unsaturated polyester resin; PET type acrylic adhesive resin 40-100; Accelerator 0.8; Low shrinkage agent 20-40; Adhesive additives 1-2; Component B: 220-240 parts of filler.

[0008] Furthermore, the modified unsaturated resin in component A is prepared from the following substances in the following weight ratios: 20-25 parts maleic anhydride 2-5 parts pure water 30-35 parts of dicyclopentadiene 10-15 parts of diol 20-24 parts of styrene 1-2 parts of α-methylstyrene Polymerization inhibitor 0.04-0.1 wt‰.

[0009] Furthermore, the preparation method of the modified unsaturated resin includes the following steps: Dicyclopentadiene and water were added to a reactor, stirred, and nitrogen gas was introduced. The reactor was heated to temperature T1. A portion of maleic anhydride was added first, and after exothermic reaction, the remaining maleic anhydride was added. After the addition was completed, the temperature was raised to T2 and held at full reflux. After reacting for a period of time, the acid value was tested until it remained constant. The temperature was raised to T3 and held for a period of time, then lowered to T4. Diol and polymerization inhibitor were added, and the temperature was raised to T5. The reaction was held until the acid value reached 22-28 mg KOH / g. The temperature was then cooled to T6 and diluted in a styrene solution to prepare the modified unsaturated polyester resin.

[0010] Furthermore, the ratio of n(maleic anhydride):n(dicyclopentadiene) = 1:(1.00-1.05), the diol is diethylene glycol or ethylene glycol, and the styrene solution is a mixed solution of styrene and α-methylstyrene; The temperatures are as follows: T1 is 50-60℃, T2 is 120-130℃, T3 is 190℃-195℃, T4 is 150-160℃, T5 is 200±2℃, and T6 is 160~180℃. First, 60% maleic anhydride is added, and after exothermic reaction, the remaining 40% maleic anhydride is added. The temperature is raised to T3 and then kept at that temperature for 45-60 minutes.

[0011] Furthermore, the PET-type acrylic adhesive resin in component A is prepared from the following substances in the following weight ratios: 5-9 parts maleic anhydride 14-17 parts of phthalic anhydride PET 15-20 portions 21-28 parts of diol 35-39 parts styrene Polymerization inhibitor 0.04-0.1 wt‰.

[0012] Furthermore, the PET-type acrylic adhesive resin in component A is prepared by the following method: Diol, PET, and catalyst were added to a reaction vessel, stirred, and heated to T7. The mixture was then kept under full reflux until the sample and propylene glycol monomethyl ether (0.8–1.5) were completely mixed and clear for more than 15 minutes, and remained clear even after freezing. The mixture was then cooled to T8, acid anhydride was added, and the temperature was raised to T9. The mixture was kept at a constant temperature until the acid value reached 38–44 mg KOH / g. The mixture was then cooled to T10 and diluted in styrene to obtain PET-type acrylic adhesive resin.

[0013] Furthermore, the PET refers to PET polyester chips, PET bottle flakes, and PET materials recycled in daily life; the acid anhydride refers to maleic anhydride and phthalic anhydride; and the diol includes one or more of propylene glycol, ethylene glycol, and diethylene glycol. The T7 is 220±5℃, T8 is 150℃, T9 is 205-210℃, and T10 is 170~180℃.

[0014] Furthermore, the low-shrinkage agent is one of PVAC type low-shrinkage agent and polyurethane modified low-shrinkage agent; The adhesive is one of MMA, ethyl acetate, or acetone. Component B consists of one or more of aluminum hydroxide, calcium carbonate, and titanium dioxide.

[0015] The ratio of component A to component B is 1:(1-2).

[0016] A method for preparing a low-shrinkage acrylic adhesive resin, the method comprising the following steps: First, mix component A evenly at 200-500 rpm, then mix it evenly with component B at 500-1000 rpm to prepare a low-shrinkage acrylic bonding casting resin.

[0017] Another object of the present invention is to provide an acrylic product.

[0018] An acrylic product is manufactured by casting a low-shrinkage acrylic adhesive resin and an acrylic sheet mold. The preparation method of the acrylic product includes the following steps: 1) At room temperature, mix component A and component B in proportion, and mix the mixture evenly at a speed of 500-1000 rpm, then set aside for use; 2) Take 100 parts of the above mixture, add 0.5 to 1.5 parts of curing agent, stir evenly, and then pour it into the shell made of acrylic sheet for curing.

[0019] The beneficial effects of adopting the technical solution of the present invention are: This invention provides a method for preparing a low-shrinkage acrylic adhesive resin, which is composed of two components, A and B. Component A contains a modified unsaturated polyester resin with high activity and low shrinkage. The PET-type acrylic adhesive resin exhibits good acrylic bonding performance. The low-shrinkage agent significantly improves the anti-shrinkage properties, and the adhesive additive further enhances the bonding strength between the resin and acrylic, complementing each other. Simultaneously, its low viscosity allows for good wetting of the filler in component B. The prepared resin possesses extremely low shrinkage, strong acrylic bonding performance, low exothermicity, and rapid curing, making it suitable for casting molding and well-suited for novel composite manufacturing processes of acrylic products. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to specific examples. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The manufacturers of the raw materials involved in this invention are as follows: phthalic anhydride (Sinopec Yizheng Chemical Fiber Co., Ltd.), maleic anhydride (Sinopec Yizheng Chemical Fiber Co., Ltd.), dicyclopentadiene (Sinopec Shanghai Petrochemical Co., Ltd., polyester grade), ethylene glycol (Nantong Runfeng Petrochemical Co., Ltd., polyester grade), diethylene glycol (Nantong Runfeng Petrochemical Co., Ltd., industrial grade), propylene glycol (Nantong Runfeng Petrochemical Co., Ltd., industrial grade), styrene (Sinopec Yizheng Chemical Fiber Co., Ltd., polymerization grade), methylstyrene (Maclean's, reagent grade), PET (industrial grade, Changzhou Dingxin Plastics Co., Ltd.) The low-shrinkage acrylic adhesive resin of this invention comprises component A and component B, and the mass fractions of each component are as follows: Component A: 100-160 parts of modified unsaturated polyester resin; PET type acrylic adhesive resin 40-100; Accelerator 0.8; Low shrinkage agent 20-40; Adhesive additives 1-2; Component B: 220-240 parts of filler.

[0022] Component A contains a modified unsaturated polyester resin with high activity and low shrinkage, while the PET-type acrylic adhesive resin exhibits excellent acrylic adhesion. The low-shrinkage agent significantly improves shrinkage resistance, and the adhesive additive further enhances the bond strength between the resin and acrylic, creating a synergistic effect. Simultaneously, its low viscosity allows for good wetting of the filler in component B. The resulting resin possesses extremely low shrinkage, strong acrylic adhesion, low exothermic properties, and rapid curing, making it suitable for casting and well-suited for the novel composite manufacturing process of acrylic bathroom bases.

[0023] Example 1 A method for preparing a low-shrinkage acrylic adhesive resin, comprising a mixture of two components, A and B, wherein each component is expressed in the following parts by weight: Component A: Modified unsaturated polyester resin 100 PET type acrylic adhesive resin 100 Accelerator 0.8 PVAC low shrinkage agent 40 MMA 1 Component B: 480 parts of aluminum hydroxide Preparation of modified unsaturated polyester resin: 34 kg of dicyclopentadiene and 5 kg of water were added to a reactor, stirred, and nitrogen gas was introduced. The reactor was heated to 50°C. 14.4 kg of maleic anhydride was added first, followed by 9.6 kg of maleic anhydride after exothermic reaction. After the addition was completed, the reactor was kept at 130°C for 2 hours. The acid value was tested until it remained unchanged. The temperature was then raised to 190°C and kept at that temperature for 45 minutes before being lowered to 150°C. 6 kg of ethylene glycol, 6 kg of diethylene glycol, and 40 g of polymerization inhibitor were added. The temperature was raised to 200°C and kept at that temperature until the acid value reached 22–28 mg KOH / g. The mixture was then cooled to 160°C and diluted in a mixed solution of styrene and α-methylstyrene to prepare a modified unsaturated polyester resin.

[0024] Preparation of PET type acrylic adhesive resin: Add 5 kg EG, 12 kg DEG, 4 kg PG, 20 kg PET and catalyst to a reactor, stir, heat to 220℃, and reflux until the sample and propylene glycol monomethyl ether (0.8-1.5) are completely mixed and clear for more than 15 minutes, and do not become turbid when frozen. Start cooling and reduce the temperature to 150℃. Add 9 kg MA and 14 kg PA, heat to 210℃, and react at a constant temperature until the acid value reaches 38-44 mg KOH / g. Cool to 170℃ and dilute in styrene to obtain PET-type acrylic adhesive resin.

[0025] Preparation method of acrylic adhesive resin: First, mix component A thoroughly at 500 rpm, then mix it thoroughly with component B at 1000 rpm to prepare a low-shrinkage acrylic bonding casting resin.

[0026] To prepare acrylic products from acrylic adhesive resin: Take 3 kg of the above-mentioned mixed resin mixture, add 10 g of methyl ethyl ketone peroxide curing agent, stir evenly, and cast the mixed resin into the shell made of acrylic sheet by casting, and wait for it to cure and form.

[0027] Example 2 A method for preparing a low-shrinkage acrylic adhesive resin, comprising a mixture of two components, A and B, wherein each component is expressed in the following parts by weight: Component A: Modified unsaturated polyester resin 120 PET type acrylic adhesive resin 80 Accelerator 0.8 Polyurethane modified low shrinkage agent 30 Ethyl acetate 1 Component B, calcium carbonate, 320 parts The preparation methods for the modified unsaturated polyester resin and PET-type acrylic adhesive resin are the same as in Example 1.

[0028] Preparation method of acrylic adhesive resin: First, mix component A thoroughly at 500 rpm, then mix it thoroughly with component B at 800 rpm to prepare a low-shrinkage acrylic bonding casting resin.

[0029] To prepare acrylic products from acrylic adhesive resin: Take 3 kg of the above-mentioned mixed resin mixture, add 10.7 g of methyl ethyl ketone peroxide curing agent, stir evenly, and cast the mixed resin into the shell made of acrylic sheet by casting, and wait for it to cure and form.

[0030] Example 3 A method for preparing a low-shrinkage acrylic adhesive resin, comprising a mixture of two components, A and B, wherein each component is expressed in the following parts by weight: Component A: Modified unsaturated polyester resin 160 PET type acrylic adhesive resin 40 Accelerator 0.8 PVAC low shrinkage agent 20 Acetone 1 Component B, calcium carbonate, 220 parts The preparation methods for the modified unsaturated polyester resin and PET-type acrylic adhesive resin are the same as in Example 1.

[0031] Preparation method of acrylic adhesive resin: First, mix component A thoroughly at 200 rpm, then mix it thoroughly with component B at 500 rpm to prepare a low-shrinkage acrylic bonding casting resin.

[0032] To prepare acrylic products from acrylic adhesive resin: Take 3 kg of the above-mentioned mixed resin mixture, add 15 g of methyl ethyl ketone peroxide curing agent, stir evenly, and cast the mixed resin into the shell made of acrylic sheet by casting, and wait for it to cure and form.

[0033] Comparative Example 1 The acrylic adhesive resin of this comparative example is prepared by mixing two components, A and B, with each component expressed in the following parts by weight: Component A: 100 parts of modified unsaturated polyester resin Accelerator 0.4 parts 10 portions of PMMA-SM solution Component B, calcium carbonate, 220 parts Preparation of modified unsaturated polyester resin: 34 kg of dicyclopentadiene and 5 kg of water were added to a reactor, stirred, and nitrogen gas was introduced. The reactor was heated to 50°C. 14.4 kg of maleic anhydride was added first, followed by 9.6 kg of maleic anhydride after exothermic reaction. After the addition was completed, the reactor was kept at 130°C for 2 hours. The acid value was tested until it remained unchanged. The temperature was then raised to 190°C and kept at that temperature for 45 minutes before being lowered to 150°C. 6 kg of ethylene glycol, 6 kg of diethylene glycol, and 40 g of polymerization inhibitor were added. The temperature was raised to 200°C and kept at that temperature until the acid value reached 22–28 mg KOH / g. The mixture was then cooled to 160°C and diluted in a styrene solution to prepare the modified unsaturated polyester resin.

[0034] Preparation method of acrylic adhesive resin: First, mix component A thoroughly at 500 rpm, then mix it thoroughly with component B at 1000 rpm to prepare acrylic adhesive resin.

[0035] To prepare acrylic products from acrylic adhesive resin: Take 3 kg of the above-mentioned mixed resin mixture, add 10 g of methyl ethyl ketone peroxide curing agent, stir evenly, and cast the mixed resin into the shell made of acrylic sheet by casting, and wait for it to cure and form.

[0036] Comparative Example 2 The acrylic adhesive resin of this comparative example is prepared by mixing two components, A and B, with each component expressed in the following parts by weight: Component A: 100 parts of PET type acrylic adhesive resin Accelerator 0.4 parts Component B, calcium carbonate, 200 parts Preparation of PET type acrylic adhesive resin: Add 5 kg EG, 12 kg DEG, 4 kg PG, 20 kg PET and catalyst to a reactor, stir, heat to 220℃, and reflux until the sample and propylene glycol monomethyl ether (0.8-1.5) are completely mixed and clear for more than 15 minutes, and do not become turbid when frozen. Start cooling and reduce the temperature to 150℃. Add 9 kg MA and 14 kg PA, heat to 210℃, and react at a constant temperature until the acid value reaches 38-44 mg KOH / g. Cool to 170℃ and dilute in styrene to obtain PET-type acrylic adhesive resin.

[0037] Preparation method of acrylic adhesive resin: First, mix component A thoroughly at 500 rpm, then mix it thoroughly with component B at 1000 rpm to prepare acrylic adhesive resin.

[0038] To prepare acrylic products from acrylic adhesive resin: Take 3 kg of the above-mentioned mixed resin mixture, add 10 g of methyl ethyl ketone peroxide curing agent, stir evenly, and cast the mixed resin into the shell made of acrylic sheet by casting, and wait for it to cure and form.

[0039] The application performance of the low-shrinkage acrylic adhesive resins prepared in Examples 1-3 of this invention was tested, and the specific test results are shown in the table below.

[0040] Linear shrinkage test of resin: Referring to HG / T 2625-1994, the acrylic adhesive resin and curing agent were mixed evenly according to the above preparation method, and then poured into a steel test mold. After curing at room temperature for 24 hours, the length of the sample was measured with a micrometer, and the linear shrinkage rate was calculated. Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent claim. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A low-shrinkage acrylic adhesive resin, characterized in that: The composition of components A and B by mass is as follows: Component A: 100-160 parts of modified unsaturated polyester resin; PET type acrylic adhesive resin 40-100; Accelerator 0.8; Low shrinkage agent 20-40; Adhesive additives 1-2; Component B: 220-240 parts of filler.

2. The low-shrinkage acrylic adhesive resin according to claim 1, characterized in that: The modified unsaturated resin in component A is prepared from the following substances in the following weight ratio: 20-25 parts maleic anhydride 2-5 parts pure water 30-35 parts of dicyclopentadiene 10-15 parts of diol 20-24 parts of styrene 1-2 parts of α-methylstyrene Polymerization inhibitor 0.04-0.1 wt‰.

3. The low-shrinkage acrylic adhesive resin according to claim 2, characterized in that: The preparation method of the modified unsaturated resin includes the following steps: Dicyclopentadiene and water were added to a reactor, stirred, and nitrogen gas was introduced. The reactor was heated to temperature T1. A portion of maleic anhydride was added first, and after exothermic reaction, the remaining maleic anhydride was added. After the addition was completed, the temperature was raised to T2 and held at total reflux. After reacting for a period of time, the acid value was tested until it remained constant. The temperature was raised to T3 and held for a period of time, then lowered to T4. Diol and polymerization inhibitor were added, and the temperature was raised to T5. The reaction was held until the acid value reached 22-28 mg KOH / g. The temperature was then cooled to T6 and diluted in a styrene solution to prepare the modified unsaturated polyester resin.

4. The low-shrinkage acrylic adhesive resin according to claim 3, characterized in that: The ratio of n(maleic anhydride):n(dicyclopentadiene) is 1:(1.00-1.05), the diol is diethylene glycol or ethylene glycol, and the styrene solution is a mixed solution of styrene and α-methylstyrene. The temperatures are as follows: T1 is 50-60℃, T2 is 120-130℃, T3 is 190℃-195℃, T4 is 150-160℃, T5 is 200±2℃, and T6 is 160~180℃. First, 60% maleic anhydride is added, and after exothermic reaction, the remaining 40% maleic anhydride is added. The temperature is raised to T3 and then kept at that temperature for 45-60 minutes.

5. The low-shrinkage acrylic adhesive resin according to claim 2, characterized in that: The PET-type acrylic adhesive resin in component A is made from the following substances in the following weight ratios: 5-9 parts maleic anhydride 14-17 parts of phthalic anhydride PET 15-20 portions 21-28 parts of diol 35-39 parts styrene Polymerization inhibitor 0.04-0.1 wt‰.

6. The low-shrinkage acrylic adhesive resin according to claim 5, characterized in that: The PET-type acrylic adhesive resin in component A is prepared by the following method: Diol, PET, and catalyst were added to a reaction vessel, stirred, and heated to T7. The mixture was then kept under full reflux until the sample and propylene glycol monomethyl ether (0.8–1.5) were completely mixed and clear for more than 15 minutes, and remained clear even after freezing. The mixture was then cooled to T8, acid anhydride was added, and the temperature was raised to T9. The mixture was kept at a constant temperature until the acid value reached 38–44 mg KOH / g. The mixture was then cooled to T10 and diluted in styrene to obtain PET-type acrylic adhesive resin.

7. The low-shrinkage acrylic adhesive resin according to claim 6, characterized in that: The PET refers to PET polyester chips, PET bottle flakes, and PET materials recycled from daily life; the acid anhydride refers to maleic anhydride and phthalic anhydride; the diol includes one or more of propylene glycol, ethylene glycol, and diethylene glycol. The T7 is 220±5℃, T8 is 150℃, T9 is 205-210℃, and T10 is 170~180℃.

8. The low-shrinkage acrylic adhesive resin according to claim 1, characterized in that: The low-shrinkage agent is one of PVAC type low-shrinkage agent and polyurethane modified low-shrinkage agent; The adhesive is one of MMA, ethyl acetate, or acetone. Component B is one or more of aluminum hydroxide, calcium carbonate, and titanium dioxide; The ratio of component A to component B is 1:(1-2).

9. A method for preparing a low-shrinkage acrylic adhesive resin according to any one of claims 1 to 8, characterized in that: The preparation method includes the following steps: First, mix component A evenly at 200-500 rpm, then mix it evenly with component B at 500-1000 rpm to prepare a low-shrinkage acrylic bonding casting resin.

10. An acrylic product, characterized in that: The acrylic product is manufactured by casting using any one of the low-shrinkage acrylic adhesive resins and an acrylic sheet mold according to claims 1-8. The preparation method of the acrylic product includes the following steps: 1) At room temperature, mix component A and component B in proportion, and mix the mixture evenly at a speed of 500-1000 rpm, then set aside for use; 2) Take 100 parts of the above mixture, add 0.5 to 1.5 parts of curing agent, stir evenly, and then cast it into a shell made of acrylic sheet for curing.

Images