A saturated polyester type thickenable low shrinkage resin for smc / bmc

Abstract

The present application relates to the technical field of B29D, and particularly relates to a saturated polyester type thickening low shrinkage resin for SMC / BMC, a preparation method and application thereof.Raw materials of the present application include saturated polybasic acid and derivatives thereof, aliphatic polyol and crosslinking agent; wherein the weight ratio of the saturated polybasic acid and derivatives thereof to the aliphatic polyol is (4-6):(5-8).The present application designs a thickening low shrinkage resin, which participates in the thickening process of SMC / BMC, solves the problems of poor appearance and low strength of products caused by the precipitation of low shrinkage resin in SMC / BMC material, and ensures that the prepared SMC / BMC material does not precipitate low shrinkage resin, the appearance of SMC product is good, there is no phenomenon of color floating, flower and burr, and the mechanical strength is high, so the present application has wide application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of B29D, in particular to a saturated polyester type thickening low shrinkage resin for SMC / BMC, a preparation method and application thereof. BACKGROUND

[0002] With the development of national economy, SMC / BMC molding method of molding material is gradually favored by the market. This process with high degree of mechanization or even automation has high technical content, and is particularly suitable for the processing and production of high-quality products with high dimensional accuracy, large batch size and excellent appearance. SMC / BMC process currently occupies an important position in the molding material process in developed countries in the world, and has a rising trend year by year, but it has not been popularized in China. In the early stage of SMC / BMC development, due to the large curing volume shrinkage of unsaturated resin, various problems occur in the products. These conditions are alleviated to some extent with the introduction of low shrinkage resin, but the conventional low shrinkage resin for SMC / BMC does not have thickening performance, and the low shrinkage resin often precipitates in SMC / BMC material at room temperature, which causes poor surface appearance and low strength of the product. Under such background, it is urgent to develop a new type of thickening low shrinkage resin.

[0003] Chinese patent CN113336925A discloses a saturated polyester resin and a preparation method thereof, which uses isophthalic acid and 1,6-hexanediol to synthesize saturated polyester, and cooperates with L-lactide, hypophosphorous acid, triphenyl phosphite and other raw materials to improve the elasticity and wear resistance of the saturated polyester resin; Chinese patent CN110951227A discloses an SMC polyester molding compound, a preparation method and application thereof, which uses isophthalononitol type unsaturated polyester resin and a polystyrene low shrinkage additive with a solid content of 35% and a viscosity of 3200 mPa.s and a number average molecular weight of 30000, and cooperates with 25 μm glass fiber, hollow glass and other raw materials to improve the mechanical strength of the SMC polyester molding compound. Chinese patent CN109608846A discloses a preparation method of magnesium oxide paste thickening SMC material, which uses unsaturated polyester resin mixed with polystyrene, and cooperates with non-active resin diluted magnesium oxide paste thickening agent to achieve thickening effect. However, these prior arts do not solve the above technical problems. SUMMARY

[0004] The present application aims to design a thickening low shrinkage resin which participates in the SMC / BMC thickening process, solves the problems of poor surface appearance and low strength of the product caused by the precipitation of low shrinkage resin in SMC / BMC material, and ensures that the SMC / BMC material prepared does not precipitate low shrinkage resin, and the SMC product has good appearance without color floating, blooming and burr phenomenon.

[0005] To solve the above problems, the present application provides a saturated polyester thickening low shrinkage resin for SMC / BMC, which raw materials include saturated polybasic acid and its derivatives, aliphatic polyol and crosslinking agent; wherein the weight ratio of saturated polybasic acid and its derivatives and aliphatic polyol is (4-6):(5-8).

[0006] In some preferred embodiments, the saturated polybasic acid and its derivatives include a combination of one or more of linear aliphatic acid, phthalic anhydride, trimellitic anhydride, dodecyl succinic anhydride, and benzenedicarboxylic acid.

[0007] In some preferred embodiments, the linear aliphatic acid has a melting point of 150-172℃, a flash point of 164-210℃, and a surface tension of 45-60 dyne / cm.

[0008] Further preferably, the linear aliphatic acid includes a combination of one or more of succinic acid, adipic acid, sebacic acid, azelaic acid, 1,9-nonane dicarboxylic acid, and lauric acid.

[0009] More preferably, the linear aliphatic acid is adipic acid, which has a melting point of 152℃, a flash point of 196℃, and a surface tension of 52.4 dyne / cm.

[0010] In some preferred embodiments, the linear aliphatic acid includes a combination of one or more of succinic acid, adipic acid, sebacic acid, azelaic acid, 1,9-nonane dicarboxylic acid, and lauric acid.

[0011] In some preferred embodiments, the benzenedicarboxylic acid includes at least one of terephthalic acid, isophthalic acid, and phthalic acid.

[0012] In some preferred embodiments, the saturated polybasic acid includes a combination of linear aliphatic acid, phthalic anhydride, and isophthalic acid.

[0013] Preferably, the saturated polybasic acid is a combination of linear aliphatic acid and phthalic anhydride.

[0014] Preferably, the saturated polybasic acid is a combination of linear aliphatic acid and isophthalic acid.

[0015] Preferably, the saturated polybasic acid is a combination of linear aliphatic acid, phthalic anhydride, and isophthalic acid.

[0016] In some preferred embodiments, the aliphatic polyol has a molecular structure in which the number of primary carbon atoms, secondary carbon atoms, tertiary carbon atoms, and quaternary carbon atoms is (0-3):(1-5):(0-4):(0-2).

[0017] Preferably, the number of primary carbon atoms, secondary carbon atoms, tertiary carbon atoms and quaternary carbon atoms in the molecular structure of the aliphatic polyol is 1, 2, 1, 0, respectively, and specifically 2-methyl-1, 3-propanediol.

[0018] Preferably, the number of primary carbon atoms, secondary carbon atoms, tertiary carbon atoms and quaternary carbon atoms in the molecular structure of the aliphatic polyol is 1, 1, 1, 0, respectively, and specifically 1, 2-propanediol.

[0019] Preferably, the number of primary carbon atoms, secondary carbon atoms, tertiary carbon atoms and quaternary carbon atoms in the molecular structure of the aliphatic polyol is 0, 3, 0, 0, respectively, and specifically 1, 3-propanediol.

[0020] Preferably, the number of primary carbon atoms, secondary carbon atoms, tertiary carbon atoms and quaternary carbon atoms in the molecular structure of the aliphatic polyol is 2, 2, 2, 0, respectively, and specifically dipropylene glycol.

[0021] Preferably, the number of primary carbon atoms, secondary carbon atoms, tertiary carbon atoms and quaternary carbon atoms in the molecular structure of the aliphatic polyol is 2, 2, 0, 1, respectively, and specifically 2, 2-dimethyl-1, 3-propanediol.

[0022] In some preferred embodiments, the crosslinking agent is an unsaturated aromatic compound having a boiling point of 130-196°C.

[0023] In some preferred embodiments, the crosslinking agent is at least one of styrene, α-methylstyrene, propenyl phenyl ether, and allyl benzene.

[0024] Further preferably, the crosslinking agent is styrene, and has a boiling point of 145°C.

[0025] In some preferred embodiments, the raw material of the saturated polyester type thickening low shrinkage resin for SMC / BMC further comprises a polymerization inhibitor; the amount of the polymerization inhibitor added is 0.1-1‰ of the thickening resin.

[0026] In some preferred embodiments, the polymerization inhibitor comprises a phenolic compound and / or a quinone compound.

[0027] Further preferably, the phenolic compound comprises one or more of a combination of hydroquinone, p-hydroxyanisole, 2, 6-di-tert-butyl-p-cresol, 2-tert-butyl-hydroquinone, 2, 5-di-tert-butyl-hydroquinone, and 2-methyl-hydroquinone.

[0028] Further preferably, the quinone compound comprises one or more of a combination of methylhydroquinone, p-benzoquinone, and chloranil.

[0029] The saturated polybasic acid and its derivatives and the aliphatic polyol are reacted to obtain the thickening type low shrinkage resin with proper molecular weight, viscosity and acid value characteristics. When the thickening type resin is applied to the processing and production of SMC / BMC material, the flowability of the mixed material can be significantly controlled in the cooperation of magnesium oxide and calcium carbonate, and the viscosity of the thickening system can be increased by 1.1*10 8 mPa·s or more in a short time scale.

[0030] It is further found that, especially when adipic acid, phthalic anhydride and isophthalic acid are used as the saturated polybasic acid and its derivatives, and the number ratio of primary carbon atoms, secondary carbon atoms, tertiary carbon atoms and quaternary carbon atoms in the aliphatic polyol is (0-3):(1-5):(0-4):(0-2), the thickening type resin can have high thickening performance and strong wettability in the participation of unsaturated aromatic compounds with a boiling point of 130-196℃, the mechanical properties of the finished product after SMC / BMC mold forming are improved, and the precipitation trend of the low shrinkage resin in the product is significantly inhibited, and the finished product has uniform and smooth appearance without color floating, blooming and burr.

[0031] The second aspect of the present application provides a preparation method of the saturated polyester type thickening low shrinkage resin for SMC / BMC.

[0032] S1. According to the formula amount, the saturated polybasic acid and its derivatives and the aliphatic polyol are sequentially added to the reaction kettle, and the temperature is increased in stages under nitrogen protection until the acid value of the material is 20-32.

[0033] S2. The material is subjected to staged cooling, and the crosslinking agent and the polymerization inhibitor are added to the reaction kettle during the cooling process, and the stirring is performed for 0.5-2h to obtain the thickening type resin finished product.

[0034] In some preferred embodiments, the staged temperature increase in the S1 step is specifically increasing the temperature to 140-160℃, and then increasing the temperature to 190-240℃ at a speed of 0.05-0.5℃ / min.

[0035] In some preferred embodiments, the temperature increasing speed during the temperature increasing to 140-160℃ is 90-150℃ / h.

[0036] In some preferred embodiments, the S2 step is specifically reducing the temperature of the material to 150-165℃, and then adding the crosslinking agent and the polymerization inhibitor, and continuing to reduce the temperature to 50-74℃.

[0037] The third aspect of the present application provides an application of the saturated polyester type thickening low shrinkage resin for SMC / BMC, which is applied to a molding material, wherein the raw material of the molding material comprises a resin impregnated material and reinforcing fibers; the weight ratio of the resin impregnated material and the reinforcing fibers is (80-96):(4-20).

[0038] The raw material of the resin impregnated material comprises, based on the total mass of the molding material, 5-25% of unsaturated resin, 2-16% of thickening resin, 0.01-1% of magnesium oxide and / or magnesium hydroxide, and the rest of filler.

[0039] In some preferred embodiments, the unsaturated resin has a viscosity of 1000-4000 mPa.s (23°C), an acid value of 10-25 mgKOH / g, a solid content of 55-75%, and a water content of 0.01-0.5 wt%.

[0040] Further preferably, the unsaturated resin is EL-6138 from Zhenjiang Lideer Molding Material Co., Ltd.

[0041] The unsaturated resin EL-6138 has a viscosity of 1750±150 mPa.s (23°C), an acid value of 17±3 mgKOH / g, a solid content of 65±2%, and a water content of 0.06-0.1 wt%.

[0042] In some preferred embodiments, the filler comprises a combination of one or more of calcium carbonate, clay, kaolin, talc, mica, white carbon black, and calcium sulfate.

[0043] In some preferred embodiments, the raw material of the resin impregnated material comprises, based on the total mass of the molding material, 5-25% of unsaturated resin, 2-16% of the above-mentioned thickening resin, 0.01-1% of magnesium oxide and / or magnesium hydroxide, 0.1-0.5% of free radical donor, 0.2-4% of release agent, 5-30% of hydrated aluminum oxide, 0-2% of amorphous carbon, and the rest of filler.

[0044] In some preferred embodiments, the reinforcing fibers comprise at least one of glass fiber, carbon fiber, ultra-high molecular weight polyethylene fiber, and coconut shell fiber, and further preferably glass fiber.

[0045] In some preferred embodiments, the glass fiber has a glass fiber length of 2-25 mm, and most preferably 6 mm.

[0046] In some preferred embodiments, the free radical donor is a peroxide; for example, tert-butyl peroxy-2-ethylhexanoate (TBPO).

[0047] In some preferred embodiments, the release agent is a combination of one or more of stearic acid, zinc stearate, calcium stearate, magnesium stearate; preferably zinc stearate (ZnSt).

[0048] In some preferred embodiments, the amorphous carbon comprises a combination of one or more of carbon black, activated carbon, graphite, coke; preferably carbon black.

[0049] Further preferably, the particle size of the amorphous carbon is 5-50 nm.

[0050] The thickening resin provided by the present application has excellent workability in the process of preparing the compression molding material. The resin not only has stable thickening effect, can be uniformly dispersed in the mixture without being precipitated, but also can significantly improve the mechanical strength and dimensional stability of the SMC / BMC material. In combination with specific release agents and fillers, the tensile strength of the compression molding material can be improved to more than 56.5 MPa, the impact strength can be improved to more than 59.8 kJ / m 2 , and the shrinkage of the product can reach 0, which gives the finished product excellent appearance and strength performance, and significantly improves the finished product quality of the compression molding material.

[0051] In some preferred embodiments, the preparation steps of the compression molding material are as follows:

[0052] S1. Preparation of resin impregnated material:

[0053] a. First, mix the unsaturated resin and thickening resin uniformly according to the formula amount;

[0054] b. Then add the filler, magnesium oxide and / or magnesium hydroxide, release agent, hydrated aluminum oxide, amorphous carbon, and stir uniformly to obtain the resin impregnated material;

[0055] c. Add the reinforcing fiber to the resin impregnated material and stir uniformly to obtain the crude material;

[0056] S2. Molding:

[0057] The crude material is placed at 10-35℃ for 10-30h, and then pressed in the molding mold at 130-180℃ and 5-25MPa for 1-20min to obtain the compression molding material.

[0058] Advantages:

[0059] The saturated polyester type thickening low shrinkage resin for SMC / BMC provided by the present application has the following advantages:

[0060] (1) Thickening effect is obvious: the resin with specific structure is synthesized by using specific saturated polybasic acid and its derivatives and aliphatic polyhydric alcohol, and the suitable molecular weight, viscosity and acid value of the resin make the system viscosity increase to 1.1 x 10 8 mPa·s after adding to the thickening formula for only 2 days, and the thickening effect is durable, and the system still has very high viscosity after 14 days;

[0061] (2) Low precipitation, excellent appearance: the obtained thickening resin has strong formula compatibility in SMC / BMC material, and is not easy to precipitate, which solves the problem that the traditional thickening resin cannot stably exist in the resin system, and the molded material prepared has no color floating, blooming and edge phenomenon, and the surface is smooth, uniform and glossy, and beautiful;

[0062] (3) High mechanical strength: the obtained thickening resin can give SMC / BMC products excellent mechanical strength, and can play a uniform and sufficient impregnation effect on 2-25 mm reinforced fibers in combination with specific unsaturated resin, magnesium oxide and filler, so that the mixed material is fully compounded and molded in the mold, and the impact resistance and dimensional stability of the molded product are significantly improved. BRIEF DESCRIPTION OF DRAWINGS

[0063] Figure 1. Physical picture of the product obtained in application example 1;

[0064] Figure 2. Physical picture of the product obtained in application example 2;

[0065] Figure 3. Physical picture of the product obtained in application example 3;

[0066] Figure 4. Physical picture of the product obtained in application example 4;

[0067] Figure 5. Physical picture of the product obtained in application example 5;

[0068] Figure 6. Physical picture of the product obtained in application example 6;

[0069] Figure 7. Physical picture of the product obtained in application example 7. DETAILED DESCRIPTION

[0070] Example 1.

[0071] The embodiment provides a saturated polyester type thickening low shrinkage resin for SMC / BMC, raw materials of which include: 130 parts of saturated polybasic acid and its derivatives, 100 parts of aliphatic polyhydric alcohol, 110 parts of crosslinking agent and 0.1 part of polymerization inhibitor according to weight parts.

[0072] The saturated polybasic acid and its derivatives are composed of linear aliphatic acid, phthalic anhydride and isophthalic acid with a weight ratio of 2:1:1.

[0073] The linear aliphatic acid is adipic acid, the melting point of adipic acid is 152℃, the flash point is 196℃, and the surface tension is 52.4 dyne / cm.

[0074] The aliphatic polyol is composed of 2-methyl-1,3-propanediol and 1,2-propanediol with a weight ratio of 1:2.

[0075] The crosslinking agent is styrene, the boiling point is 145℃.

[0076] The polymerization inhibitor is composed of p-benzenediol and 2-methyl-p-benzenediol with a weight ratio of 1:1.

[0077] The second aspect of the embodiment provides a preparation method of saturated polyester type thickening low shrinkage resin for SMC / BMC, and the preparation steps of the saturated polyester type thickening low shrinkage resin for SMC / BMC include:

[0078] S1. According to the formula amount, the saturated polybasic acid and its derivatives, and the aliphatic polyol are sequentially added into the reaction kettle, and under the protection of nitrogen, the temperature is first increased to 150℃ (the temperature increasing speed is 120℃ / h, and the initial temperature is 30℃), then the temperature is increased to 210℃ at a speed of 0.2℃ / min, and the material is kept at the temperature until the acid value of the material is 27±3 mgKOH / g;

[0079] S2. The material temperature is first reduced to 160℃, then the crosslinking agent and the polymerization inhibitor are added, and the temperature is continuously reduced to 60℃, and the stirring is performed for 1h, thereby obtaining the thickening resin finished product.

[0080] Example 2.

[0081] The second aspect of the embodiment provides a saturated polyester type thickening low shrinkage resin for SMC / BMC, and the raw materials thereof include: 130 parts of saturated polybasic acid and its derivatives, 100 parts of aliphatic polyol, 110 parts of crosslinking agent, and 0.1 part of polymerization inhibitor.

[0082] The saturated polybasic acid and its derivatives are composed of linear aliphatic acid, phthalic anhydride and isophthalic acid with a weight ratio of 1:1:1.

[0083] The linear aliphatic acid is adipic acid, the melting point of adipic acid is 152℃, the flash point is 196℃, and the surface tension is 52.4 dyne / cm.

[0084] The aliphatic polyol is composed of 2-methyl-1,3-propanediol, 1,3-propanediol and 2,2-dimethyl-1,3-propanediol with a weight ratio of 1:1:2.

[0085] The cross-linking agent is styrene, and the boiling point is 145℃.

[0086] The polymerization inhibitor is composed of hydroquinone and 2-methyl hydroquinone in a weight ratio of 1:2.

[0087] The second aspect of the embodiment provides a preparation method of the saturated polyester type thickening low shrinkage resin for SMC / BMC, and the preparation steps of the saturated polyester type thickening low shrinkage resin for SMC / BMC include:

[0088] S1. According to the formula amount, saturated polybasic acid and its derivatives and aliphatic polyol are sequentially added into a reaction kettle, and under the protection of nitrogen, the temperature is first increased to 150℃ (the temperature increasing speed is 120℃ / h, and the initial temperature is 30℃), then the temperature is increased to 210℃ at a speed of 0.2℃ / min, and the material is kept at the temperature until the acid value of the material is 27±3mgKOH / g;

[0089] S2. The material temperature is first decreased to 160℃, then the cross-linking agent and the polymerization inhibitor are added, and the temperature is continuously decreased to 60℃, and the stirring is performed for 1h, so that the thickening resin product is obtained.

[0090] Embodiment 3.

[0091] The embodiment provides a saturated polyester type thickening low shrinkage resin for SMC / BMC, and raw materials of the saturated polyester type thickening low shrinkage resin for SMC / BMC include: 135 parts of saturated polybasic acid and its derivatives, 100 parts of aliphatic polyol, 115 parts of cross-linking agent and 0.1 part of polymerization inhibitor according to weight.

[0092] The saturated polybasic acid and its derivatives are composed of straight-chain aliphatic acid and isophthalic acid in a weight ratio of 1:1.

[0093] The straight-chain aliphatic acid is adipic acid, the melting point of the adipic acid is 152℃, the flash point is 196℃, and the surface tension is 52.4 dyne / cm.

[0094] The aliphatic polyol is composed of dipropylene glycol, 1,2-propanediol and 2,2-dimethyl-1,3-propanediol in a weight ratio of 2:1:1.

[0095] The cross-linking agent is styrene, and the boiling point is 145℃.

[0096] The polymerization inhibitor is composed of hydroquinone and 2-methyl hydroquinone in a weight ratio of 1:2.

[0097] The second aspect of the embodiment provides a preparation method of the saturated polyester type thickening low shrinkage resin for SMC / BMC, and the preparation steps of the saturated polyester type thickening low shrinkage resin for SMC / BMC include:

[0098] S1. According to the formula, the saturated polybasic acid and its derivatives, aliphatic polyols are sequentially added to the reaction kettle, and under the protection of nitrogen, the temperature is first raised to 150°C (the temperature rising speed is 120°C / h, and the initial temperature is 30°C), and then the temperature is raised to 210°C at a speed of 0.2°C / min, and the acid value of the material is 27±3mgKOH / g.

[0099] S2. First, the material temperature is reduced to 160°C, then the crosslinking agent and the polymerization inhibitor are added, and the temperature is continuously reduced to 60°C, and stirred for 1h, to obtain the thickened resin product.

[0100] Example 4.

[0101] The present embodiment provides a saturated polyester type thickening low shrinkage resin for SMC / BMC, which raw materials include: by weight, 125 parts of saturated polybasic acid and its derivatives, 100 parts of aliphatic polyol, 105 parts of crosslinking agent and 0.1 part of polymerization inhibitor.

[0102] The saturated polybasic acid and its derivatives are composed of linear aliphatic acid and isophthalic acid in a weight ratio of 1:1.

[0103] The linear aliphatic acid is adipic acid, the melting point of adipic acid is 152°C, the flash point is 196°C, and the surface tension is 52.4 dyne / cm.

[0104] The aliphatic polyol is composed of 2-methyl-1,3-propanediol and 1,3-propanediol in a weight ratio of 2:1.

[0105] The crosslinking agent is styrene, and the boiling point is 145°C.

[0106] The polymerization inhibitor is 2-methyl hydroquinone.

[0107] The second aspect of the present embodiment provides a preparation method of a saturated polyester type thickening low shrinkage resin for SMC / BMC, and the preparation steps of the saturated polyester type thickening low shrinkage resin for SMC / BMC include:

[0108] S1. According to the formula, the saturated polybasic acid and its derivatives, aliphatic polyols are sequentially added to the reaction kettle, and under the protection of nitrogen, the temperature is first raised to 150°C (the temperature rising speed is 120°C / h, and the initial temperature is 30°C), and then the temperature is raised to 210°C at a speed of 0.2°C / min, and the acid value of the material is 27±3mgKOH / g.

[0109] S2. First, the material temperature is reduced to 160°C, then the crosslinking agent and the polymerization inhibitor are added, and the temperature is continuously reduced to 60°C, and stirred for 1h, to obtain the thickened resin product.

[0110] Example 5.

[0111] The embodiment provides a saturated polyester type thickening low-shrinkage resin for SMC / BMC, raw materials of which include: 130 parts of saturated polybasic acid and derivatives thereof, 100 parts of aliphatic polyol, 110 parts of crosslinking agent and 0.1 part of polymerization inhibitor according to weight parts.

[0112] The saturated polybasic acid and derivatives thereof are composed of linear aliphatic acid and phthalic anhydride with a weight ratio of 2:1.

[0113] The linear aliphatic acid is adipic acid, the melting point of the adipic acid is 152 DEG C, the flash point is 196 DEG C, and the surface tension is 52.4 dyne / cm.

[0114] The aliphatic polyol is composed of 2-methyl-1,3-propanediol and 1,2-propanediol with a weight ratio of 1:2.

[0115] The crosslinking agent is styrene, and the boiling point is 145 DEG C.

[0116] The polymerization inhibitor is hydroquinone.

[0117] The second aspect of the embodiment provides a preparation method of a saturated polyester type thickening low-shrinkage resin for SMC / BMC, and the preparation steps of the saturated polyester type thickening low-shrinkage resin for SMC / BMC include:

[0118] S1. According to the formula amount, the saturated polybasic acid and derivatives thereof and the aliphatic polyol are sequentially added into a reaction kettle, and under nitrogen protection, the temperature is first increased to 150 DEG C (the temperature increasing speed is 120 DEG C / h, and the initial temperature is 30 DEG C), then the temperature is increased to 210 DEG C at a speed of 0.2 DEG C / min, and the material is kept at the temperature until the acid value of the material is 27±3 mgKOH / g;

[0119] S2. The material temperature is first decreased to 160 DEG C, then the crosslinking agent and the polymerization inhibitor are added, the temperature is continuously decreased to 60 DEG C, and the stirring is performed for 1 h, so that the thickening resin finished product is obtained.

[0120] Embodiment 6.

[0121] The embodiment provides a saturated polyester type thickening low-shrinkage resin for SMC / BMC, raw materials of which include: 130 parts of saturated polybasic acid and derivatives thereof, 100 parts of aliphatic polyol, 115 parts of crosslinking agent and 0.1 part of polymerization inhibitor according to weight parts.

[0122] The saturated polybasic acid and derivatives thereof are composed of linear aliphatic acid and phthalic anhydride with a weight ratio of 1:1.

[0123] The linear aliphatic acid is adipic acid, the melting point of the adipic acid is 152 DEG C, the flash point is 196 DEG C, and the surface tension is 52.4 dyne / cm.

[0124] The aliphatic polyol is 1,3-propanediol.

[0125] The crosslinking agent is styrene, and the boiling point is 145°C.

[0126] The polymerization inhibitor is hydroquinone.

[0127] The second aspect of the embodiment provides a preparation method of a saturated polyester type thickening low shrinkage resin for SMC / BMC, and the preparation steps of the saturated polyester type thickening low shrinkage resin for SMC / BMC include:

[0128] S1. According to the formula amount, the saturated polybasic acid and its derivative and the aliphatic polyol are sequentially added into a reaction kettle, and under the protection of nitrogen, the temperature is first increased to 150°C (the temperature increasing speed is 120°C / h, and the initial temperature is 30°C), then the temperature is increased to 210°C at a speed of 0.2°C / min, and the material is kept at the temperature until the acid value of the material is 27±3 mgKOH / g;

[0129] S2. The material temperature is first decreased to 160°C, then the crosslinking agent and the polymerization inhibitor are added, the temperature is continuously decreased to 60°C, and the stirring is performed for 1 h, and the thickening resin product is obtained.

[0130] Example 7.

[0131] The embodiment provides a saturated polyester type thickening low shrinkage resin for SMC / BMC, and raw materials of the saturated polyester type thickening low shrinkage resin for SMC / BMC include: 130 parts of saturated polybasic acid and its derivative, 100 parts of aliphatic polyol, 115 parts of crosslinking agent and 0.1 part of polymerization inhibitor according to weight parts.

[0132] The saturated polybasic acid and its derivative are composed of linear aliphatic acid, phthalic anhydride and isophthalic acid at a weight ratio of 1:2:3.

[0133] The linear aliphatic acid is adipic acid, the melting point of the adipic acid is 152°C, the flash point is 196°C, and the surface tension is 52.4 dyne / cm.

[0134] The aliphatic polyol is composed of 2-methyl-1,3-propanediol, 1,2-propanediol and 2,2-dimethyl-1,3-propanediol at a weight ratio of 1:1:2.

[0135] The crosslinking agent is styrene, and the boiling point is 145°C.

[0136] The polymerization inhibitor is hydroquinone.

[0137] The second aspect of the embodiment provides a preparation method of a saturated polyester type thickening low shrinkage resin for SMC / BMC, and the preparation steps of the saturated polyester type thickening low shrinkage resin for SMC / BMC include:

[0138] S1. According to the formula, the saturated polybasic acid and its derivatives, and the aliphatic polyhydric alcohol are sequentially added to the reaction kettle, and the temperature is raised to 150°C under nitrogen protection, and then the temperature is raised to 210°C at a speed of 0.2°C / min, and the temperature is kept until the acid value of the material is 27±3 mgKOH / g;

[0139] S2. First, the temperature of the material is reduced to 160°C, then the crosslinking agent and the polymerization inhibitor are added, and the temperature is continuously reduced to 60°C, and stirred for 1h to obtain the thickened resin product.

[0140] Application Example 1.

[0141] The application example provides an application of the saturated polyester type thickened low shrinkage resin for SMC / BMC as described in Embodiment 1, and the saturated polyester type thickened low shrinkage resin for SMC / BMC is applied to a molding material.

[0142] The raw materials of the molding material include resin impregnated material and reinforcing fiber; the weight ratio of the resin impregnated material and the reinforcing fiber is 88:12;

[0143] The raw materials of the resin impregnated material include 15% of unsaturated resin, 10% of the thickened resin obtained in Embodiment 1, 0.1% of magnesium oxide, 0.24% of free radical donor, 1.1% of release agent, 24.6% of hydrated aluminum oxide (ATH), 0% of amorphous carbon, and the rest of filler, based on the total mass of the molding material.

[0144] The unsaturated resin is specifically EL-6138, which is from Zhenjiang Lideer Molding Material Co., Ltd.

[0145] The viscosity of the unsaturated resin EL-6138 is 1750±150 mPa.s (23°C), the acid value is 17±3 mgKOH / g, the solid content is 65±2%, and the water content is 0.06-0.1 wt%.

[0146] The magnesium oxide is specifically high-activity magnesium oxide of RA-150 type of WACKER brand.

[0147] The filler is calcium carbonate, specifically Omyacarb 5 type heavy calcium carbonate of Omya.

[0148] The free radical donor is tert-butyl peroxy-2-ethylhexanoate (TBPO).

[0149] The release agent is zinc stearate (ZnSt).

[0150] The reinforcing fiber is glass fiber; the glass fiber length of the glass fiber is 6 mm.

[0151] The preparation steps of the molding material include:

[0152] S1. Preparation of resin impregnation material:

[0153] a. First, mix the unsaturated resin and thickening resin according to the formula amount;

[0154] b. Then add the filler, magnesium oxide, release agent, hydrated aluminum oxide, amorphous carbon, and stir evenly to obtain the resin impregnation material;

[0155] c. Add the reinforcing fiber to the resin impregnation material and stir evenly to obtain the crude material;

[0156] S2. Molding:

[0157] The crude material is placed at 26°C for 24h, and then pressed in a molding mold at 150°C and 15MPa for 3min to obtain the compression molded material.

[0158] Application Example 2.

[0159] This application example provides an application of the saturated polyester type thickening low shrinkage resin for SMC / BMC as described in Example 2, and the specific implementation is the same as in Application Example 1; the difference is that the thickening resin is specifically the thickening resin obtained in Example 2.

[0160] Application Example 3.

[0161] This application example provides an application of the saturated polyester type thickening low shrinkage resin for SMC / BMC as described in Example 3, and the specific implementation is the same as in Application Example 1; the difference is that the thickening resin is specifically the thickening resin obtained in Example 3.

[0162] Application Example 4.

[0163] This application example provides an application of the saturated polyester type thickening low shrinkage resin for SMC / BMC as described in Example 2, and the specific implementation is the same as in Application Example 1; the difference is that the thickening resin is specifically the thickening resin obtained in Example 4.

[0164] Application Example 5.

[0165] This application example provides an application of the saturated polyester type thickening low shrinkage resin for SMC / BMC as described in Example 2, and the specific implementation is the same as in Application Example 1; the difference is that the thickening resin is specifically the thickening resin obtained in Example 5.

[0166] The amorphous carbon is specifically carbon black with a particle size of 10nm.

[0167] Application Example 6

[0168] The application example provides an application of the saturated polyester type thickenable low shrinkage resin for SMC / BMC as described in the embodiment 6, and the specific implementation manner is the same as the application example 5; the difference lies in that the thickening type resin is specifically the thickening type resin obtained in the embodiment 6.

[0169] Application Example 7

[0170] The application example provides an application of the saturated polyester type thickenable low shrinkage resin for SMC / BMC as described in the embodiment 7, and the specific implementation manner is the same as the application example 5; the difference lies in that the thickening type resin is specifically the thickening type resin obtained in the embodiment 7.

[0171] Performance test

[0172] 1. Resin technical index

[0173] It is tested that the viscosity of the thickening type resin obtained in the embodiments 1-7 is 800-1000 mPa·s (23℃), the solid content is 60-65%, and the acid value is 15-19 mg KOH / g.

[0174] 2. Thickening performance test

[0175] The thickening type resin of the embodiments 1-7 is mixed with calcium carbonate (Omyacarb 5) and magnesium oxide (RA-150) according to the weight ratio of 100:150:0.875, the viscosity of the material is tested in the time scale of 0-14 days, and is recorded in Table 1.

[0176] The viscosity of the material is tested by using the cone-plate viscometer produced by the American Brookfield Company, the model is CAP2000+, and the test temperature is 23℃; the viscosity unit in Table 1 is mPa·s.

[0177] Table 1. Thickening performance test results

[0178] Examples 1 2 3 4 5 6 7 5 min 6700 5215 12597 9267 5777 2929 14723 30 min 10551 6339 16729 17010 8786 4774 54078 1h 16849 7462 39145 25595 12115 6579 153000 3h 35464 13158 107000 64829 20861 12035 136*10 4 ]]> 1d 67397 122000 4060*10 4 ]]> 65.2*10 4 ]]> 30489 16047 5180*10 4 ]]> 2d 16*10 4 ]]> 112*10 4 ]]> 10500*10 4 ]]> 305*10 4 ]]> 43327 22466 9240*10 4 ]]> 7d 16*10 4 ]]> 353*10 4 ]]> Over range 1220*10 4 ]]> 48141 20861 14200*10 4 <!-- 9 -->]]> 14d 32.1*10 4 ]]> 594*10 4 ]]> / 1990*10 4 ]]> / /

[0179] 3. Strength of the compression molding material

[0180] The mechanical strength of the compression molding material of the application examples 1-7 is tested according to GB / T 15568-2008, and the results are recorded in Table 2.

[0181] Table 2. Strength test results of the compression molding material

[0182]

Claims

1. A saturated polyester-type thickening low-shrinkage resin for SMC / BMC, characterized in that, Its raw materials include saturated polybasic acids and their derivatives, aliphatic polyols and crosslinking agents; wherein the weight ratio of saturated polybasic acids and their derivatives to aliphatic polyols is (4-6):(5-8). The saturated polyacids and their derivatives include one or more combinations of straight-chain fatty acids, phthalic anhydride, trimellitic anhydride, dodecyl succinic anhydride, and phthalic acid. The aliphatic polyol is 2-methyl-1,3-propanediol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, or 2,2-dimethyl-1,3-propanediol. The crosslinking agent is an unsaturated aromatic compound with a boiling point of 130-196℃; The raw materials for the saturated polyester thickening low-shrinkage resin for SMC / BMC also include a polymerization inhibitor; the amount of polymerization inhibitor added is 0.1-1‰ of the saturated polyester thickening low-shrinkage resin for SMC / BMC.

2. The saturated polyester-type thickening low-shrinkage resin for SMC / BMC according to claim 1, characterized in that, The linear fatty acid has a melting point of 150-172℃, a flash point of 164-210℃, and a surface tension of 45-60 dyne / cm.

3. A method for preparing a saturated polyester-type thickening low-shrinkage resin for SMC / BMC according to claim 1 or 2, characterized in that, The preparation steps of the saturated polyester thickening low-shrinkage resin for SMC / BMC include: S1. According to the weight ratio of saturated polyacids and their derivatives to aliphatic polyols, add saturated polyacids and their derivatives and aliphatic polyols into the reactor in sequence, and raise the temperature in stages under nitrogen protection, and keep the temperature until the acid value of the material is 20-32. S2. The material is cooled in stages. During the cooling process, the crosslinking agent and polymerization inhibitor are added to the reactor and stirred for 0.5-2 hours to obtain the finished product of saturated polyester thickening low shrinkage resin for SMC / BMC.

4. The method for preparing a saturated polyester-type thickening low-shrinkage resin for SMC / BMC according to claim 3, characterized in that, The staged heating in step S1 specifically involves first heating to 140-160℃, and then heating to 190-240℃ at a rate of 0.05-0.5℃ / min.

5. An application of a saturated polyester-type thickening low-shrinkage resin for SMC / BMC, characterized in that, The SMC / BMC uses a saturated polyester thickening low-shrinkage resin for use in compression molding materials. The raw materials for the compression molding materials include resin impregnating material and reinforcing fiber. The weight ratio of resin impregnating material to reinforcing fiber is (80-96):(4-20). Based on the total mass of the molding material, the raw materials of the resin impregnating material are: 5-25% unsaturated resin, 2-16% saturated polyester thickening low-shrinkage resin for SMC / BMC as described in claim 1 or 2, 0.01-1% magnesium oxide and / or magnesium hydroxide, and filler to make up the balance.

6. An application of the saturated polyester-type thickening low-shrinkage resin for SMC / BMC according to claim 5, characterized in that, The filler includes one or more of the following: calcium carbonate, clay, kaolin, talc, mica, silica, and calcium sulfate.

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