Low-shrinkage resin composition and application

Abstract

The invention discloses a low-shrinkage resin composition and application thereof. The composition comprises the following raw material components in percentage by mass: 10-25% of expansion monomer resin; 35%-45% of epoxy resin; 10%-20% of an elastomer; 1%-5% of a curing agent; 19%-30% of a flame-retardant filler; 0.1%-1% of a silane coupling agent; wherein the expansion monomer resin comprises any one or more of spiro orthoester and derivatives thereof, spiro orthocarbonate and derivatives thereof, bicyclic orthoester and derivatives thereof, and ketal lactone and derivatives thereof. Volume expansion of the expansion monomer resin in the cross-linking reaction process with the epoxy resin is counteracted with volume shrinkage of the epoxy resin during curing, so that the curing shrinkage rate of the adhesive layer is close to 0, and the mechanical property and the aging resistance of the adhesive layer are improved.

Description

Technical Field

[0001] The invention relates to the technical field of electronic materials, and in particular to a low-shrinkage resin composition and application thereof. Background Art

[0002] For existing new energy power batteries and energy storage batteries, the signal acquisition components in the integrated busbars are mostly flexible printed circuit boards (FPCs). As battery modules become larger and larger, the length of FPCs is also getting longer (currently the length of FPCs is mostly 1.2-2.0m), which inevitably requires the raw material FCCL of FPC to have higher dimensional stability.

[0003] Among the existing materials used for flexible printed circuit boards (FCCL), epoxy resins with excellent bonding properties are widely used. However, epoxy resin adhesives will shrink in volume during the curing process, with a volume shrinkage rate of more than 5%. After the FCCL is cured, the insulating layer shrinks in volume, generating internal stress, causing the board surface to warp or even curl, resulting in large changes in expansion and contraction and poor dimensional stability. There is a related technology that adds elastomers and fillers to the adhesive to reduce the volume shrinkage of epoxy resin, but due to the poor aging resistance of elastomers, the aging resistance of FCCL is poor. Summary of the invention

[0004] The invention provides a low-shrinkage resin composition and application to solve the technical problem.

[0005] In order to solve the above technical problems, in a first aspect, an embodiment of the present invention provides a low shrinkage resin composition, comprising the following raw material components in percentage by mass:

[0006] Expanded monomer resin 10% to 25%;

[0007] Epoxy resin 35%~45%;

[0008] Elastomer 10% to 20%;

[0009] Curing agent 1% to 5%;

[0010] Flame retardant filler 19% to 30%;

[0011] Silane coupling agent 0.1% to 1%;

[0012] The expandable monomer resin includes any one or more of spiro orthoesters and their derivatives, spiro orthocarbonates and their derivatives, bicyclic orthoesters and their derivatives, and ketal lactones and their derivatives.

[0013] In some of the embodiments, the following raw material components are included by mass percentage:

[0014] Expanded monomer resin 15% to 20%;

[0015] Epoxy resin 40%~45%;

[0016] Elastomer 10% to 19%;

[0017] Curing agent 2% to 5%;

[0018] Flame retardant filler 19% to 30%;

[0019] Silane coupling agent 0.1%~1%.

[0020] In some embodiments, the expandable monomer resin is made of the following raw materials in parts by mass:

[0021] 20 to 30 parts of intermediate, 20 to 30 parts of diphenylmethane diisocyanate;

[0022] The intermediate is made from the following raw materials in percentage by mass:

[0023] Trimethylolpropane 25% to 30%;

[0024] Dibutyltin oxide 48% to 53%;

[0025] Carbon disulfide 19%~24%.

[0026] Preferably, the expandable monomer resin is made from the following raw materials in parts by mass:

[0027] 26.4 parts of intermediate, 25.03 parts of diphenylmethane diisocyanate;

[0028] The intermediate is made from the following raw materials in percentage by mass:

[0029] Trimethylolpropane 27.7%;

[0030] Dibutyltin oxide 51.4%;

[0031] Carbon disulfide 20.9%.

[0032] In some embodiments, the expanded monomer resin is prepared by the following steps:

[0033] Step 1, heating trimethylolpropane, dibutyltin oxide and toluene solution to 115° C. to 125° C. under electromagnetic stirring for 11 h to 13 h;

[0034] Step 2: After the reactant in step 1 is cooled to room temperature, carbon disulfide is added, and then the temperature is raised to 95°C to 105°C for reaction for 11h to 13h;

[0035] Step 3, distilling and washing the reactant in step 2 under reduced pressure to remove toluene, and then recrystallizing and drying the remaining reactant to obtain an intermediate;

[0036] Step 4: add the intermediate of step 3 and diphenylmethane diisocyanate into chloroform, stir and dissolve, react at 33° C. to 37° C. for 22 h to 26 h, heat to 70° C. to evaporate the chloroform, and obtain an expanded monomer resin.

[0037] Preferably, the expanded monomer resin is prepared by the following steps:

[0038] Step 1, heating trimethylolpropane, dibutyltin oxide and toluene solution to 120° C. under electromagnetic stirring for 12 hours;

[0039] Step 2: After cooling the reactant in step 1 to room temperature, add carbon disulfide, and then heat to 100° C. to react for 12 hours;

[0040] Step 3, distilling and washing the reactant in step 2 under reduced pressure to remove toluene, and then recrystallizing and drying the remaining reactant to obtain an intermediate;

[0041] Step 4: add the intermediate of step 3 and diphenylmethane diisocyanate into chloroform, stir and dissolve, react at 35° C. for 24 hours, heat to 70° C. and evaporate the chloroform to obtain an expanded monomer resin.

[0042] In some embodiments, the epoxy resin is any one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, biphenyl epoxy resin, DCPD epoxy resin, phenoloxy epoxy resin, phenolic epoxy resin and multifunctional epoxy resin.

[0043] In some embodiments, the elastomer includes any one or more of acrylic rubber, butadiene rubber, styrene-butadiene rubber and nitrile rubber.

[0044] In some embodiments, the curing agent includes any one or both of an amine curing agent and an acid anhydride curing agent.

[0045] In some embodiments, the flame retardant filler includes any one or more of inorganic metal oxides, phosphorus-based flame retardants, nitrogen-based flame retardants and halogen-containing flame retardants.

[0046] In some embodiments, the silane coupling agent includes any one or both of epoxy silane and isocyanate silane.

[0047] In some of the embodiments, a proper amount of solvent is further included, and the solvent includes any one or two of butanone, cyclohexanone, cyclohexane, toluene, dimethylformamide, dimethylacetamide and n-hexane.

[0048] In a second aspect, an embodiment of the present invention provides an application of a low shrinkage resin composition in a flexible printed circuit substrate.

[0049] Compared with the prior art, the present invention has at least the following beneficial effects:

[0050] The present invention adds an expansion monomer resin to the resin composition, and the expansion monomer resin undergoes a ring-opening reaction during the cross-linking reaction with the epoxy resin, and the volume expands by 2%-5%, which offsets the volume shrinkage of the epoxy resin during curing, thereby making the curing shrinkage rate of the adhesive layer close to 0. At the same time, the curing shrinkage of the epoxy resin will inevitably generate internal stress, resulting in a decrease in the strength of the adhesive layer. The present invention uses the expansion monomer resin to copolymerize with the epoxy resin, reduces the curing shrinkage rate, reduces the internal stress generated by curing, and improves the mechanical properties of the material; and the present invention reduces the amount of elastomer used to effectively improve the aging resistance of the adhesive layer. DETAILED DESCRIPTION

[0051] In order to make the above-mentioned purpose, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0052] As used herein, the term "prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0053] When amount, concentration or other value or parameter is expressed as range, preferred range or a series of upper preferred value and lower preferred value limit range, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value and any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when disclosing range "1 to 5", described range should be interpreted as including range "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5" etc. When numerical range is described in this article, unless otherwise stated, the range is intended to include its end value and all integers and fractions within the range.

[0054] In addition, the indefinite articles "a" and "an" before the elements or components of the present invention have no restrictions on the quantity requirements (i.e. the number of occurrences) of the elements or components. Therefore, "a" or "an" should be interpreted as including one or at least one, and the elements or components in the singular form also include the plural form, unless the number is obviously intended to be in the singular form.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0056] Preparation of expansion monomer resin:

[0057] Add 24.9 g (0.1 mol) of dibutyltin oxide and 13.4 g (0.1 mol) of trimethylolpropane into a three-necked flask, and then add 38.3 g of toluene solution; connect a water separator and a condenser to the three-necked flask, and heat to 120°C under electromagnetic stirring for 12 hours;

[0058] After the reactants were cooled to room temperature, 8 ml (0.13 mol) of carbon disulfide was slowly added, and the temperature was raised to 100 °C for 12 h.

[0059] The toluene in the reactant was removed by distillation under reduced pressure, and the product was washed with n-ethane three times. The remaining reactant was recrystallized with toluene and dried to obtain a white solid powder (DDTU), i.e., the intermediate.

[0060] Take 26.4g (0.1mol) of the intermediate and 25.03g (0.1mol) of diphenylmethane diisocyanate and add them to a flask containing 51.4g of chloroform, stir and dissolve, react at 35°C for 24h, raise the temperature to 70°C and evaporate the chloroform to obtain a yellow solid powder (DDTU-M), i.e., the expandable monomer resin.

[0061] Table 1 Raw material components of Examples 1 to 4 and Comparative Example 1

[0062]

[0063]

[0064] EMTE638: Epoxy resin produced by Shandong Aimonte New Materials Co., Ltd.;

[0065] NPES-901: Epoxy resin produced by Nan Ya Plastics Co., Ltd.

[0066] XER-32: Elastomer produced by JSR Corporation of Japan;

[0067] Ethylamine boron trifluoride is produced for Macklin's reagent;

[0068] OP935: Flame retardant filler produced by Clariant;

[0069] KBM-603 is a coupling agent produced by Shin-Etsu of Japan.

[0070] Performance Test:

[0071] The raw materials were weighed according to the mass percentage of the raw material components, mixed evenly, and then coated on a 25um polyimide film (dry film thickness 20um). After surface drying, a 35um rolled copper foil was attached. After curing, peel strength test, volume expansion test, solder resistance and flame retardancy test were performed. The test results are shown in Table 2 below.

[0072] Table 2 Performance test results of Examples 1 to 4 and Comparative Example 1

[0073]

[0074] It can be seen from Table 2 that after adding the expansion monomer resin, Examples 1 to 4 can achieve low volume shrinkage and good dimensional stability; while compared with Example 3, Comparative Example 1 does not add the expansion monomer resin and increase the amount of elastomer, and its volume change is significantly worse than that of Example 3, and the high content of elastomer will lead to poor aging resistance.

[0075] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0076] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A low shrinkage resin composition, characterized in that The raw material components include the following by mass percentage: Expanded monomer resin 10% to 25%; Epoxy resin 35%~45%; Elastomer 10% to 20%; Curing agent 1% to 5%; Flame retardant filler 19% to 30%; Silane coupling agent 0.1% to 1%; The expandable monomer resin includes any one or more of spiro orthoesters and their derivatives, spiro orthocarbonates and their derivatives, bicyclic orthoesters and their derivatives, and ketal lactones and their derivatives.

2. The low shrinkage resin composition according to claim 1, characterized in that The raw material components include the following by mass percentage: Expanded monomer resin 15% to 20%; Epoxy resin 40%~45%; Elastomer 10% to 19%; Curing agent 2% to 5%; Flame retardant filler 19% to 30%; Silane coupling agent 0.1%~1%.

3. The low shrinkage resin composition according to claim 1, characterized in that The expandable monomer resin is made from the following raw materials in parts by mass: 20 to 30 parts of intermediate, 20 to 30 parts of diphenylmethane diisocyanate; The intermediate is made from the following raw materials in percentage by mass: Trimethylolpropane 25% to 30%; Dibutyltin oxide 48% to 53%; Carbon disulfide 19%~24%.

4. The low shrinkage resin composition according to claim 3, characterized in that The expandable monomer resin is made from the following raw materials in parts by mass: 26.4 parts of intermediate, 25.03 parts of diphenylmethane diisocyanate; The intermediate is made from the following raw materials in percentage by mass: Trimethylolpropane 27.7%; Dibutyltin oxide 51.4%; Carbon disulfide 20.9%.

5. The low shrinkage resin composition according to claim 3 or 4, characterized in that: The expanded monomer resin is prepared by the following steps: Step 1, heating trimethylolpropane, dibutyltin oxide and toluene solution to 115° C. to 125° C. under electromagnetic stirring for 11 h to 13 h; Step 2: After the reactant in step 1 is cooled to room temperature, carbon disulfide is added, and then the temperature is raised to 95°C to 105°C for reaction for 11h to 13h; Step 3, distilling and washing the reactant in step 2 under reduced pressure to remove toluene, and then recrystallizing and drying the remaining reactant to obtain an intermediate; Step 4: add the intermediate of step 3 and diphenylmethane diisocyanate into chloroform, stir and dissolve, react at 33° C. to 37° C. for 22 h to 26 h, heat to 70° C. to evaporate the chloroform, and obtain an expanded monomer resin.

6. The low shrinkage resin composition according to claim 5, characterized in that The expanded monomer resin is prepared by the following steps: Step 1, heating trimethylolpropane, dibutyltin oxide and toluene solution to 120° C. under electromagnetic stirring for 12 hours; Step 2: After cooling the reactant in step 1 to room temperature, add carbon disulfide, and then heat to 100° C. to react for 12 hours; Step 3, distilling and washing the reactant in step 2 under reduced pressure to remove toluene, and then recrystallizing and drying the remaining reactant to obtain an intermediate; Step 4: add the intermediate of step 3 and diphenylmethane diisocyanate into chloroform, stir and dissolve, react at 35° C. for 24 hours, heat to 70° C. and evaporate the chloroform to obtain an expanded monomer resin.

7. The low shrinkage resin composition according to claim 1, characterized in that The invention can be any one or more of the bisphenol A epoxy resin, bisphenol F epoxy resin, biphenyl epoxy resin, DCPD epoxy resin, phenoloxy epoxy resin, novolac epoxy resin and multifunctional epoxy resin.

8. The low shrinkage resin composition according to claim 1, characterized in that The elastomer includes any one or more of acrylic rubber, butadiene rubber, styrene-butadiene rubber and nitrile rubber; The curing agent includes any one or both of an amine curing agent and an acid anhydride curing agent; The flame retardant filler includes any one or more of inorganic metal oxides, phosphorus flame retardants, nitrogen flame retardants and halogen-containing flame retardants; The silane coupling agent includes any one or both of epoxy silane and isocyanate silane.

9. The low shrinkage resin composition according to claim 1, characterized in that The method further comprises a proper amount of solvent, wherein the solvent comprises any one or two of butanone, cyclohexanone, cyclohexane, toluene, dimethylformamide, dimethylacetamide and n-hexane.

10. Use of the low shrinkage resin composition according to any one of claims 1 to 9 in a flexible printed circuit substrate.

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