WO2019015335A1 - Transparent sla photosensitive resin composition - Google Patents

Abstract

The invention discloses a transparent SLA photosensitive resin composition, which uses polycarbonate diol as a modified toughening agent, and the amount thereof is 3-15% of the total weight of the resin, and further comprises the following mass percentage components: cationic photocuring The composition is 45 to 70%, the radical photocuring component is 20 to 40%, the cationic photoinitiator is 2 to 10%, and the radical photoinitiator is 1 to 8%. The use of polycarbonate diol as a toughening agent of the system in the present invention can well balance the water absorption, transparency and impact strength without affecting the mechanical tensile strength of the system. No bubbles are generated during the process, the parts have low water absorption, good toughness and transparency, and can well meet the requirements of customers for the construction of transparent parts.

Description

Transparent SLA photosensitive resin composition [Technical Field]

The present invention relates to a transparent SLA photosensitive resin composition.

【Background technique】

The material used for photocuring rapid prototyping is a liquid photocurable resin, or liquid photosensitive resin, mainly composed of an oligomer, a photoinitiator, and a diluent. In the past two years, photosensitive resin is being used in the emerging industry of 3D printing, which is favored and valued by the industry because of its excellent characteristics.

In the prior art, if a transparent SLA photosensitive resin is desired to have good impact strength, it is generally required to add a polyol as a toughening agent in the formulation system, and problems such as system compatibility and poor hydrolysis resistance of the polyol are poor. In general, the introduction of polyester, polyether or polycaprolactone polyols leads to a decrease in transparency of the system and an increase in water absorption, which in turn leads to fogging of the article, deterioration in durability and dimensional stability.

The present invention has been developed based on the deficiencies of the above products and the deficiencies of the prior art.

[Summary of the Invention]

The object of the present invention is to overcome the deficiencies of the prior art and provide a transparent SLA photosensitive resin composition with good transparency and good mechanical tensile strength and impact strength, which is suitable for use in 3D printing, photocurable coatings or photoresists. .

In order to achieve the above object, the present invention adopts the following technical solutions:

A transparent SLA photosensitive resin composition characterized by using a polycarbonate diol as a modified toughening agent, and its structural formula is as follows:

Wherein n=1-7, wherein the structural formula of R ₁ , R ₂ is selected from one of the following:

Where m=1-5;

The polycarbonate diol is used in an amount of from 3 to 15% by weight based on the total weight of the resin.

Compared with other kinds of polyols, such as polyester polyols, polycaprolactone polyols or polytetrahydrofuran polyols, the polycarbonate diol has water resistance in the molecular structure compared to the ester group. The solution performance is more excellent, and the acid-base resistance and ultraviolet resistance of the ether bond in the polytetrahydrofuran polyol are better, and in the SLA 3D printing, the cationic photoinitiator used is a strong acid type material, and the resin needs to be long. The time is operated under ultraviolet irradiation conditions. Therefore, the toughening modification using polyester, polycaprolactone or polytetrahydrofuran polyol may cause molecular chain breakage or other side reactions of the resin material due to ultraviolet radiation. The production is not conducive to the stability of the performance of the workpiece, and the hydrolysis of the ester group under the strong acid condition directly leads to an increase in the polar groups in the workpiece, and the water absorption rate of the workpiece is increased, thereby causing the durability of the workpiece to be lowered, which is disadvantageous to the Late application.

The transparent SLA photosensitive resin composition of the present invention is characterized by comprising the following mass percentage components:

Further, the transparent SLA photosensitive resin composition of the present invention is characterized by comprising the following mass percentage components:

The cationic photocurable component in the present invention is one or more of a glycidyl ether epoxy resin, a glycidyl ester epoxy resin, an alicyclic epoxy resin, and a vinyl ether monomer. Preferred is bisphenol A glycidyl ether (NPEL-128), hydrogenated bisphenol A glycidyl ether (0575), 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexylformate (TTA21), double One or more of (7-oxabicyclo[4.1.0]3-heptylmethyl) adipate (TTA26).

The radical photocuring component in the present invention is composed of an acrylate monomer and a prepolymer thereof. Preferred are epoxy acrylate (CN104NS), trimethylolpropane triacrylate (SR351), polyethylene glycol 400 dimethacrylate (SR644), 1,6-hexanediol diacrylate (SR238TFN), three One or more of cyclopentane dimethanol diacrylate (SR833S), (2) ethoxylated bisphenol A dimethacrylate (SR348L NS).

The cationic photoinitiator of the present invention is preferably a propylene carbonate solution (CPI) of liquid hexafluoroantimonate (TR-PAG-20002) and 50% diphenyl-(4-phenylthio)phenylphosphonium hexafluoroantimonate. One or two of -101A).

The radical luminescent initiator in the present invention is preferably 1-hydroxy-cyclohexyl-phenyl ketone (Irgacure 184), 2-hydroxy-2-methyl-1-phenyl-1-propanone (Daracur 1173), diphenyl One or more of (2,4,6-trimethylbenzoyl)phosphorus oxide (Lucirin TPO).

The modified toughening agent in the present invention is preferably a polycarbonate diol BH-100 (wherein R1, R2 structures are respectively shown in Chemical Formulas (1) and (3), n≈3); Polycarbonate diol PH-50 (R1, R2 structures are shown in Chemical Formulas (1) and (2), respectively, n≈1); Polycarbonate diol UHC-50-200 (R1, R2 structural formulas are shown in Chemical Formulas (1) and (5), respectively, m = 2, n ≈ 4); one of the polycarbonate diols UM-90 (1/1) (wherein the structures of R1 and R2 are respectively shown in the chemical formulae (1) and (4), n ≈ 3).

The toughening agents currently used in the market are also a polyester polyol (CMA-1044) based on butanediol-adipic acid, a polycaprolactone polyol (PCL303T), and a polytetrahydrofuran polyol (PTMG1000). .

When the transparent SLA photosensitive resin composition of the present invention is prepared, the raw material components may be uniformly mixed and stirred at room temperature (20-40 ° C).

Compared with the prior art, the present invention has the following advantages:

The use of polycarbonate diol as a toughening agent of the system in the present invention can well balance the water absorption, transparency and impact strength without affecting the mechanical tensile strength of the system. No bubbles are generated during the process, the parts have low water absorption, good toughness and transparency, and can well meet the requirements of customers for the construction of transparent parts.

【Detailed ways】

The invention will be further described in more detail below with reference to specific embodiments.

Table 1: Percentage of each component of Examples A-G

Table 2: Percentage of each component of Example H-K and Comparative Examples 1-4

For the example AK, the comparative examples 1-4 were tested, and the test results are shown in Table 3, wherein: the test of the critical exposure energy E _c and the curing depth D _p :

SLA 3D printer used, in _L, the laser scanning interval _s where laser power P h is known, using different laser scanning speed V _s, for single scan curing to obtain a different thickness C _d of the sample, according to the equation C _d = D _p ln[P _L /(V _s *h _s )]-D _p lnE _c , and draw a corresponding straight line, wherein the solidification depth D _p and the critical exposure energy E _c can be obtained by the slope and slope of the straight line.

Work fill scan rate:

Scanning and curing were carried out using a SLA 3D printer at a fixed power P _L = 280 mW, taking the liquid material into a shape that can be solidified, and the maximum fill scan rate that can be removed for cleaning is the working fill scan rate of the material. The indicator directly reflects the curing rate of the photosensitive material, wherein the higher the working filling scanning rate of the material, the higher the molding efficiency of the material, and the time required for constructing the same part in the SLA 3D printer is greatly shortened. Greatly improve work efficiency and reduce time cost.

Test of tensile strength and tensile modulus:

According to the standard ASTM D638, using a computer-type tensile testing machine (Dongguan Kejian KJ-1065);

Shore hardness D test:

Measured according to standard ASTM D2240 using Shore Hardness Tester D-0-100HD; Notched Impact Strength Test:

According to the standard ASTM D256, it was measured using a digital pendulum impact tester (Dongguan Kejian KJ-3090).

Transparency test:

Self-made test method, take 15±0.2g liquid resin into PP plastic cup, let it stand until no bubble, then put it into UV curing chamber for 20min, take it upside down and then irradiate it for 20min, and carry it with standard 1cm thick PMMA board. Transparency comparison, where the standard PMMA board transparency is set to 5.

Table 3: Comparison of detailed test results of Examples A-H and Comparative Examples 1-4

It can be seen from the performance indexes in Table 3 that the SLA photosensitive resin of the embodiment AK of the present invention is superior to the comparative example in transparency, and the water absorption rate thereof is low, and the dimensional stability of the workpiece during use can be effectively ensured. And the mechanical strength is maintained, its mechanical tensile strength and toughness are also excellent, and the contradiction between strength, toughness and water absorption is well balanced, which can effectively meet the performance requirements of transparent resin materials in SLA3D printing. . In summary, the transparent photosensitive resin of the present invention has a relatively large improvement over the prior art, and is worthy of popularization and application.

The embodiments described above are merely illustrative of the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Variations and modifications are intended to fall within the scope of the invention as defined by the appended claims.

Claims (7)

A transparent SLA photosensitive resin composition characterized by using a polycarbonate diol as a modified toughening agent, and its structural formula is as follows:

Wherein n=1-7, wherein the structural formula of R ₁ , R ₂ is selected from one of the following:

Where m=1-5, The polycarbonate diol is used in an amount of from 3 to 15% by weight based on the total weight of the resin. The transparent SLA photosensitive resin composition according to claim 1, which comprises the following mass percentage components:

The transparent SLA photosensitive resin composition according to claim 2, which comprises the following mass percentage components:

The transparent SLA photosensitive resin composition according to claim 2 or 3, wherein the cationic photocurable component is a glycidyl ether epoxy resin, a glycidyl ester epoxy resin, or an alicyclic epoxy resin. And one or more of vinyl ether monomers. The transparent SLA photosensitive resin composition according to claim 2 or 3, wherein the radical photocuring component is composed of an acrylate monomer and a prepolymer thereof. The transparent SLA photosensitive resin composition according to claim 2 or 3, wherein the cationic photoinitiator is selected from the group consisting of liquid hexafluoroantimonate and 50% diphenyl-(4-phenylthio)phenyl group. One or both of propylene carbonate solutions of hexafluoroantimonate. The transparent SLA photosensitive resin composition according to claim 2 or 3, wherein the radical initiator is selected from the group consisting of 1-hydroxy-cyclohexyl-phenyl ketone, 2-hydroxy-2-methyl-1- One or more of phenyl-1-propanone, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide.