JP2010168453A - Method for producing cured product and cured product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a cured product that solves a problem, such as embrittlement or an increase in a curing shrinkage rate associated with establishment of stronger crosslinking structure. <P>SOLUTION: In the method for producing a cured product, a compound (a) having an organic group including a radically polymerizable carbon-carbon double bond and a hydrosilyl group in a molecule is radically polymerized and primarily cured while having the hydrosilyl group, and the resultant primarily cured product is brought into contact with a basic aqueous solution to conduct dehydrocondensation of the hydrosilyl group. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for obtaining a cured product by radical polymerization of a compound having a carbon-carbon double bond and a hydrosilyl group, followed by dehydrogenative condensation, and a cured product obtained thereby.

  A compound having a carbon-carbon double bond such as a vinyl group, a (meth) acryl group, or an allyl group undergoes radical polymerization by applying energy such as heat, ultraviolet rays, and electron beams in the presence of a radical polymerization initiator. It is used in various fields. In a compound having a plurality of carbon-carbon double bonds in the molecule, a three-dimensional crosslinked structure is constructed by radical polymerization, and a cured product having excellent heat resistance, mechanical properties, and chemical resistance is obtained. The obtained cured product includes, for example, a display front protective plate such as a liquid crystal television, a liquid crystal polarizing film, a retardation film, and other glass materials such as a touch panel substrate, a color filter substrate, and a TFT substrate. Lens materials for spectacles, prisms, imaging optical systems such as cameras, projection optical systems such as display devices, observation optical systems such as image display devices, laser optical systems such as magneto-optical disk drives, lenses used for waveguides, etc. These optical elements are used as various films and molded products, and are also being used as glass substitute materials.

  The characteristics of such a cured product mainly depend on the concentration of carbon-carbon double bonds in the resin. By making the concentration of carbon-carbon double bonds high, a stronger crosslinked structure can be constructed, The expansion coefficient can be reduced and the elastic modulus can be improved. For example, from a laminate (see Patent Document 1) obtained using an ethylenically unsaturated compound modified with a (meth) acrylic group, or a curable composition using an ethylenically unsaturated compound having an isocyanurate skeleton. A method for obtaining a plastic film excellent in surface hardness (see Patent Document 2) has been reported.

  However, when the crosslink density by the carbon-carbon double bond is increased, there is a problem that the curing shrinkage rate is remarkably increased and the obtained cured product becomes brittle. In addition, the residual stress due to curing shrinkage increases, and the curing rate is accelerated by the polymerization heat generated during the polymerization, and the rapid curing proceeds, so that cracks occur during the curing and a thick cured product is obtained. Becomes difficult.

  Therefore, conventionally, in order to produce a cured product, it is necessary to take a method of gradually curing by heating for a long time. The same applies to the case of using ultraviolet rays or electron beams for curing, and it is not desirable in terms of production efficiency because it is necessary to perform exposure for a long time with a weak illuminance. In addition, when the concentration of carbon-carbon double bonds is increased, many unreacted carbon-carbon double bonds that cannot fully participate in polymerization remain in the cured product, and as a result, unreacted carbon-carbon double bonds. Bonding causes oxidative degradation due to heating, leading to a decrease in transparency and mechanical properties. In particular, in the case of a (meth) acryl group, the water absorption rate of the cured product increases as the polar group increases.

JP 2005-125142 A JP 2006-225434 A

  Then, the objective of this invention is providing the novel method which can increase the crosslinking density of hardened | cured material, without relying on the density | concentration increase of a carbon-carbon double bond. Another object of the present invention is to provide a cured product that solves the trade-off problems such as embrittlement and increased cure shrinkage associated with the construction of a stronger crosslinked structure.

  As a result of repeated studies to solve the above-mentioned problems, the present inventors radically polymerized a compound having a carbon-carbon double bond and a hydrosilyl group, and included in the obtained polymer (primary cured product). The present inventors have found that by forming a siloxane bond using the hydrosilyl group thus produced, the crosslinking density can be increased without relying on an increase in the carbon-carbon double bond, and the present invention has been completed.

  That is, in the present invention, a compound a having an organic group containing a carbon-carbon double bond capable of radical polymerization in the molecule and a hydrosilyl group is subjected to radical polymerization to be primarily cured in a state having a hydrosilyl group, It is a manufacturing method of the hardened | cured material characterized by making the obtained primary hardened | cured material contact basic aqueous solution, and dehydrocondensing a hydrosilyl group.

  In addition, the present invention provides a compound a having an organic group containing a carbon-carbon double bond capable of radical polymerization in the molecule and a hydrosilyl group, and is primarily cured in a state having a hydrosilyl group by radical polymerization. It is a cured product obtained by contacting the obtained primary cured product with a basic aqueous solution to dehydrocondense a hydrosilyl group.

  Regarding the compound a used in the present invention, the organic group having a carbon-carbon double bond capable of radical polymerization is preferably a vinyl group, an allyl group, or a (meth) acryl group. This “compound a having an organic group having a carbon-carbon double bond capable of radical polymerization in the molecule and a hydrosilyl group” is not particularly limited, and may be appropriately selected according to the purpose and use of the obtained cured product. However, from the viewpoint of heat resistance and transparency, a silicon compound monomer, silicon compound oligomer, or silicon compound polymer having a number average molecular weight of 100 to 250,000 is preferable. In addition, the number of carbon-carbon double bonds and the number of hydrosilyl groups in compound a are preferably the molecular weight per carbon-carbon double bond (the molecular weight of compound a divided by the number of carbon-carbon double bonds). The molecular weight per hydrosilyl group (the value obtained by dividing the molecular weight of the compound a by the number of hydrosilyl groups) is preferably 25 to 1000, more preferably carbon-carbon dioxygen. The molecular weight per heavy bond should be 150 to 5000, and the molecular weight per hydrosilyl group should be 50 to 1000. When the molecular weight per carbon-carbon double bond is smaller than 100, the curing shrinkage becomes large and it is difficult to obtain a cured product. Conversely, when the molecular weight per carbon-carbon double bond is larger than 5000, A sufficient cross-linked structure is not constructed, and the cured product becomes brittle. On the other hand, if the molecular weight per hydrosilyl group is less than 25, the cured product may shrink due to dehydrogenative condensation, and the cured product may be damaged. On the other hand, the molecular weight per hydrosilyl group is greater than 1000. In this case, the effect of increasing the crosslinking density by dehydrogenative condensation cannot be fully exhibited.

  For compound a, specifically, monosilanes such as 3- (meth) acryloxypropylmethylsilane, 2- (meth) acryloxyethoxydimethylsilane, bis (2- (meth) acryloxyethoxy) methylsilane, and chain siloxane Siloxanes, cyclic siloxanes, caged siloxanes, incompletely condensed caged siloxanes, ladder type siloxanes, incompletely condensed ladder type siloxanes, and siloxanes obtained by combining and condensing these siloxanes. . Use of these compounds a is preferable in that the heat resistance of the resulting cured product can be improved.

  In the present invention, in addition to “the compound a having an organic group having a carbon-carbon double bond capable of radical polymerization in the molecule and a hydrosilyl group”, a “carbon-carbon double bond capable of radical polymerization in the molecule”. The primary cured product may be obtained by radical polymerization in a state containing the compound b ”. Here, examples of the compound b include monofunctional (meth) acrylate monomers, polyfunctional (meth) acrylate monomers, polyfunctional (meth) acrylate oligomers, vinyl ethers, vinyl esters, and the like.

  Further, in the present invention, preferably, the compound b has a hydroxyl group in addition to the carbon-carbon double bond. Specifically, hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate, and hydroxyl-containing polyfunctional acrylates such as glycerin di (meth) acrylate and pentaerythritol triacrylate , Hydroxyl group-containing vinyl ethers, hydroxyl group-containing allyl ethers, and the like. The compound b having such a carbon-carbon double bond and a hydroxyl group can be dehydrogenatively condensed with the hydrosilyl group of the compound a, and the crosslinking density can be improved. About the compounding ratio of "compound b having a carbon-carbon double bond and a hydroxyl group capable of radical polymerization in the molecule" and "compound a", depending on the use of the obtained cured product, that is, an improvement in elastic modulus It is preferable to increase the compounding ratio of the compound b for the purpose of improving the thermal dimensional stability (decreasing the thermal expansion coefficient), etc., but the number of hydrosilyl groups of the compound a is more than the number of hydroxyl groups of the compound b. It is desirable to increase it. If the number of hydroxyl groups increases, as will be described later, hydroxyl groups remain in the dehydrogenative condensation using hydrosilyl groups, and the water absorption of the finally obtained cured product may increase.

  In the method for producing a cured product in the present invention, radical polymerization of the compound a (which may further include the compound b) (in some cases, radical copolymerization with the compound a when the compound b is included) is described below. In some cases, it is sometimes referred to as “radical (co) polymerization”.), Thereby causing primary curing in a state including a hydrosilyl group (Si—H group). Subsequently, the obtained primary cured product is brought into contact with an aqueous base solution to form a siloxane bond by dehydrogenative condensation using a hydrosilyl group to obtain a final cured product. That is, the primary cured product is reacted with a base aqueous solution to convert at least a part of the hydrosilyl group into a silanol group (Si-OH group), and then a base is formed between the remaining hydrosilyl group and the converted silanol group. Dehydrogenative condensation occurs, and a siloxane bond is generated to increase the crosslink density. Further, when the compound b having a carbon-carbon double bond and a hydroxyl group is included, dehydrogenative condensation occurs between the hydroxyl group of the compound b and the hydrosilyl group of the primary cured product, and a silicon-oxygen-carbon bond is generated. This increases the crosslink density. Thus, if the manufacturing method of the hardened | cured material of this invention is used, a crosslinking density can be raised, without increasing the number of carbon-carbon double bonds, and it was difficult until now to make high crosslinking density high. This makes it possible to produce a cured product that suppresses the accompanying embrittlement and the increase in cure shrinkage.

  In the method for producing a cured product in the present invention, a primary cured product may be obtained using a curable resin composition containing at least compound a (which may contain compound b) and a radical polymerization initiator. Good. As the radical polymerization initiator, a known photopolymerization initiator or thermal polymerization initiator can be used, and the blending amount is in the range of 0.1 to 5 parts by weight with respect to 100 parts by weight of the curable resin composition. It is good that it is in the range of 0.1 to 3 parts by weight. If the radical polymerization initiator is less than 0.1 parts by weight, curing is insufficient, and the strength and rigidity of the resulting cured product are reduced. On the other hand, if it exceeds 5 parts by weight, problems such as coloring of the cured product may occur. There is.

  As the photopolymerization initiator used when the curable resin composition is a photocurable composition, it is preferable to use an acetophenone-based, benzoin-based, benzophenone-based, thioxanthone-based, acylphosphine oxide-based compound, or the like. it can. Specifically, trichloroacetophenone, diethoxyacetophenone, 1-phenyl-2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- (4-methylthiophenyl) -2 -Morpholinopropan-1-one, benzoin methyl ether, benzyldimethyl ketal, benzophenone, thioxanthone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, methylphenylglyoxylate, camphorquinone, benzyl, anthraquinone, Michler's ketone, etc. it can. Moreover, the photoinitiator adjuvant and the sharpening agent which show an effect in combination with a photoinitiator can also be used together.

  The thermal polymerization initiator used when the curable resin composition is a thermosetting composition includes ketone peroxides, diacylalkyl peroxides, hydroperoxides, dialkyl peroxides, and peroxyketals. , Alkyl peresters, percarbonates and the like. Among these, dialkyl peroxide is preferable from the viewpoint of catalytic activity. Specifically, cyclohexanone peroxide, 1,1-bis (t-hexaperoxy) cyclohexanone, cumene hydroperoxide, dicumyl peroxide, benzoyl peroxide, diisopropyl peroxide, di-t-butyl peroxide, t -Hexylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexanoate and the like can be exemplified, but are not limited thereto. Moreover, these may be used independently and may use two or more types of thermal polymerization initiators together. Furthermore, a thermal polymerization accelerator or a photopolymerization initiator can be used in combination.

  Various additives can be added to the curable resin composition within a range not departing from the object of the present invention. Various additives include organic / inorganic fillers, plasticizers, flame retardants, heat stabilizers, antioxidants, light stabilizers, UV absorbers, lubricants, antistatic agents, mold release agents, foaming agents, nucleating agents, colorants, Crosslinking agents, dispersion aids, resin components and the like can be exemplified.

  In the present invention, the primary cured product having a hydrosilyl group can be obtained, for example, by curing a curable resin composition containing a radical polymerization initiator by heating or light irradiation. Among these, when a polymer (or copolymer) is obtained by heating, the polymerization temperature can be selected from a wide range from room temperature to around 200 ° C., depending on the selection of a thermal polymerization initiator and an accelerator. At this time, a primary cured product having a desired shape may be obtained by polymerizing and curing the curable resin composition in a mold or on a steel belt.

  On the other hand, when a polymer (or copolymer) is obtained by light irradiation, primary curing can be performed by, for example, irradiating ultraviolet rays in the wavelength range of 10 to 400 nm or visible rays in the wavelength range of 400 to 700 nm. The wavelength of the light to be used is not particularly limited, but near ultraviolet light having a wavelength of 200 to 400 nm is particularly preferably used. In addition, lamps used as ultraviolet light sources include low-pressure mercury lamps (output: 0.4 to 4 W / cm), high-pressure mercury lamps (40 to 160 W / cm), ultra-high pressure mercury lamps (173 to 435 W / cm), metal halide lamps. (80 to 160 W / cm), pulse xenon lamp (80 to 120 W / cm), electrodeless discharge lamp (80 to 120 W / cm), and the like. Each of these ultraviolet lamps is characterized by its spectral distribution, and is therefore selected according to the type of photopolymerization initiator used.

  When obtaining a primary cured product having a hydrosilyl group by light irradiation, for example, the curable resin composition is injected into a mold having an arbitrary cavity shape and made of a transparent material such as quartz glass. A primary cured product having a desired shape can be obtained by irradiating ultraviolet rays with such an ultraviolet lamp to perform polymerization and curing, and removing the mold from the mold. When a mold is not used, for example, a curable resin composition is applied on a moving steel belt using a doctor blade or a roll-shaped coater, and polymerized and cured with an ultraviolet lamp as described above, A sheet-like primary cured product can be obtained. Furthermore, the primary cured product having a hydrosilyl group is subjected to a stretching process such as uniaxial stretching or biaxial stretching, and the primary cured product is processed into an arbitrary shape such as a film or sheet and treated with an aqueous base solution. (It is also the same in the case of curing by heat or the like).

  As already described in part, when a primary cured product is obtained, it is preferable that the curable resin composition has a predetermined shape so as to be a target cured product and is radical (co) polymerized. Here, when the obtained primary cured product is thermoplastic, various molding methods such as injection molding, extrusion molding, extrusion laminate molding, compression molding, hollow molding, calendar molding, vacuum molding, and T-die method can be employed. . However, when the number of carbon-carbon double bonds per molecule of compound a or compound b exceeds 1.0, a (co) polymer having a three-dimensional cross-linked structure is formed, so that usually molding hardening is adopted. Is done. In the present specification, radical (co) polymerization is also referred to as curing. For radical (co) polymerization, heating or irradiation with an energy beam such as an electron beam or an ultraviolet ray is suitable.

  Further, when the obtained primary cured product is brought into contact with a basic aqueous solution to dehydrocondense the hydrosilyl group, the base of the aqueous base solution is not particularly limited as long as it dissolves in water. Examples of bases include alkali metal hydroxides such as potassium hydroxide, sodium hydroxide, cesium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, benzyltrimethylammonium hydroxide, water Examples thereof include ammonium hydroxide salts such as benzyltriethylammonium oxide, hydroxylamine compounds such as hydroxylamine, N-methylhydroxylamine, N, N-dimethylhydroxylamine, N-ethylhydroxylamine, N, N-diethylhydroxylamine and the like.

  The concentration of the aqueous base solution is preferably in the range of 0.05 to 2.0 mol / L. If the base concentration is too dilute, it takes a long time for complete dehydrogenation condensation. On the other hand, if the concentration is too high, siloxane bonds and the like are broken, and the mechanical properties of the resulting cured product deteriorate. As a method for bringing the primary cured product into contact with the aqueous base solution, known methods such as dipping, spraying, showering and the like can be used. Among them, a method of immersing the primary cured product in the aqueous base solution is preferable. The immersion time varies depending on the number of hydrosilyl groups remaining in the primary cured product and the aqueous base solution to be used, but it is better to check the progress of dehydrogenative condensation with the amount of hydrogen generated from the primary cured product. In order to condense, it is preferable to immerse until generation | occurrence | production of hydrogen from a primary cured material is not recognized. In addition, since dehydrogenative condensation proceeds from the position where the primary cured product is in contact with the aqueous base solution, the crosslinking density can be partially increased by changing the dipping method. For example, the immersion time may be shortened to increase the crosslinking density only on the surface of the primary cured product. Furthermore, it is also possible to use gradient materials having different crosslink densities from the surface to the center of the finally obtained cured product, and the immersion conditions may be changed according to the use of the obtained cured product.

  After contact with the aqueous base solution, it is desirable to perform post-treatment for the purpose of removing impurities from the primary cured product and improving dimensional stability over time. As such post-treatment, for example, the primary cured product may be washed with water to remove the base, and dehydrogenative condensation by contact with an aqueous base solution is incomplete, and the hydrosilyl group may remain as a silanol group. Since it has the property, you may make it heat-process after washing with water. About this heat processing, it is preferable to heat for 1 hour or more in the temperature range of 100 to 300 degreeC, More preferably, it is good to heat for 1 to 3 hours in the temperature range of 180 to 250 degreeC.

  The cured product obtained by the present invention can be obtained in various states, for example, from a film to a thick plate, depending on the molding conditions during the primary curing, and the shape after curing is not particularly limited. Therefore, it is used as a glass substitute substrate for display front protective plates for liquid crystal televisions, liquid crystal polarizing films, retardation films, etc., as well as for touch panel substrates, color filter substrates, TFT substrates, and for eyeglass lens materials. Various types of optical elements such as lenses, prisms, imaging optical systems such as cameras, projection optical systems such as display devices, observation optical systems such as image display devices, laser optical systems such as magneto-optical disk drives, and lenses used in waveguides, etc. Applicable for use.

  According to the method for producing a cured product in the present invention, a cured product having a strong cross-linked structure can be obtained without relying on an increase in the concentration of carbon-carbon double bonds in the monomer. Problems such as an increase in cure shrinkage and embrittlement due to an increased crosslinking density can be solved. Therefore, the obtained cured product is intended to simultaneously reduce the coefficient of thermal expansion, improve the elastic modulus, suppress the curing shrinkage, prevent brittleness, etc., and the production method of the present invention is a conventional method. Then, it is also a suitable method for obtaining a thick cured product in which the occurrence of cracks is a concern.

  Furthermore, the method for producing a cured product of the present invention is an industrially advantageous method because a primary cured product is obtained in a state having a hydrosilyl group and a siloxane bond is formed by dehydrogenative condensation using an aqueous base solution. It can be said that there is. That is, when obtaining a primary cured product, instead of using a compound having a Si—OH group, which is difficult to control due to the risk of gelation or dehydration condensation reactivity, a compound a having a Si—H group is used. This is an excellent method from the viewpoint of handleability because it is used to obtain a primary cured product and then a part of Si—H groups is converted to Si—OH groups.

FIG. 1 is a 1H-NMR spectrum of reaction product A obtained in Synthesis Example 1. FIG. 2 is an IR spectrum of the molded product A-1a (primary cured product) obtained in Example 1.

  Hereinafter, based on an Example and a comparative example, the present invention is explained more concretely.

[Synthesis Example 1]
In a reaction vessel equipped with a stirrer, a dropping funnel, and a thermometer, 45-50 mol% (MeHSiO) hydrogenated terminal methylhydrosiloxane-phenylmethylsiloxane copolymer (HPM-502, manufactured by Gelest, Inc.) weight average molecular weight: 4300 ) 28.3 g and 13 mL of toluene were added and stirred until homogeneous. Next, 0.12 g of N, N-diethylhydroxylamine was added and stirred for 20 minutes at room temperature, and 1.89 g of 2-hydroxyethyl methacrylate was added dropwise from the dropping funnel and stirred for 2 hours at room temperature. After completion of the reaction, 20 mL of toluene and 20 mL of a 10 w% aqueous citric acid solution were added, the reaction solution was washed with water, and further washed with water. After washing with water, it was dehydrated with anhydrous magnesium sulfate. By filtering off anhydrous magnesium sulfate and concentrating, 30 g of reaction product A was obtained as a colorless transparent liquid. When 1H-NMR (FIG. 1) of the obtained reaction product A was measured, in addition to the signal of 4.7 ppm ( H— Si) attributed to the hydrosilyl group, 5.5 ppm attributed to the alkene of the methacryl group. And a signal of 6.1 ppm (H ₂ C = C) was confirmed, and the reaction product A was dehydrogenated with 2-hydroxyethyl methacrylate as part of the hydrosilyl group of the hydrogenated terminal methylhydrosiloxane-phenylmethylsiloxane copolymer. It was confirmed that the compound was a compound having an organic group having a carbon-carbon double bond capable of radical polymerization in the molecule and a hydrosilyl group.

[Synthesis Example 2]
Into a reaction vessel equipped with a stirrer, a dropping funnel and a thermometer, 39.5 g of trimethylsilyl-terminated polymethylhydrosiloxane (Gelest, Inc. HMS-992 weight average molecular weight: 2000) and 40 mL of toluene are added until uniform. Stir. Next, 0.35 g of N, N-diethylhydroxylamine was added and stirred for 20 minutes at room temperature, and 8.48 g of 2-hydroxyethyl methacrylate was added dropwise from the dropping funnel and stirred for 2 hours at room temperature. After completion of the reaction, 60 mL of toluene and 60 mL of a 10 w% aqueous citric acid solution were added, the reaction solution was washed with water, and further washed with water. After washing with water, it was dehydrated with anhydrous magnesium sulfate. By filtering off anhydrous magnesium sulfate and concentrating, 30 g of reaction product B was obtained as a colorless transparent liquid. When 1H-NMR of the obtained reaction product B was measured, in addition to a signal of 4.7 ppm (H-Si) attributed to the hydrosilyl group, 5.5 ppm and 6.1 ppm attributed to the alkene of the methacryl group. (H ₂ C = C) signal was confirmed, and reaction product B was a radical polymerization in the molecule, in which 2-hydroxyethyl methacrylate was added to a part of the hydrosilyl group of trimethylsilyl-terminated polymethylhydrosiloxane by dehydrogenation. It was confirmed to be a compound having an organic group having a possible carbon-carbon double bond and a hydrosilyl group.

[Synthesis Example 3]
Into a reaction vessel equipped with a stirrer, a dropping funnel and a thermometer, 39.5 g of trimethylsilyl-terminated polymethylhydrosiloxane (Gelest, Inc. HMS-992 weight average molecular weight: 2000) and 40 mL of toluene are added until uniform. Stir. Next, 0.35 g of N, N-diethylhydroxylamine was added and stirred for 20 minutes at room temperature, and 87.7 g of 2-hydroxyethyl methacrylate was added dropwise from the dropping funnel, stirred for 2 hours at room temperature, and further at 60 ° C. for 2 hours. Stir. After completion of the reaction, 60 mL of toluene and 60 mL of 10 w% aqueous citric acid solution were added, the reaction solution was washed with water, and further washed with water. After washing with water, it was dehydrated with anhydrous magnesium sulfate. Anhydrous magnesium sulfate was filtered off and concentrated to obtain 119 g of reaction product C as a colorless transparent liquid. When 1H-NMR of the obtained reaction product C was measured, the signal of 4.7 ppm (H-Si) attributed to the hydrosilyl group disappeared completely, and 5.5 ppm attributed to the alkene of the methacryl group. 6.1ppm (H ₂ C = C) signal is confirmed and the reaction product C, all of 2-hydroxyethyl methacrylate in the hydrosilyl groups trimethylsilyl-terminated polymethylhydrosiloxane were added by dehydrogenation, in the molecule It was confirmed that the compound had an organic group having a carbon-carbon double bond capable of radical polymerization.

  Table 1 shows the “average hydrosilyl group hydrogen number” in one molecule calculated from the average molecular weight of the hydrosilyl compound used as a raw material in Synthesis Examples 1 to 3. For the reaction products A to C obtained in Synthesis Examples 1 to 3, the “average hydrosilyl group hydrogen number in one molecule of reaction product” calculated from the area ratio of the hydrosilyl group hydrogen number in 1H-NMR, Similarly, “average number of methacryl groups in one molecule of reaction product” calculated from the area ratio of alkene hydrogen of methacryl groups in 1H-NMR is shown in Table 1.

  Using reaction products A to C obtained in Synthesis Examples 1 to 3, trimethylolpropane triacrylate (a compound having a carbon-carbon double bond), pentaerythritol triacrylate (carbon-carbon double bond and hydroxyl group) Compound), 1-hydroxycyclohexyl phenyl ketone (photopolymerization initiator), and ditertiary butyl peroxide (thermal polymerization initiator), as shown in Table 2, and curable resin composition A -1 to 2, B-1 to 3, and C-1 to 3 were obtained. In addition, the numerical value of each component in Table 2 represents a weight part. In addition, for each curable resin composition, whether or not the contained reaction product A to C has a hydrosilyl group is indicated.

[Example 1]
The curable resin composition A-1 obtained above is applied onto a glass plate, cast (cast) to a thickness of 0.2 mm using a roll coater, and a 30 W / cm high-pressure mercury lamp is used. It was cured with an accumulated exposure amount of 8000 mJ / cm ² to obtain a film-like molded product A-1a (primary cured product) having a predetermined thickness (0.2 mm). In the IR spectrum (FIG. 2) of the obtained molded product A-1a, a peak of 2155 cm ⁻¹ (a peak attributed to a hydrosilyl group) was confirmed.

The molded product A-1a obtained above was immersed in an aqueous base solution (1.1 mol / L N, N-diethylhydroxylamine). Immediately after the immersion, dehydrogenative condensation by the hydrosilyl group of the molded product proceeded to generate hydrogen bubbles. After being immersed for 24 hours at room temperature, the molded body was taken out and washed with water. Further, the molded body was naturally dried at room temperature for 1 hour, and then heated in an oven at 200 ° C. for 1 hour to obtain a molded body A-1b (final cured product). According to the IR spectrum (FIG. 2) of the obtained molded product A-1b, the peak at 2155 cm ⁻¹ observed in the molded product A-1a (the peak attributed to the hydrosilyl group) has disappeared. It was confirmed that the dehydrogenative condensation had progressed completely.

  About the molded object A-1b obtained above, the physical property on each condition described below was evaluated. The results are shown in Table 3.

[Formability]
The obtained molded product A-1b was visually confirmed, and a two-step evaluation was performed in which a case where there was no crack or chip was “good” and a case where a crack or chip was generated was “bad”.

[Presence or absence of hydrosilyl group]
The IR spectrum of the surface of a test piece obtained by cutting the compact A-1b to about 10 mm × 10 mm was measured and confirmed by the presence or absence of a peak attributed to a hydrosilyl group in the vicinity of 2155 cm ⁻¹ .

[Elastic modulus]
For the molded body of 0.2mm thickness finally obtained under the curing conditions 1, 1a and 1b described below, the tensile modulus (test piece: 8mm x 80mm x 0.2mm, test speed 0.5mm / min, chuck The value of the distance 50mm) is shown. For the molded body of 2mm thickness finally obtained under curing conditions 2, 2a, 3 and 3a, the flexural modulus (test piece: 25mm x 50mm x 2mm, test speed 0.3mm / min, distance between fulcrums 12mm) , Fulcrum radius 0.5 mm, indenter radius 1.5 mm). In Table 3, “x” indicates that a test piece of a predetermined size cannot be obtained and measurement is impossible.

[CTE]
A thermomechanical analysis was performed to measure the coefficient of linear expansion (CTE) from 50 ° C to 150 ° C. For a 0.2mm-thick molded body obtained under curing conditions 1, 1a and 1b, test specimens were processed to a width of 3mm, fixed at a distance of 15mm between chucks, heating rate 5 ° C / min, tensile load 4.2mN Measured with The molded body having a thickness of 2 mm obtained under the curing conditions 2, 2a, 3 and 3a was cut into 5 mm squares, measured with a test thickness of 2 mm, a heating rate of 5 ° C./min, and a compression load of 100 mN.

[Water absorption rate]
For the 0.2 mm thick molded body finally obtained under the curing conditions 1, 1a and 1b, the specimen size was 100 mm x 100 mm, and was finally obtained under the curing conditions 2, 2a, 3 and 3a. For a molded body having a thickness of 2 mm, the test piece size was set to 25 mm × 50 mm, each was dried at 50 ° C. for 24 hours, weighed, and then immersed in warm water at 25 ° C. for 24 hours. The water absorption was determined. Further, “x” in Table 3 indicates that a test piece of a predetermined size cannot be obtained and measurement is impossible.
Water absorption rate (%) = [(water absorption weight−dry weight) / dry weight] × 100

[Examples 2-6, Comparative Examples 1-6]
As shown in Table 3, molded bodies according to Examples 2 to 6 and Comparative Examples 1 to 6 were obtained from combinations of the curable resin composition and the curing conditions described below. About the obtained molded object, physical property evaluation was performed by the method mentioned above. The results are shown in Table 3.

[Curing condition 1]
Using a roll coater, cast (cast) the curable resin composition to a thickness of 0.2 mm on a glass plate, and use a 30 W / cm high-pressure mercury lamp to obtain an integrated exposure amount of 8000 mJ / cm ^2. To obtain a film-like molded product (primary cured product) having a predetermined thickness (0.2 mm).

[Curing condition 1a]
In addition to curing condition 1, the molded product obtained under curing condition 1 is immersed in an aqueous base solution (1.1 mol / L N, N-diethylhydroxylamine) at room temperature for 24 hours, washed with water, and then naturally dried at room temperature for 1 hour. Then, it was heated in an oven at 200 ° C. for 1 hour to obtain a film-like molded body (final cured product) having a thickness of 0.2 mm.

[Curing condition 1b]
A film-like molded body (final cured product) having a thickness of 0.2 mm was obtained in the same manner as in the curing condition 2 except that the basic aqueous solution was changed to water.

[Curing condition 2]
To a thickness of 2mm pouring curable resin composition into a mold of 50mm square incorporating a glass plate, cured at integrated exposure amount of 8000 mJ / cm ² using a high-pressure mercury lamp of 30 W / cm, a predetermined thickness A sheet-like molded body (primary cured product) having (2 mm) was obtained.

[Curing condition 2a]
In addition to curing condition 2, the molded product obtained under curing condition 2 is immersed in an aqueous base solution (1.1 mol / L N, N-diethylhydroxylamine) at room temperature for 72 hours, washed with water, and then naturally dried at room temperature for 24 hours. After that, it was heated in an oven at 200 ° C. for 2 hours to obtain a sheet-like molded body (final cured product) having a thickness of 2 mm.

[Curing condition 3]
A 2mm thick sheet that is injected into a mold with an inner diameter of 25mm x 50mm x 2mm at an injection pressure of 3Mpa, injection-molded under the following conditions: holding pressure: 1Mpa / 10 seconds, mold temperature: 180 ° C, curing time 1 minute A shaped product (primary cured product) was obtained.

[Curing condition 3a]
In addition to curing condition 3, the molded product obtained under curing condition 3 is immersed in an aqueous base (1.1 mol / L N, N-diethylhydroxylamine) at room temperature for 72 hours, washed with water, and then naturally dried at room temperature for 24 hours. After that, it was heated in an oven at 200 ° C. for 2 hours to obtain a sheet-like molded body (final cured product) having a thickness of 2 mm.

  From Examples 1 to 6 and Comparative Examples 1 to 6, from the results of the respective CTEs, the hydrosilyl group was dehydrogenated and condensed by bringing the molded body (primary cured product) containing the hydrosilyl group into contact with an aqueous base solution. It was confirmed that the increase in crosslink density increased the elastic modulus and reduced CTE. In addition, from the comparison of the curable resin composition using the reaction products B and C, if the production method of the present invention is used, the molding having the same elastic modulus and CET as that of increasing the carbon-carbon double bond A body (final cured product) can be obtained with good moldability and can also have low water absorption.

  According to the present invention, the dehydration condensation of the hydrosilyl group contained in the primary cured product is utilized without increasing the number of carbon-carbon double bonds, and the crosslinking density of the finally obtained cured product is increased. Is possible. Therefore, the cured product (final cured product) obtained by the present invention includes display materials such as a display front protective plate and a liquid crystal polarizing film for liquid crystal televisions, touch panel substrates, color filter substrates, TFT substrates, and the like. It can be used as a glass substitute substrate, and for example, imaging optical systems such as eyeglass lens materials and prisms, cameras, projection optical systems such as display devices, observation optical systems such as image display devices, and laser optical systems such as magneto-optical disk drives It can also be used as an optical element such as a lens used in a waveguide. That is, the cured product obtained by the present invention can be used in place of various glass materials that have so far mainly been used for glass.

Claims (5)

  A primary cured product obtained by radically polymerizing a compound a having an organic group containing a carbon-carbon double bond capable of radical polymerization in the molecule and a hydrosilyl group, and having a hydrosilyl group, thereby obtaining a primary cured product. A method for producing a cured product, wherein the hydrosilyl group is dehydrocondensed by contacting with a basic aqueous solution.   The manufacturing method of the hardened | cured material of Claim 1 which obtains a primary hardened | cured material in the state containing the compound b which has the carbon-carbon double bond which can be radically polymerized in a molecule | numerator besides the compound a.   The method for producing a cured product according to claim 2, wherein the compound b is a compound having a hydroxyl group.   The manufacturing method of the hardened | cured material of any one of Claims 1-3 which obtains a primary hardened | cured material using the curable resin composition containing the compound a and the radical polymerization initiator at least.   A primary cured product obtained by radically polymerizing a compound a having an organic group containing a carbon-carbon double bond capable of radical polymerization in the molecule and a hydrosilyl group, and having a hydrosilyl group, thereby obtaining a primary cured product. A cured product obtained by contacting the hydrosilyl group with a basic aqueous solution to dehydrocondensate the hydrosilyl group.

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