阅读说明：本技术 紫外线固化性硅酮组合物及其固化物 (Ultraviolet-curable silicone composition and cured product thereof ) 是由 松本展明 大竹滉平 北川太一 松田刚 小材利之 于 2019-09-13 设计创作，主要内容包括：提供一种即使在面曝光方式或吊起方式等的成型方式中也能够使用的低粘度的紫外线固化性硅酮组合物以及拉伸强度和断裂伸长率优异的固化物。所述紫外线固化性硅酮组合物含有：(A)以下述通式(1)表示的有机聚硅氧烷[在通式(1)中,n为1≤n≤1000,m为1≤m≤1000,Ar为芳香族基团,R～1为碳原子数1～20的一价烃基,A为以下述通式(2)表示的基团。[在通式(2)中,p为0≤p≤10,a为1≤a≤3,R～1为碳原子数1～20的一价烃基,R～2为氧原子或亚烷基,R～3为丙烯酰氧基烷基等。]](B)光聚合引发剂,及(C)不含有硅氧烷结构的单官能(甲基)丙烯酸酯化合物和/或(D)不含有硅氧烷结构的多官能(甲基)丙烯酸酯化合物。(Provided are a low-viscosity ultraviolet-curable silicone composition which can be used even in molding systems such as a surface exposure system and a lifting system, and a cured product which has excellent tensile strength and elongation at break. The ultraviolet curing propertyThe silicone composition contains: (A) an organopolysiloxane represented by the following general formula (1) [ in the general formula (1), n is 1. ltoreq. n.ltoreq.1000, m is 1. ltoreq. m.ltoreq.1000, Ar is an aromatic group, R is a hydrogen atom 1 Is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and A is a group represented by the following general formula (2). [ in the general formula (2), p is 0. ltoreq. p.ltoreq.10, a is 1. ltoreq. a.ltoreq.3, R 1 Is a monovalent hydrocarbon group of 1 to 20 carbon atoms, R 2 Is an oxygen atom or alkylene group, R 3 Is acryloyloxyalkyl, etc.]](B) A photopolymerization initiator, and (C) a monofunctional (meth) acrylate compound not having a siloxane structure and/or (D) a polyfunctional (meth) acrylate compound not having a siloxane structure.)

1. An ultraviolet-curable silicone composition characterized by comprising:

(A) an organopolysiloxane represented by the following general formula (1): 100 parts by mass of a water-soluble polymer,

in the general formula (1), n is a number satisfying 1. ltoreq. n.ltoreq.1000, m is a number satisfying 1. ltoreq. m.ltoreq.1000, the order of arrangement of siloxane units having n and m attached thereto is arbitrary, Ar is an aromatic group, R is a siloxane unit having n and m attached thereto¹Independently of each other, a monovalent hydrocarbon group having 1 to 20 carbon atoms, A is a group represented by the following general formula (2),

in the general formula (2), p is a number satisfying 0. ltoreq. p.ltoreq.10, a is a number satisfying 1. ltoreq. a.ltoreq.3, R¹Independently of each other, a monovalent hydrocarbon group of 1 to 20 carbon atoms, R²Is an oxygen atom or alkylene group, R³Is acryloxyalkyl, methacryloxyalkyl, acryloxyalkoxy or methacryloxyalkoxy, and

(B) photopolymerization initiator: 0.1 to 10 parts by mass, and

(C) one or both of (a) a monofunctional (meth) acrylate compound not containing a siloxane structure and (D) a polyfunctional (meth) acrylate compound not containing a siloxane structure: 1 to 400 parts by mass.

2. The ultraviolet-curable silicone composition according to claim 1,

r in the general formula (1)¹Is an alkyl group having 1 to 10 carbon atoms.

3. The ultraviolet-curable silicone composition according to claim 1 or 2,

the viscosity at 25 ℃ is 10000 mPas or less.

4. A cured product of the ultraviolet-curable silicone composition according to any one of claims 1 to 3.

5. The ultraviolet-curable silicone composition according to any one of claims 1 to 3,

which is used for ink for 3D printers.

Technical Field

The present invention relates to an ultraviolet-curable silicone composition and a cured product thereof.

Background

In recent years, development of molding materials used in 3D printers is becoming more active, and the kinds of molding materials thereof have various types ranging from metals to resins. The mainstream in the resin field is an acrylate-based photocurable resin composition or a urethane acrylate-based photocurable resin composition, but cured products of these compositions are very hard and cannot be bent (patent document 1).

Depending on the use, soft materials are mostly required, and materials suitable for molding have been developed. For example, as a material for a photocuring molding method (SLA), a composition including an alkenyl group-containing organopolysiloxane, a mercapto group-containing organopolysiloxane, and an MQ resin has been disclosed (patent document 2). In addition, a silicone mixture containing a platinum catalyst activated by ultraviolet light has been disclosed for a dispensing technique (patent document 3). Further, although a photocurable low-viscosity silicone material for a 3D printer using an ink jet system has been disclosed (patent document 4), a cured product of the composition has a problem of lacking heat resistance compared to a general silicone material. There is a strong demand for the development of a material having excellent heat resistance, which can cope with a molding method called a surface exposure method or a lift method, which is rapidly increasing in recent years.

Documents of the prior art

Patent document

Japanese patent laid-open No. 2012-111226 in patent document 1

Patent document 2 japanese patent No. 4788863

Patent document 3 japanese patent No. 5384656

Patent document 4 International publication No. 2018/003381

Disclosure of Invention

Problems to be solved by the invention

In view of the above problems, an object of the present invention is to provide a low-viscosity ultraviolet-curable silicone composition that can be used in a surface exposure type or a suspension type molding type, and a cured product that has excellent heat resistance.

Means for solving the problems

The present inventors have intensively studied to achieve the above object and, as a result, have found that a low-viscosity ultraviolet-curable silicone composition and a cured product of the composition having excellent heat resistance can be provided by using a specific ultraviolet-curable organopolysiloxane component, a monofunctional ethylene group-containing compound not having a siloxane structure and/or a polyfunctional ethylene group-containing compound not having a siloxane structure, and have completed the present invention.

The present invention provides the following ultraviolet-curable silicone composition and a cured product of the composition.

[1] An ultraviolet-curable silicone composition characterized by comprising:

(A) an organopolysiloxane represented by the following general formula (1): 100 parts by mass of a water-soluble polymer,

in the general formula (1), n is a number satisfying 1. ltoreq. n.ltoreq.1000, m is a number satisfying 1. ltoreq. m.ltoreq.1000, the order of arrangement of siloxane units having n and m attached thereto is arbitrary, Ar is an aromatic group, R is a siloxane unit having n and m attached thereto¹Independently of each other, a monovalent hydrocarbon group having 1 to 20 carbon atoms, A is a group represented by the following general formula (2),

in the general formula (2), p is a number satisfying 0. ltoreq. p.ltoreq.10, a is a number satisfying 1. ltoreq. a.ltoreq.3, R¹Independently of each other, a monovalent hydrocarbon group of 1 to 20 carbon atoms, R²Is an oxygen atom or alkylene group, R³Is acryloxyalkyl, methacryloxyalkyl, acryloxyalkoxy or methacryloxyalkoxy, and

(B) photopolymerization initiator: 0.1 to 10 parts by mass, and

(C) one or both of (a) a monofunctional (meth) acrylate compound not containing a siloxane structure and (D) a polyfunctional (meth) acrylate compound not containing a siloxane structure: 1 to 400 parts by mass.

[2] The ultraviolet-curable silicone composition according to [1],

r in the general formula (1)¹Is an alkyl group having 1 to 10 carbon atoms.

[3] The ultraviolet-curable silicone composition according to [1] or [2],

the viscosity at 25 ℃ is 10000 mPas or less.

[4] A cured product of the ultraviolet-curable silicone composition according to any one of [1] to [3 ].

[5] The ultraviolet-curable silicone composition according to any one of [1] to [3],

which is used for ink for 3D printers.

ADVANTAGEOUS EFFECTS OF INVENTION

The ultraviolet-curable silicone composition of the present invention has a low viscosity to such an extent that it can be used in a molding system such as a surface exposure system or a suspension system, and therefore is expected as a novel molding material that can be used in a 3D printer. In addition, the ultraviolet-curable silicone composition of the present invention can be formed into a cured product having excellent heat resistance, and therefore is expected as a molding material for 3D printers using an inkjet system, which exhibits excellent mechanical strength.

Detailed Description

The present invention will be described in more detail below.

(A) Organopolysiloxane

(A) The component (B) is an organopolysiloxane represented by the following general formula (1).

In the general formula (1), the aromatic group represented by Ar includes aromatic hydrocarbon groups such as phenyl, biphenyl, and naphthyl, and aromatic groups containing a hetero atom (O, S, N) such as furyl. The aromatic group may further have a substituent such as a halogen atom (for example, a chlorine atom, a bromine atom, or a fluorine atom). Ar is preferably an unsubstituted aromatic hydrocarbon group, and particularly preferably a phenyl group.

N in the general formula (1) is 1. ltoreq. n.ltoreq.1000, preferably 1. ltoreq. n.ltoreq.500, more preferably 1. ltoreq. n.ltoreq.400. If n is less than 1, the volatile component is easily volatilized, and if n is more than 1000, the viscosity of the composition increases, and the workability deteriorates.

M in the general formula (1) is 1. ltoreq. m.ltoreq.1000, preferably 1. ltoreq. m.ltoreq.500, more preferably 1. ltoreq. m.ltoreq.400. When m is less than 1, the composition is easily volatilized, and when m is more than 1000, the viscosity of the composition increases, and the molding by lifting is difficult.

N + m in the general formula (1) is 2. ltoreq. n + m. ltoreq.2000, preferably 2. ltoreq. n + m. ltoreq.1000, more preferably 2. ltoreq. n + m. ltoreq.800. If n + m is less than 2, the composition is easily volatilized, and if n + m is more than 2000, the viscosity of the composition increases, and it is difficult to form the composition by lifting.

A in the general formula (1) is a group represented by the following general formula (2).

In the general formula (1) and the general formula (2), R¹Independently represent a monovalent hydrocarbon group having 1 to 20 carbon atoms, preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms excluding an aliphatic unsaturated group, and more preferably a monovalent hydrocarbon group having 1 to 8 carbon atoms excluding an aliphatic unsaturated group.

In the general formula (1) and the general formula (2), R is¹The monovalent hydrocarbon group having 1 to 20 carbon atoms may be any of linear, branched or cyclic, and specific examples thereof include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-hexyl, cyclohexyl, n-octyl, 2-ethylhexyl, and n-decyl; alkenyl groups such as vinyl, allyl (2-propenyl), 1-propenyl, isopropenyl and butenyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl, phenethyl and phenylpropyl.

In addition, some or all of the hydrogen atoms bonded to the carbon atoms of these monovalent hydrocarbon groups may be substituted with other substituents, and specific examples thereof include halogen-substituted hydrocarbon groups such as chloromethyl, bromoethyl, trifluoropropyl, cyanoethyl, and the like, cyano-substituted hydrocarbon groups, and the like.

Among them, as R¹The alkyl group having 1 to 5 carbon atoms and the phenyl group are preferable, and the methyl group, the ethyl group and the phenyl group are more preferable.

In the general formula (2), R²Is an alkylene group having 1 to 20, preferably 1 to 10, more preferably 1 to 5 oxygen atoms or carbon atoms.

In the general formula (2), as R²The alkylene group having 1 to 20 carbon atoms may be any of linear, branched or cyclic, and specific examples thereof include methylene, ethylene, propylene, trimethylene, tetramethylene, and methyleneIsobutyl, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decylene and the like.

Among them, as R²Preferred are an oxygen atom, a methylene group, an ethylene group and a trimethylene group, and more preferred is an oxygen atom or an ethylene group.

Further, in the general formula (3), R³Independently expressed as acryloxyalkyl, methacryloxyalkyl, acryloxyalkoxy or methacryloxyalkoxy.

In the general formula (3), as R³The number of carbon atoms of the alkyl (alkylene) group in the acryloxyalkyl group, methacryloxyalkyl group, acryloxyalkoxy group, or methacryloxyalkoxy group is not particularly limited, but is preferably 1 to 10, more preferably 1 to 5. Specific examples of these alkyl groups include those mentioned above for R¹Examples of the group include alkyl groups having 1 to 10 carbon atoms.

As R³Specific examples of (b) include, but are not limited to, the following general formulae.

(in the general formula, b represents a number satisfying 1. ltoreq. b.ltoreq.4, R⁴Is an alkylene group having 1 to 10 carbon atoms. )

P is a number satisfying 0. ltoreq. p.ltoreq.10, and is preferably 0 or 1. a is a number satisfying 1. ltoreq. a.ltoreq.3, preferably 1 or 2.

Examples of the organopolysiloxane represented by the above general formula (1) include the following compounds.

(in the formula, R¹、R²、R⁴Ar, n, m and b are as defined above, and the siloxane units with n and m are arranged in the orderOptionally. )

Such an organopolysiloxane can be produced by a known method. The organopolysiloxane represented by the above general formula (3) is obtained, for example, as a hydrosilylation reactant of a dimethylsiloxane-diphenylsiloxane copolymer whose both terminals are capped with dimethylvinylsiloxy groups and 3- (1,1,3, 3-tetramethylsilyl ether) propyl methacrylate (CAS No. 96474-12-3).

The organopolysiloxane represented by the above general formula (4) can be obtained, for example, by reacting 2-hydroxyethyl acrylate with a hydrosilylation reaction product of a dimethylsiloxane-diphenylsiloxane copolymer whose both terminals are terminated with dimethylvinylsiloxy groups and dichloromethylsilane.

(B) Photopolymerization initiator

As the photopolymerization initiator (B), a known photopolymerization initiator can be used. Among them, for example, 2, 2-diethoxyacetophenone; 2, 2-dimethoxy-1, 2-diphenylethan-1-one (Irgacure 651, BASF corporation); 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, BASF corporation); 2-hydroxy-2-methyl-1-phenyl-propan-1-one (Irgacure 1173, manufactured by BASF corporation); 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl ] -phenyl } -2-methyl-propan-1-one (Irgacure 127, BASF); methyl benzoylformate (Irgacure MBF manufactured by BASF corporation); 2-methyl-1- [4- (methylthio) phenyl ] -2-morpholinopropan-1-one (Irgacure 907, BASF corporation); 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -1-butanone (Irgacure 369, manufactured by BASF corporation); bis (2,4, 6-trimethylbenzoyl) -phenylphosphine oxide (Irgacure 819, manufactured by BASF); 2,4, 6-trimethylbenzoyl-diphenyl-phosphine oxide (Irgacure TPO manufactured by BASF corporation); and mixtures of these compounds, and the like.

Among the above-mentioned component (B), 2-diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one (Irgacure 1173, manufactured by BASF), bis (2,4, 6-trimethylbenzoyl) -phenylphosphine oxide (Irgacure 819, manufactured by BASF) and 2,4, 6-trimethylbenzoyl-diphenyl-phosphine oxide (Irgacure TPO, manufactured by BASF) are preferable from the viewpoint of compatibility with the component (a).

The amount of the photopolymerization initiator added is 0.1 to 10 parts by mass per 100 parts by mass of the component (A). If the amount of the photopolymerization initiator added is less than 0.1 part by mass, the cured product will have insufficient curability; if the amount exceeds 10 parts by mass, the curing property at the deep part of the cured product is deteriorated.

(C) Monofunctional (meth) acrylate compound having no siloxane structure

Examples of the monofunctional (meth) acrylate compound (C) having no siloxane structure include isoamyl acrylate, lauryl acrylate, octadecyl acrylate, ethoxy-diethylene glycol acrylate, methoxy-triethylene glycol acrylate, 2-ethylhexyl-diethylene glycol acrylate, phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, tetrahydrofurfuryl acrylate, isobornyl acrylate, and mixtures thereof. Isobornyl acrylate is particularly preferred.

(D) Polyfunctional (meth) acrylate compound not containing siloxane structure

Examples of the polyfunctional (meth) acrylate compound (D) having no siloxane structure include triethylene glycol diacrylate, poly-1, 4-butanediol diacrylate, neopentyl glycol diacrylate, 1, 6-hexanediol diacrylate, dimethylol-tricyclodecane diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, and mixtures of these compounds. Particularly preferred is dimethylol-tricyclodecane diacrylate.

The (meth) acrylate compound of the component (C) and the (meth) acrylate compound of the component (D) are preferably contained in a total amount of 1 to 400 parts by mass, and more preferably in a total amount of 1 to 200 parts by mass, based on 100 parts by mass of the component (A). If the total amount of the components (C) and (D) is more than 400 parts by mass based on 100 parts by mass of the component (A), the hardness of the cured product may become more than necessary, and the desired rubber physical properties may not be obtained.

Additives such as a silane coupling agent, a polymerization inhibitor, an antioxidant, an ultraviolet absorber as a light resistance stabilizer, and a light stabilizer may be further added to the composition of the present invention within a range not to impair the effects of the present invention. The composition of the present invention may be used by being appropriately mixed with other resin compositions.

Method for producing silicone composition

The ultraviolet-curable silicone composition of the present invention can be obtained by stirring, mixing, or the like, the component (a), the component (B), the component (C) and/or the component (D), and other components. The apparatus for stirring or the like is not particularly limited, and a planetary stirrer, a separable flask, or the like may be used.

In the ultraviolet-curable silicone composition of the present invention, the viscosity of the composition is preferably 10mPa · s to 10000mPa · s, more preferably 100mPa · s to 8000mPa · s, as a standard for enabling molding by a lifting method. The viscosity was measured at 25 ℃ using a rotary viscometer.

The ultraviolet-curable silicone composition of the present invention is cured quickly by irradiation with ultraviolet light. Examples of the light source of ultraviolet rays to be irradiated to the ultraviolet-curable silicone composition of the present invention include a UVLED lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, a carbon arc lamp, and a xenon lamp. For example, the amount of ultraviolet radiation (integrated light amount) is preferably 1 to 10000mJ/cm relative to a sheet formed by molding the composition of the present invention to a thickness of about 2.0mm²More preferably 10 to 5000mJ/cm². Namely, the illumination intensity is 100mW/cm²The ultraviolet ray (365nm) of (1) may be irradiated for about 0.01 to 100 seconds.

In order to provide a cured product of the ultraviolet-curable silicone composition of the present invention with excellent rubber properties, the cured product has a hardness of 5 to 80(type a), preferably 10 to 70(type a); the tensile strength after curing is preferably 0.6MPa or more, more preferably 0.8MPa or more. The elongation at break after curing is preferably 40% or more, more preferably 50% or more. These values are measured in accordance with JIS-K6249. The rubber properties of the cured product can be adjusted by adjusting the amounts of the components (C) and (D).

[ examples ]

The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited thereto.

Examples 1 to 4 and comparative example 1

The following components were mixed in the composition ratios (numerical values are expressed in parts by mass) shown in table 1 to obtain ultraviolet-curable silicone compositions.

The viscosity of the composition obtained in each example was measured at 25 ℃ using a rotational viscometer.

Each composition was injected into a molding frame, and the mixture was heated under a nitrogen atmosphere using a lamp H (M)06-L-61 manufactured by EYE GRAPHICS K under the condition of 2000mJ/cm²The respective compositions were cured under ultraviolet irradiation, and cured sheets each having a thickness of 2.0mm were obtained. Hardness, tensile strength and elongation at break of each of the obtained cured sheets before and after the heat resistance test (standing at 200 ℃ C. for 20 hours) were measured in accordance with JIS-K6249, and the results are shown in Table 1.

■ component (A)

(A-1): an organopolysiloxane represented by the following general formula (5) produced by the above method

(in the formula, the arrangement order of the siloxane units having brackets is arbitrary.)

(A-2): an organopolysiloxane represented by the following general formula (6) produced by the above method

(in the formula, the arrangement order of the siloxane units having brackets is arbitrary.)

■ (comparative component)

(A-3): an organopolysiloxane represented by the following general formula (7)

(A-4): an organopolysiloxane represented by the following general formula (8)

■ (B) component

(B-1): 2-hydroxy-2-methyl-1-phenyl-propan-1-one (Irgacure 1173, manufactured by BASF corporation)

(B-2): 2,4, 6-trimethylbenzoyl-diphenyl-phosphine oxide (Irgacure TPO, manufactured by BASF Corp.)

■ (C) component

Isobornyl acrylate (LIGHT ACRYLATE IB-XA, Kyoeisha chemical Co., Ltd.)

■ (D) component

Dimethylol-tricyclodecane diacrylate (LIGHT ACRYLATE DCP-A, Co., Ltd., chemical Co., Ltd.)

TABLE 1

	Example 1	Example 2	Example 3	Example 4	Comparative example 1
						(A-1)	100	100	-	-	-
(A-2)	-	-	100	100	-
						(A-3)	-	-	-	-	100
(A-4)	-	-	-	-	75
						(B-1)	1.5	1.1	0.6	0.7	4.0
(B-2)	1.5	1.1	0.6	0.7	4.0
						(C)	45	-	25	45	75
(D)	-	10	-	-	-
						Viscosity (mPa. s) of the composition	780	2870	530	360	60
Initial hardness (TypeA)	29	41	30	54	25
						Initial tensile Strength (MPa)	2.3	0.9	1.8	6.2	1.2
Initial elongation at break (%)	240	66	180	250	170
						Hardness after Heat resistance test (TypeA)	31	45	34	58	30
Tensile Strength (MPa) after Heat resistance test	2.2	1.0	2.1	4.6	0.4
						Elongation at break after Heat resistance test (%)	200	50	150	190	30

As shown in table 1, the ultraviolet-curable silicone composition of the present invention has a sufficiently low viscosity, and exhibits excellent rubber properties and heat resistance after curing, and is particularly useful as a silicone material for a 3D printer of a molding system such as a use-side exposure system or a lifting system. On the other hand, in comparative example 1 in which the component (A) was not used, the cured sheet had poor rubber properties after the heat resistance test.