RU2179991C2 - Polymeric composition for coatings - Google Patents

Abstract

FIELD: coating hardenable by using low-energy radiations within wavelengths from 400 to 700 nm and used in stomatology, radio electronics and printing arts. SUBSTANCE: composition comprises oligourethan methacrylisoceanurate which is compound of general formula I:

, linear oligourethan methacrylate (comonomer I:

, branched oligourethan methacrylate (comonomer II:

Description

 The invention relates to the field of coatings, cured by one of the new and promising methods of curing - curing under the influence of low-energy radiation in the wavelength range of 400-700 nm. Such coatings can be used (depending on the composition) in dentistry for manicure of teeth and modification of areas with enamel damage, as well as in electronics and the printing industry.

 Known composite materials that cure under the influence of radiation in the visible range of the spectrum [application 61-120867, Japan, 59-242837, MKI C 09 D 3/80, C 09 D 5/00; application 62-123044, Japan, 60-261331, MKI C 03 D 25/02, C 09 D 3/727] with fairly high speeds. The composition of such compositions includes dipentaerythritol acrylate monomer [application 61-120867, Japan, 59-242837, MKI C 09 D 3/80, C 09 D 5/00], acrylic monomer of the urethane type [application 62-123044, Japan, 60-261331 MKI C 03 D 25/02, C 09 D 3/727], methyl methacrylate [application 61-120867, Japan, 59-242837, MKI C 09 D 3/80, C 09 D 5/00; Application 62-123044, Japan, 60-261331, MKI C 03 D 25/02, C 09 D 3/727] and camphoquinone polymerization initiator. Acrylurethane oligomers having isocyanurate fragments in their structure [application 61-120867, Japan, 59-242837, MKI C 09 D 3/80, C 09 D 5/00 (prototype)] can be used as film-forming in such compositions.

 These compositions have the ability to form transparent relatively hard coatings at fairly high speeds under the influence of "soft" radiation in the wavelength range of 400-700 nm. However, the wear resistance and elasticity of such coatings is not high enough. Also, in order to cure such compositions, a radiation source of a certain narrow wavelength range, which coincides with the absorption maximum of the camoquinone photoinitiator, is required.

где R - радикалы формулы [OCH₂-CH₂-CH-C(O)] _nOR₂C(O)OC-(R₁)-CH или OR₁OC(O)C(R₂)-CH, R₂ - H или метил, R₁ - этилен или пропилен, n= 1-6.The closest in technical essence to the proposed one is the polymer composition that we selected for the prototype [application 61-120867, Japan, 59-242837, MKI C 09 D 3/80, C 09 D 5/00], including polyurethane acrylate isocyanurate of the general formula as an oligomer ,

where R is the radicals of the formula [OCH ₂ —CH ₂ —CH — C (O)] _n OR ₂ C (O) OC— (R ₁ ) —CH or OR ₁ OC (O) C (R ₂ ) —CH, R ₂ - H or methyl, R ₁ - ethylene or propylene, n = 1-6.

as a comonomer, methyl methacrylate and the initiator of photopolymerization is camphoquinone, with the following ratio of components, wt. %:
Polyacrylateurethaneisocyanurate - 30-35
Methyl methacrylate - 60-65
Camphoquinone - 0.1-5
Such compositions form relatively hard transparent coatings under the influence of low-energy radiation. However, the compositions do not provide sufficient hardness and wear resistance of the coating. In addition, the disadvantage of these compositions is not sufficiently high elasticity, impact strength and increased stickiness of coatings cured for 30 s (see table 3). There is another significant problem in obtaining coatings based on such compositions. To cure such composite materials, a radiation source of a certain narrow wavelength range, which coincides with the absorption maximum of the photoinitiator, is required.

 The objective of this invention is the creation of coatings with high wear resistance, elasticity, hardness, low stickiness, capable of curing at very high speeds under the influence of low-energy radiation in the presence of a universal three-component initiating system, capable of initiating a polymerization reaction when irradiated with a source of a wide radiation range of 400-700 nm.

n= 1-3,
а также сомономеры - олигоуретанметакрилат общей формулы (I),

n= 1-3,
и олигоуретанметакрилат общей формулы (II)

n= 1-3,
и инициатор фотополимеризации - систему соединений: эфиры бензоина (смесь изобутилового и бутилового эфира бензоина в соотношении 9: 1 - продукт марки Тригонал-14), диметиланилин и динитрилазобисмасляной кислоты при следующих соотношениях компонентов, мас. %:
Олигоуретанметакрилатизоцианурат (олигомер) - 55-60
Олигоуретанметакрилат линейной структуры (сомономер I) - 15-35
Олигоуретанметакрилат разветвленной структуры (сомономер II) - 3-23,5
Эфиры бензоина (продукт марки Тригонал-14) - 1.5-3
Диметиланилин - 3-5
Динитрилазобисмасляной кислоты - 1.5-3
Олигоуретанметакрилатизоцианурат (олигомер) получают следующим образом. На первой стадии синтеза проводят циклотримеризацию 2,4-толуилендиизоцианата до степени превращения изоцианатных групп 50% при температуре ~ 65±5^oС в присутствии каталитической системы. На второй стадии к циклотримеру добавляют монометакриловый эфир этиленгликоля и катализатор - соединение олова. Синтез проходит в течение 5-6 ч. Синтез проводят в растворе органических растворителей метилэтилкетоне, циклогексаноне, бутилацетате, этилацетате. Конечный продукт представляет собой 50%-ный раствор в вышеперечисленных растворителях.This is achieved by the composition comprising a oligomer (oligourethane methacrylate isocyanurate) of the general formula

n = 1-3,
as well as comonomers - oligourethane methacrylate of the general formula (I),

n = 1-3,
and oligourethane methacrylate of the general formula (II)

n = 1-3,
and the initiator of photopolymerization is a system of compounds: benzoin esters (a mixture of isobutyl and butyl benzoin ether in a ratio of 9: 1 is a product of the Trigonal-14 brand), dimethylaniline and dinitrilazobismobutyric acid in the following ratios of components, wt. %:
Oligourethane methacrylate isocyanurate (oligomer) - 55-60
Oligourethane methacrylate linear structure (comonomer I) - 15-35
Branched oligourethane methacrylate (comonomer II) - 3-23.5
Benzoin esters (product of the Trigonal-14 brand) - 1.5-3
Dimethylaniline - 3-5
Dinitrilazobismobutyric acid - 1.5-3
Oligourethane methacrylate isocyanurate (oligomer) is prepared as follows. In the first stage of the synthesis, cyclotrimerization of 2,4-toluene diisocyanate is carried out to a degree of conversion of isocyanate groups of 50% at a temperature of ~ 65 ± 5 ^° C in the presence of a catalytic system. In a second step, ethylene glycol monomethacrylic ester and a tin compound catalyst are added to the cyclotrimer. The synthesis takes 5-6 hours. The synthesis is carried out in a solution of organic solvents methyl ethyl ketone, cyclohexanone, butyl acetate, ethyl acetate. The final product is a 50% solution in the above solvents.

A linear structure oligourethane methacrylate (comonomer I) is prepared as follows. At the first stage of the synthesis, a prepolymer is obtained - the product of the interaction of 2,4-toluene diisocyanate with a diol (for example, the diol industrial grade laprol 502) to a degree of conversion of 50% isocyanate groups at a temperature of ~ 60 ± 5 ^o С in the presence of a catalyst. In a second step, ethylene glycol monomethacrylic ester and a tin compound catalyst are added to the prepolymer. The temperature of the reaction mixture in the second stage is ~ 25 ± 5 ^o C. The synthesis takes place within 4-5 hours. The synthesis is carried out in a solution of organic solvents methyl ethyl ketone, cyclohexanone, butyl acetate, ethyl acetate. The final product is an 80% solution in the above solvents.

Branched oligourethane methacrylate (comonomer II) is prepared as follows. At the first stage of the synthesis, an adduct is obtained - the product of the interaction of 2,4-toluene diisocyanate with ethylene glycol dimethacrylic ester to a degree of conversion of isocyanate groups of 50% at a temperature of ~ 40 ± 5 ^o C in the presence of a catalyst. In the second stage, a polyol (for example, a product of the industrial brand Laprol-503) and a catalyst, a tin compound, are added to the adduct. The temperature of the reaction mixture in the second stage is ~ 25 ± 5 ^o C. The synthesis takes place within 4-5 hours. The synthesis is carried out in a solution of organic solvents methyl ethyl ketone, cyclohexanone, butyl acetate, ethyl acetate. The final product is an 80% solution in the above solvents. Characteristics of the oligomer and comonomers I and II are presented in table 1.

 As can be seen from the table, data on the molecular weight, the content of urethane and methacrylic groups, IR and UV spectroscopy confirm the structure of the oligomers.

 The components of the photoinitiating system are introduced into the composition in various forms: benzoin esters (product of the Trigonal-14 brand) as an individual compound, dimethylaniline as an individual compound, dinitrilazobismobutyric acid as an individual compound or as a 10-50% solution in methyl ethyl ketone, cyclohexanone, butyl acetate, acetone and ethyl acetate.

 The composition is prepared by mixing the components at room temperature. The oligomeric base is mixed separately from the photoinitiating system. First of all, a photo-initiating system is prepared, which is maintained for 15-30 minutes, and then the components of the base are mixed. The preliminary exposure time of the entire composition as a whole, before entering directly into the irradiation zone, is ~ 30 minutes.

 The compositions are shown in table 2.

Curing conditions: temperature - 15 ± 25 ^o С, low-energy radiation source of the wavelength range 400-700 nm, curing time - 20-25 s, optimal coating thickness - 70-150 microns. It is possible to apply compositions in a thickness range of 70-1000 microns under the same curing conditions.

 Data on the physico-mechanical properties of the coatings, their wear resistance, stickiness are given in table 3.

The data indicate that, in comparison with the prototype, the degree of curing of coatings increases, so for 20-25 seconds curing under the influence of radiation, the content of the gel fraction is 92-97% (compared with 88% of the prototype in 30 s), the hardness increases to 0.82-0.87, impact strength is 50 kgf • cm (prototype 40 kgf • cm). Wear resistance is 1.5-3 times higher than that of the prototype, the stickiness 5 seconds after curing is 0.55-0.57 g / cm ² (the prototype 0.90 g / cm ² ).

Claims (1)

A polymer coating composition comprising an oligomer, comonomers and a photopolymerization initiator, characterized in that it contains oligourethane methacrylate isocyanurate of the general formula as an oligomer

n = 1-3,
as comonomers, oligourethane methacrylate of the general formula (I)

n = 1-3,
and oligourethane methacrylate of the general formula (II)

where n = l-3,
and as the initiator of photopolymerization using a system of compounds benzoin esters (product brand Trigonal-14), dimethylaniline and dinitrilazobismobutyric acid in the following mass ratio of components, wt. %:
Oligourethane methacrylate isocyanurate (oligomer) - 55-60
Oligourethane methacrylate linear structure (comonomer I) - 15-35
Branched oligourethane methacrylate (comonomer II) - 3-23.5
Benzoin esters (product of the Trigonal-14 brand) - 1.5-3
Dimethylaniline - 3-5
Dinitrilazobismobutyric acid - 1.5-3

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