RU2385888C2 - Polymer composition for sealing piezoceramic hydroacoustic sensors - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: composition contains the following in pts. wt: 100 - triglyceride 12-hydroxy-cis-9 octadecenic acid (technical product of castor oil), 38.0-30.0 - toluene diisocyanate isomers, 2.7-30.0 - diethyleneglycol urethane and 0.1-1.0 - product of co-hydrolysis of methyltrichlorosilane with dimethyldichlorosilane. The sealant made from the proposed composition has low acoustic impedance.

EFFECT: improved electrophysical properties of sensors, resistance of hydroacoustic sensors sealed with the said sealant to effect of hydrostatic pressure of 10 MPa, which enables use of the sensors at up to 1000 m under water.

6 ex, 1 tbl

Description

The invention relates to the chemical technology of sealants and casting compounds and is intended for use in the manufacture of piezoceramic transducers, in particular in the manufacture of hydroacoustic piezoceramic sensor modules operating under hydrostatic pressures up to 10 MPa.

The polymer composition for sealing piezoceramic sensor modules must have high adhesion to the silver-plated surface of the piezoelectric elements, increased elasticity, low acoustic impedance and provide resistance to hydrostatic pressures up to 10 MPa.

Known polymer composition for sealing integrated circuits (Analog. Japanese. Application 60 - 248769. Publisher: 9.12.85. MKI C08L 63/00). The composition intended for sealing integrated circuits contains diane epoxies, a liquid acrylonitrile butadiene copolymer having terminal carboxyl groups, and has a reduced coefficient of thermal expansion and Young's modulus. A disadvantage of the known composition is the increased acoustic impedance.

The known composition of the sealant, including diane epoxy resin, the product of the interaction of oligodienurethane diepoxide with oligoamide, fillers and hardener (Analogue. A.S. CCCP No. 1745709, class C09K 3/10. Publ. 15.02.84. Bull. No. 8).

The known sealant is highly resistant to boiling water and vibration, and is used in the manufacture of piezoceramic filters and resonators in a housing design.

However, for sealing piezoceramic hydroacoustic sensors, the known composition cannot be used due to insufficient elasticity.

Known polymer composition for sealing semiconductor devices by injection molding under low pressure, containing epoxy and phenol-formaldehyde resins, amine hardeners and organosiloxane (Analog. Japan, z. 58-34825. Publ. 01.03.83. MKI C08G 59/62, C08G 59/13 )

The known composition is also not flexible enough.

Also known is a polymer composition comprising polyester, polyisocyanate and glycidol, intended for use as pouring and sealing compounds for strain-sensitive parts in the electronics industry (Analogue A.S. SU 1073265, class C08L 75/04, C08L 71/00. Publ. 02.15.84 Bull. No. 8).

A disadvantage of the known composition is the low adhesion to piezoceramic materials.

Polyurethane sealant K-31 is also known, which is a product of copolymerization of 2,4- and 2,6-isomers of toluene diisocyanate, triglyceride 12-hydroxy-cis-9 octadecenoic acid (technical product is castor oil) and styrene (Katsnelson M.Yu., Badaev, G.A., Polymer Materials (Reference), Leningrad: Chemistry, 1982. P.215

Sealant K-31 is characterized by increased frost resistance, good adhesion to metals, moisture resistance, high damping coefficient, improved impregnating ability. It is used for pouring and impregnating equipment components of high-voltage transformers, as well as sealing circuits containing fragile and sensitive elements.

The disadvantage of the K-31 sealant is the low resistance of the hydroacoustic piezoceramic sensors sealed by it to hydrostatic pressure up to 10 MPa and the low adhesion to piezoelectric elements.

The closest technical solution chosen as a prototype is a polyurethane sealant based on 12-hydroxy-cis-9 octadecenol triglyceride, toluene diisocyanate, diethylene glycolurethane, organosilicon compounds, titanium dioxide (1U) and inorganic pigments (Prototype. Polyurethane sealant No. 12. A (01/10/1998)) (D1).

The disadvantage of the prototype is the low stability of the sealed hydroacoustic piezoceramic sensors to hydrostatic pressure up to 10 MPa and increased acoustic impedance.

The problem to which this invention is directed, is to achieve a technical result, which consists in ensuring resistance to hydrostatic pressure of sealed piezoceramic sensors at a pressure of 10 MPa and reducing acoustic impedance.

The problem is solved in a polymer composition for sealing piezoceramic hydroacoustic sensors, including triglyceride 12-hydroxy-cis-9 octadecenoic acid (technical product - castor oil) and isomers of toluene diisocyanate, diethylene glycol urethane, an organosilicon compound, which is a product of the co-hydrochloride dimethylchloride hydrochloride (parts by weight):

Castor oil one hundred Toluene diisocyanate isomers 38.0-30.0 Diethylene glycol urethane 2.7-30.0 Methyltrichlorosilane Cohydrolysis Product with dimethyldichlorosilane 0.1-1.0

Distinctive features of the invention is that titanium dioxide (1U) and inorganic pigments are excluded from the composition of the polymer composition.

The specified set of distinctive features allows to achieve a technical result, which consists in ensuring resistance to hydrostatic pressure and in reducing acoustic impedance.

The invention is illustrated by the following examples.

The standards by which used substances are released are listed below.

GOST 6757-73 castor oil

Diethylene glycol urethane TU 6-03-388-75

Toluene diisocyanate 102-T TU 6-03-331-72

Toluene diisocyanate T-65/35 TU 6-03-340-73

The product of cohydrolysis of methyltrichlorosilane with

dimethyldichlorosilane TU 6-02-909-79

Example 1

Castor oil is dried at a temperature of 120-130 ° C and a pressure of not more than 10 mm Hg. within 12 hours. In 100 parts by weight castor oil add 0.01 wt.h. cohydrolysis product of methyltrichlorosilane with dimethyldichlorosilane. The mixture is stirred for at least 5 minutes, add 37.0 wt.h. toluylene diisocyanate (technical product - 102-T) and 2.5 wt.h. diethylene glycolurethane, stirred for 2-3 minutes and vacuum at room temperature and a pressure of not more than 10 mm Hg Curing is carried out at room temperature for at least 48 hours.

In example 1, the prohibitive proportions of the components are taken.

Example 2

Carried out analogously to example 1, but with the following qualitative and quantitative ratio of components (parts by weight):

Castor oil one hundred T-65 Toluene Diisocyanate 38,0 Diethylene glycol urethane 4,5 The product of cohydrolysis of methyltrichlorosilane with dimethyldichlorosilane 0.1

Example 3

Carried out analogously to example 1, but with the following qualitative and quantitative ratio of components (parts by weight):

Castor oil one hundred T-65 Toluene Diisocyanate 35.0 Diethylene glycol urethane 11.8 The product of cohydrolysis of methyltrichlorosilane with dimethyldichlorosilane 0.2

Example 4

Carried out analogously to example 1, but with the following qualitative and quantitative ratio of components (parts by weight):

Castor oil one hundred Toluene diisocyanate T-102 32,0 Diethylene glycol urethane 20.9 The product of cohydrolysis of methyltrichlorosilane with dimethyldichlorosilane 0.6

Example 5

Carried out analogously to example 1, but with the following qualitative and quantitative ratio of components (parts by weight):

Castor oil one hundred T-65 Toluene Diisocyanate 30,0 Diethylene glycol urethane 4,5 The product of cohydrolysis of methyltrichlorosilane with dimethyldichlorosilane one

Example 6

Carried out analogously to example 1, but with the following qualitative and quantitative ratio of components (parts by weight):

Castor oil one hundred T-65 Toluene Diisocyanate 29.0 Diethylene glycol urethane 30,0 The product of cohydrolysis of methyltrichlorosilane with dimethyldichlorosilane 1,2

In example 6, the extreme proportions of the components are taken, the content of toluene diisocyanate is lower than the lower claimed limit, and the product of cohydrolysis of methyltrichlorosilane with dimethyldichlorosilane is higher than the upper declared limit.

The properties of the inventive sealant in comparison with the prototype are shown in the table.

As can be seen from the table, the inventive polymer composition ensures the stability of the sealed hydroacoustic piezoceramic sensors to hydrostatic pressure of up to 10 MPa, which allows the sensors to be operated at a depth of immersion of up to 1000 m. The acoustic impedance of the sealant according to the invention is 25-30 less %, which helps to increase the electrophysical parameters of the sensors.

Table Indicators The value of the examples one 2 3 four 5 6 Prototype. Example 3 Tensile strength, MPa 4.0 5,0 5,4 5.2 4.8 4.2 5,4 Elongation in tension, MPa one hundred 140 125 160 190 140 125 Acoustic impedance, × 10 ³ g / cm ² s 1.55 1.52 1.54 1.55 1.56 1.58 1.98 Adhesive strength "sealant - piezoceramics", MPa 0.8 3.6 3.8 1.2 4.0 42 3.8 Resistance of sealed sensors to pressure 10 MPa - + + + + - - + - it is steady; - - not stable.

Claims (1)

A polymer composition for sealing piezoceramic hydroacoustic sensors, including triglyceride 12-hydroxy-cis-9 octadecenoic acid (castor oil is a technical product), isomers of toluene diisocyanate, diethylene glycol urethane and the product of co-hydrolysis of methyltrichlorosilane with dimethyldichlorosilane in the following ratio:
Castor oil one hundred Toluene diisocyanate isomers 38.0-30.0 Diethylene glycol urethane 2.7-30.0 The product of cohydrolysis of methyltrichlorosilane with dimethyldichlorosilane 0.1-1.0