Patent Application
20210187916
The present invention is related to a type of elastomer and manufacturing method thereof; particularly, a type of silicone elastomer applicable to hydrophilic or hydrophobic materials, anti-bacterial materials, conductive materials, as well as the fields of circuit printing, digital printing or film coating.
German patent number DE102011086103A1 titled “Silicone rubber on hotmelt adhesive” discloses a double-layer film comprising: (A) a first layer of silicone rubber; and (B) a hot melt adhesive film. The conditions for said double-layer film are: (i) the adhesive force between (A) and (B) is at least 50N/5 cm; (ii) softening temperature of (B) is between 80-200° C., and (iii) the double-layer film being a double-layer product having elasticity of extension at break of at least 1% according to the standards of ISO 53530.
Although the aforementioned prior art discloses an adhesive force being at least 50N/5 cm; however, the adhesive force is still insufficient for actual industrial applications. Furthermore, the double-layer film disintegrates easily due to the characteristic of its physical structure, which is disadvantageous for the following manufacturing processes and applications. This drawback is needed to be remedied.
U.S. Pat. No. 5,147,725A discloses “Method for bonding silicone rubber and polyurethane materials and articles manufactured thereby”. The disadvantage of said patent resides in that halogen biproducts may be produced during the manufacturing process and may cause environmental contamination, which is not desirable for industrial applicability.
In order to resolve the above-mentioned problems in the prior arts, the present invention provides a silicone elastomer, comprising: a first layer, being polyurethane; a second layer, being silicone rubber; and an intermediate layer, coated on an end surface of the first layer and the second layer and provided between the first layer and the second layer. The intermediate layer undergoes an addition reaction respectively with the first layer and the second layer and undergoes curing, so the intermediate layer is respectively bonded firmly with first layer and the second layer. Another end surface of the first layer is combined with a substrate. The substrate is a textile material or a conductive material. The substrate may be hydrophilic, hydrophobic, anti-bacterial, or conductive and may be suitable for circuit printing, digital printing or film coating.
Preferably, the intermediate layer is cured via thermal curing or photo-curing.
Preferably, an adhesive force between the intermediate layer and the first layer, and an adhesive force between the intermediate layer and the second layer is respectively from 50N/5 cm to 300N/5 cm.
A manufacturing method for the silicone elastomer comprises the steps of: coating an intermediate layer on a first layer, the intermediate layer and the first layer being placed in a curing apparatus to cure the intermediate layer; the intermediate layer and the first layer undergoing an addition reaction to bond the first layer with the intermediate layer; stacking a second layer on the intermediate layer, curing the second layer in the curing apparatus; and the intermediate layer and the second layer undergoing an addition reaction to bond the second layer with the intermediate layer.
Preferably, the curing apparatus is a thermal curing apparatus or a photo-curing apparatus.
Preferably, the thermal curing apparatus is provided with a predetermined temperature, the predetermined temperature is from 80° C. to 200° C.
As shown in
The first layer 10 is polyurethane, polyurethane (PU) having a functional group comprising: isocyanate group, or polyalcohol (hydroxyl Group).
The second layer 20 is a silicone rubber having a functional group comprising: SiH or —CH═CH2. An intermediate layer 30 is provided between the second layer 20 and the first layer 10; the intermediate layer 30 is self-crosslinking with: silane, acrylic acid, methyl acrylate, or acrylic acid ethyl ester.
The intermediate layer 30 is cured via thermal curing or photo-curing. The intermediate layer 30 respectively undergoes an addition reaction with the first layer 10 and the second layer 20, so the intermediate layer 30 respectively bonds with the first layer 10 and the second layer 20 firmly. The adhesive force between the intermediate layer 30 and the first layer 10, and the adhesive force between the intermediate layer 30 and the second layer 20 are respectively from 50 N/5 cm to 300 N/5 cm.
The double bond of C═N in the isocyanate functional group in the first layer 10 is highly active and can undergo autopolymerization to form a dimer or a trimer. The double bond can also undergo addition reaction with functional group containing active hydrogen such as water, alcohol, phenol, acid, or amine. The order activities of the chemicals in the functional group are as the following (Ar represents aryl functional group):
RNH2>R2NH>ArNH2>RCH2OH>H2O>R2CHOH>R3COH>ArOH>RCOOH>RNCO
The first layer 10 contains isocyanate group; the intermediate layer 30 thus can crosslink with the first layer 10 via the aforementioned functional group.
One of the mechanisms for cross-linking the intermediate layer 30 with the second layer 20 is as follows: an addition reaction is carried between the SiH functional group and the double bond; the reaction condition and speed is controlled by the usage of platinum catalyst; therefore, the second layer 20 can cross-link with the intermediate layer 30 via SiH functional group or double bond functional group.
According to the silicone elastomer 1 of the present invention, when used, an end surface of the first layer 10 is attached to a substrate 40 via thermal lamination (but not limited to this method). The substrate 40 is, but not limited to, textile material or conductive material. And the substrate may be hydrophilic or hydrophobic materials, anti-bacterial materials, or conductive materials, and may be suitable for circuit printing, digital printing, or film coating.
A method for manufacturing silicone elastomer comprises the following steps: coating an intermediate layer 30 on a first layer 10, the intermediate layer 30 and the first layer 10 being placed in a curing apparatus to cure the intermediate layer 30, meanwhile, the intermediate layer 30 and the first layer 10 undergoing an addition reaction in the curing apparatus to bond the first layer 10 with the intermediate layer 30; taking out the intermediate layer 30 and the first layer 10 and stacking a second layer 20 on the intermediate layer 30; curing the second layer 20 in the curing apparatus; and the intermediate layer 30 and the second layer 20 undergoing an addition reaction to bond the second layer 20 with the intermediate layer 30.
After completing the addition reaction between the intermediate layer 30 and the first layer 10 in the curing apparatus, another side of the intermediate layer 30 is still adhesive and is able to bond with the second layer 20. The intermediate layer 30 and the second layer 20 are cured again in the curing apparatus.
The curing apparatus is a thermal curing apparatus or a photo-curing apparatus. When the thermal curing apparatus is used, thermal curing apparatus is provided with a predetermined temperature, the thermal curing apparatus is heated with predetermined temperature of 80° C. to 200° C.
More specifically, the present invention can be obtained from the following methods.
In one embodiment, the present invention utilizes siloxane functional group condensation polymerization to achieve self-crosslinking reaction of the intermediate layer 30. 1% and 25% of trimethoxy(vinyl) silane (CAS:2768-02-7) and (3-Glycidyloxypropyl) triMethoxysilane (CAS:2530-83-8) are respectively dissolved in an organic solution. Appropriate and small amount of cross-linking catalysis is added to complete preparing the intermediate layer 30 original solution. The intermediate layer 30 original solution is diluted with appropriate ratio and coated on the first layer 10. The first layer 10 is baked in the curing apparatus with preheated temperature of 90° C. for 5 minutes to complete the addition reaction of the intermediate layer 30 and the first layer 10; and to evaporate the solvent in the intermediate layer 30. The second layer 20 is stacked on the intermediate layer 30; the second layer 20 and the intermediate layer 30 is baked in the curing apparatus with preheated temperature of 110° C. for 3 minutes to complete the addition reaction of the intermediate layer 30 and the second layer 20, and to cure the second layer 20. The adhesive force between the intermediate layer 30 and the first layer 10, and the adhesive force between the intermediate layer 30 and the second layer 20 are respectively from 55N/5 cm to 65N/5 cm.
In a preferred embodiment, the present invention utilizes siloxane functional group condensation polymerization to achieve self-crosslinking reaction of the intermediate layer 30. 3% and 25% of trimethoxy(vinyl) silane (CAS:2768-02-7) and (3-Glycidyloxypropyl) triMethoxysilane (CAS:2530-83-8) are respectively dissolved in an organic solution. Appropriate and small amount of cross-linking catalysis is added to complete preparing the intermediate layer 30 original solution. The intermediate layer original solution is diluted with appropriate ratio and coated on the first layer 10. The first layer 10 is baked in the curing apparatus with preheated temperature of 130° C. for 5 minutes to complete the addition reaction of the intermediate layer 30 and the first layer 10, and to evaporate the solvent in the intermediate layer 30. The second layer 20 is stacked on the intermediate layer 30; the second layer 20 and the intermediate layer 30 is baked in the curing apparatus with preheated temperature of 110° C. for 3 minutes to complete the addition reaction of the intermediate layer 30 and the second layer 20, and to cure the second layer 20. The adhesive force between the intermediate layer 30 and the first layer 10, and the adhesive force between the intermediate layer 30 and the second layer 20 are respectively from 90N/5 cm to 110N/5 cm.
Although particular embodiments of the present invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the present invention. Accordingly, the present invention is not to be limited except as by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201810568629.4 | Jun 2018 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2018/099971 | 8/10/2018 | WO | 00 |
