Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/70—Siloxanes defined by use of the MDTQ nomenclature
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/12—Polysiloxanes containing silicon bound to hydrogen
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/14—Polysiloxanes containing silicon bound to oxygen-containing groups
  • C08G77/18—Polysiloxanes containing silicon bound to oxygen-containing groups to alkoxy or aryloxy groups
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/20—Polysiloxanes containing silicon bound to unsaturated aliphatic groups
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/42—Block-or graft-polymers containing polysiloxane sequences
  • C08G77/44—Block-or graft-polymers containing polysiloxane sequences containing only polysiloxane sequences
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L83/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
  • C08L83/04—Polysiloxanes
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D183/00—Coating compositions based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon, with or without sulfur, nitrogen, oxygen, or carbon only; Coating compositions based on derivatives of such polymers
  • C09D183/04—Polysiloxanes

Definitions

• the present invention relates to an organosiloxane block copolymer and its preparation method.
• the copolymer can be used to prepare protective coating products for electronic components.
• CN103189420B discloses a resin-linear organosiloxane block copolymer that contains linear D units of the formula [R 1 2 SiO 2/2 ] , T resin units of the formula [R 2 SiO 3/2 ] , and silanol groups [ ⁇ SiOH] , wherein the resin component consists of the T units of the formula [R 2 SiO 3/2 ] .
• the copolymer can be used to prepare protective and functional coatings for electronic packaging.
• CN103189419B discloses a high-refractive-index solid composition comprising the aforesaid copolymer.
• CN103201317B discloses a thermally stable solid composition comprising the aforesaid copolymer.
• CN103201318B discloses a process for preparing the aforesaid copolymer by condensation.
• CN103189421B discloses a copolymer that contains diorganosiloxane units having the formula R 1 2 SiO 2/2 , and siloxane units having the average formula R 2 x (OR 3 ) y SiO (4-x-y) /2 , where 0.5 ⁇ x ⁇ 1.5, and 0 ⁇ y ⁇ 1, and at least 50 mol%of R 2 are aryl groups.
• the siloxane units of formula (II) in Examples therein are all phenyl-T units.
• CN104254575A discloses a process for preparing resin-linear organosiloxane block copolymers.
• the resulting sheet was an optically clear, grabby elastomer at room temperature.
• the present invention relates to a new resin-linear organosiloxane block copolymer that comprises linear units of the formula [R 1 2 SiO 2/2 ] , resin units of the formula [R 2 3 SiO 1/2 ] [SiO 4/2 ] (i.e., D-MQ structure) , and preferably further comprises hydrolyzable groups X, more preferably further comprises vinyl groups.
• the new block copolymer of the present invention features a structure combining hard and soft blocks.
• its hard blocks contain resin units of the formula [R 2 3 SiO 1/2 ] [SiO 4/2 ]
• the new block copolymer is more compatible with solvents and easier to form a film, and offers suitable hardness and flexibility to cured coatings.
• the block copolymer can be mixed with multifunctional alkoxysilanes and catalysts to obtain a composition that can be rapidly cured in the presence of moisture.
• the composition is in low viscosity and easy to apply, and after cured at room temperature forms a coating film that is transparent and hard with excellent mechanical properties, low internal stress and high elongation.
• the composition can be used to prepare circuit board conformal coatings for electronic packaging or protective coatings for electronic appliances.
• the preparation of the new block copolymer features easy access to raw materials, simple and controllable processes, stable quality and good reproducibility.
• the present invention relates to an organosiloxane block copolymer comprising
• R 1 and R 2 can be the same or different independently in each occurrence, and is selected from among C1-C30 linear or branched alkyl groups, C1-C30 aryl groups, C1-C30 hydrocarbon groups having one or more hetero atoms, hydrolyzable group X, C1-C30 hydrocarbon groups having one or more olefinic bonds, and H,
• T units of the formula [R 1 SiO 3/2 ] are present in an amount of less than or equal to 30 mol%, preferably less than or equal to 10 mol%, and more preferably less than or equal to 1 mol%, based on the total amount, as 100 mol%, of all the silicone units.
• the D units of the formula [R 1 2 SiO 2/2 ] are linked to each other to form a block of D units.
• the M units of the formula [R 2 3 SiO 1/2 ] and the Q units of the formula [SiO 4/2 ] are linked to each other to form a block of MQ units.
• R 1 and/or R 2 are selected from the hydrolyzable group X
• the hydrolyzable group X can be the same or different, selected from among ketoximino groups, acetoxy groups, alkoxy groups or hydroxyl groups, and is preferably alkoxy groups of the formula OR 6 , where R 6 can be the same or different independently in each occurrence, selected from among C1-C30 linear or branched alkyl groups and aryl groups, and is preferably methyl group, ethyl group and isopropyl group, more preferably methyl group or ethyl group; and the hetero atom is selected from among O, N and S, preferably O and N, and more preferably O.
• X is alkoxy groups represented by OR 6 , preferably X functional groups are methoxy and/or ethoxy groups.
• the moral ratio of [R 2 3 SiO 1/2 ] M unit to hydrolyzable group X is equal to or smaller than 20, preferably between 3-10, more preferably between 3-7, more preferably between 4-5, calculated according to 1 H NMR and 29 Si NMR.
• the moral ratio of [R 2 3 SiO 1/2 ] M unit and methoxy groups is equal to or smaller than 30, preferably between 5-25, more preferably between 6-20, more preferably between 6-17, more preferably between 6-12, more preferably between 6-11, calculated according to 1 H NMR and 29 Si NMR.
• the moral ratio of [R 2 3 SiO 1/2 ] M unit and Si-vinyl groups is equal to or smaller than 40, preferably between 5-35, more preferably between 10-30, more preferably between 15-25, more preferably between 18-25, calculated according to 1 H NMR and 29 Si NMR.
• the moral ratio of [R 2 3 SiO 1/2 ] M unit and Si-vinyl groups is equal to or larger than 15, preferably equal to or larger than 18, equal to or larger than 20.
• R 2 are selected from among methyl group, ethyl group, vinyl group, phenyl group, H, hydrolyzable group X, preferably from methyl group, vinyl group and hydrolyzable group X.
• less than or equal to 20 wt%, preferably less than or equal to 15 wt%, more preferably from 0 to 10 wt%, more preferably from 0 to 5 wt%, more preferably from 1 to 5 wt%or 0 wt%of R 2 are phenyl groups, based on the total amount, as 100 wt%, of the total weight of the block copolymer.
• R 1 is selected from among methyl group, ethyl group, vinyl group, phenyl group, H, hydrolyzable group X, preferably from methyl group, vinyl group and hydrolyzable group X, preferably methyl.
• less than or equal to 20 wt%, preferably less than or equal to 15 wt%, more preferably from 0 to 10 wt%, more preferably from 0 to 5 wt%, more preferably from 1 to 5 wt%or 0 wt%of R 1 are phenyl groups, based on the total amount, as 100 wt%, of the total weight of the block copolymer.
• the blocks of D units have a number average molecular weight (Mn) of from 1,000 to 27,000 g/mol, preferably from 4,000 to 25,000 g/mol, more preferably from 10,000 to 25,000 g/mol.
• Mn number average molecular weight
• the number of repeating units in the blocks of D units having the formula [R 1 2 SiO 2/2 ] linked by Si-O-Si bond is greater than or equal to 20, preferably from 50 to 1,000, more preferably from 50 to 400, more preferably from 70 to 400.
• the D units of the formula [R 1 2 SiO 2/2 ] are present in an amount of greater than or equal to 20 mol%, preferably greater than or equal to 22 mol%, more preferably from 22.5 to 35 mol%, most preferably from 25 to 32.5 mol%, based on the total amount, as 100 mol%, of all the silicone units.
• the M units of the formula [R 2 3 SiO 1/2 ] are present in an amount of greater than or equal to 20 mol%, preferably greater than or equal to 22 mol%, more preferably from 22.5 to 32.5 mol%, most preferably from 25 to 32.5 mol%, based on the total amount, as 100 mol%, of all the silicone units.
• the Q units of the formula [SiO 4/2 ] are present in an amount of greater than or equal to 25 mol%, preferably greater than or equal to 30 mol%, more preferably from 35 to 55 mol%, most preferably from 35 to 45 mol%, based on the total amount, as 100 mol%, of all the silicone units.
• the M units of the formula [R 2 3 SiO 1/2 ] and the Q units of the formula [SiO 4/2 ] are present in a combined amount of from 60 to 80 mol%, preferably from 75 to 80 mol%, based on the total amount, as 100 mol%, of all the silicone units.
• the raw materials involved in the reaction include MQ type silicone resins and linear silicone fluids containing the D units, preferably obtained via an addition reaction.
• the block copolymer mentioned above has a weight average molecular weight (Mw) of from 10,000 to 200,000 g/mol, preferably from 20,000 to 150,000 g/mol, more preferably from 40,000 to 100,000 g/mol.
• R 1 or R 2 can be the same or different independently in each occurrence, and is selected from among C1-C30 linear or branched alkyl groups, C30 hydrocarbon groups having one or more hetero atoms, C1-C30 aryl groups, hydrolyzable group X, C1-C30 hydrocarbon groups having one or more olefinic bonds, and H, where the T units of the formula [R 1 SiO 3/2 ] are present in an amount of less than or equal to 30 mol%, preferably less than or equal to 10 mol%, and more preferably less than or equal to 1 mol%, based on the total amount, as 100 mol%, of all the silicone units.
• the hydrolyzable group X can be the same or different, and is preferably ketoximino groups, acetoxy groups, alkoxy groups or hydroxyl groups, more preferably alkoxy groups of the formula OR 6 , where R 6 can be the same or different independently in each occurrence, selected from among C1-C30 linear or branched alkyl groups and aryl groups, and is preferably methyl group, ethyl group and isopropyl group, more preferably methyl group or ethyl group.
• the hetero atom is selected from among O, N and S, preferably O and N, and more preferably O
• X is alkoxy groups represented by OR 6 , preferably X functional groups are methoxy and/or ethoxy groups.
• the moral ratio of [R 2 3 SiO 1/2 ] M unit to hydrolyzable group X is equal to or smaller than 8, preferably between 3-8, more preferably between 3-7, more preferably between 4-5, calculated according to 1 H NMR and 29 Si NMR.
• the moral ratio of [R 2 3 SiO 1/2 ] M unit and methoxy groups is equal to or smaller than 30, preferably between 5-25, more preferably between 6-20, more preferably between 6-12, more preferably between 6-11, calculated according to 1H NMR and 29Si NMR.
• the moral ratio of [R 2 3 SiO 1/2 ] M unit and Si-vinyl groups is equal to or smaller than 40, preferably between 5-35, more preferably between 10-30, more preferably between 15-25, more preferably between 18-25, calculated according to 1H NMR and 29Si NMR.
• the moral ratio of [R 2 3 SiO 1/2 ] M unit and Si-vinyl groups is equal to or larger than 15, preferably equal to or larger than 18, preferably equal to or larger than 20, calculated according to 1H NMR and 29Si NMR.
• the T units of the formula [R 1 SiO 3/2 ] are present in an amount of less than or equal to 30 mol%, preferably less than or equal to 10 mol%, and more preferably less than or equal to 0.1 mol%, based on the total amount, as 100 mol%, of all the silicone units.
• the D units of the formula [R 1 2 SiO 2/2 ] are present in an amount of from 22.5 to 35 mol%, preferably from 25 to 32.5 mol%, based on the total amount, as 100 mol%, of all the silicone units.
• the M units of the formula [R 2 3 SiO 1/2 ] are present in an amount of from 22.5 to 35mol%, preferably from 25 to 32.5 mol%, based on the total amount, as 100 mol%, of all the silicone units.
• the Q units of the formula [SiO 4/2 ] are present in an amount of from 30 to 55 mol%, preferably from 35 to 45 mol%, more preferably from 35-40 mol%, based on the total amount, as 100 mol%, of all the silicone units.
• the M units of the formula [R 2 3 SiO 1/2 ] and the Q units of the formula [SiO 4/2 ] are present in a combined amount of from 60 to 80 mol%, preferably from 65 to 80 mol%, based on the total amount, as 100 mol%, of all the silicone units.
• the molar ratio of M units of the formula [R 2 3 SiO 1/2 ] to Q units of the formula [SiO 4/2 ] ranges from 0.5 to 0.9, preferably 0.6 to 0.8.
• the mixture mentioned above has a weight average molecular weight (Mw) of from 10,000 to 100,000 g/mol, preferably from 20,000 to 70,000 g/mol, more preferably from 25,000 to 60,000 g/mol.
• the mixture mentioned above is a transparent, viscous liquid at 1 atm and 25°C.
• the 70 wt%solution in toluene of the mixture mentioned above has a viscosity of from 50 to 500 mPa ⁇ s, preferably from 100 to 200 mPa ⁇ s, more preferably from 100 to 150 mPa ⁇ s, most preferably from 110 to 150 mPa ⁇ s, measured according to GB ⁇ T21059-2007 (DIN EN ISO3219: 1994) .
• a method for preparing the resin-linear organosiloxane block copolymer comprising Step 1:
• Component (a) a MQ type silicone resin
• Component (b) a hydrosilane having the formula (I)
• n is an arbitrary integer from 1 to 3, preferably 2 or 3, more preferably 2;
• X represents hydrolyzable groups that can be the same or different, and is preferably ketoximino groups, acetoxy groups, alkoxy groups or hydroxyl groups, more preferably alkoxy groups of the formula OR 6 , where R 6 can be the same or different independently in each occurrence, selected from among C1-C30 linear or branched alkyl groups and aryl groups, and is preferably methyl group, ethyl group and isopropyl group, more preferably methyl group; and
• R 5 can be the same or different independently in each occurrence, and is selected from among C1-C30 linear or branched alkyl groups and aryl groups, C1-C30 hydrocarbon groups having one or more hetero atoms, and C1-C30 hydrocarbon groups having one or more olefinic bonds, preferably from among methyl, ethyl and isopropyl,
• Component (c) a hydrogen silicone oil
• Component (d) a hydrosilylation catalyst
• Component (e) a hydrosilylation inhibitor, is added to the product obtained above to deactivate Component (d) , a hydrosilylation catalyst.
• Step 1 Component (a) , a MQ type silicone resin, and Component (b) , a hydrosilane, are pre-reacted, and then the resulting product is mixed with Component (c) , a hydrogen silicone oil, and Component (d) , a hydrosilylation catalyst.
• Component (a) a MQ type silicone resin, has a Mw of from 1000 to 20000 g/mol, preferably from 2000 to 10000 g/mol, more preferably from 2000 to 8000 g/mol.
• Component (a) a MQ type silicone resin has a glass transition temperature Tg midpoint of greater than or equal to 35 °C, preferably greater than or equal to 37 °C, more preferably between 37-50°C.
• Component (a) a MQ type silicone resin, is solid at 1 atm and room temperature.
• Component (b) comprises one or more hydrosilanes that are selected from the group consisting of methyldimethoxysilane, methyldiethoxysilane, ethyldimethoxysilane, ethyldiethoxysilane, trimethoxysilane, and triethoxysilane, wherein methyldimethoxysilane is present in an amount of more than 80 wt%, preferably more than 90 wt%, more preferably more than 95 wt%, most preferably more than 99 wt%, based on the total amount, as 100 wt%, of Component (b) .
• each of the hydrogen silicone oil molecules has an average of greater than or equal to 2 Si-H groups, preferably 2 Si-H groups, and is preferably terminated with two hydrogen atoms.
• the D units of the formula [R 1 2 SiO 2/2 ] in Component (c) have a number average molecular weight (Mn) of 1,000 to 27,000 g/mol, preferably 4,000 to 25,000 g/mol, more preferably 10,000 to 25,000 g/mol.
• Component (d) a hydrosilylation catalyst
• a hydrosilylation catalyst is a platinum-based catalyst, preferably a Karstedt's catalyst.
• a curable composition comprising
• Component (i-1) the block copolymer mentioned above,
• Component (ii) a silane with multi-hydrolyzable groups, having the formula (II)
• n 3 or 4, preferably 3;
• R 7 can be the same or different independently in each occurrence, and is selected from among C1-C30 linear or branched alkyl groups and aryl groups, C1-C30 hydrocarbon groups having one or more hetero atoms, and C1-C30 hydrocarbon groups having one or more olefinic bonds; and
• X represents hydrolyzable groups that can be the same or different, and is preferably ketoximino groups, acetoxy groups, alkoxy groups or hydroxyl groups, more preferably alkoxy groups of the formula OR 6 ,
• R 6 can be the same or different independently in each occurrence, selected from among C1-C30 linear or branched alkyl groups and aryl groups, and is preferably methyl group, ethyl group and isopropyl group, more preferably methyl group;
• Component (iii) a condensation and/or hydrolysis catalyst.
• a curable composition comprising
• Component (i-2) the mixture containing the block copolymer mentioned above,
• Component (ii) a silane with multi-hydrolyzable groups, having the formula (II) , and
• Component (iii) a condensation and/or hydrolysis catalyst.
• multi-hydrolyzable groups herein refers to having functional groups of greater than or equal to 3.
• Component (ii) a silane with multi-hydrolyzable groups, having the formula (II) are one or members selected from the group consisting of methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxy Silane, phenyltrimethoxysilane, phenyltriethoxysilane, epoxypropyltrimethoxysilane, aminomethyltriacetoxysilane, methyltriacetoxysilane, phenyltriacetoxysilane, methyltris (methylethylketoximino) silane, vinyltris (methylethylketoximino) silane, phenyltris (methylethylketoximino) silane, and phenylanilinemethyltri
• Component (iii) a condensation and/or hydrolysis catalyst, is selected from among complexes of lead, tin, titanium, zinc and iron, preferably from among alkoxy organotitanium and organotitanium compounds, and more preferably is one, or a combination, of tetrabutyl titanate, diisopropoxy-bisethylacetoacetatotitanate, diisobutoxy-bisethylacetoacetatotitanate, isopropyl titanate, polybutyl titanate, and tetraisooctyl titanate.
• Component (ii) a silane with multi-hydrolyzable groups, having the formula (II) is present in an amount of from 5 to 7 wt%, based on the total amount, as 100 wt%, of Component (i-2) , the mixture mentioned above.
• Component (iii) a condensation and/or hydrolysis catalyst, is present in an amount of from 2 to 4 wt%, based on the total amount, as 100 wt%, of Component (i-2) , the mixture mentioned above.
• the weight ratio of Component (ii) to Component (iii) ranges from 1.1 to 3, preferably from 1.5 to 2.5.
• the present invention provides a method for preparing solid compositions that comprise a step of removing the organic solvent from any one of the curable compositions mentioned above.
• the present invention provides a method for preparing a coating that comprises a step of removing the organic solvent from any one of the curable compositions mentioned above.
• the silicone units have the formula of [R (4-a) SiO a/2 ] , where a is an integer between 1 and 4, and the M, D, T and Q units respectively have the formulas [R 3 SiO 1/2 ] , [R 2 SiO 2/2 ] , [RSiO 3/2 ] and [SiO 4/2 ] .
• M Vi has the formula [R 3 SiO 1/2 ] , where parts of R are vinyl groups, and preferably one of three R substituents is a vinyl group;
• T ph has the formula [RSiO 3/2 ] , where parts of R are phenyl groups, and preferably one of three R substituents is a phenyl group.
• the M units of the formula [R 3 SiO 1/2 ] may be present in the blocks of D units in a small amount of less than or equal to 10 mol%, preferably less than or equal to 5 mol%, more preferably less than or equal to 1 mol%, based on the total amount, as 100 mol%, of all the silicone units in the blocks of D units.
• the T units of the formula [RSiO 3/2 ] may be present in the blocks of D units in a small amount of less than or equal to 1 mol%, preferably less than or equal to 0.1 mol%, based on the total amount, as 100 mol%, of all the silicone units in the blocks of D units.
• the MQ type silicone resins means such resins contain [R 2 3 SiO 1/2 ] M units and [SiO 4/2 ] Q units. Such resins may also contain a small amount of other silicone units, such as [R 1 2 SiO 2/2 ] D units, [R 1 SiO 3/2 ] T units. However, the sum of [R 2 3 SiO 1/2 ] M units and [SiO 4/2 ] Q units account for more than 80 mol%, preferably more than 90 mol%, more preferably more than 95 mol%, most preferably more than 99 mol%, based on the total amount, as 100 mol%, of all the silicone units.
• the weight ratio of M units of the formula [R 3 SiO 1/2 ] to Q units of the formula [SiO 4/2 ] ranges from 0.5 to 0.8, preferably from 0.6 to 0.8, more preferably from 0.6 to 0.7.
• R 1 , R 2 is defined as above.
• the present invention relates to organopolysiloxanes of a “resin-linear” organosiloxane block copolymer.
• Linear organopolysiloxanes generally contain predominantly D units of the formula [R 2 SiO 2/2 ] and usually are polydiorganosiloxane fluids having various viscosities, which are determined by the “degree of polymerization” (or DP) as indicated by the number of D units in the polydiorganosiloxanes. “Linear” organopolysiloxanes generally have a glass transition temperature (Tg) (midpoint) of lower than 25 °C.
• Tg glass transition temperature
• “resin-based” organopolysiloxanes When most of the units are selected from T units of the formula [R 2 SiO 3/2 ] or Q units of the formula [SiO 4/2 ] , “resin-based” organopolysiloxanes are obtained. An increase in the content of T units of the formula [R 2 SiO 3/2 ] or Q units of the formula [SiO 4/2 ] in the organopolysiloxanes generally results in an improvement in the hardness and/or glass-like properties of the polymers.
• the “resin-based” organopolysiloxanes shall be solid at room temperature and may be in the form of powder, granule or flake, and therefore have higher Tg values. For example, siloxane resins typically have Tg midpoint values of above 35 °C.
• the term “resin-linear organosiloxane block copolymer” refers to organopolysiloxanes containing “linear” D units and “resin-based” MQ units used in combination therewith. “Block” copolymers herein are opposed to “random” copolymers.
• the “resin-linear organosiloxane block copolymer” herein refers to organopolysiloxanes containing D and MQ units, wherein D units are primarily bonded together to form a polymer chain having a plurality of D units, which is referred to herein as a “linear block” , and MQ units are primarily bonded to each other to form a branched polymer chain, which is referred to as a “non-linear block” .
• a large amount of these non-linear blocks can be further aggregated when provided with block copolymers in a solid form.
• the block copolymers herein may be linear or branched.
• One block of MQ units may be connected to one or more linear blocks of D units.
• the solid organosiloxane block copolymer herein contains the first phase, mainly comprising D units of the formula [R 1 2 SiO 2/2 ] as defined herein, and the second phase, mainly comprising MQ units as defined herein.
• silicone resin 1 that is white solid powder at room temperature, consist of M units of the formula [R 2 3 SiO 1/2 ] and Q units of the formula [SiO 4/2 ] , where some M units contain vinyl and alkoxy (mainly ethoxy) groups, and M and Q units have a weight ratio of about 0.67, and a Mw of 5015 g/mol, based on the total weight of the silicone resin;
• Hydrogen silicone oil terminated with two hydrogen atoms, having a hydrogen content of 0.123 mmol/g and a Mw of about 16266.32 g/mol;
• Hydrogen silicone oil 2 terminated with two hydrogen atoms, having a hydrogen content of 0.493mmol/g and a Mw of about 4056.32 g/mol;
• SIPELL RE 61 F an alkynol inhibitor.
• Phase I comprises Component (a) , a MQ type silicone resin, Component (b) , a hydrosilane of the formula
• Component (c) a hydrogen silicone oil
• Component (d) a hydrosilylation catalyst
• Phase II comprises Component (e) , a hydrosilylation inhibitor.
• Phase I All ingredients of Phase I were mixed at 100 to 120 °C and reacted for 3 to 5 hours under closed conditions;
• step (3) The mixture obtained in step (3) was mixed with an organic solvent (comprising xylene, Isopar E by ExxonMobil, n-hexane, cyclohexane, n-heptane, and preferably xylene) to prepare a 70 wt%solution.
• an organic solvent comprising xylene, Isopar E by ExxonMobil, n-hexane, cyclohexane, n-heptane, and preferably xylene
• the mixture containing the block copolymer mentioned above refers to the mixture obtained in step (3) , referred to as “the mixture” in present invention.
• the Karstedt's catalyst listed in Table 1 has an active Pt content of about 12 ppm, based on the total weight, as 100 wt%, of Phase I.
• the amounts in Table 1 are in parts by weight.
• test results of the mixture containing the block copolymer mentioned above are shown in Table 2-1 and Table 2-2. Tested and calculated according to 1 H NMR, 29 Si NMR and GPC.
• the components in the coating composition were uniformly mixed, they were applied on a substrate and cured at room temperature for 7 days to obtain a coating film.
• Coating example B9 is in low viscosity and easily applied to release paper treated with a silicone release agent and cures at room temperature to obtain an about 2.5 mm thick, visually transparent coating film. After cured, the coating films are flat and have no deformation, which indicates a small internal stress.
• the coating films formed from Coating Examples B9 have a high Shore A hardness and a moderate elongation at break, which makes them excellent products with a sound balance between hardness and flexibility. After the low molecular weight impurities are removed, and the Mw of the block copolymer from Ex9 is around 51950 g/mol.
• Coating Example B8 has a relatively low hardness, yet a very high elongation at break, which makes it suitable for application on bonds. After the low molecular weight impurities are removed, and the Mw of the block copolymer from Ex8 is around 74700 g/mol.
• the hardness of the film obtained from Coating example A1 is relatively high. After the low molecular weight impurities are removed, and the Mw of the block copolymer from Ex1 is around 57100 g/mol.
• Coating Example A5 has a tack-free time shorter than 10 mins. It shall be applied to electronic devices in a short period of time. After cured, few cracks appear on the film surface.

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