(meth)acryl group-modified polysiloxane and a method for synthesizing the same

Abstract

The present application relates to a method for preparing a (meth)acryl-modified polysiloxane, comprising the following steps: (1) providing a polysiloxane having at least two epoxy-functional groups at the end or side; (2) reacting the polysiloxane having epoxy-functional groups with (meth)acrylic acid in the presence of a catalyst to obtain a product containing at least two carbon-carbon unsaturated double bonds and at least two secondary hydroxyl groups; (3) reacting the product obtained in step (2) with (meth)acryloyl halide in the presence of an acid binding agent to obtain the (meth)acryl-modified polysiloxane. Furthermore, the present application also relates to a (meth)acryl-modified polysiloxane compound having the following structural formula (II): and also to a release agent comprising the (meth)acryl-modified polysiloxane compound of formula (II) or prepared by the method.

Description

TECHNICAL FIELD

[0001] The present application relates to a new method for synthesizing (meth)acryl-modified polysiloxane, (meth)acryl-modified polysiloxane prepared by the method, and a mold releasing agent comprising the polysiloxane. BACKGROUND

[0002] A mold releasing agent is a release film applied between a molded composite product and a mold to prevent the product from sticking to the mold, so that the product can be easily removed from the mold while ensuring the surface quality of the product and the integrity of the mold.

[0003] It is known in the art that polysiloxane containing (meth)acryl groups (i.e., CH(CH3)=CH-C(O)O-) can be used as a material for a mold releasing agent. However, such modified polysiloxane can sometimes have problems of incomplete curing, low residual adhesion strength, or high release force when used as a mold releasing agent.

[0004] It has been found that in the case of a synthesized (meth)acryl-modified polysiloxane, when the content of the modifying group within the same molecule is too low, the degree of curing of the product under the same conditions is poor and the release force retention rate is not satisfactory, and when the content of the modifying group within the same molecule is too high, the degree of curing is improved, but the release force of the product becomes too high.

[0005] In order to improve the balance between the release force and the degree of curing, it is necessary to react more unsaturated double bonds at limited modification sites such as end groups. For example, US6211322B1 discloses a method for synthesizing an organic polysiloxane containing a (meth)acrylate group, in which a terminal or lateral hydrogen-containing polysiloxane is first subjected to a hydrosilylation reaction with a polyhydroxy alkenyl ether compound in the presence of a catalyst, and then subjected to an esterification reaction with (meth)acrylic acid in the presence of an acid catalyst and a water removing agent.

[0006] However, in this way, the esterification of (meth)acrylic acid with a primary hydroxyl group requires dehydration at a high temperature for a long time, and the unsaturated double bond is sensitive to free radicals, so a polymerization inhibitor is required to prevent the polymerization of the double bond. However, higher heat and longer time generate more free radicals, which puts higher requirements on how to prevent the polymerization of the unsaturated double bond in large-scale production, thereby significantly increasing the cost of large-scale production. At the same time, the carboxyl group can only be esterified with a primary hydroxyl group at a low temperature, and cannot be esterified with a secondary hydroxyl group under the same reaction conditions. SUMMARY

[0007] Accordingly, it is an object of the present application to overcome the above-mentioned drawbacks in the prior art and to provide a novel synthetic route and a synthetic release agent product. It has been found that the above-mentioned objects can be achieved by the preparation method described below, the (meth)acryl-modified polysiloxane obtained by the method and the release agent comprising the modified polysiloxane.

[0008] A first aspect of the present application relates to a method for preparing a (meth)acryl-modified polysiloxane, comprising the following steps:

[0009] (1) providing a polysiloxane having at least two epoxy-functional groups at the end or laterally;

[0010] (2) reacting the polysiloxane having epoxy-functional groups with (meth)acrylic acid in the presence of a catalyst to obtain a product containing at least two carbon-carbon unsaturated double bonds and at least two secondary hydroxyl groups;

[0011] (3) reacting the product obtained in step (2) with (meth)acryloyl halide in the presence of an acid-binding agent to obtain the (meth)acryl-modified polysiloxane.

[0012] A second aspect of the present application relates to the (meth)acryl-modified polysiloxane compound obtained by the above-mentioned preparation method.

[0013] Furthermore, a third aspect of the present application relates to a release agent comprising the (meth)acryl-modified polysiloxane.

[0014] The inventors of the present application have found that by employing the novel synthetic route of the present application, the molar mass of the (meth)acryl groups in the prepared (meth)acryl-modified polysiloxane is higher in proportion to the molar mass of the non-silicone chemical groups. At the same time, the release agent containing the polysiloxane can have both higher curing efficiency and a balance of curing efficiency, residual adhesion strength and release force, in particular, higher curing efficiency and lower release force.

[0015] In particular, the molecular weight of the modified part in the modified polysiloxane of the present application can be further reduced (e.g. by 15%) compared to those (meth)acrylate-based organopolysiloxanes prepared in US6211322 B1, but it has been found that such a reduction in molecular weight can significantly reduce the release force without compromising the residual adhesion strength.

[0016] It is also worth noting that the modified part in the modified polysiloxane prepared according to the present application has a structure different from that of the product modified part of US6211322 B1, i.e. the structure part as defined in detail below This small change in structure brings unexpected performance improvements to the release agent, particularly in terms of balancing residual adhesion strength and release force.

[0017] The polysiloxane provided in the first step according to the present application having at least two epoxy-functional groups at the end or laterally, is also called epoxy-modified polysiloxane.

[0018] In one embodiment, such epoxy-modified polysiloxane can be represented by the following general formula (I):

[0019] (R 1 ) n -[A](I)

[0020] wherein A represents an n-valent polysiloxane backbone, R 1 represents an epoxy-functional group containing one or more epoxy groups and being connected to the polysiloxane backbone via a C-Si bond and n represents a number greater than or equal to 1, such as greater than or equal to 2, 3 or 4, provided that at least two epoxy groups are contained in formula (I).

[0021] In an advantageous embodiment, n can represent a number greater than or equal to 1 to less than or equal to 10, more preferably less than or equal to 8 or 7 or 6 or 5; and / or at most 10, e.g. 9, 8, 7, 6, 5 or 4 epoxy groups are contained in formula (I).

[0022] The groups R 1 may be attached at the end or laterally to the polysiloxane backbone.

[0023] In the present application, the "polysiloxane backbone" refers to a polymer having Si—O—Si bonds constituting the backbone structure and different organic groups or H atoms being attached to the silicon atoms, which can be linear, cyclic, branched or network polymer. For example, the "polysiloxane backbone" can comprise:

[0024] (i) siloxy units of formula (X-1):

[0025] Z d R 2 e SiO [4-(d+e)] / 2 (X-1)

[0026] wherein

[0027] R 2 may identically or differently represent a monovalent hydrocarbon group, which is preferably selected from the group consisting of C 1-8 alkyl groups, including alkyl groups optionally substituted by at least one halogen atom, and also preferably from the group consisting of aryl groups, in particular C 6-20 aryl groups,

[0028] Z represents a single bond to a functional group such as H, an epoxy-containing group such as R 1 or a (meth)acrylic group,

[0029] d is 1 or 2, e is 0, 1 or 2 and the sum of d + e is 1, 2 or 3,

[0030] and optionally (ii) at least one further unit of formula (X-2)

[0031] R 3 f SiO (4-f) / 2 (X-2)

[0032] wherein

[0033] R 3 have the meaning as described above for R 2 and f is 0, 1, 2 or 3.

[0034] Of course, in the present application it has to be ensured that the polysiloxane backbone as a whole is at least n-valent, i.e. comprises at least one or n single bonds represented by Z in the backbone.

[0035] In the present application, an "epoxy-functional group" or "epoxy-containing group" denotes a moiety comprising one or more epoxy groups (such as a monovalent or divalent oxirane group wherein the dotted line represents the bond of attachment) which is attached to the polysiloxane backbone via a C-Si bond. For example, in a preferred embodiment, such an "epoxy-functional group" can be represented as -X-(EO)x, wherein EO represents an epoxy group, x represents 1 to 4, such as 1 or 2 and X represents an x+1 valent, linear, branched or cyclic, substituted or unsubstituted hydrocarbon group such as a Ci-C2o, C3-Ci5 hydrocarbon group, in particular an alkyl group, and which can comprise one or more ether oxygen (-0-), carbonyl (-C(O)-) or ester (-C(O)O-) groups. The epoxy-functional group is attached to the polysiloxane backbone via a C-Si bond between X and the polysiloxane backbone. In a further preferred embodiment, X represents an x+1 valent, preferably 2 valent, linear or branched, preferably linear, alkyl group (such as a C3-C8 or C4-C6 and preferably unsubstituted alkyl group) which can comprise one or more ether oxygen (-0-) spacer groups. More preferably, only one or more ether oxygen (-0-) spacer groups are comprised.

[0036] Preferably, R 1 represents an epoxy-functional group containing one epoxy group and n is a number equal to or greater than 2. Correspondingly, in an advantageous embodiment, in the formula X-(EO)x x represents 1 and EO represents

[0037] Suitable epoxy-functional groups include, for example, the following:

[0038]

[0039] Among the preferred epoxy-functional moieties are the first six.

[0040] Thus, preferred epoxy-functional groups include glycidoxypropyl, glycidoxy(t- butyl), glycidoxybutyl, glycidoxyhexyl, and the like, with glycidoxypropyl being particularly preferred.

[0041] Such polysiloxanes having at least two epoxy-functional groups terminally or laterally can be obtained by reacting a hydrogen-containing polysiloxane having at least two hydrogen atoms terminally or laterally in total with a compound having an epoxy-functional group and a carbon-carbon unsaturated double bond. Such polysiloxanes are also commercially available in principle, for example, MP-200 from Momentive, and the like.

[0042] Thus, in particular, in a preferred embodiment, the process according to the present application comprises a step (0) prior to step (1), wherein the polysiloxane having at least two epoxy-functional groups terminally or laterally is obtained by reacting at least one hydrogen-containing polysiloxane having at least two hydrogen atoms bonded to the same or different silicon atom per molecule with an epoxy compound having an epoxy-functional group and a carbon-carbon unsaturated double bond (vinyl group), such as a (meth)allyl glycidyl ether, preferably an allyl glycidyl ether.

[0043] In the present application, the hydrogen-containing polysiloxane must have at least two hydrogen atoms bonded to the same or different silicon atom to crosslink with the vinyl group in the epoxy compound. Here, the H atoms can be at the end of the molecular chain of the hydrogen-containing polysiloxane or in the middle or both.

[0044] The hydrogen-containing polysiloxane having SiH groups forms an epoxy-modified polysiloxane by reacting the SiH groups in the component with the vinyl group in the epoxy compound. Preferably, as the hydrogen-containing polysiloxane, at least one hydrogen-containing polysiloxane having two, three or more SiH groups per molecule is employed. The number of SiH groups can depend on the number of epoxy-functional groups to be attached.

[0045] In a preferred embodiment, the hydrogen-containing polysiloxane comprises

[0046] (i) siloxy units of the formula (I-3):

[0047] H d R 2 e SiO [4-(d+e)] / 2 (I-3)

[0048] wherein

[0049] R 2 may be the same or different and denote a monovalent hydrocarbon radical, which is preferably selected from the group consisting of C 1-8 alkyl radicals, including alkyl radicals optionally substituted by at least one halogen atom, and also preferably from the group consisting of aryl radicals, in particular C 6-20 aryl radicals,

[0050] d is 1 or 2, e is 0, 1 or 2 and the sum of d + e is 1, 2 or 3,

[0051] and optionally (ii) at least one further unit of formula (I-4)

[0052] R 3 f SiO (4-f) / 2 (I-4)

[0053] wherein

[0054] R 3 have the meanings as described above for R 2 and f is 0, 1, 2 or 3.

[0055] In a more preferred embodiment, R 2 or R 3 may be selected independently from each other from the group consisting of methyl, ethyl, propyl, 3,3,3-trifluoropropyl, phenyl, xylyl and tolyl radicals and the like.

[0056] The dynamic viscosity of the hydrogen-containing polysiloxane can be at least 1 mPa-s and preferably between 3 and 1000 mPa-s, more preferably 5-100 mPa-s.

[0057] The hydrogen-containing polysiloxane can be formed only from units of formula (I-3) or can also comprise additionally units of formula (I-4). The hydrogen-containing polysiloxane can have a linear, branched or cyclic structure.

[0058] Examples of units of formula (I-3) are H(CH3)2SiO 1 / 2 ,HCH3SiO 2 / 2 and H(C6H5)SiO 2 / 2 .

[0059] Examples of units of formula (I-4) are SiO 4 / 2 units, dimethylsiloxy, methylphenylsiloxy, diphenylsiloxy, methylsiloxy and phenylsiloxy.

[0060] Examples of useful hydrogen-containing polysiloxanes include linear or cyclic compounds such as dimethylpolysiloxane (with hydrogenated dimethylsilyl end groups), copolymer with (dimethyl)(hydrogenmethyl)polysiloxane units (with trimethylsilyl end groups), copolymer with (dimethyl)(hydrogenmethyl)polysiloxane units (with hydrogenated dimethylsilyl end groups), hydrogenated methylpolysiloxane with trimethylsilyl end groups, and cyclic hydrogenated methylpolysiloxane.

[0061] In one embodiment, the hydrogen-containing polysiloxane can be a dimethylpolysiloxane comprising two hydrogenated dimethylsilyl end groups.

[0062] In one preferred embodiment, the hydrogen-containing polysiloxane is at least one of hydrogen-terminated polydimethylhydrosiloxane H1, polydimethylhydrosiloxane H2 with lateral hydrogen groups, and hydrogenated Q resin H3.

[0063] In one preferred embodiment, the hydrogen-containing polysiloxane suitable for use in the present application has a viscosity range of 2-200 mPa-s, such as 5-150 mPa-s, more preferably 10-100 mPa-s.

[0064] Preferably, the hydrogen-containing amount of H1 is 0.02 wt-0.8 wt%, and the mole percentage of methyl hydrogen units in H2 is 2-50%.

[0065] In the context of the present application, the viscosity is measured as follows: for a viscosity range of 1-200 mPa-s, the pipe viscometer method is used. This is a continuous flow measurement method well known to the skilled person, in which the liquid to be measured is made to flow through a pipe of known diameter and length and the kinematic viscosity of the liquid is calculated by measuring the pressure difference and the flow rate at both ends of the pipe. For a viscosity range of 200-3000 mPa-s, the rotational viscometer method is used, which is a method for measuring the kinematic viscosity by rotating a liquid sample. In this method, the liquid to be measured is placed in the rotor of a rotational viscometer, and the liquid is then rotated at a certain rotational speed. The kinematic viscosity of the liquid is calculated by measuring the resistance to rotation and the rotational speed.

[0066] In this step (0), a catalyst C) of at least one platinum group metal can generally be used, which can consist of at least one platinum group metal or compound, in an amount sufficient to promote the addition reaction of the olefinic groups in the epoxide compound and the silicon-hydrogen in the hydrogen-containing polysiloxane. In one advantageous embodiment, the catalyst can be used in an amount in the range of 0.1-1,000 ppm by weight of metal, preferably 1-50 ppm.

[0067] Catalysts of at least one platinum group metal are known in the art of organosilicon and are commercially available. Platinum group metals include, in addition to platinum, ruthenium, rhodium, palladium, osmium and iridium. The catalyst can consist of a platinum group metal or a compound thereof or a combination thereof. Such catalysts include, for example, but are not limited to, platinum black, chloroplatinic acid, platinum dichloride, monohydrated chloroplatinic acid. Preferably, compounds of platinum and rhodium are used, such as chloroplatinic acid.

[0068] Accordingly, step (0) of synthesizing the epoxy-modified polysiloxane can be carried out, if desired, by reacting a mixture comprising the hydrogen-containing polysiloxane with an epoxy compound having an epoxy functional group and a carbon-carbon unsaturated double bond (vinyl group), such as a (meth)allyl glycidyl ether, preferably an allyl glycidyl ether, in the presence of a catalyst, such as a platinum group metal, in particular chloroplatinic acid, at an elevated temperature, such as 60 to 120 °C, at 1 atmosphere pressure. In this reaction, the preferred temperature is 70 to 100 °C, further preferred 80 to 90 °C. In addition, the reaction can be carried out in the presence of a solvent. Suitable solvents are, for example, aromatic hydrocarbon solvents, alkanes solvents, and alcohol, ester solvents, preferably toluene, xylene, isopropyl alcohol, n-butanol, n-hexane, and the like.

[0069] In an advantageous embodiment, a stoichiometric excess of the epoxy compound can be used in step (0) to ensure that all Si-H bonds have reacted. For example, the molar ratio of the vinyl group in the (meth)allyl glycidyl ether to the silicon hydride is 1.0 to 3.0, preferably 1.1 to 2.0, further preferred 1.3 to 1.8.

[0070] The process according to the present application comprises a step (2) wherein the polysiloxane having an epoxy functional group is reacted with a (meth)acrylic acid in the presence of a catalyst to obtain a product containing at least two carbon-carbon unsaturated double bonds and at least two secondary hydroxyl groups.

[0071] Preferably, the product contains at least two (meth)acrylic acid groups and at least two secondary hydroxyl groups, and each secondary hydroxyl group is linked to a (meth)acrylic acid group via a C2 linker (i.e. separated by two carbon atoms).

[0072] In one embodiment, the reaction can be carried out at an elevated temperature, for example at a temperature of 80 to 150 °C, preferably 90 to 120 °C.

[0073] The reaction in this step can be carried out, if desired, in the presence of a solvent. These solvents are organic solvents, such as hydrocarbons, alcohols, esters, ketones, in particular aromatic hydrocarbons and ketones, including, for example, toluene, xylene, 2-butanone, isopropyl alcohol, and the like.

[0074] Such a reaction is promoted by a catalyst. Such a catalyst can include, for example, a quaternary ammonium salt, a metal salt, for example a transition metal salt or a complex thereof, such as a chromate or chromium acetylacetonate, and a basic catalyst, for example an alkali metal or alkaline earth metal oxide or hydroxide such as sodium hydroxide and an organic amine compound, preferably a basic catalyst.

[0075] A preferred organic amine compound can be represented as N(R')3, wherein R' is independently H or a C1-C18 hydrocarbon group, in particular a C1-C8 alkyl group, such as methyl or ethyl, with the proviso that at least one organic group R' is not H. Thus, the organic amine compound can be a primary, secondary or tertiary amine. A preferred basic catalyst is an alkyl amine, in particular triethylamine is especially preferred.

[0076] It has surprisingly been found that if an organic amine compound, in particular an alkyl amine such as triethylamine, is used as catalyst, the use of a solvent can be dispensed with. In other words, the reaction of step (2) can be carried out without problems essentially without a solvent, in particular essentially without an organic solvent. This is certainly very advantageous for the environment. In particular, it has further been found that the use of the above-mentioned organic amine and essentially without a solvent can further improve the residual adhesion strength compared to a scenario in which a transition metal salt or a complex thereof, in particular a chromate or a complex thereof, is used as catalyst - in which scenario a solvent usually has to be used. Thus, in one preferred embodiment a transition metal salt or a complex thereof, in particular a chromate or a complex thereof, can not be used as catalyst.

[0077] Herein, "essentially without a solvent" means that the proportion of solvent is less than 1 wt.%, preferably less than 0.5 wt.%, more preferably less than 0.1 wt.%, such as 0.05 wt.% and 0.01 wt.% and 0 wt.% based on the total weight of the reaction mixture.

[0078] In step (2), the ratio of the two reactants, i.e. the epoxy-modified polysiloxane and the (meth)acrylic acid, should be such that the epoxy functional groups can be converted to (meth)acrylic acid groups as far as possible, i.e. (meth)acrylate groups are attached to the polysiloxane backbone, while secondary hydroxyl groups are formed. For example, the reaction process of this step can be illustrated as follows:

[0079]

[0080] wherein "R" represents H or methyl, n represents a number greater than or equal to 2, X is as defined above, and "~" represents that each group X is connected to Si on the polysiloxane backbone via a Si-C bond. Thus, after this step a product is obtained which contains at least two carbon-carbon unsaturated double bonds and at least two secondary hydroxyl groups. It is noted that the skilled person will understand that in the product structure as shown above, the moiety with the secondary hydroxyl group and the (meth)acrylic group, i.e. Depending on the initial position of the epoxy groups, these can be located either laterally or terminally to the polysiloxane main chain.

[0081] In a preferred embodiment, X represents a divalent linear or branched, preferably linear, alkyl group (e.g. C3-C8or C4-C6and preferably unsubstituted alkyl group), which can contain one or more ether oxygen (-O-) spacer groups.

[0082] Subsequently, according to the (3) step of the present application, the product obtained in the (2) step is reacted with a (meth)acryloyl halide, preferably (meth)acryloyl chloride, in the presence of an acid binding agent, to obtain a (meth)acryl-modified polysiloxane.

[0083] This step can be carried out at room temperature (about 23°C).

[0084] The acid binding agent suitable for use in this step can be any substance (usually a basic substance) for absorbing the acid produced in the reaction, which can form a salt with the acid. Examples of the acid binding agent include pyridine, carbonate or organic amine compounds, etc. In an advantageous embodiment, an organic amine compound is used as the acid binding agent, which can be those organic amine compounds as described above, preferably triethylamine, pentamethyldiethylenetriamine, dimethylcyclohexylamine.

[0085] Preferably, in this step, the amount of (meth)acryloyl halide added is such that all the secondary hydroxyl groups are reacted therewith. Thus, the molar ratio of (meth)acryloyl halide to hydroxyl group can be, for example, 1.0-1.5, preferably 1.03-1.3, and particularly preferably 1.05-1.1.

[0086] In particular, no other substance capable of reacting with the secondary hydroxyl group (particularly to undergo esterification) is added in this step, such as saturated or unsaturated organic carboxylic acids, including aliphatic carboxylic acids such as alkyl carboxylic acids and aromatic carboxylic acids, etc., such as acetic acid, propionic acid, butyric acid, valeric acid, acetoacetic acid, benzoic acid, sorbic acid, etc.

[0087] In this step, the secondary hydroxyl groups in the product from the (2) step (e.g. ) are further converted to (meth)acryl groups by further reaction with the acryloyl halide. As a result, the final product obtained in this step can have at least 4 (meth)acryl groups, which can be located at the end or laterally to the polysiloxane main chain.

[0088] For example, the (meth)acryl-modified polysiloxane obtained according to the (3) step of the present application can have the following structural formula (II):

[0089]

[0090] wherein R, n, X and "~" are as defined above.

[0091] In a preferred embodiment, the (meth)acryl-modified polysiloxane can have the following structural formula (II-1):

[0092]

[0093] wherein R and n are each as defined above, and the (meth)acryl-modified moieties between the brackets are connected to the polysiloxane backbone terminally and / or laterally via Si-C bonds.

[0094] To obtain a compound such as formula (II-1), a hydrogen-containing polysiloxane (preferably a hydrogen-containing polysiloxane containing two hydrogenated dimethylsilyl end groups, more preferably a dimethyl polysiloxane containing two hydrogenated dimethylsilyl end groups) can be first reacted with a (meth)allyl glycidyl ether to give a corresponding polysiloxane having an epoxypropoxypropyl group, which is then further reacted with a (meth)acrylic acid in a second step (2) and finally with a (meth)acryloyl halide in a third step (3).

[0095] The production method according to the present application can comprise or consist of the steps (1) to (3) or (0) to (3) in this order.

[0096] If necessary, the obtained (meth)acryl-modified polysiloxane can be further subjected to a purification treatment after step (3). For example, the reaction product can be treated under reduced pressure or vacuum (e.g., 1000 Pa or less) and / or at an elevated temperature (e.g., about 60°C) to remove low-boiling components. In addition, the product obtained can be further filtered to obtain the target product of the (meth)acryl-modified polysiloxane.

[0097] According to another aspect of the present application, the present application relates to a (meth)acryl-modified polysiloxane compound obtained by the above production method.

[0098] In a specific embodiment, the (meth)acryl-modified polysiloxane compound can have the following structural formula (II):

[0099]

[0100] wherein R, n, X and "~" are each as defined above.

[0101] According to still another aspect of the present application, the present application relates to a releasing agent comprising the (meth)acryl-modified polysiloxane.

[0102] The (meth)acryl-modified polysiloxane according to the present application can be used as a release agent, which is a cured adhesive coating material on a substrate such as a sheet substrate, for example, a coating obtained by radiation curing. The (meth)acryl-modified polysiloxane can be used as it is after preparation.

[0103] In the case of UV curing, a free radical initiator can be additionally added in an amount of, for example, 1 to 5% by weight, based on the weight of the (meth)acryl-modified polysiloxane. The free radical initiator is selected based on the wavelength range of the radiation source used for curing. Such free radical initiators are known and include, for example, the following:

[0104] - benzoin and derivatives (e.g., benzoin, benzoin dimethyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, etc.);

[0105] - benzil (e.g., diphenyl ketone, α,α-dimethoxy-α-phenylacetophenone, etc.);

[0106] - alkyl phenone (e.g., α,α-diethoxyacetophenone, α-hydroxyalkyl phenone, α-amine alkyl phenone, etc.);

[0107] - acyl phosphine oxide (e.g., arylacyl phosphine oxide, dibenzoyl phenyl phosphine oxide, etc.);

[0108] - benzophenone (e.g., benzophenone, 2,4-dihydroxybenzophenone, Michler's ketone, etc.);

[0109] - thioxanthone (e.g., thioxanthone, isopropyl thioxanthone, etc.).

[0110] Specific examples of the initiator include, for example, 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-2-(4-morpholinyl)-1-[4-(methylthio)phenyl]-1-propanone, 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide, 2,4,6-trimethylbenzoyl phenyl phosphinic acid ethyl ester, 2-dimethylamino-2-benzyl-1-[4-(4-morpholinyl)phenyl]-1-butanone, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone, or methyl benzoylformate, etc.

[0111] In addition to the initiator, additional additives can be added to the resulting (meth)acryl-modified polysiloxane if desired when formulating the release agent. These additives include, for example, siloxanes having groups that can chemically bond into the coating composition during curing. An example of a suitable additive is a silane having a (meth)acryl group attached to a silicon atom. They can be beneficial to the viscosity of the coating composition, thereby improving the ease of application on the sheet-like substrate. The amount of silane added can be 1-5%, preferably 2-3%, of the total weight of the release agent.

[0112] Additives that can be added to the coating composition also include, for example, inert materials that can be dispersed and encapsulated into the coating composition during curing. Such inert additives include, for example, highly dispersed silica or (meth)acryl-modified fluorocarbon polymers. The amount of silica added can be 1-10%, preferably 3-5%, of the total weight of the release agent. The amount of (meth)acryl-modified fluorocarbon polymers added can be 3-50%, preferably 10-30%, of the total weight of the release agent.

[0113] The present application will be further illustrated by the following examples. Example

[0114] The present application will be further described in connection with the following examples. However, the present application is not limited to the examples described below. In addition, the percentage data and the proportion of parts in the present application are by weight, unless otherwise explicitly stated.

[0115] Description of the main raw materials

[0116]

[0117] Preparation of (meth)acryl group-modified polysiloxane

[0118] Example 1: Into a reaction kettle, 200 g of hydrogen-terminated polydimethylsiloxane (D-15), 44 g of allyl glycidyl ether, 5 ppm (in terms of Pt, based on the total mass) of chloroplatinic acid were added. Stirring was carried out at 80°C for 3 hours. The resulting product was subjected to removal of volatile components at 1000 Pa at 150°C to obtain an epoxy-modified polysiloxane (epoxy-modified silicone oil). Into the resulting silicone oil, 26 g of acrylic acid, 1.44 g of sodium hydroxide, 40 g of isopropyl alcohol, and 0.1 g of p-hydroxyanisole were added. Stirring was carried out at 110°C for 10 hours under reflux, and isopropyl alcohol was removed by distillation. Then, the temperature was lowered to room temperature, 39 g of triethylamine was added, 34.8 g of acryloyl chloride was slowly added dropwise, stirring was continued for 3 hours, and low-boiling components were removed at 1000 Pa at 60°C to obtain a crude product, which was filtered to obtain an acryl-modified polysiloxane IE-1.

[0119] According to 1H-NMR spectrum, the product obtained contains 95% by weight of a compound with the following chemical structure:

[0120]

[0121] Example 2: In a reaction kettle, 200 g of hydrogen-terminated polydimethylsiloxane (D-15), 44 g of allyl glycidyl ether, 5 ppm (in terms of Pt, based on the total mass) of chloroplatinic acid were added. Stirring was carried out at 80°C for 3 hours. The product obtained was subjected to removal of volatile components at 150°C under a pressure of 1000 Pa to obtain an epoxy-modified polysiloxane (epoxy-modified silicone oil). To the obtained silicone oil, 26 g of acrylic acid, 1000 ppm (in terms of chromium, based on the total mass) of chromium acetylacetonate, 40 g of isopropyl alcohol, 0.1 g of p-hydroxyanisole were added. Stirring was carried out at 110°C under reflux for 10 hours, and isopropyl alcohol was removed by distillation. Then, the temperature was lowered to room temperature, 39 g of triethylamine was added, 34.8 g of acryloyl chloride was slowly added dropwise, stirring was carried out for 3 hours, low-boiling components were removed at 60°C under a pressure of 1000 Pa, and the obtained crude product was filtered to obtain an acrylic acid-modified polysiloxane IE-2.

[0122] According to 1 H-NMR spectrum, the product obtained contains 98% by weight of a compound with the following structure:

[0123]

[0124] Example 3: In a reaction kettle, 200 g of hydrogen-terminated polydimethylsiloxane (D-15), 44 g of allyl glycidyl ether, 5 ppm (in terms of Pt, based on the total mass) of chloroplatinic acid were added. Stirring was carried out at 80°C for 3 hours. The product obtained was subjected to removal of volatile components at 150°C under a pressure of 1000 Pa to obtain an epoxy-modified polysiloxane (epoxy-modified silicone oil). To the obtained silicone oil, 26 g of acrylic acid, 6.5 g of triethylamine, 40 g of isopropyl alcohol, 0.1 g of p-hydroxyanisole were added. Stirring was carried out at 110°C under reflux for 10 hours, and isopropyl alcohol was removed by distillation. Then, the temperature was lowered to room temperature, 39 g of triethylamine was added, 34.8 g of acryloyl chloride was slowly added dropwise, stirring was carried out for 3 hours, low-boiling components were removed at 60°C under a pressure of 1000 Pa, and the obtained crude product was filtered to obtain an acrylic acid-modified polysiloxane IE-3.

[0125] According to 1 H-NMR spectrum, the product obtained contains 99% by weight of a compound with the following structure:

[0126]

[0127] Example 4: In a reaction kettle, 200 g of hydrogen-terminated polydimethylsiloxane (D-15), 44 g of allyl glycidyl ether, and 5 ppm (as Pt, based on total mass) of chloroplatinic acid were added. The mixture was stirred at 80°C for 3 hours. The resulting product was subjected to removal of volatile components at 150°C under a pressure of 1000 Pa to obtain an epoxy-modified polysiloxane (epoxy-modified silicone oil). To the resulting silicone oil, 26 g of acrylic acid, 6.5 g of triethylamine, 40 g of isopropyl alcohol, and 0.1 g of p-hydroxyanisole were added. The mixture was stirred at reflux at 110°C for 10 hours, and the isopropyl alcohol was distilled off. Then, the temperature was lowered to room temperature, 30.5 g of pyridine was added, 34.8 g of acryloyl chloride was slowly added dropwise, and stirring was continued for 3 hours. The low-boiling components were removed at 60°C under a pressure of 1000 Pa, and the resulting crude product was filtered to obtain an acrylic acid-modified polysiloxane IE-4.

[0128] According to 1 H-NMR spectrum, the resulting product contained 96% by weight of a compound having the following structure:

[0129]

[0130] Example 5: In a reaction kettle, 200 g of hydrogen-terminated polydimethylsiloxane (D-15), 44 g of allyl glycidyl ether, and 5 ppm (as Pt, based on total mass) of chloroplatinic acid were added. The mixture was stirred at 80°C for 3 hours. The resulting product was subjected to removal of volatile components at 150°C under a pressure of 1000 Pa to obtain an epoxy-modified polysiloxane (epoxy-modified silicone oil). To the resulting silicone oil, 26 g of acrylic acid, 6.5 g of triethylamine, and 0.1 g of p-hydroxyanisole were added. The mixture was stirred at reflux at 110°C for 10 hours. Then, the temperature was lowered to room temperature, 39 g of triethylamine was added, 34.8 g of acryloyl chloride was slowly added dropwise, and stirring was continued for 3 hours. The low-boiling components were removed at 60°C under a pressure of 1000 Pa, and the resulting crude product was filtered to obtain an acrylic acid-modified polysiloxane IE-5.

[0131] According to 1 H-NMR spectrum, the resulting product contained 96% by weight of a compound having the following structure:

[0132]

[0133] Example 6: In a reaction kettle, 200 g of hydrogen-terminated polydimethylsiloxane (D-50), 17.8 g of allyl glycidyl ether, and 5 ppm (as Pt, based on total mass) of chloroplatinic acid were added. Stirring was carried out at 80°C for 3 hours. The resulting product was subjected to removal of volatile components at 150°C under a pressure of 1000 Pa to obtain an epoxy-modified polysiloxane (epoxy-modified silicone oil). To the resulting silicone oil, 9.0 g of acrylic acid, 2.1 g of triethylamine, 40 g of isopropyl alcohol, and 0.1 g of p-hydroxyanisole were added. Stirring was carried out at 110°C under reflux for 10 hours. Then, the temperature was lowered to room temperature, 12.6 g of triethylamine was added, 11.3 g of acryloyl chloride was slowly added dropwise, stirring was continued for 3 hours, low-boiling components were removed at 60°C under a pressure of 1000 Pa, and the resulting crude product was filtered to obtain an acrylic acid-modified polysiloxane IE-6.

[0134] According to 1 H-NMR spectrum, the resulting product contained 98% by weight of a compound having the following structure:

[0135]

[0136] Example 7: In a reaction kettle, 200 g of hydrogen-terminated polydimethylsiloxane (D-60), 15.0 g of allyl glycidyl ether, and 5 ppm (as Pt, based on total mass) of chloroplatinic acid were added. Stirring was carried out at 80°C for 3 hours. The resulting product was subjected to removal of volatile components at 150°C under a pressure of 1000 Pa to obtain an epoxy-modified polysiloxane (epoxy-modified silicone oil). To the resulting silicone oil, 7.56 g of acrylic acid, 1.77 g of triethylamine, 40 g of isopropyl alcohol, and 0.1 g of p-hydroxyanisole were added. Stirring was carried out at 110°C under reflux for 10 hours. Then, the temperature was lowered to room temperature, 10.6 g of triethylamine was added, 9.44 g of acryloyl chloride was slowly added dropwise, stirring was continued for 3 hours, low-boiling components were removed at 60°C under a pressure of 1000 Pa, and the resulting crude product was filtered to obtain an acrylic acid-modified polysiloxane IE-7.

[0137] According to 1 H-NMR spectrum, the resulting product contained 96% by weight of a compound having the following structure:

[0138]

[0139] Example 8: In a reaction kettle, 200 g of hydrogen side containing polydimethylsiloxane (H-67), 123.3 g of allyl glycidyl ether, 5 ppm (Pt basis, based on total mass) of chloroplatinic acid were added. Stirring at 80°C for 3 hours. The resulting product was removed from volatile components at 150°C under 1000 Pa pressure to obtain an end epoxy modified polysiloxane (epoxy modified silicone oil). In the resulting silicone oil, 71.88 g of acrylic acid, 16.8 g of triethylamine, 400 g of xylene, 0.1 g of p-hydroxyanisole were added. Stirring at 110°C under reflux for 10 hours. Then cool to room temperature, add 100.8 g of triethylamine, slowly drop 89.8 g of acryloyl chloride, continue stirring for 3 hours, remove low boiling point components at 60°C under 1000 Pa pressure, and the resulting crude product is filtered to obtain an acrylic acid modified polysiloxane IE-8.

[0140] According to 1 H-NMR, 29 Si-NMR and 13 C-NMR spectrum, the resulting product contains 99% by weight of the compound with the following structure:

[0141]

[0142] Example 9: In a reaction kettle, 200 g of hydrogen side containing polydimethylsiloxane (H-05), 19.8 g of allyl glycidyl ether, 5 ppm (Pt basis, based on total mass) of chloroplatinic acid were added. Stirring at 80°C for 3 hours. The resulting product was removed from volatile components at 150°C under 1000 Pa pressure to obtain an end epoxy modified polysiloxane (epoxy modified silicone oil). In the resulting silicone oil, 11.6 g of acrylic acid, 2.7 g of triethylamine, 400 g of xylene, 0.1 g of p-hydroxyanisole were added. Stirring at 110°C under reflux for 10 hours. Then cool to room temperature, add 16.2 g of triethylamine, slowly drop 14.4 g of acryloyl chloride, continue stirring for 3 hours, remove low boiling point components at 60°C under 1000 Pa pressure, and the resulting crude product is filtered to obtain an acrylic acid modified polysiloxane IE-9.

[0143] According to 1 H-NMR, 29 Si-NMR and 13 C-NMR spectrum, the resulting product contains 96% by weight of the compound with the following structure:

[0144]

[0145] Comparative Example 1:

[0146] The end group acrylic acid modified polysiloxane CE-1 with the following structure was synthesized according to Example 3 of US6211322B1.

[0147]

[0148] Comparative Example 2:

[0149] The end group acryl-modified polysiloxane CE-2 of the following structure was synthesized according to Example 3 of US6211322B1.

[0150]

[0151] Comparative Example 3:

[0152] Into a reaction vessel was added 200 g of hydrogen-terminated polydimethylsiloxane (D-50), 17.8 g of allyl glycidyl ether, and 5 ppm (in terms of Pt, based on the total mass) of chloroplatinic acid. It was stirred at 80°C for 3 hours. The resulting product was subjected to removal of volatile components at 150°C under a pressure of 1000 Pa to obtain an epoxy-modified polysiloxane (epoxy-modified silicone oil). Into the resulting silicone oil was added 9.0 g of acrylic acid, 2.1 g of triethylamine, 40 g of isopropyl alcohol, and 0.1 g of p-hydroxyanisole. It was stirred under reflux at 110°C for 10 hours. Then, it was cooled to room temperature, and low-boiling components were removed at 60°C under a pressure of 1000 Pa. The resulting product was filtered to obtain an acryl-modified polysiloxane CE-3.

[0153] According to 1 H-NMR spectrum, the resulting product contained 96% by weight (including isomers) of a product of the following main chemical structure:

[0154]

[0155] Comparative Example 4:

[0156] Into a reaction vessel was added 200 g of hydrogen-terminated polydimethylsiloxane (D-50), 17.8 g of allyl glycidyl ether, and 5 ppm (in terms of Pt, based on the total mass) of chloroplatinic acid. It was stirred at 80°C for 3 hours. The resulting product was subjected to removal of volatile components at 150°C under a pressure of 1000 Pa to obtain an epoxy-modified polysiloxane (epoxy-modified silicone oil). Into the resulting silicone oil was added 9.0 g of acrylic acid, 2.1 g of triethylamine, 40 g of isopropyl alcohol, and 0.1 g of p-hydroxyanisole. It was stirred under reflux at 110°C for 10 hours. Then, it was cooled to room temperature, and low-boiling components were removed at 60°C under a pressure of 1000 Pa. The resulting product was filtered to obtain an acryl-modified polysiloxane CE-3.

[0157] According to 1 H-NMR, 29 Si-NMR and 13 C-NMR spectrum, the resulting product contained 98% by weight (including isomers) of a product of the following main chemical structure:

[0158]

[0159] Comparative Example 5:

[0160] Into a reaction vessel was added 200 g of hydrogen-terminated polydimethylsiloxane (D-15), 44 g of allyl glycidyl ether, and 5 ppm (as Pt, based on total mass) of chloroplatinic acid. The mixture was stirred at 80°C for 3 hours. The resulting product was subjected to removal of volatile components at 150°C under a pressure of 1000 Pa to obtain an epoxy-modified polysiloxane (epoxy-modified silicone oil). Into the resulting silicone oil was added 26 g of acrylic acid, 6.5 g of triethylamine, and 0.1 g of p-hydroxyanisole. The mixture was stirred at 110°C for 10 hours under reflux. The mixture was then cooled to room temperature, and low-boiling components were removed at 60°C under a pressure of 1000 Pa. The resulting crude product was filtered to obtain an acrylic-modified polysiloxane CE-5.

[0161] According to the above-mentioned method, the following products were obtained. 1 The resulting product contained 98% by weight of a compound having the following structure:

[0162]

[0163] Comparative Example 6:

[0164] Into a reaction vessel was added 200 g of hydrogen-terminated polydimethylsiloxane (H-05), 19.8 g of allyl glycidyl ether, and 5 ppm (as Pt, based on total mass) of chloroplatinic acid. The mixture was stirred at 80°C for 3 hours. The resulting product was subjected to removal of volatile components at 150°C under a pressure of 1000 Pa to obtain an epoxy-modified polysiloxane (epoxy-modified silicone oil). Into the resulting silicone oil was added 11.6 g of acrylic acid, 2.7 g of triethylamine, 400 g of xylene, and 0.1 g of p-hydroxyanisole. The mixture was stirred at 110°C for 10 hours under reflux. The mixture was then cooled to room temperature, and low-boiling components were removed at 60°C under a pressure of 1000 Pa. The resulting crude product was filtered to obtain an acrylic-modified polysiloxane CE-6.

[0165] According to the above-mentioned method, the following products were obtained. 1 The resulting product contained 96% by weight of a compound having the following structure: 29 Si-NMR and 13 C-NMR spectrum, the resulting product contained 96% by weight of a compound having the following structure:

[0166]

[0167] Formulation of the release agent

[0168] Each component was mixed uniformly under light shielding, and after standing for 24 hours, the mixture was used for performance tests.

[0169] Performance testing

[0170] Release force performance test: The product of the present invention and the comparative product were applied to a flat substrate (oriented polypropylene film), wherein 2% photoinitiator (Darocur) was added. TM 1173 (from BASF) was cured by exposure to UV light at 120 W / cm and a belt speed of 20 m / min. The amount applied in each case was approximately 1 g / m³. 2 Subsequently, TESA products coated with acrylic adhesive were used. TM 7475 tape was used to measure its adhesiveness. These tapes were rolled onto a substrate and tested at 70 g / cm². 2 The tapes were stored at 23°C for 20 hours under load. Then, the force required to remove each tape from the substrate at a speed of 30 cm / min and a peel angle of 180 degrees was measured; this force is called the room temperature release force. The general test procedure basically corresponds to FINAT test method No. 10. To check the aging behavior, the temperature was increased to 70°C and stored for 20 hours before testing; the force measured is called the aging release force.

[0171] Curing Degree Test: This test is to quickly determine the degree of curing of the release coating. For this purpose, after the product has cured as described in the release force test, approximately 20cm long strips of TESA tape are applied. TM 4154 is rolled three times on the substrate and immediately peeled off by hand. The two ends of the tape are then placed together to form a loop, ensuring the adhesive areas at both ends are in contact within approximately one centimeter. The ends are then separated by hand again, during which time the contact area should move evenly to the center of the tape. In cases of contamination with poorly cured release material, the adhesive strength of the tape is no longer sufficient to maintain the contact area when the ends are pulled apart. In such cases, the test is considered a failure.

[0172] Residual Adhesive Strength (SA): The determination of residual adhesive strength is basically carried out according to FINAT Test Method No. 11. For this purpose, after curing the product as described in the release force test, Nito tape 31B is rolled onto the substrate and then stored at 23°C and subjected to 70 g / cm³. 2 Under load. After 20 hours of storage, the tape is separated from the release substrate and rolled onto a specified substrate (steel plate, glass plate, foil). After one minute, the force required to peel the tape from the substrate at a speed of 30 cm / min and a peel angle of 180 degrees is measured. The value measured in this way is divided by the value given to untreated tape under other identical test conditions. The result is called residual adhesive strength, usually expressed as a percentage.

[0173]

[0174]

[0175]

[0176]

[0177]

Claims

1. A method for preparing (meth)acrylic acid-modified polysiloxanes, comprising the following steps: (1) A polysiloxane having at least two epoxy functional groups at the end or laterally; (2) The polysiloxane having epoxy functional groups is reacted with (meth)acrylic acid in the presence of a catalyst to obtain a product containing at least two carbon-carbon unsaturated double bonds and at least two secondary hydroxyl groups. (3) React the product obtained in step (2) with (meth)acryloyl halide in the presence of an acid-binding agent to obtain the (meth)acrylic acid-modified polysiloxane; The catalyst is triethylamine.

2. The method according to claim 1, characterized in that... The (meth)acryloyl halide is (meth)acryloyl chloride.

3. The method according to claim 1, characterized in that... The acid-binding agent includes pyridine, carbonate, or organic amine compound.

4. The method according to claim 3, characterized in that... The acid-binding agent includes triethylamine.

5. The method according to any one of claims 1 to 4, characterized in that... The polysiloxane having at least two epoxy functional groups is represented by the following general formula (I): (R 1 ) n -[A] (I) Where A represents the n-valent polysiloxane backbone, R 1 The group represents an epoxy-functional group containing one or more epoxy groups and connected to the polysiloxane backbone via C-Si bonds, and n represents a number greater than or equal to 1, provided that formula (I) contains at least two epoxy groups.

6. The method according to claim 5, characterized in that... n means greater than or equal to 2.

7. The method according to claim 5, characterized in that... n means greater than or equal to 3.

8. The method according to claim 5, characterized in that... n means greater than or equal to 4.

9. The method according to claim 5, characterized in that... n is less than or equal to 10.

10. The method according to claim 5, characterized in that... n is less than or equal to 6.

11. The method according to claim 5, characterized in that... n is less than or equal to 5.

12. The method according to claim 5, characterized in that... Formula (I) contains up to 10 epoxy groups.

13. The method according to claim 5, characterized in that... Formula (I) contains up to 5 epoxy groups.

14. The method according to claim 5, characterized in that... Formula (I) contains up to 4 epoxy groups.

15. The method according to claim 5, characterized in that... R 1 It is represented as -X-(EO)x, where EO represents an epoxy group, x represents 1 to 4 and X represents a straight-chain, branched or cyclic substituted or unsubstituted hydrocarbon group with a valence of x+1, and the hydrocarbon group may contain one or more ether oxygen (-O-), carbonyl (-C(O)-) or ester group (-C(O)O-).

16. The method according to claim 15, characterized in that... x represents 1 or 2.

17. The method according to claim 15, characterized in that... The hydrocarbon group is a C1-C20 hydrocarbon group.

18. The method according to claim 15, characterized in that... The hydrocarbon group is a C3-C15 hydrocarbon group.

19. The method according to claim 15, characterized in that... The hydrocarbon group is an alkyl group.

20. The method according to claim 15, characterized in that... X represents a divalent straight-chain alkyl group, which optionally contains one or more ether oxygen (-O-) spacer groups.

21. The method according to claim 20, characterized in that... The alkyl group is a C3-C8 alkyl group.

22. The method according to claim 5, characterized in that... The group R 1 It is epoxypropoxypropyl, epoxypropoxybutyl, epoxybutyl, and epoxyhexyl.

23. The method according to claim 22, characterized in that... The group R 1 It is epoxypropoxypropyl.

24. The method according to any one of claims 1 to 4, characterized in that... The method includes a step (0) prior to step (1), wherein the polysiloxane having at least two epoxy functional groups at the ends or sides is obtained by reacting at least one hydrogen-containing polysiloxane having at least two hydrogen atoms per molecule bonded to the same or different silicon atoms with an epoxy compound having epoxy functional groups and carbon-carbon unsaturated double bonds.

25. The method according to claim 24, characterized in that... The epoxy compound having epoxy functional groups and carbon-carbon unsaturated double bonds is (methyl)allyl glycidyl ether.

26. The method according to claim 24, characterized in that... The epoxy compound having epoxy functional groups and carbon-carbon unsaturated double bonds is allyl glycidyl ether.

27. The method according to claim 24, characterized in that... The hydrogen-containing polysiloxane is selected from at least one of hydrogen-terminated polydimethylmethylhydrosiloxane H1, polydimethylmethylhydrosiloxane H2 having lateral hydrogen groups, and hydrogenated Q resin H3.

28. The (meth)acrylic acid-modified polysiloxane compound prepared by the method according to claim 1.

29. A release agent comprising a (meth)acrylic acid-modified polysiloxane compound prepared according to claim 1.

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