JPS61200111A - Production of polysiloxane graft polymer - Google Patents

Abstract

PURPOSE:To obtain the titled polymer capable of imparting a surface characteristics such as water-repellency, slipperiness, etc., to the surface of a substrate, by adding a specific alcohol in the polymerization of a monomer mixture containing a polymerizable silane compound in the presence of a polysiloxane containing terminal OH group. CONSTITUTION:The objective polymer is produced by polymerizing (A) a monomer mixture containing a polymerizable silane compound such as vinyl triethoxysilane, etc., in the presence of a polysiloxane of formula [R<1> and R<2> are (halogen-substituted) hydrocarbon group; n is integer of >=1] containing terminal hydroxyl group, and adding a 1-10C alcohol to the polymerization system immediately before or after the development of Weissenberg effect in the system.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for producing a polysiloxane graft polymer by solution polymerizing a monomer mixture containing a polymerizable silane compound in the presence of a polysiloxane containing a terminal hydroxyl group. It is something.

The polysiloxane graft polymer produced by the present invention is a composition that can be applied to the surface of a base material such as a film, fiber, or steel plate to provide surface properties such as water repellency, slipperiness, heat resistance, and migration resistance. This is what we provide.

(Prior art) In recent years, with the development of electronic equipment, the requirements for performance such as slipperiness, heat resistance, and abrasion resistance of magnetic tapes, floppy disks, thermal printing materials, etc. have become increasingly sophisticated. Various improvements have been made to meet these demands. For example, for the purpose of improving the slipperiness of polyester films, which are most commonly used as base materials for magnetic tapes and thermal printing materials, a method of introducing polysiloxane containing terminal hydroxyl groups into the polyester main chain (Japanese Patent Laid-Open No. 59-16802
No. 7) has been disclosed, but since the polysiloxane is distributed throughout the base material, a large amount is required, and it also causes problems in the adhesion of the magnetic film or ink layer. Furthermore, a method of coating the surface of the base material with silicone resin to modify the surface (U.S. Pat. No. 4,310,600, Japanese Patent Publication No. 59-39308
No., JP-A No. 55-7467) is shown as u8, but
There was a drawback that properties aimed at improving slipperiness and heat resistance were not compatible with the adhesion of the resin film to the substrate. In addition, a method using a silicone graphyl copolymer using acrylic modified silicone (Japanese Patent Application Laid-open No. 154766/1983,
JP-A-58-164656) is shown as fffl
First, it is possible to achieve both slipperiness and adhesion, but the problem remains that the production of the acrylic-modified silicone raw material is complicated and expensive.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned problems of the prior art and provides a simple method for producing a polysiloxane graft polymer that can be used industrially.

(Means and effects for solving the problem) The present inventors effectively utilize polysiloxane that has excellent heat resistance, slipperiness, and migration resistance, and also exhibits good adhesion to the base material. As a result of intensive research on the H-soaking method for polysiloxane graft polymers, we found that when solution polymerizing a monomer mixture containing a polymerizable silane compound in the presence of polysiloxane containing terminal hydroxyl groups, a specific solvent is added to the polymerization system at a specific time. The present invention was completed based on the discovery that a polysiloxane graft polymer having both surface properties such as slipperiness and heat resistance and adhesion to a substrate can be obtained in the form of a stable solution free of gel-like substances.

That is, the present invention is directed to producing a polysiloxane graft polymer by solution polymerizing a monomer mixture containing a polymerizable silane compound in the presence of a polysiloxane containing a terminal hydroxyl group. The present invention relates to a method for producing a polysiloxane graft polymer, which is characterized in that an alcohol having 1 to 10 carbon atoms is immediately added to the polymerization system.

The terminal hydroxyl group-containing polysiloxane used in the present invention has a general formula (wherein R1 and R are each independently a hydrocarbon group that may be substituted with a monovalent halogen, and n is an integer of 1 or more.) Currently, various types are easily available and can be used depending on the purpose. The molecular weight of the polysiloxane used is preferably one in which n is in the range of 10 to 2,000. If n is less than 10, the composition comprising the polysiloxane graph 1 to polymer may not exhibit the desired surface properties sufficiently;
If it is more than 000, the viscosity becomes high and handling and polymerization operations may become difficult, which is not preferable. In addition to the polysiloxanes represented by the above general formula, polysiloxanes having partially branched side chains can also be used without any problem.

The amount of the terminal hydroxyl group-containing polysiloxane to be used is the total amount of the polysiloxane and the monomer mixture (hereinafter referred to as raw material monomer E), taking into account the degree of surface modification of the resulting polysiloxane graft polymer. ) from 1 to 20
It is desirable to keep it within the range of weight M%. If the amount used is less than 1% by weight, the surface properties will not be sufficient, and if it exceeds 20% by weight, the adhesion to the substrate will decrease. The monomer mixture containing a polymerizable silane compound used in the present invention contains an appropriate amount of a polymerizable silane compound that can undergo a condensation reaction with the terminal hydroxyl group-containing polysiloxane, depending on the amount of the polysiloxane used. Good to have.

In addition, mineral acids such as sulfuric acid and organic acids such as acetic acid, trifluoroacetic acid, and para-toluenesulfonic acid are generally used as catalysts to promote the condensation reaction. In order to obtain a polysiloxane graft polymer with excellent properties, it is preferable to use an unsaturated organic acid as one component of the monomer mixture. Therefore, as the monomer mixture, a monomer mixture consisting of a polymerizable silane compound (^), an unsaturated organic acid (B), and other m-composable monomers (C) that can be copolymerized with these is used. It is preferable to use

The polymerizable silane compound (8) is a compound having in its molecule at least one polymerizable unsaturated group and at least one group capable of condensation reaction with the polysiloxane, such as vinyltrimethoxysilane, vinyltriethoxysilane, etc. silane,
Vinyltributoxysilane, vinyltris(β-methoxyethoxy)silane, allyltriethoxysilane, γ-
(meth)acryloxypropyltrimethoxysilane, 7
- (meth)acryloxypropyltrimethoxysilane,
γ-(meth)acryloxypropylmethyldimethoxysilane, γ-(meth)acryloxypropylmethyljethoxysilane, γ-(meth)acryloxypropyltris(β-me1-xyel-xy)silane, 2-styryl Examples include ethyl 1-rimethoxysilane, (meth)acryloxyethyldimethyl(3-trimethoxysilylpropyl)ammonium chloride, vinyltriacetoxysilane, vinyl 1-lychlorosilane, and one or more selected from these groups. A mixture of two or more types can be used.The layer using the polymerizable silane compound (A) preferably has an amount of 0.05 to 10% by weight based on the raw material monomer amount.0.05 If the amount of the layer used is less than % by weight, the bonding between the polysiloxane and the polymer made of the monomer mixture will be insufficient, and the effective grafting reaction (a) will not occur, and the resulting product will tend to undergo layer separation. If the amount exceeds 10 weight percent, gelation tends to occur during production, resulting in poor product stability.

Examples of unsaturated organic 156 (B) include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, and itaconic acid; Examples include sulfonic acids, and one or a mixture of two or more of these can be used, preferably within a range of 0.5 to 10% by weight based on the amount of raw material monomers.

Other polymerizable monomers (e) include, for example, acrylic esters such as butyl acrylate and 2-ethylhexyl acrylate; methacrylic esters such as methyl methacrylate and butyl methacrylate; vinyl acetate, propion Vinyl esters such as acid vinyl; aromatic vinyls such as styrene and vinyltoluene; unsaturated nitriles such as acrylonitrile and methacrylate; unsaturated amides such as acrylamide and N-methylolacrylamide; ethylene, propylene, isobutylene, etc. α-Olefins; Vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, and t-butyl vinyl ether; Halogen-containing α, β-unsaturated monomers such as vinyl chloride, vinylidene chloride, vinyl fluoride, and vinylidene fluoride: (meth ) Trifluoroethyl acrylate, 2.2.3.3-tetrafluoropropyl acrylate, 1H, 1H, 2H
, 2H-hebutadecafluorodecyl acrylate, 11
-1.11-1゜5H~Fluorine-containing (meth)acrylic acid esters such as octafluoropentyl acrylate: 2
Examples include aromatic fluorine-containing (meth)acrylic esters such as 3.5.6-titrafluorophenyl acrylic ester and 2.3.4.5.6-pentafluorophenyl methacrylic ester, One or a mixture of two or more of these can be used.

In J3 of the present invention, a monomer mixture containing a polymerizable silane compound is polymerized by a solution polymerization method in the presence of a polysiloxane containing a terminal hydroxyl group.

The solvent used at this time is the polysiloxane, the monomer mixture and the produced! Solvents that can dissolve any of the F polymers are desirable, such as aromatic hydrocarbons such as penzene, toluene, and xylene; saturated hydrocarbons such as hexane, petroleum ether, and cyclohexane; and chelons such as acetone and methyl ethyl ketone. Solvents such as esters such as ethyl acetate and butyl acetate can be used, and one type or a mixture of two or more of these can be used. However, it is not desirable to use alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, and benzyl alcohol at the initial stage of polymerization. Immediately,
When alcohols are used alone as a polymerization solvent or mixed with other solvents from the initial stage of polymerization, the graft reaction is suppressed, and 1q of the desired useful polysiloxane graft polymer is not produced. Polymer solutions tend to undergo phase separation. On the other hand, if no alcohol is used at all during the polymerization reaction, it is difficult to control the grafting reaction and the crosslinking reaction between polymer chains, causing gelation and making it impossible to obtain a satisfactory polysiloxane graft polymer.

The present invention is characterized in that an alcohol having 1 to 10 carbon atoms is used at a specific time during the polysiloxane graft polymer production process, and the time when the alcohol is added to the polymerization system is determined depending on the time when the polysiloxane is added. After grafting
It is preferable to do this before crosslinking of polymer chains occurs. That is, in the present invention, polymerization is initiated in a solvent that does not contain the alcohol, and crosslinking between polymer chains progresses. The alcohol is added to the polymerization system immediately before or after the Weissenberg effect is observed. The specific period immediately before or after cannot be determined unconditionally because the suitable period differs depending on the polymerization system, but for example, in the case of polymerization at 80°C, 30 minutes after the Weissenberg effect is observed and 2 minutes after the polymerization.
Addition within 0 minutes is desirable. The Weissenberg effect can be easily confirmed by observing the curling up of the polymer solution around the stirring rod of the polymerization vessel. Also,
By controlling the polymerization reaction conditions to a constant level, it is possible to predict when the Weissenberg effect will be observed, or by starting the polymerization reaction under the same reaction conditions at a certain time interval in multiple polymerization vessels of the same type, we can predict the Weissenberg effect that occurs in one polymerization system. It is also possible to predict the other timing from the timing of the effect, and it is also possible to add the alcohol to the polymerization system within a certain period of time before the Weissenberg effect is observed.

Examples of the alcohol having 1 to 10 carbon atoms used in the present invention include methyl alcohol, ethyl alcohol, n-
Aliphatic alcohols such as propyl alcohol, isopropyl alcohol, n-butyl alcohol, t-butyl alcohol, hexyl alcohol, octyl alcohol,
Examples include monohydric alcohols such as alicyclic alcohols such as cyclohexyl alcohol, aromatic alcohols such as benzyl alcohol, and polyhydric alcohols such as propylene glycol, 1,4-butanediol, and 1,6-hexanediol. , one or a mixture of two or more of these can be used. Among them, lower aliphatic saturated alcohols having 1 to 4 carbon atoms are more preferable, considering the degree of surface modification of the obtained polysiloxane graft polymer in terms of coating film formation and ease of solvent removal.

The alcohol having 1 to 10 carbon atoms may be added all at once, continuously, or intermittently. The amount of the alcohol used varies depending on the type of solvent used in the polymerization system, but it is 5 to 5% of the total solvent including the alcohol used.
It is desirable to use the alcohol in an amount within the range of 60% by weight. If it is added at a temperature outside of this range, gelation may occur during polymerization after addition, the polysiloxane graft polymer may not be obtained as a stable solution, or it may have poor adhesion to the substrate. It may become.

After adding the alcohol having 1 to 1 carbon atoms to the polymerization system as described above, the normal polymerization operation is continued for an appropriate amount of time depending on the type and amount of the monomer and solvent used, and then it is cooled. Thus, the desired polysiloxane graft polymer can be easily obtained as a stable solution.

(Effects of the Invention) According to the method of the present invention, a polysiloxane graft polymer that provides a coating film with excellent adhesion to a substrate and excellent water repellency, slipperiness, heat resistance, and migration resistance is added to a gel-like material. It can be obtained very easily as a stable solution that does not have any phase separation and does not undergo phase separation even when left standing. The polysiloxane graft polymer obtained by the method of the present invention is
It exhibits excellent properties when applied to bank coating agents for magnetic tapes, thermal printing materials, etc., fiber processing agents, etc.

The present invention will be specifically explained below with reference to Examples, but the present invention is not limited in any way by these examples. In addition, all parts in the examples indicate parts by weight.

Example 1 In a four-necked flask equipped with a thermometer, a reflux condenser, a dropping funnel, a nitrogen inlet tube and a stirrer, dihydroxydimethyl polysiloxane represented by 2〇H3 (where n is 1500 on average) as a polysiloxane containing terminal hydroxyl groups was added. Siloxane 30
10 parts of 1-toluene solution containing 1% sodium chloride and 100 parts of toluene were charged, and the temperature was raised to 80°C under a nitrogen atmosphere. To this, 64.4 parts of medyl methacrylate, 20 parts of butyl acrylate,
Add 20% by weight of a homogeneous monomer solution consisting of 5 parts of acrylic acid, 5.6 parts of hydroxyethyl acrylate, 5 parts of γ-methacryloxypropyltrimethoxysilane, and 2 parts of azobisisobutyronitrile, and heat to 80°C. Initial polymerization was carried out for 30 minutes. Next, the remaining monomer homogeneous solution was added dropwise over a period of 2 hours at the same temperature, and when the polymerization was continued for 20 minutes after the completion of the addition, a Weissenberg effect was observed, so 100 parts of isopropyl alcohol was immediately added. Subsequently, stirring was continued for 3 hours and 40 minutes while maintaining the temperature at 80° C. to continue the polymerization reaction, and then cooling to obtain a solution of a polysiloxane graft polymer.

The resulting polysiloxane graft polymer solution has a viscosity of 5
0C1)S (25°C, B-type viscometer, 60 rl)m), it was a homogeneous solution with a solid content of 33.3% polymerization and no gel-like substances. Further, even when the solution was left for a day and night, it remained a stable homogeneous solution without causing layer separation.

Example 2 The same initial polymerization operation and dropping operation of a homogeneous monomer solution as in Example 1 were performed. Immediately after the dropwise addition of the monomer homogeneous solution was completed, 10 parts of isopropyl alcohol was added to suppress the roll-up of the polymer solution due to the Weissenberg effect, which would occur if the polymerization continued for 20 minutes after the dropwise addition if no isopropyl alcohol was added. . Subsequently, the temperature was maintained at 80° C. and the polymerization reaction was carried out for 3 hours. Since the Weissenberg effect was observed, 90 parts of isopropyl alcohol was added. Roughly, a polymerization reaction was carried out at 80° C. for 1 hour to obtain a solution of a polysiloxane graft polymer.

The obtained polysiloxane graft polymer solution had a viscosity of 85 cps (25° C., B-type viscometer, 60 rpm), and was a homogeneous solution with a solid content of 33.1%, without gel-like substances.

Example 3 Into a four-bottle flask similar to that used in Example 1, 3 parts of dihydroxydimethylpolysiloxane represented by the formula (where n is 650 on average) as a terminal hydroxyl group-containing polysiloxane and 100 parts of toluene were charged. 80℃ under nitrogen atmosphere
The temperature rose to . To this was added a homogeneous monomer solution consisting of 30 parts of methyl methacrylate, 30 parts of styrene, 30 parts of vinyl acetate, 5 parts of acrylic acid, 5 parts of γ-methacryloxypropyltrimethoxysilane, and 2 parts of azobisisobutyronitrile. Using the same method as in Example 1, the initial 19J polymerization operation and the dropping operation of a homogeneous monomer solution were performed.

When the polymerization was continued for 15 minutes after the dropwise addition of the monomer homogeneous solution, the Weissenberg effect was observed, so 100 parts of isopropyl alcohol was immediately added. The polymerization reaction was further continued at 80°C for 3 hours and 4 hours, and then cooled for 1'J) to obtain a polysiloxane graft polymer solution. The prepared polysiloxane graft polymer solution has a viscosity of 70c.
ps (25° C., B-type viscometer, 60 rl) IN), it was a homogeneous solution with a solid content of 34.1 fliffi% without gel-like substances.

Example 4 Example 1 was added to a fourth flask similar to that used in Example 1.
33.3 parts of a 30% by weight toluene solution of the same terminal hydroxyl group-containing polysiloxane as used in the above and 100 parts of toluene were charged, and the temperature was raised to 80° C. under a nitrogen atmosphere. To this, 50 parts of methyl methacrylate, 20 parts of butyl acrylate, 20 parts of acrylonitrile, 5 parts of acrylic acid, γ
- Using a homogeneous monomer solution consisting of 5 parts of methacryloxypropyl trime-1 hexysilane and 2 parts of azobisisobutyronitrile, the same initial polymerization operation and dropping operation of the homogeneous monomer solution as in Example 1 were performed. . When the polymerization was continued for 30 minutes after the monomer homogeneous solution was added dropwise, the Weissenberg effect was observed, so ethyl alcohol 100%
Added a section. The reaction was further continued at 80° C. for 3 hours and 30 minutes, and then cooled to obtain a polysiloxane graft polymer solution. The obtained polysiloxane graft polymer solution had a viscosity of 70 cps (25°C, B type viscometer, 5 Qr.
pm) and was a homogeneous solution with a solid content of 33.0% by weight and no gel-like substances.

Example 5 The same initial polymerization operation and dropping operation of a homogeneous monomer solution as in Example 1 were performed. When the polymerization was continued for 20 minutes after the completion of the dropwise addition of the monomer homogeneous solution, the Weissenberg effect was observed, so 100 parts of benzyl alcohol was immediately added. Subsequently, the polymerization reaction was continued for 3 hours while maintaining the temperature at 80° C., and then cooled to obtain a solution of a polysiloxane graft polymer. The obtained polysiloxane graft polymer solution had a viscosity of 80 cps (25°C, B-type viscometer, 60r
pm) and was a homogeneous solution with a solid content of 33.3% by weight and no gel-like substances.

Example 6 The same initial polymerization operation and dropping operation of a homogeneous monomer solution as in Example 4 were performed. When the polymerization was continued for 30 minutes after the completion of the dropwise addition of the lllffi homogeneous solution, the Weissenberg effect was observed, but when the polymerization was continued for an additional 10 minutes, 100 parts of 1,4-butanediol was added. Further 80℃
The reaction was continued for 3 hours and 20 minutes and then cooled to obtain a polysiloxane graft polymer solution. The resulting polysiloxane graft polymer solution had a viscosity of 85 cps.
(25° C., B-type viscometer, 60 rpm), it was a homogeneous solution with a solid content of 33.1% by weight and no gel-like substances.

Comparative Example 1 Example 1 was placed in a four-loaf flask similar to that used in Example 1.
10 parts of a 30% toluene solution of the same terminal hydroxyl group-containing polysiloxane as used in , 90 parts of toluene and 10 parts of isopropyl alcohol were charged, and the temperature was raised to 80'G under a nitrogen atmosphere. Using the same homogeneous monomer solution as used in Example 1, the initial polymerization operation and the dropping operation of the homogeneous monomer solution were performed in the same manner as in Example 7. After the monomer homogeneous solution was added dropwise, a polymerization reaction was carried out for 4 hours while maintaining the temperature at 80° C., but no Weissenberg effect was observed. Add 10 parts of toluene and 90 parts of isopropyl alcohol to the polymer solution obtained by the polymerization reaction.
When the resulting solution was left overnight, a large amount of polysiloquiline separated into the upper layer.

Comparative Example 2 The same initial polymerization operation and dropping operation of a homogeneous monomer solution as in Example 1 were performed. The Weissenberg effect was observed when the polymerization was continued for 20 minutes after the completion of the dropwise addition of the homogeneous monomer solution, but 100 parts of isopropyl alcohol was added when the polymerization was continued for an additional 30 minutes after the Weissenberg effect was confirmed. Further, the polymerization reaction was continued for 3 hours and 10 minutes while maintaining the temperature at 80° C., and then cooled to obtain a polymer solution. The obtained polymer solution had a viscosity of 350 cps (25° C., Type B viscometer, 60 rpm), a solid content of 32.2% by weight, and contained a large amount of gel-like material. In addition, a considerable amount of aggregates adhered to the four-hole flask used for polymerization.

Claims (1)

[Claims] 1. In producing a polysiloxane graft polymer by solution polymerizing a monomer mixture containing a polymerizable silane compound in the presence of a polysiloxane containing a terminal hydroxyl group,
A method for producing a polysiloxane graft polymer, which comprises adding an alcohol having 1 to 10 carbon atoms to a polymerization system immediately before or after the Weissenberg effect is observed during the polymerization reaction.