JPS6173712A - Production of graft polymer - Google Patents

Abstract

PURPOSE:To produce a graft polymer excellent in both water and oil repellencies and useful for paints, by polymerizing a specified copolymer with an alkyl (meth)acrylate in the presence of a polymerization initiator in an inert organic solvent. CONSTITUTION:A copolymer (A) of an average degree of polymerization of 10-10,000 is obtained by copolymerizing 50-99wt% (meth)acrylate having a perfluoroalkyl group with 50-1wt% alkyl (6C or lower) (meth)acrylate at 50-130 deg.C in the presence of a polymerization initiator. 100pts.wt. component a and 10-1,500pts.wt. alkyl (16C or lower) (meth)acrylate are emulsion- polymerized or suspension-polymerized at 50-160 deg.C for 15min-6hr in an inert organic solvent (e.g., pentane) in the presence of a polymerization initiator of a half-life period at 50-160 deg.C of 0.5-2hr.

Description

DETAILED DESCRIPTION OF THE INVENTION [1] Object of the Invention The present invention relates to a method for producing a graft polymer having excellent water repellency and oil repellency and suitable for use in paints.

More specifically, acrylate or methacrylate is added to a copolymer of an alkyl acrylate or methacrylate having a perfluoroalkyl group and an alkyl acrylate or methacrylate in the presence of a polymerization initiator.
The present invention relates to a method for producing a graft polymer, which is characterized by polymerizing in an inert organic solvent at a temperature of 0 to 10°C, and provides a graft polymer that is suitable for use in paints and has excellent water and oil repellency. The purpose is to

[H] Background of the Invention Undersea structures such as the bottoms of ships, tanks, buoys, and waterway conduit pipes for thermal power plants are home to a large number of plants and animals such as Fujibo, oysters, serpura, blue laver, and Ulva, which cause various damage to these structures. is bringing about. For example, in the case of a ship, the growth of barnacles and sea lettuce on the bottom of the ship increases the resistance of the ship, which increases fuel consumption during service. Conventionally, antifouling paints containing cuprous oxide, organic tin compounds, etc., which are harmful to humans and animals, have been used to prevent these damages. By diffusing or eluting toxic substances in the antifouling paint into seawater, it is possible to prevent animals and plants from adhering to the coated object. However, the antifouling validity period of such antifouling paints is limited to two years at most, and usually only about one year, and it is necessary to reapply each time to prevent damage from animals and plants in the seawater. Furthermore, since this antifouling paint contains the above-mentioned toxic substances, there are problems in terms of safety and health during painting.

It is said that attached animals and plants in seawater produce sticky secretions, which act as adhesives and adhere to the surfaces of the underwater structures such as the bottoms of ships and grow.

Therefore, in addition to the above-mentioned method of using toxic substances, it is thought that if the surface of the underwater structure to be antifouled is coated with a surface to which substances secreted by animals and plants do not adhere, basically these animals and plants will not adhere. . In this regard, compounds having a perfluoroalkyl group in the molecule have extremely low surface energy, and surfaces made of compounds with low surface energy have poor adhesion and can be used in antifouling paints. In addition, by taking advantage of the property that the surface of perfluoroalkyl groups has low surface energy, fluorine-containing polymers with perfluoroalkyl group-containing side chains can be made into fibers! dF is used as a water and oil repellent for textiles, etc. In addition, as a coating film forming material containing a perfluoroalkyl group,
Thermosetting resins containing perfluoroalkyl group-containing side chains and functional groups such as carboxyl groups, methylol groups, hydroxyl groups, epoxy groups, and amide-aldehyde reactive groups have been proposed. In order to achieve compatibility with paints, coating materials, and other film-forming materials, a fluorine-containing polymer having a perfluoroalkyl group-containing side chain is randomly copolymerized with an aromatic copolymer component, and It is known that fluorine-containing polymers having perfluoroalkyl groups are used as antifouling paints. It is thought that it is possible to do so.

It is effective to incorporate a fluorine-containing polymer having such a perfluoroalkyl group into a coating film that requires water/oil repellency and antifouling properties, but perfluoroalkyl groups such as those already proposed are effective. In the case of containing side chains and other random copolymers, the compatibility with the film-forming resin bases has not yet been resolved. Further, the effects of conventionally proposed fluorine-containing copolymers having perfluoroalkyl group-containing side chains are not noticeable unless the fluorine content is increased.

[m] Structure of the Invention Based on the above, the present inventors have found that not only is the water and oil repellency excellent, but also the compatibility with the coating film-forming resin base material, stain resistance, hygiene, and sustainability. As a result of various searches for obtaining resins (polymers) that are promising as raw materials for excellent paints, we found that at least 50% by weight of "acrylates or methacrylates having perfluoroalkyl groups" [hereinafter referred to as "fluorine-containing (meth)acrylates"] were found. ] and 1 to 50% by weight
10 to 1,50 parts by weight per 100 parts by weight of a copolymer whose main component is "alkyl acrylate or methacrylate whose alkyl group has at most 16 carbon atoms" [hereinafter referred to as "(meth)acrylate"]. 0 parts by weight of (meth)acrylate in the presence of a polymerization initiator from 50 to 160 parts by weight.
The method for producing a graft polymer, which is characterized by polymerization in an inert organic solvent at a temperature of °C, does not have the above-mentioned drawbacks and not only has good water repellency and oil repellency.
We have discovered that this resin is a promising resin as a raw material for paints that has excellent compatibility with film-forming resins, antifouling properties, hygienic properties, and sustainability, and have arrived at the present invention.

[■] Effects of the invention The polymer obtained by the invention, including its production method, exhibits the following effects.

(1) By mixing a small amount of the grafted product of the present invention into paints such as acrylic paints and urethane paints, the coated surface can be made to have low surface energy, resulting in water and oil repellency. . Therefore, it is effective as a paint for metal articles, ships, tanks, buoys, and waterway conduit pipes of thermal power plants.

(2) Since it has good compatibility with acrylic paints and urethane paints, even if it is immersed in water for a long time, it will not be eluted into water and its effect can be maintained for a long time.

(3) It does not cause environmental pollution because it does not elute to the outside.

(4) Hygienic.

(5) Excessive water repellency, oil repellency, and antifouling effects can be exhibited with a small amount of fluorine content.

(6) By performing graft polymerization using an appropriate organic solvent, the resulting graft polymer solution can not only be used as it is as a paint, but also provide water and oil repellency to the coating film, and can be made to have low surface energy. The coating film thus obtained is resistant to water-soluble stains and can prevent the diffusion of water into the coating film.

[V] Detailed Description of the Invention (A) Copolymer The copolymer used in the present invention is mainly composed of at least 50% fluorine-containing (meth)acrylate and 1 to 50% by weight of (meth)acrylate. It is a copolymer that

(1) Fluorine-containing (meth)acrylate This fluorine-containing (meth)acrylate is an acrylate or methacrylate having a perfluoroalkyl group, and it is important that the terminal group has a side chain having the general formula RfQCH2. Rf represents a perfluoroalkyl group having 4 to 20 carbon atoms, and may be branched or linear. If Rf is 3 or less, the resulting graft polymer will not have sufficient proofreading properties. On the other hand, when the number of carbon atoms is 21 or more J-, it is not only difficult to obtain the monomer but also poses a problem in producing a graft polymer. In particular, those having 6 to 12 carbon atoms are preferred. Q is CnH2n-, and preferably n is 5 or less. Therefore, the fluorine-containing monomer used in the wood invention has the following formula [(■)
It is preferable to use the formula shown in Formula 1.

CH2-♂-COOCH2QRf (I)
In formula (I), Rf and Q are the same as above,
R represents a hydrogen atom or a methyl group.

Among the fluorine-containing tops used in the present invention, preferred representative examples include 3, 3, 4, 4, 5°, 5.
8, 8, 7. ? , 8, 8. ! a, 9.9-hebutadecafluorononyl-2-methyl-2-propenoate, 3,3
,4,4,5,5,8. B.

? , 7, 8, 8, 9, 9, 10, 10, 11, 11, 1
2,12.12-heneicosafluorododecyl-2-propenoate, 3,3,4,4,5°5, f3,8,7,
7,8,8,9,9,10,10.10-heptadecafluorodecyl-2-propenoate, 3,3,4,4,5
,5. El, B,? .

? , 8.8, 9. ．． 9.10.10.11, 11, 12
, 12.13,13,14.14.14-pentacosafluorotetradecyl-2-propenoate and 3,3,
4,4,5,5,6,13,7,7,8,8.8-)
Lidecaflobutyl-2-propenoate is mentioned.

(2) (Meth)acrylate Also, (meth)acrylate is a polymer whose main component is alkyl acrylate or methacrylate in which the alkyl group has at most 16 carbon atoms. The alkyl group may be linear or branched, and preferably has 12 or less carbon atoms, particularly preferably 8 or less carbon atoms. Suitable alkyl groups include methyl, propyl, n- or isobutyl, hexyl and octyl. In the wood invention, among these (meth)acrylate polymers, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate,
Butyl acrylate or 2-ethylhexyl acrylate is preferred.

(3) Copolymerization ratio The copolymerization ratio of fluorine-containing (meth)acrylate in the copolymer of the present invention is small (both 50% by weight, 55% by weight).
It is preferably at least 60% by weight, particularly preferably at least 60% by weight. If the copolymerization ratio of the fluorine-containing (meth)acrylate in the copolymer is less than 50% by weight, the water repellency and oil repellency of the resulting graft polymer will decrease.

The copolymerization ratio of (meth)acrylate is 1 to 50% by weight, preferably 2 to 45% by weight, especially 5 to 50% by weight.
40% by weight is suitable. If the copolymerization ratio of (meth)acrylate is less than 1% by weight, the solubility of the resulting graft polymer in the solvent will decrease. On the other hand, if it exceeds 50% by weight, the resulting graft polymer will have low water and oil repellency.

In addition, examples of copolymerization components include olefinic monomers such as ethylene, propylene, and butene-1, acrylic monomers having functional groups such as acrylamide, N-methylolamide, and glycylacrylate, and unsaturated carboxylic acid anhydrides. . The copolymerization ratio of these copolymerization components is usually preferably 15% by weight or less.

(4) Polymerization method This copolymer is made of the fluorine-containing (meth)acrylate and (
Obtained by copolymerizing meth)acrylate or these and other third components (comonomers) in the presence of a polymerization initiator by any polymerization method such as bulk polymerization, solution polymerization, emulsion polymerization, or suspension polymerization. be able to.

There are no particular limitations on the polymerization initiator, but the half-life is 50-18
Preferably, the treatment time is 0.5 to 2 hours at a temperature of 0°C.

Preferred polymerization initiators include organic peroxides such as benzoyl peroxide, di-tert-butyl peroxide, lauryl peroxide and cumene hydroperoxide, and azo compounds such as azobisisobutyronitrile.

In producing this copolymer, the polymerization temperature is usually 50°C.
-160°C, preferably 50-140°C, particularly preferably 80-140°C.

In addition, the proportion of the polymerization initiator used can be changed as appropriate depending on the type of polymerization initiator, polymerization conditions, etc., but in general, the total amount (total amount) of fluorine-containing (meth)acrylate and (meth)acrylate 100 polymerization 0.005~
5.0 parts by weight, 0. 1 to 5.0 parts by weight of O is desirable, particularly 0.01 to 3.0 parts by weight. 1
00 parts by weight of fluorine-containing (meth)acrylate and (meth)
If the proportion of the polymerization initiator used is less than 0.005 parts by weight with respect to the total amount (total amount) of acrylate, a long time will be required for copolymerization, and unreacted fluorine-containing (meth)acrylate will remain in the copolymerization system. remain. On the other hand, if more than 5.0 parts by weight is used, rapid copolymerization will occur, making it difficult to control the copolymerization.

Among the copolymers obtained as above.

In producing the graft polymer of the present invention, the average degree of polymerization is generally 10 to 10,000,
20 to 5,000 is preferred, particularly 50 to 3.
000 copolymers are preferred. If a copolymer having an average degree of polymerization of less than 10 is used to produce a graft polymer, the resulting graft polymer will have poor water and oil repellency. On the other hand, if it exceeds 10,000, it is difficult to carry out graft polymerization, and there are problems in handling the resulting graft polymer.

(B) Graft polymerization For 100 parts by weight of this copolymer, lO~1.50
The graft polymer of the present invention can be produced by polymerizing 0 parts by weight of the above (meth)acrylate in an inert organic solvent in the presence of a polymerization initiator at a temperature of 50 to 180°C.

(1) Inert organic solvent The inert organic solvent is used as the above (meth)
It dissolves the acrylate and polymerization initiator, and also dissolves or disperses the copolymer. moreover,
It is inert to (meth)acrylates, copolymers and polymerized DH initiators. The inert organic solvent is liquid at normal temperature and pressure, but one having a boiling point of 50°C to 300°C is preferable. Typical inert organic solvents include aliphatic or aliphatic hydrocarbons (e.g., pentane, hexane, heptane, octane, cyclohexane), aromatic hydrocarbons (benzene, toluene, xylene), petroleum ether, tetrahydrofuran. ,1
．． 4-dioxane, methyl ethyl ketone, methyl chloroform, trichloroethylene, tetrachloroethylene,
Examples include tetrachlorodifluoroethane and trichlorotrifluoroethane. These inert organic solvents contain the total amount of the (meth)acrylate and copolymer 10
0 g +,: 30 g +, 30 g +, 2 g is common.

Bowft to 0.4 sentences are preferred. If the ratio of the inert organic solvent used is less than 30 mu with respect to the total amount of (meth)acrylate and copolymer of 100 g, it is not preferable because it takes a long time to dissolve or disperse the (meth)acrylate and copolymer. In addition, the viscosity becomes high, making it difficult to perform stirring during graft polymerization.

On the other hand, even if more than two sentences are used, there is a problem because the concentration of water- and oil-repellent components in the solution decreases.

(2) Polymerization initiator The polymerization initiator used in this graft polymerization is the same type as that used in the production of the above-mentioned copolymer. For the same reason as above, the proportion used is generally 0.005 to 5.0 parts by weight, preferably 0.01 to 5.0 parts by weight, particularly 0.005 to 5.0 parts by weight, and preferably 0.01 to 5.0 parts by weight.
．． 01 to 3.0 parts by weight is suitable.

(3) Usage ratio of (meth)acrylate The usage ratio of (meth)acrylate to 100 parts by weight of the above copolymer is 10 to 1,500 parts by weight, and 50 to I,00.
0 parts by weight is preferred, and 100 to 800 parts by weight is particularly preferred. If the ratio of (meth)acrylate used to 100 parts by weight of the copolymer is less than 10 parts by weight, the resulting graft polymer will have poor compatibility with the paint. On the other hand, 1
If the amount exceeds 500 parts by weight, the water repellency and oil repellency of the resulting graft polymer will decrease.

(4) Other graft polymerization conditions The polymerization temperature is 50 to 160°C, preferably 50 to 140°C, and particularly preferably 60 to 140°C. 50℃
If the polymerization is carried out at less than Graph I, it will take a long time to produce the graft polymer, which is industrially undesirable.

On the other hand, if the polymerization is carried out at a temperature exceeding 180°C, the polymerization can be completed in a relatively short time, but this is not desirable because the physical properties of the resulting graft polymer are poor.

In addition, the polymerization time is usually 15 minutes to 8 hours, and 30 minutes to 8 hours.
Minutes to 5 hours are preferred, particularly 30 minutes to 4 hours. Attempting to complete the polymerization in less than 15 minutes requires higher polymerization temperatures and makes it difficult to control the polymerization.

On the other hand, if the polymerization time exceeds 6 hours, although it is easy to control the polymerization, it is not industrially advantageous because the polymerization time is long.

When the above-mentioned copolymer is produced by an emulsion polymerization method or a suspension polymerization method, it is necessary to almost completely remove the water used in the copolymerization and to dry the copolymer. However, when produced by a solution polymerization method or a bulk polymerization method, graft polymerization can be carried out as is by adjusting the graft polymerization conditions as described above.

Note that only one type of fluorine-containing (meth)acrylate and (meth)acrylate used in producing the copolymer and (meth)acrylate used in producing the graft polymer may be used,
Two or more types may be used in combination.

The proportion of fluorine-containing (meth)acrylate in the graft polymer obtained as described above is generally 3.0 to 90% by weight in units of 1,000, making it difficult to control the polymerization.

On the other hand, if the polymerization time exceeds 6 hours, although it is easy to control the polymerization, it is not industrially advantageous because the polymerization time is long.

When the above-mentioned copolymer is produced by an emulsion polymerization method or a suspension polymerization method, it is necessary to almost completely remove the water used in the copolymerization and keep it in a dry state. However, when produced by a solution polymerization method or a bulk polymerization method, graft polymerization can be carried out as is by adjusting the graft polymerization conditions as described above.

Note that only one type of fluorine-containing (meth)acrylate and (meth)acrylate used in producing the copolymer and (meth)acrylate used in producing the graft polymer may be used,
Two or more types may be used in combination.

The proportion of fluorine-containing (meth)acrylate in the graft polymer obtained as described above is generally 3.0 to 80% by weight per monomer unit, and 3.0 to 6.
0% by weight is preferred, and 5.0 to 40% by weight is particularly optimal. Fluorine content (meth) in the graft polymer
The proportion of acrylate is 3.0% by weight as one monomer unit.
If it is less than that, the resulting graft polymer will not have sufficient water repellency and oil repellency. On the other hand, if it exceeds 80% by weight, the compatibility with other oil-soluble paints becomes poor when used in combination with the paint.

[VI] Examples and Comparative Examples The present invention will be explained in more detail with reference to Examples below.

In Examples and Comparative Examples, water repellency is expressed by applying a solution of the obtained graft polymer onto an acrylic plate and determining the contact angle of water of the resulting coating film. Further, the oil proofing properties were determined by applying the coating in the same manner as above, and determining the contact angle of the resulting coating film with n-hexadecane. In both cases, the larger the contact angle, the greater the water repellency or oil repellency. moreover,
The resulting graft polymer solution was visually observed and expressed as follows.

O: Precipitate is not present in solution ×: Precipitate is present in solution Example 1 4 g of methyl methacrylate [hereinafter referred to as "compound (1)"]
), leg CH=CHC00CH2CH
2C8F17 [hereinafter referred to as "compound (a)"], 0
．． 05 g of benzoyl peroxide and 60 g of toluene were placed in a 300 cc flask. Copolymerization was carried out at a temperature of 80° C. for 3 hours under a nitrogen atmosphere while stirring. The yield of the obtained copolymer was 98%, and the average degree of polymerization was about 200.

To the toluene solution containing this copolymer, 20 g of compound (1), O, and 1 g of benzoyl peroxide were further added, and graft polymerization was carried out at a temperature of 80 ° C. for 311!7 minutes in a nitrogen atmosphere with stirring. . The grafting ratio of the obtained graft polymer was 52%.

Examples 2 to 12, Comparative Examples 1 to 4 The proportion of compound (a) used in producing the copolymer in Example 1 was changed as shown in Table 1, and 4 g of compound (1) was added. Instead, ethyl acrylate [hereinafter referred to as "compound (2)"], butyl acrylate [hereinafter referred to as "compound (3)]" or compound (1) was used in the proportions shown in Table 1. Copolymerization was carried out under the same conditions as in Example 1. Table 1 shows the yield and average degree of polymerization of each copolymer obtained. Graft polymerization was carried out in the same manner as in Example 1, except that Compound (1) was used in each of the obtained copolymers in the amount shown in Table 1. Table 1 shows the grafting ratio of each of the obtained graft polymers.

The water repellency and oil repellency of each of the graft polymers thus obtained were measured.

The results and the compatibility of the resulting graft polymer solutions are shown in Table 2.

(The following is a blank space) From the results of the Examples and Comparative Examples shown in Table 2, it is clear that the graft polymer obtained by the present invention not only has excellent water repellency and oil repellency, but also has excellent compatibility with solutions (toluene). It is clear that it is good.

Claims (1)

[Claims] 1 to 50% by weight of acrylate or methacrylate with at least 50% by weight of perfluoroalkyl groups;
10 to 1,500 parts by weight of an alkyl group having at most 16 carbon atoms per 100 parts by weight of a copolymer containing an alkyl acrylate or methacrylate as a main component. A method for producing a graft polymer, which comprises polymerizing an alkyl acrylate or methacrylate in an inert organic solvent at a temperature of 50 to 160°C in the presence of a polymerization initiator.