JP2018145058A - Surface preparation agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface preparation agent, in which the number of carbon in a perfluoroalkyl group is reduced to 6 or less to eliminate the possibility of causing PFOA, specifically to provide the surface preparation agent that shows little influence on an organism and environment and is excellent in water repellency and water proofness by using, as a substituent, a compound obtained by replacing (CF)F in the formula with (CF)F, (CF)F or the like.SOLUTION: This invention relates to a treatment agent for water repellency and water-proofness of concrete, comprising in a solvent, a polymer containing a unit based on a compound expressed by the following formula (a): CH=C(R)-COO-(CH)-(CF)F, where Ris a hydrogen atom or a methyl group, n is an integer of 0-4, and m is an integer of 1-6.SELECTED DRAWING: None

Description

  The present invention relates to a surface treatment agent that imparts water repellency and waterproof performance to concrete.

Conventionally, a polymer of (meth) acrylic acid ester having a linear or terminally branched perfluoroalkyl group having a carbon chain length of 8 or more has been used as a fluorine-based surface treatment agent. This is because the crystallinity of the (CF ₂ ) ₈ F group in the side chain exhibits high water repellency and waterproof performance.

The US Environmental Protection Agency (USEPA) published a preliminary risk study report on the safety of perfluorooctanoic acid (PFOA) detected in various environments, including wild animals and human blood, in March 2003. In the report, it was pointed out that the perfluoroalkyl group that has the possibility of generating PFOA has 8 carbon atoms and has an impact on the living body and the environment. In January 2006, PFOA, its related substances, and their precursor substances were proposed to fluororesin manufacturers and others to participate in a reduction plan in the environment and a content reduction plan in products.
Examples of the structure to be used here include compounds having a linear perfluoroalkyl group having 8 carbon atoms shown below (see Patent Document 1).
_{CH 2 = CH-COO- (CH} 2) 2 - (CF 2) 8 F
_{CH 2 = C (CH 3)} -COO- (CH 2) 2 - (CF 2) 8 F

JP-A-10-303536

In such a situation, in order to reduce the possibility of the occurrence of PFOA, the carbon number of the perfluoroalkyl group is shortened to 6 or less, specifically, (CF ₂ ) ₈ F in the above formula is changed to (CF ₂ ) By using a compound substituted with ₆ F or (CF ₂ ) ₄ F as an alternative, it is intended to provide a surface treatment agent that has little influence on the living body and the environment, and has excellent water repellency and waterproof performance. And

  As a result of intensive studies to solve the above problems, the present inventors have found that a copolymer of a (meth) acrylic acid ester having a perfluoroalkyl group having 6 or less carbon atoms has little influence on the living body and the environment, In addition, it has been found that it has excellent water repellency and waterproof performance.

That is, the present invention provides the following surface treatment agent.
[1] A water repellent or waterproofing agent for concrete containing a polymer containing a unit based on a compound represented by the following formula (a) in a solvent.
^{_{CH 2 = C (R 1)}} -COO- (CH 2) n - (CF 2) m F formula (a)
(In the formula, R ¹ is a hydrogen atom or a methyl group, n is an integer of 0 to 4, and m is an integer of 1 to 6.)
[2] A repair and reinforcement method using the treatment agent according to [1].
[3] Concrete treated with the treating agent according to [1].

  The surface treating agent of the present invention uses a polymer containing a polymer unit derived from the (meth) acryl compound specified by the above formula (a) while suppressing the carbon number of the perfluoroalkyl group to 6 or less. Thus, it is possible to provide concrete having high water repellency or waterproof performance.

In the present specification, the compound represented by the formula (a) is also referred to as a compound (a). The compounds represented by other formulas may be expressed similarly.
In addition, in this specification, (meth) acrylate represents both or one of acrylic ester and methacrylic ester.

The polymer which is an essential component of the surface treating agent of the present invention (hereinafter also referred to as “the polymer of the present invention”) contains units based on the following compound (a) (hereinafter also referred to as units (A)). Polymer.
^{_{CH 2 = C (R 1)}} -COO- (CH 2) n - (CF 2) m F formula (a)
(In the formula, R ¹ is a hydrogen atom or a methyl group, n is an integer of 0 to 4, and m is an integer of 1 to 6.)

In the compound (a), R ¹ is preferably a hydrogen atom or a methyl group. n is preferably from 0 to 3, and more preferably 1 or 2. From the viewpoint of good water repellency or waterproof performance, m is preferably 4 or 6, and 6 is particularly preferable.

The polymer of the present invention may be a homopolymer composed of one of the above units (A), or may be a copolymer composed of two or more of the units (A). Moreover, the copolymer containing 1 type or 2 types or more of units other than a unit (A) may be sufficient.
In this case, the content of the unit (A) in the polymer of the present invention is preferably 50% by mass or more. This is because when the mass ratio of the unit (A) in the polymer of the present invention is within the above range, the water and oil repellency of the surface treatment composition of the present invention is better.

  In the present invention, the mass ratio of each unit in the polymer is a value considered that all raw materials used for polymerization constitute a unit. Therefore, for example, the mass ratio of the unit (A) (percentage of the mass of the unit (A) contained therein with respect to the total mass of the constituent units) is substantially equal to the mass of the polymerization raw material compound (a) used in the polymerization. It is determined as a percentage of the total mass. The mass ratio of other units in the polymer can be obtained in the same manner.

  In the polymer of the present invention, the total content of the units (A) is preferably 50% by mass or more, and more preferably 70% by mass or more.

The polymer of the present invention preferably has units based on other compounds (hereinafter also referred to as units (B)).
The content of the unit (B) is preferably 50% by mass or less. 30 mass% or less is more preferable. When the unit (B) is contained excessively, the water repellency and waterproofing performance are deteriorated.

The other compound is a compound having a polymerizable functional group, for example, (meth) acrylic acid ester having a chain alkyl group having 1 to 18 carbon atoms such as (meth) acrylic acid and stearyl (meth) acrylate, cyclohexyl (Meth) acrylate and (meth) acrylic acid ester having a cyclic alkyl group having 3 to 18 carbon atoms, such as isobornyl (meth) acrylate. In addition, a compound containing a functional group having reactivity, for example, ethylenically unsaturated carboxylic acids such as maleic acid, itaconic anhydride, succinic anhydride, maleic anhydride, (meth) acrylamide, N-methyl (meth) acrylamide, Amide compounds such as N-methylol (meth) acrylamide and N-butoxy (meth) acrylamide, hydroxyl-containing compounds such as hydroxyethyl (meth) acrylate and hydroxyethyl (meth) acrylate, and oxyalkylenes such as polyethylene glycol (meth) acrylate Group-containing compounds, alkoxysilyl group-containing compounds such as vinyl alkoxysilane, γ- (meth) acryloxypropyltrimethoxysilane, epoxy group-containing compounds such as glycidyl (meth) acrylate, 2- (meth) acryloyloxyethylsucci Acid etc. Carboxyl group-containing compounds, amino group-containing compounds such as diethylaminoethyl (meth) acrylate, a compound having an organopolysiloxane group and a (meth) acrylate groups, but such as but not limited to.
The compound (b) may have a plurality of polymerizable functional groups. For example, the compound which has multiple (meth) acrylates, such as ethylene glycol di (meth) acrylate, is mentioned. Moreover, you may have a cyclic structure like triallyl isocyanurate.

  Specific examples of the compound (b) include the compounds (c) described in [0026] to [0038] of WO2010 / 113646 and the compounds (d) described in [0039] to [0048], including the above examples. ).

Although the molecular weight of the polymer of this invention is not specifically limited, It is preferable that it is 1 * 10 < ³ > -1 * 10 < ⁷ > by a mass mean molecular weight (Mw), and it is preferable that it is 1 * 10 < ⁴ > -1 * 10 < ⁶ >. This is because if the molecular weight is within such a range, the water sliding performance can be sufficiently exhibited. On the other hand, if the molecular weight is too large, the solubility of the polymer of the present invention in a solvent tends to be poor.

  The polymer of the present invention is not particularly limited, such as a polymerized form, except that it may contain the unit (A) and the unit (B) as described above. The form of polymerization in the case of a copolymer is not particularly limited and may be any of random, block, graft and the like, but is preferably a random polymer.

  The method for producing the polymer is not particularly limited, and various known methods can be adopted. For example, addition polymerization can be performed based on an unsaturated group in each compound. The polymerization can be carried out by appropriately adopting known addition polymerization conditions for unsaturated compounds. For example, a normal initiator such as an organic peroxide, an azo compound, or a persulfate can be used as a polymerization initiation source. In order to adjust the molecular weight, a molecular weight modifier can be used during the polymerization reaction.

The surface treating agent of the present invention is in a liquid form containing the above polymer as a coating component and containing the polymer in a solvent.
The method for producing the surface treatment agent of the present invention is not limited. For example, it can be obtained by dissolving the polymer of the present invention in a known solvent. Further, for example, the compound (a) is added to a solvent, and the polymer of the present invention is produced by solution polymerization using the solvent as a polymerization medium to obtain the solvent containing the polymer of the present invention. It can also be used as a surface treatment agent. A solution containing the polymer of the present invention can be obtained by emulsion polymerization, and this can be used as the surface treatment agent of the present invention. The polymer of the present invention obtained here may be separated and dissolved in another solvent. Further, when the polymerization raw material compound is in a gaseous state, it may be continuously supplied under pressure using a pressure vessel.

  The surface treating agent of the present invention may be a solution in which the polymer of the present invention is dissolved in a solvent or a dispersion in which the polymer is dispersed in a solvent. In the case of a dispersion, it is preferable that the polymer of the present invention is uniformly dispersed. Examples of the production method include obtaining the polymer of the present invention by emulsion polymerization and then removing coarse particles by filtration.

  The solvent for forming the surface treatment composition of the present invention is not particularly limited as long as it can dissolve or disperse the polymer of the present invention, and examples thereof include various organic solvents, water, or a mixed medium thereof. For example, a general organic solvent or a fluorinated solvent can be used. Common solvents include alcohol (ethanol, 2-propanol, etc.), ketone (acetone, methyl ethyl ketone, etc.), ester (ethyl acetate, etc.), ether (tetrahydrofuran, etc.), hydrocarbon (hexane, heptane, Octane). Examples of the fluorine-based solvent include xylene hexafluoride in addition to PFC and HFE. Moreover, you may use these solvents in mixture of 2 or more types.

Although the specific example of a preferable solvent is given as a solvent which forms the surface treating agent of this invention below, it is not limited to these.
Ethanol, 1-propanol, 2-propanol (hereinafter referred to as IPA), 1-butanol, t-butanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl acetate, ethyl acetate, butyl acetate, tetrahydrofuran, m-xylene hexafluoride de (hereinafter, referred to as m-XHF.), p- xylene _{hexafluoride, CF 3 CH 2 CF 2 CH} 3, CF 3 CH 2 CF 2 H, C 6 F 13 OCH 3, C 6 F 13 OC 2 H ₅ , C ₆ F ₁₃ CH ₂ CH ₃ , C ₃ F ₇ OCH ₃ , C ₃ F ₇ OC ₂ H ₅ , C ₆ F ₁₃ H, CF ₂ HCF ₂ CH ₂ OCF ₂ CF ₂ H, CF ₃ CFHCHFCF ₂ CH _{3, CF 3 (OCF 2 CF} 2) n (OCF 2) m OCF 2 H, C 8 F 17 OCH _{, C 7 F 15 OCH 3,} C 4 F 9 OCH 3, C 4 F 9 OC 2 H 5, in _{C 4 F 9 CH 2 CH 3} , CF 3 CH 2 OCF 2 CF 2 CF 2 H ( illustrated above, the subscript m and n each independently represents an integer of 1 to 20) and mixtures thereof.

The surface treatment agent of the present invention preferably contains the polymer of the present invention at 0.1 to 20% by mass, and more preferably 0.1 to 5% by mass. When the concentration of the polymer of the present invention in the surface treatment composition of the present invention is within this range, water repellency and waterproof performance can be sufficiently exhibited.
The concentration of the polymer of the present invention in the surface treatment composition of the present invention may be a final concentration. For example, when the surface treatment composition of the present invention is directly prepared as a polymerization composition, the polymerization composition immediately after polymerization is used. Even if the polymer concentration (solid content concentration) exceeds 20 mass%, there is no problem. The high-concentration polymerization composition can be appropriately diluted so that the final desired concentration is obtained.

  The surface treatment composition of the present invention may contain other components other than those described above as long as the stability, water / oil repellency, appearance and the like of the composition are not adversely affected. Such other components include, for example, pH control agents, rust preventives for preventing corrosion of the coating surface, and the purpose of controlling the concentration of the polymer in the liquid when the composition is used diluted. Examples thereof include dyes for distinguishing them from treated parts, dye stabilizers, flame retardants, antifoaming agents, and antistatic agents.

  The surface treating agent of the present invention can be diluted to an arbitrary concentration and treated on the surface according to the purpose and application, thereby coating the polymer and imparting performance. As a coating method, a general coating method can be adopted. For example, there are methods such as dip coating, spray coating or coating with a roller.

  After application of the surface treatment composition of the present invention, it is more preferable to perform drying at a temperature equal to or higher than the boiling point of the solvent. Of course, when it is difficult to heat and dry due to the material of the part to be processed, it should be dried while avoiding heating. In addition, what is necessary is just to select the conditions of heat processing according to the composition of the composition to apply | coat, an application area, etc.

The present invention will be specifically described below, but the present invention is not limited to the following examples. Unless otherwise specified, what is indicated by “%” in the description of the following examples represents “mass%”.
The compounds used in the following examples are shown in Table 1. The compound used can be obtained as a reagent from the market or can be easily synthesized by a known synthesis method.

[Polymer solutions 1 to 66]
Each compound (each solvent and initiator (V-601, manufactured by Wako Pure Chemical Industries, Ltd.)) was charged in a sealed container so that the charging ratio (parts by mass) described in the table was obtained, and reacted at 70 ° C. for 18 hours or more. And polymer solutions 1 to 66 were obtained.
[Surface treatment agents 1-35, 37-42, 47-54, 56-66]
Dilution solvents listed in Table 2 were added to obtain a surface treating agent so that the concentration of the obtained polymer was 2% by mass.
[Surface treatment agent 36]
Surface treatment agent 36 was obtained by adding hexyltrimethoxysilane and the dilution solvent shown in Table 2 so that the concentration of the obtained polymer was 2 mass% and the concentration of hexyltrimethoxysilane was 10 mass%. .
[Surface treatment agents 43 to 46]
The concentration of the obtained polymer was 2% by mass, ethyl polysilicate (containing ethyl silicate) was 5% by mass, decyltrimethoxysilane was 5% by mass, dibutyltin dilauryl phosphate was 0.5% by mass, ethyl polysilicate. Surface treatment agent 43 was obtained by adding (ethyl silicate-containing), decyltrimethoxysilane, dibutyltin dilauryl phosphate and diluting solvents listed in Table 2. Similarly, surface treatment agents 44 to 46 were obtained.
[Surface treatment agent 55]
Acetic acid and ion-exchanged water were added to the obtained polymer solution to make the polymer acetate, and then TFE was distilled off under reduced pressure to obtain a polymer dispersion solution 55a. Ion exchange water was added so that the concentration of the obtained polymer was 2% by mass, and a surface treating agent 55 was obtained.

[Surface treatment agents 67-87]
In a closed container, each other than the initiator was charged at the charging ratio (parts by mass) shown in Table 3, and after emulsification for 1 hour at 50 ° C., the initiator (W-50 Pure Chemical Industries, V-50) was added. In addition, the reaction was performed at 60 ° C. for 18 hours or longer to obtain polymer dispersion solutions 67 to 87. The polymer dispersion was filtered through a filter paper having a pore size of about 6 μm, and then adjusted to a dry residue concentration of 2% with a 20% aqueous solution of denatured ethanol to obtain surface treating agents 67 to 87.

Modifier: n-dodecyl mercaptan _{Emulsifier: C 12 H 25 O- (CH} 2 CH 2 O) n -H, n = average 20

About obtained Examples 1-87, the contact angle performance of water was evaluated by the method shown below. All the evaluation results showed a water contact angle of 100 degrees or more, and confirmed that there was high water repellency.
[Measurement of contact angle]
Immerse the glass plate in the surface treatment agent. The glass plate was taken out after 1 minute and dried at 120 ° C. for 5 minutes to obtain a glass plate having a coating of the surface treatment agent of the present invention.
After cooling the glass plate which processed the implementation surface treating agent to room temperature, ion-exchange water was dripped on the film of the glass plate, and the contact angle of water was measured. An automatic contact angle meter OCA-20 [manufactured by dataphysics] was used for the measurement of the contact angle.

  In the present invention, it was found that a surface treatment composition can be obtained on concrete having sufficient water repellency.

Claims (3)

A water repellent or waterproofing agent for concrete containing a polymer containing a unit based on a compound represented by the following formula (a) in a solvent.
^{_{CH 2 = C (R 1)}} -COO- (CH 2) n - (CF 2) m F formula (a)
(In the formula, R ¹ is a hydrogen atom or a methyl group, n is an integer of 0 to 4, and m is an integer of 1 to 6.)   A repair and reinforcement method using the treatment agent according to claim 1.   Concrete treated with the treating agent according to claim 1.