JP2910225B2 - Conductive resin composition - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive material, and more particularly to a conductive material having high conductivity by dispersing a conductive filler in a resin very uniformly.

Conventional technology and its problems The technology of imparting conductivity by filling an organic matrix with a conductive filler such as metal powder or carbon black is known as a conductive paint, a conductive ink, an antistatic material, an electromagnetic wave shielding material or the like. It is widely applied to many other conductive materials. Since fillers such as metal powder and carbon black are inorganic substances with high surface energy, they are poorly compatible with organic matrices with low surface energy. Not done.

As a method for solving such a problem, there is a method of performing a surface treatment for making the surface of the inorganic substance hydrophobic. The surface treatment is usually performed using a higher fatty acid, a silane coupling agent, a titanium coupling agent, or the like. However, in the case of higher fatty acids, there is no direct reaction with a functional group oriented on the surface of the inorganic substance to form a covalent bond. Moreover, surface water is usually present on the surface of the inorganic material, and since the H2O layer is oriented on the surface with the H2O layer interposed therebetween, it can be said that it is very easy to remove.

In the case of a conventional coupling agent, it is generally said that a covalent bond is formed with a functional group on the surface of an inorganic substance. When a surface-treated filler is filled in a resin, a silane-based resin improves the strength and a titanium-based resin improves the processing characteristics. Conductive fillers intended for high filling in resins are often treated with a titanium-based coupling agent as shown in JP-A-57-149356, which has been shown to be actually effective. Also, JP-A-01-5170
0 shows an example in which oxidation of copper powder treated with a mixture of a certain type of titanium polymer and a fatty acid ester is suppressed.

However, as is generally the case with composite materials, as the amount of filler to be filled is larger, characteristics such as conductivity are improved.
At present, in the pursuit of higher functionality of composite materials, conventional surface treatment techniques are not always satisfactory.

Problem to be solved by the present invention That is, a problem to be solved by the present invention is to develop a conductive resin having high conductivity.

In order to solve the above problems, the present inventors have found that a conductive resin containing a certain kind of titanium oligomer and an organic acid ester has significantly improved dispersibility of the conductive filler in the resin, resulting in a very conductive property. The present invention has been completed. That is, the present invention relates to (1) having one or more of the following partial structures A or B, and
X OH groups bonded to Ti and RO groups bonded to Ti
i has one y or more, and z has one or more kinds of partial structures selected from the following partial structure group C bonded to Ti per Ti.
0 ≦ x ≦ 2, 0 ≦ y ≦ 2, 0 ≦ z ≦ 2, 0 <x + y + z
≦ 2), a highly condensed polytitanoxane compound having a molecular weight of 200 to 10,000 or / and in the following general formula, x% of the total number of W is at least one of the following partial structure groups C, y%
Is OH and z% is -OCmH2m + 1 (where x + y + z = 100 and
x, y, z are respectively 0 <x <10, 0 ≦ y ≦ 99.5, 0 ≦ z ≦ 99.
5, y + z> 90, 1 ≦ m ≦ 40), and p is an integer of 2 to 100, and has a low hydrophobic group content.
1 part by weight of an inorganic conductive filler treated with 0.01 to 10% by weight of a surface modifier prepared by mixing 0.5 to 50 parts by weight of an organic acid ester and 0.2 to 9 parts by weight of a resin. Conductive resin composition.

(However, n represents an integer of 1 or more and 100 or less, and R represents an alkyl group having 1 to 40 carbon atoms.) (2) having one or more of the following partial structures A or B, and
X OH groups bonded to Ti and RO groups bonded to Ti
i has one y or more, and z has one or more kinds of partial structures selected from the following partial structure group C bonded to Ti per Ti.
0 ≦ x ≦ 2, 0 ≦ y ≦ 2, 0 ≦ z ≦ 2, 0 <x + y + z
≦ 2), a highly condensed polytitanoxane compound having a molecular weight of 200 to 10,000 or / and in the following general formula, x% of the total number of W is at least one of the following partial structure groups C, y%
Is OH and z% is -OCmH2m + 1 (where x + y + z = 100 and
x, y, z are respectively 0 <x <10, 0 ≦ y ≦ 99.5, 0 ≦ z ≦ 99.
5, y + z> 90, 1 ≦ m ≦ 40), and p is an integer of 2 to 100, and has a low hydrophobic group content.
1 part by weight of an inorganic conductive filler treated with 0.01 to 10% by weight of a surface modifier prepared by mixing 0.5 to 50 parts by weight of an organic acid ester and 0.2 to 9 parts by weight of a resin. A conductive coating composition comprising a solvent in an amount of 1 to 5 times by weight.

(However, n represents an integer of 1 to 100, and R represents an alkyl group having 1 to 40 carbon atoms.) (3) When the conductive filler is carbon black, silver, copper, nickel, iron, aluminum, titanium, The conductive resin composition according to claim 1, which is any one of chromium, platinum, zinc, and an alloy containing these.

(4) The conductive paint according to (2), wherein the conductive filler is one of carbon black, silver, copper, nickel, iron, aluminum, titanium, chromium, platinum, zinc, and an alloy containing these. Composition.

It is.

 Hereinafter, the present invention will be described in more detail.

The surface modifier in the present invention efficiently removes the surface water of the filler and then orients the hydrophobic groups on the surface, thereby making the surface of the copper powder highly hydrophobic.

The total number of titanium atoms of the highly condensed polytitanoxane compound in the present invention is from 2 to 100, preferably from 4 to 50. If the amount is less than this, the degree of condensation becomes small and the catalytic ability for surface modification becomes poor. If the amount is more than this, the molecular weight becomes large, and the catalyst becomes poorly soluble in the solvent and the catalytic ability becomes poor.

The partial structure A or B of the highly condensed polytitanoxane compound in the present invention indicates a repeating structure of a (TiO2) unit. The number of (TiO2) units is preferably 10 to 90% of the total number of titanium atoms. If the amount is less than this, the degree of condensation is reduced and the surface modification effect is reduced. If the amount is more than this, the effect of increasing the inorganicity and the solubility in the solvent become poor, resulting in poor catalytic ability.

W in the present invention is 0 <x, where x% of the total number is a functional group in the partial structure group, y% is OH, and z% is -OCmH2m + 1.
<10, 0 ≦ y ≦ 99.5, 0 ≦ z ≦ 99.5, preferably 5 ≦ x ≦ 9.5, 0 ≦ y ≦ 50, 50 ≦ z ≦ 99.5. x
If y is small and y and z are large, hydrophobicity cannot be imparted to the filler surface, and if x is large and y and z are small, the polytitanoxane compound becomes hydrophobic and cannot approach the inorganic surface, or interacts with the filler surface. And the surface modification effect is reduced.

In the present invention, p is 2 to 100, preferably 4 to 50.
It is. If it is smaller than this, the interaction of the oligomer structure with the filler surface becomes weak, and if it is larger than this, the molecular weight becomes large and it becomes hardly soluble in an organic solvent.

-CmH2m + 1 in the present invention satisfies 1 ≦ m ≦ 40, but preferably satisfies 1 ≦ m ≦ 8. If it is larger than this, the alcohol generated as a result of the reaction with the filler surface becomes non-volatile, and the reaction equilibrium on the surface does not easily progress in the reaction progress direction.

The partial structure in the present invention, that is, the carboxylic acid residue, the phosphate ester residue, the pyrophosphate ester residue, and the sulfonic acid residue are not particularly limited on the presumed action mechanism, but R in the partial structure C is An alkyl group having 1 to 40 carbon atoms which is easily available is suitable.

The highly condensed polytitanoxane compound in the present invention is generally prepared through the following steps. One to one molar equivalent of tetraalkoxy titanium, 0.1 to 3.8 molar equivalents, preferably 3 to 3.5 molar equivalents of one or more organic acids selected from carboxylic acid, dialkyl phosphate, dialkyl pyrophosphate, and sulfonic acid. It is obtained by mixing molar equivalents in a solvent or without solvent, and stirring at a high temperature in the presence of an alcohol to be produced. In this step, since the condensation of the titanoxane proceeds by the by-produced ester of the added organic acid, if the amount of the added organic acid is small or the alcohol is distilled off and reacted, No highly condensed polytitanoxane is obtained. If the amount of the organic acid to be added is too large, the condensation proceeds too much to form a reactant insoluble in the solvent.

The method for preparing the polytitanoxane compound having a low hydrophobic group content in the present invention will be described. One way is to
With respect to 1 molar equivalent of alkoxy titanoxane in which the number q of Ti is 2 to 100, (q + 1) / 100 to 19 (q + 1) / 100 molar equivalents of carboxylic acid are mixed and stirred. Isopropyl alcohol to be removed under reduced pressure. In this case, when the reaction temperature is high, an ester is produced as a by-product, and a highly condensed polytitanoxane is produced. In addition, it can be prepared by mixing tetraisopropyl titanate and a fatty acid. However, control of reaction conditions such as temperature, distillation of isopropyl alcohol, reaction time and the like is indispensable, and various conditions can be produced depending on the conditions.

The organic acid ester in the present invention preferably has an organic acid residue having a hydrophobic property, and more preferably has an alcohol residue having a low molecular weight. Examples of the organic acid residue of such an organic acid ester include, in the case of a fatty acid residue, isostearic acid, stearic acid, palmitic acid, myristic acid, lauric acid, decanoic acid, octanoic acid, oleic acid, linoleic acid, and the like. Of these, isostearic acid is preferred from the viewpoint of imparting hydrophobicity. Also in the case of sulfonic acid, phosphoric acid, and pyrophosphate residues, those having an alkyl group having the same carbon number as in the case of fatty acid residues are preferable. Examples of the alcohol residue of the organic acid ester include isopropyl, propyl, ethyl, methyl, butyl, isobutyl, t-butyl and the like. Among them, isopropyl is preferred from the viewpoint of easy hydrolysis and volatility after hydrolysis. Is preferred.

The method for producing the conductive filler treated with the mixture of the titanium oligomer and the organic acid ester in the present invention is not particularly limited. The surface modification method may be a commonly used method. For example, 0.1 to 10% by weight, preferably 0.5 to 5% by weight of a surface modifier is directly added to the filler, and a ribbon mixer, a Henschel mixer, or the like is used. And a wet method in which the solvent is removed after infiltrating the filler into the solution. It should be noted that integral blending is not a problem.

Although the conductive filler in the present invention is not particularly limited, an inorganic substance having surface water is preferred from the viewpoint of the mechanism of action. Examples of such conductive fillers include carbon black,
Examples thereof include silver, nickel, iron, aluminum, titanium, chromium, platinum, zinc, and alloys containing these.

The method of modifying the surface of conductive fillers
A dry method in which 0.1 to 10% by weight, preferably 0.5 to 5% by weight of a surface modifier is directly added and uniformly dispersed with a Henschel mixer or the like, or a wet method in which a filler is penetrated into a solution and then the solvent is removed. is there. At most, no effect is obtained at most.

The resin for filling the conductive filler in the present invention is not particularly limited, but various resins such as polyolefin, nylon, polyester, polyether, polyvinyl chloride, polycarbonate, polyurethane, phenol resin, epoxy resin, urethane resin, and alkyd resin. It can be applied to

Next, the action mechanism of the surface modifier in the present invention is characterized in that surface water is efficiently removed. The generally known mechanism of action of a Ti coupling agent is a chemical bond type in which a titanium compound having a hydrophobic group is bonded to a functional group on the inorganic material surface to modify the surface. ,
The surface modification using the highly condensed polytitanoxane compound of the present invention is based on the mechanism of action based on the transesterification catalytic activity of titanium. When the polytitanoxane has a hydrophobic group, these titanium compounds bond to the surface of the inorganic substance to hydrophobize the surface as conventionally known. On the other hand, when the titanium polymer cannot completely cover the surface by this mechanism, or when the titanium polymer does not have a hydrophobic group, the following action mechanism operates. Surface modifier used in the present invention,
It has the function of chemically removing the surface water of inorganic substances. That is,
In the presence of polytitanoxane having transesterification catalytic ability,
Organic acid esters are hydrolyzed to organic acids and alcohols by surface water. By this reaction, undesired surface water is removed during the surface treatment, and the generated organic acid is oriented directly or closer to the place where the surface water was adsorbed, that is, the inorganic surface. In the case of polytitanoxane having a low hydrophobic group content, the ratio of the hydrolyzable functional group is high, so that surface water is also efficiently removed.

As described above, the conductive paint and the conductive resin in which the titanium oligomer and the organic acid ester are blended, the surface energy of the conductive filler to be dispersed is reduced and the compatibility with the resin is improved. Said processability is significantly improved. This enables high filling, and further improves conductivity by improving dispersibility.

Next, the contents of the present invention will be described in detail with reference to examples.
In addition, comparisons were made with untreated and titanium polymers represented by JP-A-61-118438. It should be noted that the following examples do not limit the scope of the present invention, but rather exemplify the properties of the present invention more clearly.

Example 1 10.2 g (170 mmol, 3.2 eq) of acetic acid was gradually added dropwise to 15 g (52.8 mmol) of tetraisopropyl titanate at room temperature with stirring, and the mixture was heated and stirred and reacted at reflux temperature for 2.5 hours. During this time, the clear reaction solution gradually became cloudy. Next, by-produced isopropyl alcohol, isopropyl acetate, and unreacted acetic acid were distilled off under reduced pressure, and the remaining acetic acid was azeotropically distilled with toluene to obtain a white powder. Melting point is over 200 ° C, but it is soluble in chloroform. A solution of 1 part by weight of this titanium polymer and 9 parts by weight of isopropyl isostearate in 490 parts by weight of chloroform was prepared to obtain a surface modifier solution. 100 parts by weight of this surface modifier solution (2 parts by weight in terms of surface modifier) was added to 100 parts by weight of flaky nickel powder (NI287-R, manufactured by Fukuda Metal Co., Ltd.)
After stirring for 0 minutes, chloroform was distilled off at 60 ° C. 70 parts by weight of this treated powder is kneaded with 30 parts by weight of a phenol resin,
A conductive paint was prepared. This paint was applied to a glass plate to a thickness of 20 μm, and the specific resistance was measured. Further, the specific resistance after the heat resistance test at 85 ° C. for 2,000 hours was measured (Table 1).

Example 2 At room temperature with stirring, 10 g (35.2 mmol) of tetraisopropyl titanate was stirred at room temperature with 32 g of isostearic acid (112.7 mmol,
3.2eq) is gradually added dropwise and then heated and stirred at reflux temperature.
The reaction was performed for 2.5 hours. Next, the by-produced isopropyl alcohol was distilled off under reduced pressure to obtain a brown liquid. Dissolve 10 parts by weight of this surface modifier in 490 parts by weight of chloroform,
This was a surface modifier solution. Except for using this surface modifier solution, the specific resistance was measured in exactly the same manner as in Example 1 (Table 1).

Comparative Example 1 Except for using untreated powder, the specific resistance was measured in exactly the same manner as in Example 1 (Table 1).

Comparative Example 2 10 g of isopropyl titanate having an average degree of condensation of 10 (4.16 mmo
1), 17.8 g of isostearic acid (62.7 mmol, 15.1 g)
eq) was slowly added dropwise. Then, while stirring at 40 ° C, 4.5
After reacting for an hour, isopropyl alcohol by-produced was removed under reduced pressure to obtain a light brown liquid. A solution of 5 parts by weight of this titanium polymer and 5 parts by weight of isopropyl isostearate in 490 parts by weight of chloroform was prepared. Except that this surface modifier solution was used instead of the surface modifier solution prepared in Example 1,
The specific resistance was measured (Table 1).

Comparative Example 3 A titanium polymer solution prepared by dissolving 10 parts by weight of the titanium polymer obtained in Example 1 in 490 parts by weight of chloroform was used in place of the surface modifier solution obtained in Example 1. The specific resistance was measured in exactly the same manner as in Example 1 (Table 1).

Comparative Example 4 Exactly the same as Example 1 except that an ester solution prepared by dissolving 10 parts by weight of isopropyl isostearate in 490 parts by weight of chloroform was used instead of the solution of the surface modifier obtained in Example 1. Then, the specific resistance was measured (Table 1).

Example 3 100 parts by weight of the surface modifier solution obtained in Example 1 (2 parts by weight of the surface modifier) was added to 100 parts by weight of conductive carbon black (Ketjen Black EC, manufactured by Lion Akzo), After stirring for 10 minutes, chloroform was distilled off at 60 ° C. 100 parts by weight of polyethylene (manufactured by Mitsui Petrochemical Co., Ltd.) having a density of 0.922 g / cm ³ was mixed with 15 parts by weight of the treated powder, and kneaded at 140 ° C. with two rolls. 150 ° C, 20
It was molded to 100 × 100 × 3 mm at 0 kg / cm ² and the specific resistance was measured (Table 2).

Example 4 The resistivity was measured in exactly the same manner as in Example 3 except that the surface modifier solution prepared in Example 2 was used instead of the surface modifier solution prepared in Example 1. 2).

Comparative Example 5 Except that untreated conductive carbon black was used instead of the surface-treated powder, the same procedure as in Example 3 was carried out.
The specific resistance was measured (Table 2).

Comparative Example 6 The specific resistance was measured in exactly the same manner as in Example 3 except that the surface modifier solution prepared in Comparative Example 2 was used instead of the surface modifier solution prepared in Example 1. (Table 2) ).

Comparative Example 7 The specific resistance was measured in exactly the same manner as in Example 3 except that the titanium polymer solution prepared in Comparative Example 3 was used instead of the surface modifier solution prepared in Example 1 (Table 2).

Comparative Example 8 Example 3 except that the ester solution prepared in Comparative Example 4 was used instead of the surface modifier solution prepared in Example 1.
The resistivity was measured in exactly the same manner as in (2).

Example 5 Electrolytic Copper Powder (CE115, 1.5
g / cm ³ ) 100 parts by weight of the surface modifier solution obtained in Example 1
50 parts by weight were added, and chloroform at 60 ° C. was distilled off under reduced pressure.
A paint obtained by mixing 100 parts by weight of the surface-treated copper powder, 50 parts by weight of an acrylic resin (Acribondo BC-415B, manufactured by Mitsubishi Rayon Co., Ltd.) and 200 parts by weight of xylene was screen-printed on a phenol plate. After drying, the specific resistance was measured (Table 3).

Example 6 The specific resistance was measured in exactly the same manner as in Example 5 except that the surface modifier solution prepared in Example 2 was used instead of the surface modifier solution prepared in Example 1. 3).

Comparative Example 9 The specific resistance was measured in exactly the same manner as in Example 5 except that the surface modifier solution prepared in Comparative Example 2 was used instead of the surface modifier solution prepared in Example 1. (Table 3) ).

Comparative Example 10 The specific resistance was measured in exactly the same manner as in Example 5 except that the titanium polymer solution prepared in Comparative Example 3 was used instead of the surface modifier solution prepared in Example 1 (Table 3).

Comparative Example 11 Example 5 except that the ester solution prepared in Comparative Example 4 was used instead of the surface modifier solution prepared in Example 1.
The specific resistance was measured in exactly the same manner as in (Table 3).

Effect of the Invention It has been found that the conductive resin of the present invention achieves higher conductivity than the one using a conventional surface modifier, and the decrease in conductivity due to oxidation is small.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H01B 1/20 H01B 1/20 Z // C09C 3/00 C09C 3/00 (56) References JP-A-64-52786 (JP) , A) JP-A-60-36573 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08K 3/00-13/08 C09C 1/00-3/12 C09D 5/00 , 5/24 C09D 7/00-7/12 H01B 1/20-1/24

Claims (4)

(57) [Claims] (1) having at least one of the following partial structures A or B,
And x number of OH groups bonded to Ti per Ti, R bonded to Ti
It has y O groups per Ti, and z per Ti having at least one kind of partial structure selected from the following partial structure group C bonded to Ti (provided that 0 ≦ x ≦ 2, 0 ≦ y ≦ 2, 0 ≦ z ≦ 2, 0 <x
+ Y + z ≦ 2), a highly condensed polytitanoxane compound having a molecular weight of 200 to 10,000 or / and in the following general formula:
X% of the total number of W is at least one of the following substructure groups C, y% is OH, z% is -OCmH2m + 1 (where x + y + z =
100 and x, y, z are respectively 0 <x <10, 0 ≦ y ≦ 99.5, 0 ≦ z
≦ 99.5, y + z> 90, 1 ≦ m ≦ 40), and p is 2 to 10.
Conductive filler 1 which is an inorganic substance treated with 0.01 to 10% by weight of a surface modifier prepared by mixing 1 part by weight of a polytitanoxane compound having a low hydrophobic group content, which is an integer of 0, and 0.5 to 50 parts by weight of an organic acid ester. A conductive resin composition, which is prepared by blending parts by weight and 0.2 to 9 parts by weight of a resin. (However, n represents an integer of 1 to 100, and R represents an alkyl group having 1 to 40 carbon atoms.) 2. It has one or more of the following partial structures A or B,
And x number of OH groups bonded to Ti per Ti, R bonded to Ti
It has y O groups per Ti, and z per Ti having at least one kind of partial structure selected from the following partial structure group C bonded to Ti (provided that 0 ≦ x ≦ 2, 0 ≦ y ≦ 2, 0 ≦ z ≦ 2, 0 <x
+ Y + z ≦ 2), a highly condensed polytitanoxane compound having a molecular weight of 200 to 10,000 or / and in the following general formula:
X% of the total number of W is at least one of the following substructure groups C, y% is OH, z% is -OCmH2m + 1 (where x + y + z =
100 and x, y, z are respectively 0 <x <10, 0 ≦ y ≦ 99.5, 0 ≦ z
≦ 99.5, y + z> 90, 1 ≦ m ≦ 40), and p is 2 to 10.
Conductive filler 1 which is an inorganic substance treated with 0.01 to 10% by weight of a surface modifier prepared by mixing 1 part by weight of a polytitanoxane compound having a low hydrophobic group content, which is an integer of 0, and 0.5 to 50 parts by weight of an organic acid ester. A conductive coating composition comprising a solvent in an amount of 1 to 5 parts by weight based on parts by weight of the resin, 0.2 to 9 parts by weight of the resin, and 1 to 5 parts by weight of the resin. (However, n represents an integer of 1 to 100, and R represents an alkyl group having 1 to 40 carbon atoms.) 3. The conductive filler is carbon black, silver,
The conductive resin composition according to claim 1, which is any one of copper, nickel, iron, aluminum, titanium, chromium, platinum, zinc, and an alloy containing these. 4. The conductive filler is carbon black, silver,
The conductive coating composition according to claim 2, which is any one of copper, nickel, iron, aluminum, titanium, chromium, platinum, zinc, and an alloy containing these.