JP2009167247A - Primer composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a primer composition which prevents environmental pollution by toluene and formaldehyde, and further exhibits excellent adhesion with low-polarity materials such as polyolefinic materials. <P>SOLUTION: A primer composition includes (A) a chlorinated polyolefin resin, (B) a novolac-type phenolic resin, and (C) methylcyclohexane, substantially without toluene. More preferably, the present primer composition further contains (D) isocyanate silane or (E) tin catalyst, as appropriate. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a primer composition, and more particularly, to a primer composition that improves adhesion to difficult-to-adhere adherends, for example, polyolefins such as polypropylene and polyethylene, and does not cause environmental pollution.

  In recent years, the use of polyolefin-based materials such as polyethylene and polypropylene has been promoted in automobiles, home appliances, and the like in order to improve recyclability. However, since polyolefin-based materials are chemically inert with no polar groups or functional groups in the molecule, and poorly soluble in solvents, secondary processing such as painting, printing, and adhesion is performed on the surface of the molded product. There was a problem that it was difficult to apply.

  As a method for solving the above-mentioned problems, a method for improving the secondary processability of the resin itself by blending another resin that is easily secondary processed into polyolefin, and a corona discharge treatment, plasma treatment, chromic acid on the surface of the molded product -A surface treatment method such as chemical oxidation treatment with sulfuric acid or a method of improving the secondary workability by applying a primer is used. In particular, primer coating is performed to improve the paintability of the surface of the molded product. However, polyolefin is a low-polarity material and has a problem of poor adhesion.

  As a primer composition with improved adhesion, Patent Document 1 discloses a double bond in a molecule, a mixture of either one or both of low-chlorinated polypropylene, para-position-substituted alkylphenol or terpenephenol as a starting material and novolak. And a primer for a polyolefin resin obtained by dissolving a monomer having a glycidyl group or a hydroxyl group in a mixed solvent of a terpene solvent and an aromatic solvent. However, since the primer composition described in Patent Document 1 uses toluene as an aromatic solvent, there is a problem in terms of the environment.

Japanese Patent Laid-Open No. 7-3060

  An object of the present invention is to provide a primer composition that prevents environmental pollution due to toluene, formaldehyde, and the like, and further exhibits excellent adhesion to low-polar materials such as polyolefin-based materials.

  In order to solve the above problems, the primer composition of the present invention is a primer composition comprising (A) a chlorinated polyolefin resin, (B) a novolac-type phenol resin, and (C) methylcyclohexane. It is characterized by not containing toluene.

The primer composition of the present invention preferably further contains (D) an isocyanate silane.
In addition, the primer composition of the present invention preferably further includes (E) a tin catalyst.

According to the present invention, it is possible to provide a primer composition that does not adversely affect the human body, prevents environmental pollution due to toluene, formaldehyde, and the like, and further exhibits excellent adhesion to low-polar materials such as polyolefin-based materials. . Moreover, according to this invention, the primer composition excellent in the drying property (film forming property) after application | coating can be obtained.
The primer composition of the present invention exhibits stable adhesion to adherends of polyolefin materials, which are difficult adhesion members, as well as glass and aluminum, and is also suitable for silicone, polyurethane and modified silicone sealants. It can also be used particularly suitably as a primer for an adhesive to a polyolefin material that exhibits stable adhesiveness and is positioned as low polarity typified by polyethylene and polypropylene used in automobiles, home appliances, and the like.

  Embodiments of the present invention will be described below, but these are exemplarily shown, and it goes without saying that various modifications are possible without departing from the technical idea of the present invention.

The primer composition of the present invention is a primer composition comprising (A) a chlorinated polyolefin resin, (B) a novolac type phenol resin, and (C) methylcyclohexane, which is substantially free of toluene. To do. In the present invention, substantially free of toluene means that the toluene emission rate measured by JIS A1901 (small chamber method) is 38 μg / m ² · h or less.
In the primer composition of the present invention, the formaldehyde emission rate measured by JISA1901 (small chamber method) is 5 μg / m ² · h or less, which is not regulated in the examination method for formaldehyde-emitting building materials in the Building Standards Act. It is preferable.

The chlorine content of the (A) chlorinated polyolefin resin may be appropriately determined according to the intended coating film performance, but is preferably 50% by weight or less, more preferably 10 to 30% by weight. The chlorine content is a value measured by a combustion method.
Examples of the (A) chlorinated polyolefin resin include chlorinated polyethylene resin, chlorinated polypropylene resin, maleic anhydride-modified chlorinated polypropylene resin, urethane-modified chlorinated polypropylene resin, chlorinated ethylene-propylene copolymer, and chlorination. And ethylene-vinyl acetate copolymer. Among these, it is preferable to use a chlorinated polypropylene resin because the resulting primer composition has good adhesion. These chlorinated polyolefin resins may be used alone or in combination of two or more.

  The weight average molecular weight (standard polystyrene equivalent value by gel permeation chromatography method) of the (A) chlorinated polyolefin resin is preferably 10,000 to 300,000, and preferably 30,000 to 250,000. Is more preferable.

  As the (A) chlorinated polyolefin resin, for example, “Super Clone” manufactured by Nippon Paper Chemicals Co., Ltd. (“Super Clon” is a registered trademark of Nippon Paper Industries Co., Ltd.), “Hard Ren manufactured by Toyo Kasei Co., Ltd.” ("Hardren" is a registered trademark of Toyobo Co., Ltd.), "Daisolac" manufactured by Daiso Corporation ("Daisolac" is a registered trademark of Showa Denko KK), "Unistall" manufactured by Mitsui Chemicals, Inc. ("Unistol" is a registered trademark of Mitsui Chemicals, Inc.) and other products sold under the trade name may be used.

The (B) novolac type phenol resin is a thermoplastic phenol resin obtained by condensing phenols and aldehydes with an acid catalyst such as hydrochloric acid, sulfuric acid or oxalic acid.
Examples of the phenols include monovalent and polyhydric phenols such as phenol, cresol, xylenol, naphthol, p-tert-butylphenol, bisphenol A, resorcinol, amylphenol, and terpenephenol.
Examples of the aldehydes include formaldehyde and paraformaldehyde.

  As the (B) novolac type phenol resin, those appropriately modified with aromatic hydrocarbon resin, dimethoxyparaxylene, dicyclopentadiene, magnesium chelate or the like may be used, and a phenol resin modified with magnesium chelate is more preferably used. It is done.

  The blending ratio of the (B) novolac type phenol resin in the primer composition of the present invention is not particularly limited, but is preferably 10 to 1000 parts by mass, and 10 to 150 parts by mass with respect to 100 parts by mass of (A) chlorinated polyolefin resin. More preferred. These novolac type phenol resins may be used alone or in combination of two or more.

The primer composition of the present invention uses (C) methylcyclohexane as the organic solvent to obtain a primer composition substantially free of toluene.
The organic solvent used in the present invention may be methylcyclohexane alone, or may be a combination of methylcyclohexane as the main component and another organic solvent. However, when other organic solvents are used in combination, organic solvents other than toluene are selected. Specifically, organic solvents (formaldehyde, toluene, xylene, paradichlorobenzene, It is preferable to use an organic solvent other than ethylbenzene, di-n-butyl phthalate, tetradecane, di-2-ethylhexyl phthalate, acetaldehyde).

  (C) Examples of other organic solvents that can be used in combination with methylcyclohexane include ketone solvents such as acetone and methyl ethyl ketone, ester solvents such as ethyl acetate and butyl acetate, hydrocarbon solvents such as n-hexane and cyclohexane, and methanol. And alcohol solvents such as ethanol and mixed solvents thereof.

The blending ratio of the organic solvent in the primer composition of the present invention is not particularly limited, but is preferably 200 to 4000 parts by mass, more preferably 1500 to 2500 parts by mass with respect to 100 parts by mass of (A) chlorinated polyolefin resin.
The blending ratio of (C) methylcyclohexane in the organic solvent is preferably 10% by weight to 100% by weight, and more preferably 20% by weight to 80% by weight. The combination and blending ratio of cyclohexane and another organic solvent are appropriately adjusted according to the solubility and purpose of the resin used.

It is preferable that the primer composition of the present invention further contains (D) an isocyanate silane. By blending the (D) isocyanate silane, the adhesion to the modified silicone sealant can be improved.
The (D) isocyanate silane is a compound having an isocyanate group and a hydrolyzable silicon-containing group. For example, the isocyanate silane has an isocyanate group-containing compound, a functional group capable of reacting with the isocyanate group, and a hydrolyzable silicon-containing group. It can be obtained by reacting with a compound.

  Specific examples of the (D) isocyanate silane compound include compounds obtained by reacting diisocyanates such as MDI and TDI with silane coupling agents such as aminoalkoxysilane and mercaptoalkoxysilane. Can be mentioned. An isocyanate silane compound obtained by reacting an isocyanate group-containing compound described in JP-A-2002-53798 with a silane coupling agent having an imino group in which a phenyl group or a derivative thereof is directly bonded to a nitrogen atom is also suitable. Used. As the isocyanate group-containing compound, an aliphatic or alicyclic polyisocyanate is suitable. Moreover, it is preferable to obtain the said isocyanate group containing compound and the said silane coupling agent by making it react with the reaction ratio of NCO / NH = 3 / 1-3 / 2.

  The blending ratio of (D) isocyanate silane in the primer composition of the present invention is not particularly limited, but is preferably 0.5 to 80 parts by mass, and 10 to 40 parts by mass with respect to 100 parts by mass of (A) chlorinated polyolefin resin. More preferred. These isocyanate silanes may be used alone or in combination of two or more.

The primer composition of the present invention preferably further comprises (E) a tin catalyst. By blending the (E) tin catalyst, it is possible to improve hot water adhesion.
The (E) tin catalyst is not particularly limited, and specific examples thereof include tin carboxylates such as dimethyltin dilaurate, dibutyltin dilaurate, dibutyltin maleate, dibutyltin diacetate, tin octylate, and tin naphthenate. It is done. These tin catalysts may be used alone or in combination of two or more.

  The blending ratio of the (E) tin catalyst in the primer composition of the present invention is not particularly limited, but is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of (A) chlorinated polyolefin resin, and 3 to 10 parts by weight. More preferred. These tin catalysts may be used alone or in combination of two or more.

In addition to the above components, the primer composition of the present invention may contain other additives as necessary. Specific examples of the additive include, for example, inorganic pigments such as lamp black, titanium white, bengara, titanium yellow, zinc white, red lead, cobalt blue, iron black, and aluminum powder; Neozapon Black X51 (BASF Japan ( ), Orazol Black CN (manufactured by Ciba Japan Co., Ltd., “Orazol” is a registered trademark of Ciba Specialty Chemicals Holdings Inc.), Spiron Blue 2BH (Hodogaya Chemical Co., Ltd., “Spiron” Organic pigments such as Hodogaya Chemical Co., Ltd.); Siasorb (for example, Cyasorb UV24, manufactured by Cytec Industries Inc., “Siasorb” is a registered trademark of Cytec Technology Corporation), Ubinal (for example, Uvinul D-49 , D-50, N-35, N-539, manufactured by BASF Japan Ltd.) Can be mentioned, when containing them can be shielded, or absorb ultraviolet and visible light, it is effective for improving weather resistance.
In addition, fillers such as glass powder, clay, powdered silica gel, ultrafine silicic acid, molecular sieves (which also have water absorption ability), thickeners, plasticizers such as butylbenzyl phthalate, diisononyl phthalate, chlorinated paraffin, A stabilizer such as diethyl malonate may be contained.

  The primer composition of the present invention can be applied to an adherend using a commonly applied application method such as brush coating, spray coating, wire bar method, blade method, roll coating method, dipping method and the like. it can.

  The present invention will be described more specifically with reference to the following examples. However, it is needless to say that these examples are shown by way of illustration and should not be construed in a limited manner.

(Examples 1-12)
The primer composition (parts by mass) shown in Table 1 was mixed and sufficiently kneaded at room temperature using a ball mill to prepare a primer composition.

  In Table 1, the compounding amount is parts by mass. * 1: Super Clon 822S (manufactured by Nippon Paper Chemicals Co., Ltd., solid content 100%, “Super Clon” is a registered trademark of Nippon Paper Industries Co., Ltd.) * 2: Novolac type phenylphenol resin is Resitop PS-2980 (manufactured by Gunei Chemical Industry Co., Ltd., solid content 100%), * 3: Novolac type terpene phenol resin is Mighty Ace G125 (manufactured by Yasuhara Chemical Co., Ltd., solid * 4: Isocyanate silane is KBE9007 (manufactured by Shin-Etsu Chemical Co., Ltd.), * 5: Tin catalyst is 28% of Nikka Octix tin (manufactured by Nippon Chemical Industry Co., Ltd.).

About the obtained primer composition, it evaluated by the following test method. The results are shown in Table 2.
<Solubility of resin>
After producing the primer composition, it was stored in a sealed container at 50 ° C. for 1 month, and the presence or absence of phase separation and the presence or absence of turbidity were visually determined. The evaluation criteria are as follows.
A: A chlorinated vinyl chloride resin and a phenol resin dissolve quickly without phase separation or turbidity.
○: A material in which chlorinated vinyl chloride resin and phenol resin are soluble without phase separation or turbidity.
X: Phase separation or turbidity or chlorinated PVC resin and phenol resin remain undissolved.

<Measurement and calculation of toluene emission rate>
Based on JISA1901, the toluene diffusion rate of the primer composition was measured under the following conditions.
The primer composition was applied to two glass plates (application area 80 cm ² , application amount 300 g / m ² ), cured at 23 ° C. for 1 hour, installed in a chamber with a volume of 20 L, and a sample load factor of 0.4 m Sampling was performed after 24 hours had passed under the conditions of ² / m ³ , temperature of 28 ° C., relative humidity of 50%, and ventilation rate of 0.5 times / hour. Sampling was performed using a Tenax adsorption tube as a collection tube and a sampling amount of 3.2 L and a flow rate of 167 mL / min.
Measuring apparatus: Heat desorption apparatus / GC-MS, Column used: BD-5 ms (30 m × 0.25 mm ID.), Column temperature 40 ° C. (5 minutes) → 320 ° C. (0 minutes), injection amount: in split = 30 mL / Min, out split = 15 mL / min, gas toluene collected under the measurement conditions was measured, and the toluene emission rate was calculated.
The results are shown in Table 2. Less than the lower limit of detection (5 μg / m ² · h) D. It showed in. The evaluation criteria for the presence or absence of toluene in the table are as follows.
◯: The toluene diffusion rate is less than 5 μg / m ² · h.
X: The toluene diffusion rate is 5 μg / m ² · h or more.

<Measurement and calculation of formaldehyde emission rate>
Based on JISA1901, the formaldehyde emission rate of the primer composition was measured under the following conditions.
The primer composition was applied to two glass plates (application area 80 cm ² , application amount 300 g / m ² ), cured at 23 ° C. for 1 hour, installed in a chamber with a volume of 20 L, and a sample load factor of 0.4 m Sampling was performed after 24 hours had passed under the conditions of ² / m ³ , temperature of 28 ° C., relative humidity of 50%, and ventilation rate of 0.5 times / hour. Sampling was performed using a DNPH cartridge as a collection tube at a sampling amount of 10 L and a flow rate of 167 mL / min.
Formaldehyde was extracted from the collected gas using 5 mL of acetonitrile as an extraction solvent, and measurement conditions: HPLC, column used: Symmetry C18 (250 m × 4.6 mm ID.), Column temperature 40 ° C., injection amount: 20 μL. Formaldehyde was measured and the formaldehyde emission rate was calculated.
The results are shown in Table 2. The evaluation criteria for the presence or absence of formaldehyde in the table are as follows.
○: Formaldehyde emission rate is less than 5 μg / m ² · h.
×: Formaldehyde emission rate is 5 μg / m ² · h or more.

<Environmental measures>
In the above-mentioned item of presence / absence of toluene / formaldehyde, the case where both the toluene and formaldehyde were evaluated as “good” was evaluated as “good”, and the evaluation of one or both of toluene and formaldehyde was evaluated as “poor”.

<Adhesion test>
The primer composition is applied to the surface of polypropylene, which is an adherend, by the brushing method, left for 30 minutes at 23 ° C. and 50% RH, and then the modified silicone sealing is applied to the coated surface of the applied primer composition. A material (made by Cemedine Co., Ltd., trade name “POS seal”, “POS seal” is a registered trademark of Cemedine Co., Ltd.) was pressure-bonded to a thickness of 3 mm to obtain a test piece.

  After curing under the following two conditions using this test piece, cut the vicinity of the interface where the modified silicone sealant is pressure-bonded with a knife, peel the peeled portion by hand, and observe the peeled state. Thus, the state of the peeled surface (fracture surface) was evaluated. Cohesive fracture of the sealing material was evaluated as ◎ for 90% or more, ○ for 80% or more and less than 90%, Δ for 70% or more and less than 80%, and × for 70% or less.

Curing condition 1: Initial adhesion Curing for 5 days in an environment with a temperature of 23 ° C. and a relative humidity of 50%.
Curing condition 2: Warm water resistant adhesion After curing for 5 days in an environment with a temperature of 23 ° C. and a relative humidity of 50%, immersed in warm water of 50 ° C. for 2 days.

<Drying test>
The primer composition was applied to the surface of polypropylene as an adherend by a brushing method, and allowed to stand for 30 minutes at 23 ° C. and 50% RH, and then the surface state of the applied primer composition was evaluated. The evaluation criteria are as follows.
A: Drying 15 minutes after application and the stickiness disappearing promptly.
◯: Not liquid after 30 minutes of application and stickiness disappeared.
X: After 30 minutes of application, liquid or with stickiness remaining on the surface.

(Comparative Examples 1-6)
A primer composition was prepared in the same manner as in Example 1 except that the formulation was changed as shown in Table 3. The obtained primer composition was evaluated by the same test method as in Example 1. The results are shown in Table 4.

  In Table 3, a compounding quantity is a mass part, * 1- * 5 is the same as Table 1, * 6: Resole type | mold alkylphenol resin is shounol CKM-1634 (Showa High Polymer Co., Ltd. product, solid content 50 % Toluene 50%, “Shonol” is a registered trademark of Showa Polymer Co., Ltd.) * 7: Resol-type alkylphenol resin is Hitanol 2192-50 (manufactured by Hitachi Chemical Co., Ltd., solid content 50% toluene 50 %, “Hitanol” is a registered trademark of Hitachi Chemical Co., Ltd.

  The primer composition of Comparative Example 6 was not measurable because toluene had a high concentration and the load on the measuring device was large.

Claims (3)

(A) chlorinated polyolefin resin,
A primer composition comprising (B) a novolac-type phenolic resin and (C) methylcyclohexane,
A primer composition characterized by being substantially free of toluene.   The primer composition according to claim 1, further comprising (D) an isocyanate silane.   The primer composition according to claim 1, further comprising (E) a tin catalyst.