JPH05247345A - Flame-retardant heat-resistant resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition useful for printed-wiring board for electronic devices, having low dielectric properties and safety by blending a specific heat-resistant resin composition with a specific bismaleimide. CONSTITUTION:(A) A heat-resistant resin composition obtained by reacting an alkylene bond type bismaleimide compound of formula I (R<3> to R<8> are H or l-4C alkyl; (n) is 1-3) as the whole or part of a maleimide compound containing two or more maleimide groups with a diamine compound is blended with (B) a bismaleimide such as a halogen atom-containing 2,2-bis [3,5- dibromo-4-(4-bismaleimidophenoxy)phenyl]propane of formula II (X<1> to X<4> are H, chlorine or bromine; R<1> and R<2> are H, methyl, ethyl, trifluoromethyl or trichloromethyl; (m) is 0-3). The amount of the component B blended is preferably an amount to give 0.1-30 pts.wt. content of halogen atom based on 100 pts.wt. resin composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyimide-based flame-retardant resin composition for use in printed wiring boards for electronic devices that require a low dielectric constant.

[0002]

2. Description of the Related Art In printed wiring boards for electronic devices, glass cloth epoxy resin laminates using epoxy resin as a binder have been widely used. In order to respond to downsizing and higher wiring density, it is required to improve the heat resistance of printed wiring boards. Furthermore, in recent years, in order to improve the data processing speed, it has become necessary to lower the dielectric constant of the resin for the substrate.

Polyamino bismaleimide obtained by reacting bismaleimide with diamine by heating has heat resistance superior to that of epoxy resin. For example, kelimide 60
A printed wiring board using 1 (product name of Rhone-Poulin) has been developed. However, kelimide 6
The flame retardancy of 01 is UL94 standard V-1, and in order to achieve V-0, flame retardation by some method is required. Further, in recent years, in order to reduce the dielectric constant of the polyamino bismaleimide resin composition, it has been attempted to apply a bismaleimide compound containing a fluorine atom to a resin for a substrate of a printed wiring board, but a bismaleimide compound containing a fluorine atom is attempted. Has not been put to practical use because it is expensive.

On the other hand, as disclosed in JP-A-3-14836 and JP-A-2-298548, by using an alkylene bond type bismaleimide compound and a diamine compound, the hydrocarbon ratio can be increased to increase the polyaminobissalt. There is a method of lowering the dielectric constant of the maleimide resin composition. However, flame retardance is indispensable because the composition ratio of combustible components increases.

As a method of making a polyimide resin composition such as polyaminomaleimide flame-retardant, various methods of mixing or reacting a compound containing a bromine atom have been conventionally proposed. For example, an acrylate compound of tetrabromobisphenol A disclosed in JP-B-1-48298, an alkylenebistetrabromophthalimide compound disclosed in JP-B-63-10178, and JP-A-63-51457. There is a method using a methacrylate compound of a tetrabromobisphenol A ethylene oxide adduct shown in JP-A No. 3-131629 and tribromophenylmaleimide shown in JP-A-3-131629. As a method of using other compounds,
There is a method using a cyclic phosphonitrile compound disclosed in JP-A-1-113427.

[0006]

In the conventional flame-retardant method, a bromine-containing compound of an acrylic acid ester or an addition type compound having no reaction site can impart flame retardancy, but polyaminomaleimide has However, there is a problem that the original heat resistance is impaired. Further, although it is reactive, the monofunctional tribromophenylmaleimide has a drawback that the heat resistance is lowered. The phosphorus-based flame retardant is
There is a problem that the flame retardant effect is small for a compound having a small oxygen atom content such as an alkylene-bonded polyaminomaleimide resin composition.

The present invention provides a flame-retardant and heat-resistant polyimide resin composition which is excellent in both flame retardancy and heat resistance and is suitable for printed wiring boards for electronic devices which require a low dielectric constant. ..

[0008]

That is, the present invention provides a heat-resistant resin composition obtained by reacting a maleimide compound having at least two or more maleimide groups with a diamine compound by heating.

[0009]

[Chemical 4] (In the formula, X ^{1 to} X ⁴ represent a hydrogen atom, a chlorine atom or a bromine atom, and at least one of X ^{1 to} X ⁴ is a chlorine atom or a bromine atom, which may be the same or different. R ¹ and R ² represent a hydrogen atom, a methyl group, an ethyl group, a trifluoromethyl group or a trichloromethyl group, and may be the same or different from each other, and m represents an integer of 0 to 3. The flame-retardant heat-resistant resin composition is characterized by imparting flame retardancy by adding and mixing a bismaleimide containing a halogen atom represented by the formula (1).

The flame-retardant heat-resistant resin composition of the present invention is obtained by heating and reacting a maleimide compound having at least two maleimide groups with a diamine compound, and a halogen atom which is a flame-retardant component. A flame-retardant heat-resistant resin composition is obtained by simply adding and mixing a bismaleimide containing

The blending amount of the bismaleimide containing a halogen atom, which is a flame retardant component, varies depending on the degree of flammability of the flame-retarded resin composition, but the content of the halogen atom is preferably 100 parts by weight of the resin composition. Is used in an amount of 0.1 to 30 parts by weight.

Preferred specific examples of the bismaleimide containing a halogen atom represented by the general formula [1] of the present invention include:
2,2-bis [3,5-dibromo-4- (4-maleimidophenoxy) phenyl] propane and 2,2-bis {3,5-dibromo-4- [β- (4-maleimidophenoxy) ethoxy] phenyl } Propane etc. are mentioned.

As the maleimide compound used in the present invention, an aromatic bismaleimide derived from an aromatic diamine, a polyamine compound or a polymaleimide compound obtained by maleating an aniline-formaldehyde resin is used. As aromatic bismaleimide, paraphenylene bismaleimide, 4,4′-bismaleimide diphenylmethane, 4,4′-bismaleimide diphenyl ether, 4,4′-bismaleimide phenyl sulfone,
Xylylene bismaleimide, 2,2-bis [4- (4-
Maleimidophenoxy) phenyl] propane, 2,2-
Bis [4- (3-maleimidophenoxy) phenyl] propane, and general formula [2]

[0014]

[Chemical 5] (In the formula, R ^{3 to} R ⁸ represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R ^{3 to} R ⁸ has 1 carbon atom.
To 4 alkyl groups, which may be the same or different from each other. n shows the integer of 1-3. ) And an alkylene bond-type bismaleimide compound represented by the formula (1).
Specific examples of the alkylene bond type bismaleimide compound represented by the general formula [2] include 3,3 ′, 5,5′-tetramethyl-4,4′-bismaleimide diphenylmethane, 3,3 ′, 5. , 5'-Tetraethyl-4,4'-bismaleimidodiphenylmethane, 3,3 ', 5,5'-
Tetraisopropyl-4,4'-bismaleimidodiphenylmethane, 2,2-bis (3,4'-maleimidophenyl) propane, α, α'-bis (4-maleimidophenyl) -m-diisopropylbenzene, α, α ' Examples thereof include -bis (4-maleimidophenyl) -p-diisopropylbenzene and α, α'-bis (3,5-dimethyl-4-maleimidophenyl) -p-diisopropylbenzene.

In particular, when the alkylene-bonded bismaleimide compound represented by the general formula [2] is used, the resin composition has a low dielectric constant and is suitable for a printed wiring board of electronic equipment such as a computer. Since the bismaleimide containing the halogen atom represented by the formula [1] is added and mixed, the flame retardancy of the resin composition is not a problem. In order to obtain a flame-retardant heat-resistant resin composition having a low dielectric constant according to the present invention, it is necessary to use as many alkylene-bonded bismaleimide compounds represented by the general formula [2] as much as possible, but at least all maleimide compounds. It is preferable to use 50% by weight or more.

Although various diamine compounds are used as the diamine compound used in obtaining the flame-retardant heat-resistant resin composition of the present invention, aromatic diamines are preferably used in consideration of heat resistance. Examples of the aromatic diamine compound include phenylenediamine, diaminodiphenylmethane, diaminodiphenyl ether, diaminodiphenyl sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, bis [4- (4-aminophenoxy) phenyl. ] Sulfone and General Formula [3]

[0017]

[Chemical 6] (In the formula, R ^{3 to} R ⁸ represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R ^{3 to} R ⁸ has 1 carbon atom.
To 4 alkyl groups, which may be the same or different from each other. n shows the integer of 1-3. ) An alkylene-bonded aromatic diamine represented by Specific examples of the alkylene-bonded aromatic diamine represented by the general formula [3] include 3,3 ′, 5,5′-tetramethyl-
4,4'-diaminodiphenylmethane, 3,3 ', 5
5'-tetraethyl-4,4'-diaminodiphenylmethane, 3,3 ', 5,5'-tetraisopropyl-4,
4'-diaminodiphenylmethane, 2,2-bis (3,3
4'-aminophenyl) propane, α, α'-bis (4
-Aminophenyl) -m-diisopropylbenzene,
Examples include α, α′-bis (4-aminophenyl) -p-diisopropylbenzene and α, α′-bis (3,5-dimethyl-4-aminophenyl) -p-diisopropylbenzene.

In particular, when the above alkylene-bonded aromatic diamine compound is used, the resin composition has a low dielectric constant and is suitable for a printed wiring board of electronic equipment such as a computer, and is represented by the general formula [1]. Since bismaleimide containing halogen atom is added and mixed, there is no problem in flame retardancy. In order to obtain a flame-retardant heat-resistant resin composition having a low dielectric constant according to the present invention, it is necessary to use the alkylene-bonded aromatic diamine compound represented by the general formula [3] as much as possible, but at least the total amount. 5 for diamine compounds
It is preferable to use 0% by weight or more.

In the flame-retardant heat-resistant resin composition of the present invention, a bismaleimide containing a halogen atom represented by the general formula [1], a maleimide compound having at least two maleimide groups and a diamine compound are used. The heat-resistant resin composition obtained by heating and reacting can be made into a composition by dissolving and mixing both in a suitable solvent.

The flame-retardant heat-resistant resin composition of the present invention may optionally contain an acid catalyst, an anionic polymerization initiator or an organic peroxide as a catalyst for addition reaction and curing reaction. Examples of the acid catalyst for the addition reaction include carboxylic acids such as formic acid, acetic acid, benzoic acid, phthalic acid and their derivatives, and acid anhydrides such as maleic anhydride. The blending amount of these catalysts is preferably 0.01 to 10% by weight with respect to the resin composition.
Added. As the anionic polymerization initiator for the curing reaction, 2
-Imidazoles such as methyl imidazole, 2-ethyl-4-methyl imidazole and 2-phenyl imidazole, benzyl dimethyl amine, triethylene diamine,
There are amines such as DBU (1,8-diazabicyclo (5,4,0) undecene-7), dicyandiamide, triphenylphosphine and organometallic compounds, and preferably 0.1 to 10% by weight based on the resin composition. Added. The organic peroxide includes, for example, benzoyl peroxide, dicumyl peroxide, methyl ethyl ketone peroxide, t-butyl perbenzoate and the like, and is preferably added in an amount of 0.1 to 10% by weight based on the resin composition.

In the flame-retardant heat-resistant resin composition of the present invention, epoxy resin, unsaturated polyester, triallyl isocyanurate, diallyl phthalate resin, aniline resin and the like can be used in appropriate combination.

When a prepreg for printed wiring boards and a laminated board are produced using the flame-retardant heat-resistant resin composition of the present invention, the flame-retardant heat-resistant resin composition is dissolved in an appropriate organic solvent, and this is dissolved. Further, if necessary, an anionic polymerization initiator, an organic peroxide, etc. are added as a curing catalyst to prepare an impregnating varnish. Further, additives such as a filler can be used in combination, if necessary. Then, this varnish is impregnated into glass fiber or the like and dried to form a prepreg sheet, and several prepreg sheets are stacked and laminated at a predetermined temperature and pressure to form a laminated plate.

[0023]

The flame-retardant heat-resistant resin composition of the present invention is a heat-resistant resin composition obtained by reacting a maleimide compound having at least two maleimide groups and a diamine compound with heat by the general formula [1]. Represents flame retardancy by adding and mixing a bismaleimide containing a halogen atom, and the flame-retardant component is a bismaleimide with high heat resistance containing a halogen atom, so it is flammable without impairing heat resistance. It is possible to impart flame retardancy to the polyaminomaleimide compound. Further, an alkylene bond-type bismaleimide represented by the general formula [2] or an alkylene bond-type aromatic compound represented by the general formula [3] in all or part of a maleimide compound or a diamine compound having two or more maleimide groups. By using diamine, it is possible to reduce the dielectric constant and flame retardancy of the resin composition.

[0024]

EXAMPLES The present invention will now be described in detail based on examples, but the present invention is not limited thereto.

EXAMPLE 1 179 g of 4,4'-bismaleimidediphenylmethane was used as the maleimide compound, and 40 g of diaminodiphenylmethane was used as the diamine compound.
-Dissolved in 250 g of dimethylformamide (hereinafter referred to as DMF) and reacted at 120 ° C for 1 hour to obtain a resin composition. After cooling the reaction product to room temperature, 97 g of 2,2-bis {3,5-dibromo-4- [β- (4-bismaleimidophenoxy) ethoxy] phenyl} propane was added and mixed, and a resin containing no solvent was added. 0.5% by weight of the composition of 2-
Ethyl-4-methylimidazole and DMF were added to prepare a varnish having a resin content of 50% by weight.

This varnish was mixed with E glass cloth (0.1 mm
(Thickness, manufactured by Nitto Boseki), and then dried at 170 ° C. for 3 minutes to obtain a prepreg having a resin content of 45% by weight. 16 pieces of this prepreg and 35 μm electrolytic copper foils were stacked on top and bottom, laminated and molded under the conditions of pressure 400 MPa, temperature 200 ° C., molding time 2 hours, and further cured at 225 ° C. for 4 hours to obtain 1.6
A mm-thick copper clad laminate was prepared.

With respect to this copper clad laminate, the dielectric constant, solder heat resistance (hereinafter JIS-C-6481), glass transition temperature Tg (TMA method) and flame retardancy (UL-94-vertical method) were measured. The results are shown in Table 1.

The obtained copper-clad laminate had no voids or scratches, and had excellent dielectric constant, solder heat resistance, glass transition temperature Tg, and flame retardancy.

Example 2 179 g of 4,4'-bismaleimidediphenylmethane was used as a maleimide compound and 40 g of diaminodiphenylmethane was used as a diamine compound to dissolve and react in DMF, and then 2,2-bis [3,5-dibromo -4-
An impregnating varnish having a resin content of 50% by weight was prepared in the same manner as in Example 1 except that 89 g of (4-bismaleimidophenoxy) phenyl] propane was added and mixed, and then a copper clad laminate was prepared in the same manner and its characteristics Was measured. The results are shown in Table 1.
It was shown to.

The obtained copper clad laminate was free from voids and scratches, and had excellent dielectric constant, solder heat resistance, glass transition temperature Tg, and flame retardancy.

Example 3 185 g of BMI-M20 (maleinated aniline-formaldehyde resin, trade name of Mitsui Toatsu Chemicals, Inc.) was used as the maleimide compound, and 2,2-bis [4- (4-aminophenoxy) phenyl was used as the diamine compound. ] 74 g of propane was dissolved in DMF and reacted, and then 2,2
-A varnish for impregnation having a resin content of 50% by weight was prepared in the same manner as in Example 1 except that 89 g of bis [3,5-dibromo-4- (4-maleimidophenoxy) phenyl] propane was added and mixed. A copper clad laminate was prepared and its characteristics were measured. The results are shown in Table 1.

The obtained copper clad laminate was free from voids and scratches, and had excellent dielectric constant, solder heat resistance, glass transition temperature Tg, and flame retardancy.

Example 4 252 g of α, α'-bis (4-maleimidophenyl) -m-diisopropylbenzene was used as the maleimide compound, and α, α'-bis (4-aminophenyl) -m-diisopropylbenzene was used as the diamine compound. The same procedure as in Example 1 was carried out except that 62 g of the product was dissolved in DMF and reacted, and then 89 g of 2,2-bis [3,5-dibromo-4- (4-maleimidophenoxy) phenyl] propane was added and mixed. A varnish for impregnation having a resin content of 50% by weight was prepared, and then a copper clad laminate was prepared in the same manner and its characteristics were measured. The results are shown in Table 1.

The obtained copper-clad laminate was free from voids and scratches, and had excellent dielectric constant, solder heat resistance, glass transition temperature Tg, and flame retardancy.

COMPARATIVE EXAMPLE 1 286 g of 4,4'-bismaleimidediphenylmethane was used as a maleimide compound and 47.5 g of diaminodiphenylmethane was used as a diamine compound. A varnish for impregnation having a resin content of 50% by weight was prepared in the same manner as in Example 1 except that 30 g of bromophthalimide, a trade name of Cytex Co., Ltd.) was added and mixed, and then a copper clad laminate was prepared in the same manner and its characteristics were evaluated. It was measured. The results are shown in Table 1.

The obtained copper-clad laminate had no voids or scrapes, but the heat resistance of the flame-retardant component was low, and therefore the solder heat resistance was poor.

Comparative Example 2 324 g of α, α'-bis (4-maleimidophenyl) -m-diisopropylbenzene was used as the maleimide compound, and α, α'-bis (4-aminophenyl) -m-diisopropylbenzene was used as the diamine compound. After using 62 g to dissolve and react in DMF, a resin component was prepared in the same manner as in Example 1 except that 60 g of D-5001 (TBA methacrylate, Dai-ichi Kogyo Seiyaku Co., Ltd.), which is a commercially available flame retardant, was added and mixed. A 50% by weight varnish for impregnation was prepared, and then a copper clad laminate was prepared in the same manner, and its characteristics were measured. The results are shown in Table 1.

The obtained copper-clad laminate had neither voids nor scrapes, but the heat resistance of the flame-retardant component was low, and therefore the solder heat resistance was poor.

Comparative Example 3 Commercially available kelimide 601 (polyamino bismaleimide,
A varnish for impregnation having a resin content of 50% by weight was prepared in the same manner as in Example 1 except that 300 g of Rhone Poulin's product name) was used, and then a copper-clad laminate was prepared in the same manner and its characteristics were measured. The results are shown in Table 1.

The obtained copper-clad laminate had neither voids nor scratches, but did not achieve UL standard 94V-0 in flame retardancy.

[0041]

[Table 1]

[0042]

According to the present invention, by adding and mixing a maleimide compound having a halogen atom, it is possible to impart flame retardancy to a flammable polyaminomaleimide without impairing the heat resistance, and further to add an alkylene bond. By using the maleimide compound and / or diamine compound of the type, it becomes possible to obtain a resin composition having good heat resistance and flame retardancy and having a low dielectric constant, and the industrial value of the present invention is extremely large. is there.

[Procedure amendment]

[Submission date] December 11, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[ Claims ]

[Chemical 1] (In the formula, X ^{1 to} X ⁴ represent a hydrogen atom, a chlorine atom or a bromine atom, and at least one of X ^{1 to} X ⁴ is a chlorine atom or a bromine atom, which may be the same or different. R ¹ and R ² represent a hydrogen atom, a methyl group, an ethyl group, a trifluoromethyl group or a trichloromethyl group, and may be the same or different, and m is 0.
Indicates an integer of ˜3. And a bismaleimide containing a halogen atom represented by the formula (1) is added and mixed to impart flame retardancy.

[Chemical 2] (In the formula, R ^{3 to} R ⁸ represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R ^{3 to} R ⁸ is an alkyl group having 1 to 4 carbon atoms and is the same as each other. Or n may be different. N represents an integer of 1 to 3) A heat-resistant resin composition obtained by heating and reacting with a diamine compound using an alkylene bond-type bismaleimide compound represented by the formula 1. Flame-retardant heat-resistant resin composition of.

[Chemical 3] (In the formula, R ^{3 to} R ⁸ represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R ^{3 to} R ⁸ is an alkyl group having 1 to 4 carbon atoms and is the same as each other. Or n may be different. N represents an integer of 1 to 3) Heat resistance of the alkylene-bonded aromatic diamine represented by the formula (2) and the reaction with a maleimide compound having at least two maleimide groups by heating. The resin composition according to claim 1 or 2.
The flame-retardant heat-resistant resin composition described.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

The flame-retardant heat-resistant resin composition of the present invention may contain a basic catalyst as a catalyst for addition reaction and curing reaction, if necessary.
Further, an anionic polymerization initiator and an organic peroxide are mixed.
As a basic catalyst for the addition reaction, alkali hydroxide, metal
Examples thereof include alkalis, alkoxides, pyridines and imidazoles . The catalyst is preferably added in an amount of 0.01 to 10% by weight based on the resin composition. As the anionic polymerization initiator for the curing reaction, imidazoles such as 2-methylimidazole, 2-ethyl-4-methylimidazole and 2-phenylimidazole, benzyldimethylamine, triethylenediamine, DBU (1,8-diazabicyclo (5,5) 4,0) amines such as undecene-7), dicyandiamide, triphenylphosphine, and organometallic compounds, etc., and preferably 0.1 to 10% by weight is added to the resin composition. Examples of the organic peroxide include benzoyl peroxide, dicumyl peroxide, methyl ethyl ketone peroxide, t
-Butyl perbenzoate and the like, which are preferably added in an amount of 0.1 to 10% by weight based on the resin composition.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0041

[Correction method] Change

[Correction content]

[0041]

[Table 1]

Claims (5)

[Claims] 1. A heat-resistant resin composition obtained by reacting a maleimide compound having at least two maleimide groups and a diamine compound with heating, has the general formula [1]: (In the formula, X ^{1 to} X ⁴ represent a hydrogen atom, a chlorine atom or a bromine atom, and at least one of X ^{1 to} X ⁴ is a chlorine atom or a bromine atom, which may be the same or different. R ¹ and R ² represent a hydrogen atom, a methyl group, an ethyl group, a trifluoromethyl group or a trichloromethyl group, and may be the same or different from each other, and m represents an integer of 0 to 3. The flame-retardant heat-resistant resin composition is characterized by imparting flame retardancy by adding and mixing a bismaleimide containing a halogen atom represented by the formula (1). 2. A heat-resistant resin composition to which flame retardancy is imparted by adding and mixing a bismaleimide containing a halogen atom represented by the general formula [1] has a maleimide compound having at least two maleimide groups. As all or part of the general formula [2] (In the formula, R ^{3 to} R ⁸ represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R ^{3 to} R ⁸ has 1 carbon atom.
To 4 alkyl groups, which may be the same or different from each other. n shows the integer of 1-3. The flame-retardant heat-resistant resin composition according to claim 1, which is a heat-resistant resin composition obtained by heating and reacting with a diamine compound using an alkylene-bonded bismaleimide compound represented by the formula (1). 3. A heat-resistant resin composition to which flame retardancy is imparted by adding and mixing a bismaleimide containing a halogen atom represented by the general formula [1], as a whole or a part of a diamine compound, ] [Chemical 3] (In the formula, R ^{3 to} R ⁸ represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R ^{3 to} R ⁸ has 1 carbon atom.
To 4 alkyl groups, which may be the same or different from each other. n shows the integer of 1-3. ) With an alkylene-bonded aromatic diamine represented by
The flame-retardant heat-resistant resin composition according to claim 1 or 2, which is a heat-resistant resin composition obtained by heating and reacting with a maleimide compound having one or more maleimide groups. 4. The bismaleimide containing a halogen atom represented by the general formula [1] is 2,2-bis [3,5-dibromo-4- (4-bismaleimidophenoxy) phenyl] propane. The flame-retardant heat-resistant resin composition according to 2 or 3. 5. The bismaleimide containing a halogen atom represented by the general formula [1] is 2,2-bis {3,5-dibromo-4- [β- (4-bismaleimidophenoxy) ethoxy] phenyl} propane. The flame-retardant heat-resistant resin composition according to claim 1, 2 or 3.